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RF-Opedia^®- Glossary of RF Terms

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1.0-2.3 DIN Connector	A micro-miniature coaxial connector that is 40% smaller than the 1.6-5.6 connector, with transmission frequency up to 10 GHz and an impedance of 50 Ohms
1.6-5.6 Connector	A coaxial connector which is usable for frequencies at max of 12 GHz. They were designed to be stable, compact, and have high data rates.
1.85mm and 2.4mm Connector	Both 1.85mm and 2.4mm connectors are physically compatible and require 5/16" wrench. They will not thread onto SMA, 3.5mm or 2.92mm connectors, and are commonly known as "V" connectors.
1mm Connector	An RF connector that can perform up to 110 GHz. It performs at the highest frequency when compared to other millimeter wave connectors on the market.
2.92mm Connector	Both 2.92mm and 3.5mm connector styles mate with SMA connectors, and with each other. These connectors offer higher maximum frequencies than SMA connectors. 2.92mm connectors usually work up to 46 GHz.
3 dB Bandwidth	The bandwidth described by the width between the points at which the signal's strength is reduced by 3 db.
3.5mm Connector	Both 3.5mm and 2.92mm connector styles mate with SMA connectors, and with each other. These connectors offer higher maximum frequencies than SMA connectors 3.5mm connectors usually work up to 34 GHz.
4.1-9.5 Connector	4.1-9.5 connectors are especially rugged and weatherproof due to their screw-lock mechanism. They are generally operable up to 10 GHz and offer low reflection ratios and low PIM performance.
7/16 Connector	A coaxial connector that works with medium/high power low transmission up to 8.3 GHz that provides little attenuation. Usable in more harsh conditions (such as in the presence of moisture) and often employed for its low PIM characteristics.
7mm Connector	These unique 7mm connectors, which perform at frequencies up to 18 GHz, are sexless. Every connector can be fitted to each other based on the direction of the coupling nut. They also have the lowest VSWR.
A
ABCS	ABCS is an acronym that stands for Antimonite-based compound semiconductors. They are semiconductors that are capable of running with only 100 millivolts and have applications in low noise amps.
Ablation, RF and Microwave	The separation of radio and microwave frequencies.
Absorption	Loss of power in fiber optic cable, due to heat, which is also known as scattering.
Acceptance angle	The angle that is acceptable for signal transmission in fiber optic cable, which is measured from the centerline of the fiber optic core.
Acousto-optic modulator	A device the uses sound waves in order to vary the phase and amplitude of a light beam (i.e. a laser).
Active Device	A device that affects the magnitude of one or multiple responses caused by an external energy source.
Active port diameter	The diameter of the area in the particular part of a light source in which light is guided to or from an optical fiber.
Adapters	Connectors that allow the connection between two cables whose male-female types do not necessarily match. Adapters exist in male to male (a barrel), female to female (a bullet), and male to female (a connector saver) connectors.
AESA	Active Electronically Steered Antenna
Albaloy	Albaloy is a plating finish which has a high resistance to tarnish compared to silver. It's non-magnetic properties has exceptional passive intermodulation (PIM) performance similar to silver. It is a mixture of copper, tin, and zinc.
Alloy	A metallic compound that combines multiple types of metals to produce controllable select properties pertaining to tensile strength, shear strength ductility, malleability, and/or conductivity.
Alloy, Fusible	These alloys are in liquid state below room temperature (similar to mercury). These solders are not commonly used in microwave engineering
Alloys, Low Expansion	A material that has been experimented on by engineers for over 100 years because of their temperature expansion characteristic. Alloys that have low expansion are often used in glass feedthroughs and microwave housings.
Alumina	Alumina is a ceramic material used mostly in the Microwave Integrated Circuit industry. It is offered in 96% and 99.5% concentrations, each of which have different applications. For example, high-temperature circuits generally use 96%, while thin-film circuits use 99.5%.
Aluminum	Material used as either a conductor or packing material. Symbol: Al, Atomic number: 13.
Aluminum Nitride	A material classified in the ceramics family, AIN has high thermal conductivity and is often used in heat sinks, IC packages, and substrates in electronic packages. A safe substitute for Beo substrates.
Aluminum silicon carbide (AlSiC)	These housings that were net-shaped were very popular in the 1990's
Amplifier	A device whose purpose is to take an input signal and increase its amplitude by a certain amount.
Amplifier, Active Directivity of	Measurement of the potential effect of output impedance based on an amplifier's source match, or the effect on input impedance based on an amplifier's load match. Larger active directivity is better.
Amplifier, Balanced	A device that has two amplifiers run at 90 degrees difference in phase transmission. At the input, two signals are set 90 degrees apart, and at the output the difference is removed so that they are at the same phase.
Amplifier, Classes of	Types of Amplifiers, classified based on the bias point (quiescent point "Q"). In class A, the bias point divides the distance between the saturated current and pinch-off current in two. Examples include gain-block and linear amplifiers. Class B amplifiers only conduct half of a signal's cycle. Class AB amplifiers' bias point lie somewhere between class A and B, which provides a good balance between gain, efficiency, and power. In class C, a tuning circuit filters the signal for a single frequency, and behaves like a class B. Classes D, E, and F are switching amplifiers.
Amplifier, Conditionally Stable	An undesirable condition where the amplifier will oscillate under a specific load or source impedance.
Amplifier, Directivity of	A parameter used represent the amount that the input impedance is influenced by the load impedance and also how much the output impedance is affected by the source impedance.
Amplifier, Distributed (Traveling Wave Amplifiers)	Distributed Amplifiers are used as amplification solutions for up to 100 GHz, and down to DC applications. These amplifiers use the capacitive qualities of FETs as well as high-impedance lines to mimic a standard 50 Ohm line for impedance-matching.
Amplifier, Doherty	A type of amplifier that is often used in communications (radios), and performs more efficiently than balanced amplifiers.
Amplifier, Dynamic Range of	The range of power wherein the amplifier operates linearly.
Amplifier, Feedback of	Two types of feedback exists, series and parallel. They can be used to change the characteristics of an amplifier such as its gain vs. frequency, its K-factor, and its input matching characteristics.
Amplifier, Feed-forward	Feed-forward Amplifiers are used in applications where low distortion is key, such as in base station equipment.
Amplifier, Gain Block	Gain block amplifiers are simple and convenient and are used for general purpose applications. They offer a wide bandwidth, but usually at the cost of efficiency and noise.
Amplifier, Gain Flatness of	Gain Flatness refers to the variation in gain over the bandwidth, and is represented as a value ±dB. To calculate this value, subtract the highest gain in the band from the lowest and divide by two.
Amplifier, Gain of	A ratio of the output of an amplifier over its input. The equation for gain is in decibels and is define as follows: G = 10 log10 (Out/In).
Amplifier, Harmonic Distortion of	Harmonic distortion presents itself in the form of output frequencies at integer multiples of the input frequency. It is generally caused by non-linearity in the amplifier, and is described in terms of the relative level to input power.
Amplifier, Isolation of	The ratio of applied output power to measured input power.
Amplifier, Linearity of	Refers to how well the output of an amplifier can be described by a linear function of the amplifiers input. In other words, the output is scaled by a constant factor of the input without much distortion.
Amplifier, Log	An amplifier in which the output voltage is scaled by the log of the input.
Amplifier, Low Noise (LNA)	An amplifier that is used to take weak signals and amplify them so that they can be more easily used. The effect of noise is reduced by the gain of the LNA, while the noise of the LNA itself is injected directly into the received signal.
Amplifier, Maximum Signal Level of	A threshold for which the greatest CW or pulse RF signal can be used without permanent noise figure degradation, amplified distortion, amplification reduction, and/or overheating of the amplifier.
Amplifier, Noise Factor of	Noise Factor is the ratio of the relative amount of noise at the input signal compared to the relative amount of noise at the output signal
Amplifier, Nonlinearity of	Amplifiers can only magnify a signal so much. At small input signals, the gain in the signal appears to be linear, however at large input signals, the output will reach a maximum value and may no longer be the same gain as with the small signal, hence non-linear.
Amplifier, Power	Takes a small signal and increases it to make a large signal. Power is generally considered between 0.5 Watts up to 4 Watts. High Power amplifiers are designed for power above 4 Watts.
Amplifier, Pulsed	For an amplifier to be pulsed, it is electrically switched off when the signal is not being amplified. The majority of CW amplifiers are able to be used as pulsed amplifiers but not the other way around. The pulsing of an amplifier results in cooler operating temperatures by the reduction of DC power dissipation. In this way, pulse amplifiers can be run at higher power. Due to this design, continuously powered amp will cause damage from heat. Therefore, the magnitude of duty cycle will directly affect the temperature of the amp. These devices need special power supplies to provide DC bias point during its duty cycle. One feature of these power supplies often require large storage capacitors. The amp bandwidth should be taken into consideration for very short pulses.
Amplifier, Push-Pull	A device that uses two amplifiers which have 180 degrees difference in phase.
Amplifier, Return Loss (RL)	Return loss (RL) describes reflected-to-incident power ratio at an RF port of an amplifier. Expressed as RL = -20 log \|?\|, ? = voltage reflection coefficient and RL is in units of dB.
Amplifier, Reverse Gain of	The ratio of input over output when power is applied at the output amplifier, and the input power is measured.
Amplifier, Tube	Amplifiers that uses vacuum tubes to amplify a signal.
Amplifier, Wideband	Amplifiers that are capable of amplifying signals in a wide range of frequencies.
Amplitude	Amplitude refers to variation in value of a signal relative to some point, called its zero. Words such as "peak", "maximum" and "rms" are often used to describe the type of amplitude.
Amplitude Balance	The difference in peak-to-peak amplitude (measured in dB) between a power divider's output ports over a specific range of frequency.
Amplitude Match	A comparison between a reference filter and a filter being tested which analyzes the absolute difference of the amplitude response.
Amplitude Modulation Measurement	An accurate measurement of modulation levels which is acquired through a spectrum analyzer.
Amplitude tracking	Difference in amplitude between a test filter and a reference filter.
Analog	A continuously varying signal (such as sound waves). The bandwidth and frequency of an analog signal is measured in Hertz (Hz).
Angle of Arrival	Angle of arrival is the angle at which the radio wave collides with the antennas.
Angle of Incidence	Angle measured from the angle perpendicular to the surface and the angle of the ray of light that strikes the surface.
Angstrom ( Å )	Named after Anders Jonas Angstrom, the Angstrom is a length equal to one tenth of a nanometer
Angular Misalignment Loss	The energy that is lost in an optical signal because two optical components are not properly aligned.
Anode	The anode, generally paired with a cathode, is a positive terminal for a component. Being that it is positive, electron flow is directed toward the anode.
Antenna	A device which interprets electrical signals/radio waves and transforms it to the other form (signal to waves, waves to signal)
Antenna, Horn	A horn shaped directional antenna, designed by William T. Slayton in 1954.
Antenna, Microstrip Patch	A flat antenna which sits atop a microstrip, with a wide beam and a narrow bandwidth.
Antenna, Monopulse	An antenna capable of gathering angle data with only a single pulse
Antenna, Vivaldi	Vivaldi antennas, also known as "tapered slot antennas," are used for their surprisingly large bandwidth and ease of fabrication.
Antimonide-Based Compound Semiconductors	A semiconductor device that only requires 100 millivolts to operate. Has applications in low power systems
Anti-Reflection Coating	A material which is applied to a surface and is used to reduce the amount of reflection and increase light transmission
APC-7 Connector	APC is an acronym for Amphenol Precision Connectors. APC-7 describes a 7 millimeter connector. It is a coaxial connector used for microwave signals for 18 GHz frequencies maximum.
Arbitrary Waveform Generator	A piece of electrical equipment used to generate waveforms.
Arc Suppression Diodes	Diodes used for arc suppression. The goal of arc suppression is to minimize the amount of sparks created when two contacts that are passing current are separated.
Atmospheric Pressure	Atmospheric pressure is measured in various units such as mmHg (Torr), inches Hg, inches water, Pascals (Pa), and atm (atmosphere). Lower atmospheric pressure results in the breakdown of voltage at lower electric field strength. Some conversions include: 1atm = 760 Torr = 760mmHg = 14.69 PSI = 101325 Pa. SI unit for pressure is Pascals.
Attenuation	The loss of amplitude of a signal as it passes through a medium
Attenuation Accuracy	The magnitude of variation in attenuation from the expected value across the operating band.
Attenuation Coefficient	Also called linear attenuation coefficient, the attenuation coefficient is calculated by summing the absorption and scattering coefficients. A large attenuation coefficient means that a signal is quickly weakened as it passes through a medium.
Attenuation Constants	The reduction of amplitude in voltage and current. The reduction is an exponential function which changed with line length.
Attenuation-Limited Operation	When a fiber optic system's performance becomes limited due to the incoming signal amplitude as opposed to distortion. (Bandwidth-limited operation; Distortion-limited operation.)
Attenuator	Used in the extension of dynamic range of devices like power meters and amplifiers, this device transmits an input signal with minimal distortion by absorbing part of the signal itself. The attenuator is also used as a way to equalize signal levels in transmission lines.
Attenuator, Continuously Variable	An attenuator whose attenuation value can be changed along a series of continuous values.
Attenuator, Digital	A type of attenuator that can be controlled by digital signals. The number of attenuation states it has depends on the number of states the digital signals have.
Attenuator, Fixed	Fixed attenuators are available in many forms such as chip, coaxial, and waveguide forms. The frequency of operation and the power handling are the main points to consider when choosing a fixed attenuator.
Attenuator, Flatness of	The total variation in the attenuation of an attenuator over a specific range of frequency. Flatness typically worsens at higher frequencies.
Attenuator, In-control Isolation of Bi-phase	The electronic attenuator's insertion loss, which depends on the transformer used to give coupling from the RF input to the internal diodes, and is independent of the amount of control current. It is measured from the RF input to the control port.
Attenuator, In-out Isolation of Bi-phase	The insertion loss, when no current flows through the control port, from input to output
Attenuator, Insertion Loss of Bi-phase	The loss in power from input to output at a particular input current.
Attenuator, L-Pad	Used to match two impedances. This particular type of solution results in signal loss
Attenuator, Maximum RF Power of	The maximum power that can be supplied to the attenuator without overheating.
Attenuator, Reflection	Contains a four-port quadrature coupler, consisting of two matched terminations on the through and coupled ports. These terminations must show an impedance that is at least partially real in order for the device to work.
Attenuator, Return Loss of	Measure from one port while the other port is connected to a 50 or 75 ohm termination.
Attenuator, Return Loss of Bi-phase	The magnitude of power returned involving the input in relation to the incident power at the input for a given control current. A low control current level will result in small return loss while a high control current will result in very high return loss.
Attenuator, Step	Divisions in which the attenuator can be set to reduce the signal by specific amounts.
Attenuator, Switchable	Switchable attenuators consist of two general categories: switched network attenuators and switched element attenuators. They offer electrically or mechanically controllable attenuation states.
Attenuator, Switched-Element	Similar to a pi pad network using resistive elements capable of realizing multiple values. It uses field effect transistors for switching.
Attenuator, Switched-Network	Versatile attenuators that can that can support multiple values of attenuation.
Attenuator, Temperature Compensating Fixed	Used with amplifiers so as to counteract the gain vs. temperature effect amplifiers. In these types of attenuators, the loss of the attenuator decreases as the temperature increases.
Attenuator, Variable	Attenuators which can change the amount of attenuation via an applied voltage.
Attenuator, VSWR of	Voltage standing wave ratio is a representation of signal reflection in RF devices. In attenuators, VSWR is a metric describing the impedance mismatch between the input and the attenuator.
Avalanche Photodiode (APD)	A light sensor which is capable of detecting weak light signals and needs high voltage to operate.
AWG	(American Wire Gage) it is a unit of measure to measure thickness of solid wires.
Axial Ray	Light that travels along the same axis as the fiber.
Axis	A straight reference line which passes through the center of some object or body. This can be represented as a real or imaginary line.
Azimuth	The angle from a reference zero point along the horizontal axis. It is usually represented by the Greek letter phi (?) or abbreviated AZ.
B
Backplane Panels	PC cards or other panels can be plugged into this type of interconnection panel. Backplane panels range from PC motherboards to a metal frame mounted with individual connectors. Panels have automated wiring.
Backscattering	Scattered light that travels in the opposite direction of the light,
Backside Processing	This term is comprised of three to four critical process steps lumped together. It takes place after final-front side, in which the wafer, which was previously thinned to the desired thickness of the RF designers, is flipped face-down and mounted onto a high-tech wax material.
Balun	Derived from the words BAL-ance and UN-balance. A balun is a device that changes an unbalanced signal to a balanced one or vice versa.
Band Reject Filter	A band reject filter passes all frequencies above and below a specific band of frequencies. The frequencies in this band are stopped from passing.
Band-gap	Band-gap represents a material's ability to resist breakdown under high voltage. The higher a material's band-gap, the higher its breakdown voltage, and the more power it can withstand.
Bandpass Filter	A filter that lets a specific range of frequencies pass, while rejecting higher and lower frequencies.
Bandwidth	The width of the frequencies between the two points where half the power of the signal is lost.
Barrel Adapter	A two ended, male-to-male adapter for various connector types.
Barrier Seal	A material which seals the gap between the insulator (dielectric) and the conductor (inner and outer), preventing gasses and moisture from permeating the connector it is mounted on.
Base Material	The underlying metal material used in the production of connectors, contacts, or other accessory parts. The base material may have one or more metals deposited onto it.
Base Station	A device from which a mobile radio transceiver establishes a connection. This fixed device allows the transceiver to gain access to the public switched telephone network.
Bayonet Coupling	A method of connection in which a rotating peg-and-slot mechanism secures the plug and receptacle together.
Beam Divergence	The widening of a beams diameter as a result of it traveling farther from the source.
Beam-splitter	Used to split an optical beam into several beams
Bending Radius	The minimum radius at which a cable is still able to successfully transmit a signal. If the radius of the cable becomes any less the signal will not be properly transferred.
Beryllium Oxide ()	A material with high thermal conductivity and low expansion properties. While it may seem like a optimal solution to prevent sumiconductor overheating, BeO is a toxic material.
Bessel Filter	A Bessel filter is an analog filter that displays constant time delay and preserves the wave shape of filtered signals in the pass-band.
Bias Networks	A network used to set the quiescent operating point of a FET in a device.
Bias Tee	A type of diplexer, used to supply DC voltage or current to RF devices.
Bi-directional Coupler	A single coupler that doesn't terminate internally, this 4-port coupler allows the forward and reflected signals to be sampled at the same time.
Birefringence	The phenomenon of when two diverging beams separate after passing through a doubly refracting object. These two beams are also known as ordinary and extraordinary beams.
Bit Error Rate (BER)	The number of errors divided by the overall number of bits.
Bluetooth	Uses radio waves of short wavelength in the ISM band from 2.4 to 2.485 GHz in order to send and/or receive data over short distances. Commonly used in personal electronic devices and in-home networks.
BMA	Blind-Mate A connector used in microwave applications to 18 GHz - 26.5 GHz . BMAs utilize a slide-on interface and are designed to allow minimal radial and axial misalignment.
BNC Connector (50 Ohms)	This is a type of coaxial connector that has a two stud bayonet coupling mechanism, and is used for telecom and data system applications that perform up to 4 GHz (maximum 10 GHz). BNC connectors make fast and easy connections, and are very reliable.
BNC Connector (75 Ohms)	A coaxial connector with a Bayonet fastening mechanism.
BNC Reverse Polarity Connector	The non-standardized versions of common BNC connectors, these coaxial connectors operate up to 4GHz. While being similar to standard BNC connectors, the center contacts are reversed and the dielectric may be reversed as well. For instance, a male polarity connector using a female center contact and dielectric and visa versa. The purpose and application of this type of connector is regulated by IEEE/FCC. The type with bayonet coupling mechanism have a max frequency up to 10GHz (optimum at 4GHz) with characteristic impedances of Z=50 Ohms. The bayonet design allows for quick and dependable connections and disconnections.
BNO	A connector appropriate for shielded twin-axial cables. The connector uses a bayonet coupling system.
BNT	Bayonet Coupling Mechanism is a connector designed to be used for triaxial cables.
Boltzmann Constant	A constant whose value is 1.38 x 10^-23 J/K.
Bonded Assembly	A method of assembling connectors in which an appropriate adhesive bonds components together, sealing them from the elements while not interfering with the connector's electrical properties.
Boresight	The direction that an antenna physically pointed to achieve maximum object illumination.
Boresight error (BSE)	Difference between the physical or optical boresight and the electromagnetic boresight.
Brazing	Similar to welding but uses lower temperatures and materials that melt at lower temperatures.
Bulkhead	Commonly used to refer to the connector mounting method. Bulkhead connectors are made to be inserted either from the front side or rear (component) side of a panel.
Bullet Adapter	A two ended, female-to-female adapter for various connector types.
Butted Contact	Conductors which connect on their axes without overlapping.
Butterworth (maximally flat amplitude)	A filter that has lower stop band attenuation, group delay flatness, and overshoot than Chebyshev. It also has best in-band amplitude flatness.
Butterworth Filter	This filter provides the flattest possible, monotonic response in its passband which rolls off consistently at 6dB per octave per pole.
C
C band	Used for long distance radio and telecommunications, IEEE standard C band frequencies operate between 4-8 GHz.
C Connector	A coaxial connector capable of frequencies up to 11 GHz uses bayonet coupling for connection.
Cable	A material capable of passing some signal usually surrounded by strengthening strands and a protective jacket.
Cable Assembly	The cable itself along with the related hardware.
Capacitance	The primary electrical property of capacitor, measured in Farads. It is a measure of energy storage.
Capacitor, Charge-Storage	Capacitors are capable of storing a charge/voltage in their plates.
Capacitor, DC Blocks	Stops the flow of DC current through the use of capacitors.
Capacitor, Electrolytic	This kind of capacitor is usually made of tantalum, and provides the highest capacitance density. They are polarized, and often used for filtering power supply for microwave circuits. However, they are not microwave quality. At least two electrolytic capacitors are needed for linear regulators to remain stable (one on the input and one on the output).
Capacitor, Multi-Layer Ceramic	Capacitors with large capacitance to volume ratios utilizing a ceramic material as its dielectric. Because of their size, they are ideal for use as surface-mount devices on PCBs.
Capacitor, RF Bypass	An RF bypass parallel element that is meant to reflect RF signals by shorting them out. This filter uses microwave capacitors.
Capacitor, Single Layer	Capacitors using a single thin film as a dielectric, which are ideal for high frequency uses. They are often used in systems using frequencies higher than 110 GHz.
Captivated	A term for center conductors that are held in place by the body of the connector, degrades performance.
Cathode	A terminal on an electrical component where electrons flow into. The terminal in which the electrons leave is known as the anode.
Center Frequency	The mean (average) frequency of all of the frequencies in the bandwidth of a given filter. See Bandwidth.
Characteristic Angle	The angle in which a certain mode travels down an optical fiber. Also see: Mode.
Characteristic Impedance	The ratio of the current and voltage phase at any place along the transmission line, given that only one wave travels down a line.
Chebyshev (equal-ripple amplitude) Filter	A very popular filter configuration offering very high stop-band attenuation and overshoot, but at the expense of group delay.
Chebyshev Filter	A filter that more quickly attenuates signals which are beyond the cutoff frequency and that has a predetermined pass band ripple.
Circulator	A passive device whose purpose is to control the flow of the incident signal through one of its three ports.
Cladding	A transparent layer surrounding the light-carrying core of an optical fiber. The cladding has a lower refractive index compared to the core and coatings may be applied to it.
Cladding Mode	The cladding has a larger refractive index than the material surrounding it.
Clamp	A connector style that installs without crimp tools.
Closed Entry Contact	A female contact that is made to prevent an entry of a probing device or pin that has a diameter which is greater than the mating pin.
Coaxial Braid	Wires which are woven into flat braids that cover a conductor or cable. The purpose is for the protection of insulated wires and cables.
Coaxial Cable	Cable that is used for transmission of radio signals. The cable consists of a core which transmits the signal, a dielectric insulator, a metallic shield, and plastic jacket.
Coaxial Cavity Resonator	Transmission line sections of certain termination resistances and lengths that have similar resonance characteristics to oscillating circuits that contain resistance, inductance, and capacitance.
Coaxial Connector	This type of connector provides a connection between two lines that not only have the same characteristic impedance, but also are as reliable, reflection-free, and uniform as possible. It has good electrical transmission characteristics, offers a insensitivity of a high degree toward electromagnetic interference, and is simple to connect and disconnect. The characteristic impedance of the different cables can be well matched to the characteristic impedance of the coaxial connector.
Coherent	Light which not only has waves that are in phase with each other, but also have identical frequencies. This kind of light is only produced by lasers.
Collimated	To make rays of light or particles accurately parallel. Parallel light rays, like in a laser beam, are collimated.
Combiner	A common point in a single fiber collects optical power from several input fibers in this passive device. Also see: Coupler.
Conductivity	How well a material can conduct current. It is the inverse of resistance and has units of 1/Ohm
Conductors	A conductor is a material that, simply put, conducts electricity and allows current to flow. Technically speaking, the definition of a conductor dictates that the material be between 10^6 and 10^4 Ohm-cm. Outside of that range lie superconductors, semiconductors, and insulators.
Connector	A fitting that is installed at the ends of fiber optic cables, light sources, receivers or housings. The connector mates to corresponding devices that also have installed fittings. For example, a connector can join two fiber optic cables and extend the light transmission.
Connector Gender	The gender of a connector can be male or female. Male connectors have a protruding connection, while the female connector has a crevice where the male connector can sit. There do exists some "sexless" connectors when can connect to any other sexless connector of the same type.
Connector, Elbow	A connector that is bent so that it can connect two components that are not parallel to each other. These connectors exist in right angle connectors and swept connectors which are better at high frequencies than angle connectors.
Connector, Push-On	Connectors with a simple "push-on" mechanism. May be used when there are not threads on the components or simply for ease of use.
Connector, Reverse Polarity	For a connector to be considered "reverse polarity," its inner conductor's gender must be the opposite of the outer conductor or sheath. For example, a male reverse-polarity connector has a female inner conductor contact.
Contact	The part of the connector that physically touches the other connector through which a signal is passed.
Contact Alignment	This defines the degree of loose fit which contacts are restricted to within the insert cavity so that mated contacts can still self-align. Also called the contact float.
Contact Cavity	The area of a connector on which the contact must be fitted.
Contact Durability	A number defining the expected number of connections that a connector can withstand before performance dips below a certain standard.
Contact Engaging & Separating Force	The amount of force required to remove and insert pin-and-socket contact connectors. The required specification will vary based on product application.
Contact Plating	A plating used on contacts that provides protection for the contact.
Contact Pressure	The pressure between mating surfaces exerted on each other.
Contact Resistance	The electrical resistance of a connector under normal use, as measured at a particular testing current.
Contact Retention	The smallest axial force that a contact has to endure while it is connected in its appropriate position.
Continuous Wave	A wave which has a constant amplitude.
Convection	The process of transferring heat through the air.
Conversion Loss	A property of mixers referring to the total loss of signal power from input to output. It is measured by inputting a known control signal and LO, and measuring the output.
Coplanarity	The separation length of a connector when one a flat surface between the highest and lowest lead.
Core	The center of an optical fiber, often made out of glass, that is used to transfer light.
Coupler	A device used to take one signal at a single input and splits it among several outputs. It can also take several inputs and merge them into one output signal.
Couplers and Splitters	Components used to combine or split microwave/RF signals. Both components work in both directions, with splitters either dividing or combining power, and couplers either sampling or adding a signal to a main path.
Coupling efficiency	The fraction of light that exists at the source compared to the amount of light that passes into the optical fiber.
Coupling loss	The amount of power lost at discrete junctions (i.e. fiber-to-detector, fiber-to-fiber, source-to-fiber) in a fiber optic link.
Coverage	A percentage which indicates how much the shield or broad covers the component underneath.
Crimp	To deform a connector ferrule around a cable to make an electrical connection.
Crimping Dies	The part of a crimping tool that makes contact with the terminal.
Crimping Termination	A connection that is made by mechanically crimping a metal sleeve with crimp dies, presses, or pliers, in order to secure in to a conductor.
Crimping Tool	A hand-held tool used to crimp, but not sever, certain electrical components such as contacts, ferrules, or terminals. Crimping tools are most commonly used to secure connectors to a coaxial cable.
Critical Angle	The smallest angle, relative to the normal, that light may contact the outer edge of a medium so as to ensure total internal reflection.
Crosstalk	Crosstalk is mutual interference of signals in electrical systems or adjacent transmission lines, which is caused by magnetic, electromagnetic, and/or electrical coupling.
Crystal Oscillator	A circuit that uses a vibrating crystal to produce an electrical signal at a specific frequency.
Cutback technique	Used to measure the attenuation/distortion of a fiber by taking measurements with the full cable length and another when the cable has been cut at a point less than full length.
Cutoff Frequency	The largest frequency at which a signals is not attenuated much. Any frequencies beyond the cutoff frequency become greatly reduced.
Cycle	One complete sequence of periodically occurring values, measured from a relative zero to some maximum value and back.
D
Dark current	A current that a photo detector creates despite the fact that there is no light or voltage supplied to the detector.
DAS (Distributed Antenna System)	A network of separated antennas connected to a common source that provides wireless service within a geographic area or structure such as an office building or school campus.
dB – (Decibel)	The logarithmic unit measuring the ratio of input to output. It is generally used as the unit for gain and loss.
dBc	Power ratio for a signal carrier. Typically, this unit is used for measuring passive intermodulation distortion.
dBm	Decibels that are related to 1 mW. The microwave industry uses 1 mW as the standard unit to measure power level. Examples: 0 dBm = 1 mW, +10 dBm = 10 mW, +20 dBm = 100 mW, etc.
dBW	A decibel watt describes the power of a signal relative to a watt in decibels.
DC block	An electrical component, often a capacitor in series or a parallel coupled line, that separates DC voltages from an RF signal.
DC return	A DC ground is added to an RF line through DC return. For example, it can provide a path for the current of a series diode to return to in a PIN diode switch.
De-embedding	Calibration of ports in measuring or testing equipment.
Delay Line	A cable with the ability to delay electrical signals by a specific quantity of time.
Demodulator	A component used to split the desired data signal from the carrier signal.
Detector	A component used to convert light or infrared radiation to electrical signal, used in fiber optics.
Dewetting	When a wire, pad or lead becomes disconnected from its soldered connection. This could be due to prolonged exposure to temperature, inconsistencies or impurities.
Dielectric	A insulating material is dielectric if it can transmit an electrical force. In coaxial, the dielectric changes the cable's impedance, capacitance, and other characteristics.
Dielectric Constant (Permittivity)	A property that determines how a material is affected by an electric field.
Dielectric Loss	A loss in power due to heat dissipation in the dielectric material.
Dielectric Strength	The maximum voltage at which an insulating material can withstand before electrical breakdown.
Dielectric Withstanding Voltage	Also known as breakdown voltage, this is the potential at which dielectric material breakdown occurs.
Diffuse Reflection	The opposite of spectral reflection, diffuse reflection describes light which bounces in arbitrary directions after impacting a surface.
DIN	The German standards organization. A type of electrical connector used for various applications.
Diode	Diodes were first used in crystal radios about 100 years ago, and are now used in the switching, mixing, detection, and generating of microwave signals. Diodes are 2-terminal, nonlinear semiconductors.
Diode Laser	A diode laser is a solid state semiconductor device which has at least one p-n junction that, under specified conditions, can emit stimulated, coherent radiation.
Diodes, Gunn	A diode that is used as an electrical oscillator which produces microwaves.
Diodes, PIN	This type of diode can be made on silicon or GaAs. "PIN" is an acronym that stands for P-type, intrinsic, and N-type, which corresponds to a stack of semiconductor materials.
Diodes, Schottky	Diodes which are composed of a metal connected to a semiconductor. Schottky diodes can be accidentally created by using connectors with different metals.
Diodes, Tunnel	A semiconductor junction diode that has an I-V curve which has a portion of negative resistance. These diodes are heavily impregnated with impurities and are used in many microwave applications. The region of negative resistance can be used to create oscillators and efficient detectors.
Diodes, Zener	A diode similar to an ideal diode but also allows the flow of current in the opposite direction when the voltage has reached a certain level known as the breakdown voltage.
Dip Solder Terminal	Ends on connector that are place in the holes on a printed circuit board which are then soldered to keep them in place.
Diplexer	A circuit which takes an input and then output it to one of two output ports depending on the frequency of the signal. A signal in a certain bandwidth gets output to a specific port.
Direct Current (DC)	Current traveling in one direction as opposed to alternating current which changes directions.
Directional Coupler	A passive device used couple a defined amount of power in a transmission line to a single port, enabling the signal to be used in another circuit. Unlike bi-directional couplers, directional couplers only couple power signals flowing in one direction.
Directional Couplers, Average Power of	The handling capability of the CW average power through the coupler's main line under matched load conditions with one-way transmission.
Directional Couplers, Bandwidth of	The set of frequencies where the performance is lands between certain margins.
Directional Couplers, Coupling Coefficient of	Coupling coefficient of directional couplers is the ratio of the incident power fed to the couple port through the main port when reflection-less terminations have terminated all ports. This is measured in dB.
Directional Couplers, Coupling Flatness of	The max peak-to-peak difference at a range of frequencies in the coupling coefficient.
Directional Couplers, Coupling Loss of	The power lost from the main line by sampling the signal with a coupler.
Directional Couplers, Coupling Tolerance of	Tolerated variation in power from unit to unit conversion during nominal coupling.
Directional Couplers, Directivity of	Defined as the ratio of the isolation (see Isolation) of the coupler to its coupling factor.
Directional Couplers, Main-line Loss of	Main-line loss of directional couplers is the change in load power, which is caused by the insertion of the coupler into a transmission system, where ports of the coupler are connected with reflection-less terminations. This includes the effect of power moved to the coupled line.
Directional Couplers, VSWR of	VSWR quantifies the degree of match relative to a characteristic impedance. This is determined using a standing-wave ratio for any port of a coupler that is designated for reflection-less terminations.
Directivity	Directivity, a term generally associated with antennas, refers to the ratio of the measured power density at its peak point, versus the ideal power density.
Discrete	A discrete component is one that does not need other components to function such as resistors, LED's, etc.
Dispersion	The distortion of electromagnetic signals by varying the propagation speed of a signal. For example, dispersion in an optical fiber causes the pulses to spread out.
Dissipation	Dissipation is energy that is either lost or unusable. Electrical energy is lost (dissipated) in dielectric materials, usually in the form of heat.
Distortion	The deviation from input of the output wave form. One example of this phenomenon is clipping.
Distributed Antenna System (DAS)	A network of separated antennas connected to a common source that provides wireless service within a geographic area or structure such as an office building or school campus.
Dog Bone	An adapter that has two males on both ends and is in a straight configuration.
Dual Directional Coupler	The combination of two 3-port couplers wherein the mainline is shared, and the terminating ports are connected. This allows for bi-directional use of the couplers.
Dummy Load	A Passive device that terminates an open RF connection to prevent leakage.
Duplex	An optical cable containing two fibers.
Dust Cap	A device that caps the end of an RF connector to seal out dust. RF connection remains open.
DWV	The lowest voltage level that a conducting material can withstand.
Dynamic Range	A range for which if a given signal is in that a electrical component can amplify the signal without distortion.
E
Eccentricity	In a coaxial cable, the conductor's position in relation to the true center of the circular insulation. This measurement is expressed in percentage deviation of the conductor's center from the insulator's center.
Efficiency, Antenna	A measure of resistive loss in an antenna, calculated by dividing the actual emitted power from an antenna by its theoretical value.
Electromagnetic Compatibility (EMC)	The capability of a system to not be affected by electromagnetic interference.
Electromagnetic Interference (EMI)	Electrical/Electromagnetic energy that can interfere with other desirable signals or equipment and cause problems.
Electromagnetic Spectrum	The range of all possible frequencies of electromagnetic radiation usually considered between ELF (3 Hz) up to Gamma Rays (300 EHz).
Electron	An elementary particle with what is known as the fundamental charge: 1.6 x 10^-19 Coulombs. The movement of electrons conductive materials generates current and voltage, and causes the phenomenon we study in the RF field.
Electronically Steered Array	A smart antenna system that utilizes beam forming rather than physically moving the azimuth to direct the signal.
Electro-optic Effect	A change in the properties of a material as a result of an electric field. This also encompasses a change of absorption and a change in the refractive index as well as the permittivity.
Electroplating	Process of placing metallic layers of varying thickness on a base metal to obtain some electrical property.
Elevation	The angle between +90 degrees (up) and -90 degrees (down), starting from 0 degrees horizontal. It is usually represented by the Greek letter theta (?).
Elliptic Filter	A signal processing filter that has equalized ripple behavior to stabilize a signal. The amount of ripple can be adjusted.
Elliptic Function	A function used in finding the amplitude filter for a particular circuit. However, this filter has a worse transient and phase response compared to classical transfer functions.
EMI Filter	Electromagnetic Interference Filter. Also known as "feedthroughs", EMI filters prevent stray signals from creating noise in your design by using a low-pass filter in combination with shunt capacitance and series inductance.
End Launch	Refers to attaching a connector on the end of a printed circuit board.
End Separation Loss	The optical power loss between the source and destination of an optical fiber. This is caused by increasing the distance between source and destination.
Envelope Delay	Time delay caused by a filter, as noticed by the envelope in an AM signal. It is linearly proportional to the phase-shift versus frequency curve for the filter.
Equilibrium Length	In order to achieve a stable distribution of optical power for different propagating modes, the equilibrium length is used. This is the length of a multimode optical wave guide for specific excitation conditions.
Equilibrium Mode Distribution (EMD)	EMD is the condition in which the distribution of relative power among the propagating modes is independent of length in a multimode optical fiber.
Equivalent Line Circuit	Equivalent line circuit is calculated by line parameters per unit length of the section of line that is being considered. This represents the line circuit through circuit elements that are locally concentrated.
Eutectic	A word describing metal alloys that melt and solidify at the temperature. This is a possible property of soldering material.
Eutectic Bonding	Eutectic bonding is a process in which an alloy can be melted from solid to completely liquid at a very fast rate, bonding two contacts together. This alloy has properties such as low melting point and excellent heat transfer capabilities.
Eutectic Solder	A solder alloy with 63% Tin and 37% Lead in composition. It is most common because of its low melting point.
F
F Connector	A type of coaxial connector with high electrical and mechanical stability, and is often used in satellite TV, MATV, and CATV equipment. It is very suitable for measurement applications that perform up to 4 GHz since it contains a screw-lock system.
Failsafe	A feature for relays that prevents other component damage on the same system.
Fall Time	The time it takes a signals to drop from 90% of its maximum to 10% of its maximum. Fall times may also be measured using the 80%, 20% points.
Feed-through	A feed-through is a terminal block or connector which permits bussing and simple distribution of electrical circuits by using double-ended terminals. This term is also used to describe a bushing inside a wall or bulkhead that separates compartments at varying levels or pressure, that has terminations on each side.
FEP (Fluorinated Ethylene Propylene)	A copolymer of hexafluoropropylene and tetrafluoroethylene that is commonly used as a jacketing material on coaxial cables.
Ferrule (Coaxial)	A short, hollow metal tube generally used for joining or reinforcing two pieces of wire or cable or to make a termination on the end of a cable.
Ferrule (Fiber Optic)	Holds a fiber optic cable in place to help align its connection.
FET	FET, or field effect transistor, has three terminals known as the gate, drain, and the source. It has uses in microwave amplifying and switching.
Fiber	A conductor or core that carries light; an optical wave guide. In general, the cluster of cladding and optical core.
Fiber Amplifier	Amplifies an optical signal which passes through it.
Fiber Bandwidth	A frequency at which a specified fraction of the optical power at DC (0 frequency) is achieved. Typically, 0.5 is used as this value.
Fiber Buffer	A material that provides mechanical isolation between external influences and optical fibers in order to protect the fibers from physical damage.
Fiber Bundle	A bundle of unimpeded fiber optic cables used as a single transmission channel.
Fiber Optics	The technology of transmission of radiant energy through an optical medium made of glass or plastic.
Filter	A network of capacitors, inductors, and/ or resistors that is selective as to which frequencies can pass through and which frequencies cannot.
Flange	An extension of a connector which allows the mounting to a panel or the mating to another connector. This extension is usually located at the edge around the connector.
FMC Connector	FMC is an acronym for Flexible Microstrip Connector. This type of connector is very small and uses repeatable electrical characteristics to compensate misalignments. It is also used on the tightest spaces of PCB applications.
FME Connector	A connector designed specifically for use in cellular applications in vehicles, due to their compact size and convenient connection properties. They operate at frequencies up to 3 GHz.
Footprint	The layout of the circuits on a board which is used in order properly connect components
Fourier Analysis	The process in which the equation of a complex wave is separated into parts of component wave, each having a certain phase displacement, amplitude, and frequency.
Free Space Impedance	In a vacuum, free space impedance represents the ratio of electrical to magnetic field strength for a plane wave. Mathematically, it is the relationship two-wire lines equation.
Frequency	The number of cycles of a periodic activity per unit time. The typical measurement is Hz (Hertz), which is cycles per second.
Frequency Doubler	As the name implies, this non-linear device produces an output frequency that is twice the input.
Frequency Modulation (FM)	A method in which the amplitude of a signal remains the same while the frequency of the signal is modulated. Higher frequencies represent higher amplitudes in the original signal.
Frequency Range	The range of frequencies in which a component will function properly to its specification.
Frequency Sensitivity	Also known as "flatness", frequency sensitivity describes the maximum peak-to-peak variation of a directional or hybrid coupler across a specified frequency range.
Fresnel Reflection	Loss due to reflection caused by the difference in refractive indexes between the output face and the receiving optical material.
G
Gain	Ratio between output and input power of an amplifier, antenna, or other device measured in decibels.
Gain Compression Point	The point in amplifier power at which gain is no longer linear.
Gallium Arsenide (GaAs)	A compound of the elements gallium and arsenic. It is often used to make devices such as laser diodes, solar cells, and microwave frequency integrated circuits.
Gallium Nitride (GaN)	A compound commonly used in light emitting diodes (LEDs)
Gaussian Filter	Filters that have no overshoot when the input is a step function and minimizes rise/fall time.
GHz	A unit of measurement denoting the number of cycles in one second. One GHz is one billion cycles every second.
Global System for Mobile Communications (GSM)	The standard that describes protocols for 2G cellular networks. This was created by the European Telecommunications Standards Institute (ETSI).
Graded-index Fiber	A type of optical fiber that contains a refractive index, which gradually changes from the edge to the center. Compared to step-index fiber, graded-index fiber has much less dispersion.
Ground	Voltages in a circuit are measured in relation to a reference point, called ground.
Group Delay	The time delay for a signal to pass through a device.
Group Delay Deviation	The deviation in delay between two points within the passband. Increased delay deviation produces modulated signal distortion.
Guide Pin	A protruding pin whose purpose is to guide two connectors in order to facilitate proper mating of the two halves.
H
Harmonic	A signal in which the frequency is some integer multiple of a reference signal's frequency.
Heat Shock	A test in which a sudden, high temperature change takes place on a material for a short period of time in order to determine its stability.
Heat Shrink	A plastic tube that is typically made of polyolefin or nylon, that is used as a booting on a cable assembly. When heat is applied to the heat shrink material, it 'shrinks' in size to provide a snug jacket at the base of the coaxial connector and cable termination. Heat shrink provides added durability and ruggedness to the cable assembly.
Heat Treating	A set of methods using specific heat and tools whose goal is to change the properties of metals so as to improve certain characteristics.
Helical	A type of coax cable that is spirally corrugated.
Henry	The standard unit for electrical inductance.
Hermaphroditic Connector	A connector which has identical mating faces. There are no gender-specific members.
Hermaphroditic Contacts	When contacts contain mating components that are exactly the same at their mating face, they are known as hermaphroditic contacts.
Hermetic Seal	An airtight seal commonly found on critically sensitive electronic components. This seal protects against the flow of gasses, liquids and other foreign matter.
Hertz (Hz)	A frequency unit equal to one cycle per second. 1 Hz = 1/sec. The name Hertz comes from Heinrich Hertz, the German physicist that discovered the existence of electromagnetic waves in the 19th century.
High-Pass Filter	A HPF allows higher frequencies to pass, while rejecting lower frequencies; the opposite of a lower-pass filter.
Hi-Pot Testing	It tests the maximum voltage and current of a cable.
HN (High Voltage N) Connector	A high-voltage application version of the popular N connector. A high-strength dielectric is used, as well as structural properties that ensure the outer conductor connects before the inner connector.
Hot Switching	Having the ability to "switch" the status of a relay without having to shut off the power / signal.
HV 4-10 (High Voltage C) Connector	A type of coaxial connector contains a bayonet coupling mechanism. Although similar to a C connector, an HV 4-10 connector cannot mate with a C connector. It has fast and reliable connection and disconnection due to its 2 pin bayonet locking system, and has high dielectric strength because of a layout of overlapped dielectric in the connection area. The inner contacts are always closed after the outer contacts. HV 4-10 (High Voltage C) connectors are typically used for high-voltage applications, such as Geiger-Muller counter tubes.
Hybrid Coupler	A 4 port coupler that splits the input signal equally, and as a result, shifts the signal 90 degrees between output signals. It is also capable of combining signals while preserving high isolation between them.
I
IEC Antenna Connectors DIN 45325	A snap-in coaxial connector for IEC antenna's which is capable of transmitting frequencies at max of 1 GHz
IEEE	An acronym for Institute of Electrical and Electronics Engineers. IEEE sets many of the standards in the fields of electronics.
IEEE 802.11	The set of standards used for the design and implementation of wireless LAN
Impedance	A ratio of the current and voltage phases of a component. Impedance changes with frequency. When selecting which type of connector to use, the connectors impedance must match the impedance of the system being used.
Impedance Matching	A condition in which the internal impedance of a source or the surge impedance of a transmission line is the same as the impedance of a component or circuit, which gives minimum reflection and distortion, as well as maximum energy transfer from the source to the load.
Inclusion	The property of glass bodies referring to impurities.
Incoherent Light	Light rays that are not emitted with the same phase angle.
Indicators	Indicators are used to monitor the state of switches in an RF system.
Infrared	Wavelengths are shorter than 1 mm and longer than 700 nm. They can be felt as heat, but cannot be seen by the human eye.
Injection Laser Diode	See: Diode Laser
Insert Coax 0.8-2.7 (75 Ohms)	Inserts designed for DIN-Hybrid connections. They have a maximum operating frequency of about 1.5 GHz, and offer great mechanical and electrical stability, as well as a small profile for applications where space is limited.
Insert Coax 1.0-2.3 DIN	A smaller version of a coaxial insert for DIN-Hybrid connectors, typically used with mixed card edge connectors. They have very good electrical stability and have a maximum operating frequency of about 2 GHz.
Insert Coax D-Sub	Small coaxial inserts for D-sub Hybrid Connections that have high electrical and mechanical stability. With a maximum operating frequency of 2 GHz, their small size are ideal for cramped layouts in various electronic devices and have applications in rack/plug-in chassis technology along with PCB.
Insert High Voltage DIN	Miniature connector inserts for DIN hybrid connections. This type of insert is very small, thus requiring very low space, and allowing applications in tight layouts in all types of electronic devices. They also have electrical and mechanical stability, and are made for use in mixed card edge connections. Female contacts are made from high quality beryllium copper, while male connectors are made with a plastic body.
Insert Mini Coax	A smaller version of a coax connector for hybrid connections for use in limited-space applications, with a maximum operating frequency of about 6 GHz.
Insertion Loss	Insertion loss is the loss of power caused by having a switch located between two connectors in the transmission. It is measured in decibels (dB). All RF/Microwave devices have insertion loss > 0.
Insulation	Material used to prevent or impede the flow of current, also known as dielectric in certain applications.
Insulation Resistance	The electrical resistance of a material which insulates in specific conditions between any pair of conductors, contacts, or grounding device in different combinations.
Insulators	Materials with very high resistance, insulators includes glass, plastic, rubber etc…
Interconnection	A connection between two components which joins and completes electric circuits.
Interface	A multiple-contact connector has two surfaces on the contact side of both of its halves, which face each other during the assembly of the connector. These two surfaces are called the interface.
Interference	The process in which the amplitudes of multiple waves are systematically weakened and reinforced. Also, the process in which one wave is divided into two or more waves, then joined again back into a single wave.
Intermediate Frequency	The frequency in which a carrier frequency is converted to during the process of transmission.
Intermodulation	Usually undesirable in radio or audio processing, this is a process that modulates the amplitude of a signal containing two or more frequencies that have a non-linear relationship.
ISO	Known as the International Standards Organization. This organization develops standardized methodologies which are used worldwide.
Isolation	A metric describing the quality of separation between signals at adjacent ports. The higher the isolation value, in dB, the less interference exists.
Isolator	A ferromagnetic passive device containing two ports which utilizes an internal resistor and controls the direction of signal flow. Other RF components are protected from excessive signal reflection by the isolator.
Isotropic Radiator	Theoretically, this radiator emits electromagnetic radiation uniformly in every direction without loss of energy. In reality, a no-loss radiator does not exist as proved by the "hairy ball theorem".
J
Jacket	A protective cover present on the outside of a cable. The jacket should be insulating if insulation does not already exist.
Joule	The SI unit for measuring energy.
Jumper Cable	A cable consisting of a male to female connector of the same style.
K
K band	Frequency range between 18 GHz to 27 GHz. IEEE Standard 521-1984
Ka band	An IEEE standard concerning frequencies from 27 to 40 GHz
Kilo	SI unit prefix meaning 1000 times the unit it is attached to. Example: 1 kilogram = 1000 grams.
Ku band	Frequencies between 12 and 18 GHz as specifies by IEEE Standard 521-1984
L
L band	The frequency band from 1-2 GHz. IEEE Standard 521-1984.
LAN	Local Area Network. A data communications network that exists only in a local area up to 6 miles or about 10 kilometers.
Land mobile radio (LMR)	Vehicle mounted or human-portable wireless communication systems for land transportation.
Laser	May refer to either a narrow band of coherent light, or the source of that light. The name is derived from an acronym, "Light Amplification by Stimulated Emission of Radiation."
Launch Angle	The difference in angle between an optical fiber's axis and the light ray's angle.
LED	Light Emitting Diode
Limiter	A device whose goal is to reduce the input power so that certain components are not damaged.
Limiting Level	Input power level at which gain is no longer linear. See "Gain Compression Point."
Line Impedance	The impedance of a transmission line as measured via the its terminals.
Line Transformer	Transformation properties owned by transmission lines which depend on the length of the line.
Linear and Non-Linear Analysis	Testing devices in a simulation where the outcome is not dependent on whether power and voltage levels are linear. When power amplifiers and frequency conversion devices are tested, the simulation will require nonlinear analysis.
Linear Phase Filter	Simply put, a phase filter whose curve is linear, and whose time delay is constant.
Linear Phase Response	A linear relationship between change in phase angle per unit of frequency.
Liquidus	The temperature at which a solder melts.
Loaded Q (Working Q)	The ratio of the center frequency to the 3 dB bandwidth of a bandpass filter.
Low Loss	Refers to a style of cable that has lower loss of signal compared to a regular coax.
Low Noise Block (LNB)	A low noise block takes the small signals it receives from the dish and amplifies the signal to a usable level and converts the signals.
Low Noise Cable	Mechanical movements can cause spurious electrical disturbances. A low noise cable is designed to prevent these disturbances.
Low-Pass Filter	This type of filter lets lower frequencies pass while rejecting higher frequencies. It is the opposite of a high-pass filter.
LSOH	An acronym for Low Smoke Zero Halogen.
M
Macro-bending loss	When fiber bends are greater than its diameter, the critical angle becomes greater than the incident angle, causing light rays to exit a wave guide and resulting in light loss, or macro bending loss. This does not cause radiation loss.
Magnetron	Invented by Albert Wallace Hull, the magnetron is a high-powered vacuum tube that works as microwave oscillator. The strong magnetic fields produced by the magnetron produce the high-power output required in radar equipment. It enabled airborne radar at microwave frequencies during WWII.
MCX Connector	Micro-miniature Coaxial Connectors are made to be very reliable, easy to mount, and very small, containing a snap-on connecting system and used for frequencies up to 6 GHz.
Measurement Line	In RF, this refers to the transmission line whose field distribution is sampled.
Mega	In the SI system, a prefix that means one million (1 x 10^6). Its abbreviation is M. 1 MHz = 1 x 10^6 Hz.
Megahertz (MHz)	Equal to 1 million Hz. Uses the SI Prefix Mega, meaning 10^6.
Meridional Ray	Ray passing through the axis of an optical fiber.
MHV Connector	Coaxial connector that uses bayonet coupling mechanism with a working voltage of 2.2kV DC.
Micro	The SI prefix meaning 10^-6. Abbreviated by the Greek letter "mu" (?).
Microbending Loss	In an optical fiber, sharp curvatures that involve spatial wavelengths of a few millimeters and local axial displacements of a few micrometers may cause light loss, or micro bending loss. These bends may be caused by packaging, installation, fiber coating, and cables. Micro bending can cause mode coupling and significant radiation losses.
Microdot	Connectors with high contact quality and screw-lock system for high stability and shielding. For use with low noise cables.
Micrometer	A micrometer (?m) is a unit of length in the SI system. 1 ?m = 1 x 10^-6 meters.
Microstrip	This type of transmission line configuration is separated by a dielectric and uses a conductor over a parallel ground plane
Microstripline	Microstripline is a type of transmission line that has a solid ground plane metallization and a metalized strip, which is separated by a solid, thin dielectric. It is commonly used on PC board and ceramic substrates in the range of 400 MHz to 6 GHz since it allows transmission lines to be manufactured accurately. Stripline technology is often used for broadband devices or higher frequencies.
Microwave	A section of the electromagnetic spectrum extending between 1 and 300 GHz. The microwave spectrum is between the RF and infrared spectrums, and is used in many applications, including communications.
MIL	An abbreviation for the word "military." Often appears as "MIL-SPEC," implying that a part meets military specifications.
Milli	Milli (m) is a prefix in the SI system, which means one thousandth (1 x 10^-3). For example, 1 mm = 1 x 10^-3 m.
Mini SMP Connector	The smallest connector on the market, with operating frequencies up to 65 GHz and an impedance of 50 Ohms.
Mini UHF Connector	A type of miniature coaxial connector with an impedance of 50 Ohms and improved electrical performance compared to normal UHF series connectors. It is fitted with notched edges for adjustment and the typical UHF screw-locking system. Also, this connector has a high vibration security and torsional protection, which are provided by lugs located on the plug, corresponding to the notched edges on the jack. Mini UHF connectors are commonly used in mobile devices that perform up to 2.5 GHz.
Mismatch (Connector Impedance or Line Impedance)	The event when the load and the source do not have the same impedance. This results in reflection and loss of power.
Mismatching	A line is mismatched if its characteristic impedance is different from its termination resistance. This often causes reflections, which lead to undesirable losses.
MMBX Connector	A Micro-Miniature Board connector is used for "sandwich" and vertical direct Board-to-board interconnection. It is typically used for applications from DC to 6 GHz, and has an impedance of 50 Ohms.
MMCX Connector	Stands for Micro Miniature Coaxial connector which have snap on connection and can have frequencies from DC up to 6 GHz.
Modal Noise	When a coherent light source is used, there is noise generated at the wave guide's exit aperture. This effect, called modal noise, is caused by modal interference in the wave guide. Also see: Mode, Interference.
Mode	An electromagnetic field distribution that satisfies boundary conditions as well as Maxwell's equations in a transmission line or cavity. Dependencies of a mode's field pattern include wave guide geometry, refractive index, cavity, and wavelength. Also see: Equilibrium Mode Distribution.
Mode Coupling	Describes the exchange of signal power in an optical fiber among modes, which eventually approaches some equilibrium.
Modulation	Modification of a signal created by super imposing the data signal onto a carrier frequency.
Modulator	An electronic device the takes in a baseband signal as input and converts it to a modulated RF signal.
Moisture Resistance	A materials ability to not absorb or resist the absorption of water.
Mono Mode Range for Coaxial Cables	When a coaxial cable operates at a certain frequency range, in which only the Lecher wave is capable of propagation and therefore also controls the propagation parameters.
MTBF – (Mean Time Between Failure)	The average time between the occurrence of failures in a component.
Multi-fiber Cable	This type of optical cable consists of two or more fibers that carry separate information channels.
Multimode Fiber	A type of fiber that allows more than one mode to propagate. The number of modes in a fiber is determined by Maxwell's equations and boundary conditions. The multimode fiber's core diameter can range from 25-2,000 microns.
Multiple Reflections	Multiple reflection waves are caused by continuous new reflections which are the result of propagated waves that are repeatedly reflected both at the input and the output ends of a transmission line. These reflected waves superimpose themselves on the primary waves.
Multiplexer	A network or device that receives multiple signals through its input, and outputs the signals separately, according to their frequency.
Multiplier Nonlinearity	A frequency multiplier has an output power that is proportional to the squared input power. This condition is called a "square-law" curve. Its power transfer characteristic is very different from an amplifier, limiter, or mixer.
N
N (50 Ohms) Connector	Coaxial connectors capable of frequencies up to 12 GHz. They have screw locking system and are reliable.
N (75 Ohms) Connector	There are two versions of the N connectors: one with 50 Ohms and another with 75 Ohms impedance that cannot be mated. N connectors have a high degree of protection from weather with a screw locking system in medium dimension. They are robust, reliable and provide excellent intermodulation.
Nanometer	A length equal to one billionth of a meter.
Noise	Random fluctuations of electrical signals caused by natural disturbances or circuit components.
Noise Currents	Refers to any noise that inhibits the ability to take accurate measurements.
Noise Equivalent Power (NEP)	The point at which the rms of the optical power compared to the rms noise results in a signal to noise ration of 1.
Noise Figure / Noise Factor (Transducer)	The noise factor is described as the ratio of a/b where a is the available signal to noise(SNR) ratio. The ratio, a, is taken at the signal generator terminals when the temperature of the input is 290K and the bandwidth is restricted by a transducer. The b is the available SNR per unit bandwidth at the output terminals of the transducer.
Noise Floor	Noise floor refers to the lowest input power that produces a detectable output.
Noise Temperature	Noise temperature is the amount of thermal noise found in components. In electronics, it is a way of expressing the total level of available noise power introduced by a component or power source.
No-load Impedance	Input impedance when no load is present.
Non-unilateral Device	A non-unilateral devise is active component such as an amplifier with poor directivity.
Normally Open	A term for relays in which the conductors are normally open.
Numerical Aperture (NA)	The value that describe the ability of a fiber to accept light. Generally speaking, a higher value is more desirable.
O
Omnidirectional Antenna	Ideally, it is an antenna that is capable of radiating in all directions on the horizontal plane.
Operating Mode	When the actuating voltage is removed, the characteristic that decides the operation of the switch is called the operating mode.
Operating Mode-Failsafe	A mode which is standard on RLC switches. When actuating voltage is applied, the switch will move to the closed position. The switch returns to open position only when the voltage is removed.
Operating Mode-Latching	In latching mode, the RLC switch will remain in any switched position when the actuating voltage is removed. This mode is optional on my RLC switches. In many standard RLC latching switches, the actuating current is automatically cut after the switch has changed position due to its "Cutthroat" solid state circuit.
Optical Waveguide	Any structure capable of carrying the radiant energy along a path along its axis.
Optoelectronics	A branch of study whose focus is light in the context of electronics. This includes LEDs, Lasers, photo sensors or any devices the utilize optics/light.
Oscillator	Provides an electrical signal that oscillates in voltage magnitude depending on the voltage input.
Oscilloscope	An electronic testing equipment use in the analysis of waveforms. From an oscilloscope, one can gather data about the shape of the waveform, it's frequency, distortion, rise-time, etc.
P
Pad	In a printed circuit board, the metal portion in which the leads located on a surface mount component are mated is called the pad. It is also known as a land or footprint.
Passband	The frequency range for a filter that does not get rejected.
Passband Ripple	Attenuation of the signal within the passband that varies with frequency.
Passivated	A type of finish for Stainless Steel parts.
Passivation	Creating an insulated layer over bare metal by treating it with a chemical. This layer protects the metal from contaminants, moisture, and particles.
Passive Device,	A device with no power source. A passive device cannot add energy to a signal
Passive Intermodulation (PIM)	Occurs in passive devices such as cables or antennas that are subjected to two or more high power tones. PIM is the result of multiple tones mixing. The higher the signal amplitudes, the more pronounced the effect of PIM.
PCB Connector	A connector mounted on printed circuit boards (PCB).
Peak Sidelobe Ratio	Ratio between the highest side lobe intensity to the intensity of the beam parallel the azimuth of an antenna.
Permeability (magnetic)	The measure that compares how magnetic force lines travel through a material compared to air. Air is designated with a permeability of 1.
Permittivity	A measure of the amount of resistance that results when creating an electric field throughout a medium. It describes how an electrical field affects a medium.
Phase	In electronic signals, phase is defined as the position of a point in time on a waveform cycle. A complete cycle is defined as 360 degrees of phase.
Phase Balance	Given a frequency range, it is the max peak-to-peak difference in phases of power divider output ports.
Phase Constant	Designated as ?, this is the imaginary component of propagation which gives evidence to the gradient of the current and voltage phases as a function with respect to transmission line length.
Phase Detector	A device that outputs a DC voltage proportional to the phase difference between two RF input signals.
Phase Distortion	A distortion caused by non-linearity in the phase-response.
Phase Jitter	The undesired variation in the phase from its desired level
Phase Modulation	A method of encoding data onto an AC waveform by varying the instantaneous phase of the wave.
Phase Noise	The representation of random fluctuations in a waveform's phase as a frequency domain.
Phase Shift	After a current or voltage passes through a cable or circuit, any change in its phase is called the phase shift.
Phase Shifter	Device used to shift the phase of a signal, ideally with very low insertion loss and amplitude output that is equal on all phase states.
Phase Speed	Speed of a voltage-phase relationship that is propagated on a transmission line. Measured in vph.
Phase Stability	Change in electrical length in a cable based on changes in temperature and other parameters.
Phase-locked Loop (PLL)	A process that keeps the phase of the input and output in step with each other.
Pig Tail	A cable assembly with only one connector attached. The opposite side of the assembly is unterminated or open-ended.
PIM (Passive Intermodulation)	A nonlinear response from a passive device caused by inconsistencies or impurities in the materials or connections. This is seen when there are two or more signals in the device.
Pin Contact	A type of male contact designed to mate with a socket or female contact.
PIN Diode	A diode that has properties similar to a variable resistor that varies based on the DC bias. This diode is designed with a thin layer that is present between the P and N sections.
Planck's Constant	Denoted by h, this is the universal constant that represents the ratio of a quantum of radiant energy to the frequency of the source, or E/f. Its value is 6.62606957 × 10^-34.
Plastic clad silica (PCS) fiber	High quality fiber optic cable with high light transmission, made with a glass core and plastic cladding.
Plated Through-Hole	A hole into which components can be soldered into place in order to connect them to other circuit components.
Polarization	A property of electromagnetic waves which describes its orientation in space. Polarization is dependent on the type of wave, the type of source, and the source's orientation.
Power (Average)	The average power rating limits high-frequency operation, while the peak power rating usually specifies the low frequency.
Power (Peak)	Peak power rating usually specifies the low frequency or pulse energy of a signal, while the average power rating limits high-frequency operation.
Power Splitter	Delivers multiple output signals with phase and amplitude specifications. This is a passive device that takes in one input signal. Bidirectional splitters can combine signals as well. Also called power divder.
Precision	A term used to identify higher quality / performance products.
Press-Fit Contact	An electrical contact that can be installed into a hole in a printed board, insulator, or metal plate using an interference fit.
Primary Attenuation Step	The port of the step attenuator that is activated, or in the "high" state.
Printed Circuit Board (PCB)	A PCB, or PC Board, is a composite of multiple materials like metal, epoxy glass, silicon, copper and non-conductive substrate. Hardware such as passive and active components can be attached to transmit signals and data. Circuits are also etched onto the PCB.
Propagating	Moving or transmitting energy along some path.
Propagation Constant	The longitudinal wave propagation along a conductor is represented by the propagation constant. Along with the characteristic impedance, it enables the calculation of the transformation characteristics of the current and voltage on the conductor, as well as their distribution.
Propagation Delay	A transmission network or digital device requires an amount of time to transfer information from its input to its output. This is known as propagation delay.
Prototype	A pre-production model of a product that exhibits full or partial functionality of the final product.
PTFE (Polytetrafluoroethylene)	PTFE has a stable and low dielectric constant and loss factor over a broad frequency and temperature range. Therefore, it is used as an insulator in microwave and RF coaxial connectors.
Pulse	A brief change in value, usually voltage in the positive direction, that returns to the steady state.
Pulse Width	The amount of time wherein an electrical pulse is transient.
Pushing	Relationship between the change in frequency per unit voltage changed.
Q
Q Factor	The Q is a measure of a filter's frequency selectivity or sharpness of response. It is also known as the figure merit of a filter.
QLA	A subminiature connector using a quick latch coupling connection and whose resistance is 50 ohms.
QMA Connector	A QMA connector is based on the dimensions of an SMA connector, however, it contains a snap-lock mechanism rather than a threaded coupling mechanism. It has frequency range DC - 18 GHz.
QN Connector	Connector with a snap-lock mating mechanism based on N dimension
Quantum Efficiency	A factor of efficiency calculated using the conversion between photon/second and electrons/second for a light sources and detectors.
QUICK-FIT	Internationally approved N and 7/16 connectors used for copper tube cables with foam dielectric.
Quick-Lock	A connector that allows for quick connecting/disconnecting.
QUICK-MATE	A type of adapter that is used for test applications since it enables quick connection and disconnection. It can be plugged without the need of a coupling nut.
R
Radiator	The basic element in an antenna that actually emits a signal.
Radio Frequency (RF)	Electromagnetic energy emitted between 50 MHz to 1 GHz.
Rated Voltage	Maximum voltage that can be constantly applied to a cable, connector, or any electrical component without destroying the component or causing any permanent alterations to its technical parameters.
Ray	Pictorial representation of the path which a light wave travels.
Rayleigh Scattering	Scattering by index fluctuations that are both refractive and small in relation to wavelength. The fourth power of the wavelength is inversely proportional to the scattered field.
Reactive Splitter	A device that divides power equally on the input onto several output ports. This is done without much change in the phase relationship and causes little distortion.
Receiver	Any device that receives and interprets an optical signal into an electrical or digital one for use by other devices.
Receptacle	A two-piece multiple contact connector's stationary half. It also commonly has socket contacts and is mounted on a panel.
Reciprocity	An antenna works in exactly the same manner in receiving the signal as it does when sending a signal.
Reentrant Modes	Reentrant modes occur when a band-pass filter is designed for one frequency, but it also passes RF at integer multiples of the intended frequency.
Reflection	The return of waveform after bouncing on an object. This is sometimes used as a metric of inefficiency for cables and other devices when referring to internal reflection.
Reflection Coefficient	Measured at the terminating resistance, the complex reflection coefficient is the ratio of the voltage returning from the load to the voltage supplied by the generator. From this, return loss and VSWR can be calculated.
Reflection Loss	When power is reflected at a line discontinuity, part of a signal is lost. This is known as reflection loss.
Reflow Soldering	A process that wets the leads and pads with solder by screen printing and then heating to cause the solder to melt.
Refraction	When oblique incident rays pass a medium that has a certain refractive index into another medium with a different refractive index, the rays will bend. This is known as refraction.
Refractive index	A number that indicates how much light will bend when it enters a medium. It a ratio of the speed of light in a vacuum over the speed of light in the given medium.
Relative Attenuation	Attenuation relative to the minimum.
Repeater	A module that receives an optical signal and converts it to an electronic signal while amplifying it and then re-transmitting in optical form.
Responsivity	The ratio of output to input (gain) of a detector system. Standard units of measurement are amps per watt.
Return Loss	The measure of the amount of reflected power when it is connected to any active or passive device or terminated on a transmission line. Return loss can be used to calculate VSWR and the Reflection Coefficient Expressed in dB.
Return Loss (from Reflection Coefficient)	Loss from reflection due to scattering, measured in dB, measured by taking the logarithm of the reflection coefficient and multiplying by -20.
Reverse Polarity	Has opposite contact from normal connector.
RF (Radio Frequency)	Frequencies typically ranging between 50 - 999 MHz where radiation of electromagnetic energy is possible. Microwave frequency is considered to be 1,000 MHz (1 GHz) and up.
RF Choke	A component that allows low frequency or DC to pass through, but blocks RF signals.
RF Leakage	An amount of a signal that is lost in (or radiated by) a connector.
RF Mixer	A device that translates frequency from the input signal to the output signal. When a mixer is used for up-conversion, the input is an IF signal and the output is an RF signal. It is the opposite for down-conversion.
RF Shielding	The process of blocking an electromagnetic field with magnetic or conductive barriers in order to suppress it.
RG/U	Denotes certain coaxial cables that are manufactured to Government Specification. For example, RG-58U: R represents radio frequency, G represents government, 58 is the number assigned to the government approval, and U represents universal specification.
Right Angle	The connector or adapter looks like the letter "L" due to the 90 degree body.
Ringing	When a transient waveform is applied to a filter, it may tend to oscillate for a period of time. This is known as ringing.
Ripple	Sinusoidal changes in the amplitude response of a particular filter.
Rise Time	The amount of time a signal takes to get from its steady state to some peak value. It is the opposite of fall time.
RoHS	Restriction of Hazardous Substances discusses the amount of particular materials that may be used in electronic devices.
Root Mean Square	A mathematical operation done to a set of values. Specifically, it means "the square-root of the mean of the squared values." This has many applications in electrical engineering, including the calculation of average power.
Rubber Duck Antenna	An electrically short monopole antenna that is protected by a plastic or rubber jacket. Its function is similar to a base-loaded whip antenna.
S
S band	S band is a band of frequency between 2 - 4 GHz; IEEE Standard 521-1984.
Scattering	While there are no changes in the wavelengths of radiation, scattering causes changes in the direction of light within the optical fiber core, often due to core and cladding imperfections.
Screening Effectiveness	The ratio of the input power to a coaxial cable to the power transmitted by it and outputted by the outer conductor.
Screw Machine Contact	Solid bar stock is used to machine this type of contact.
Self Alignment	A phenomenon caused by surface tension of liquid solder, which occurs when leads align themselves on solder pads.
Semiconductor	A substance that has resistance between that of a metal conductor and an insulator. Silicon is an example of a highly used semiconductor.
Semi-Insulators	Made from GaAs wafers, they possess resistivities between 103 and 1010 Ohm-centimeters.
Semi-Rigid	Cables whose outer insulators are relatively rigid, while the inner conductor are more flexible. This allows the cable to be more rigid but still be marginally flexible.
Sensitivity	The input power level which is required for the system to operate as intended.
Shape Factor	The ratio of Attenuation Bandwidth to 3 dB. bandwidth for a bandpass filter, 3 dB Bandwidth to Attenuation Bandwidth for a band-stop filter, Attenuation Frequency to Fco for a low pass filter and Fco to Attenuation Frequency for high pass filter.
Shape Factor (Bandwidth Ratio)	The ratio between High and low attenuation level bandwidth or between 3 dB Bandwidth to the stop band bandwidth
SHF	SHF = Super High Frequency, Range: 3 GHz to 30 GHz
Shield	A conducting screen or housing that greatly reduces the effect of magnetic or electric fields coming from one side onto any circuits or devices on the other side. Cable shields can be taped, braided, or solid. Also, the metallic layer in a cable that prevents electromagnetic or electrostatic interference between the external fields and enclosed wires. This metallic layer is placed around a conductor, or group of conductors.
Shielding	A metallic coating used to prevent signal interference or current leakage in a circuit or coaxial cable.
Short Circuit Impedance	The very small to non-existent impedance in a short circuit.
Shot Noise	Noise produced from the process of single electrons passing through the p-n junction. The mean square shot noise current is related to the diode's average current and bandwidth. RMS shot noise = square root (2qI*B), where q is the elementary charge, I is current, and B is the bandwidth.
SHV (Save High Voltage) Connector	While similar to the design of BNC connectors, SHV (Safe High Voltage) connectors are not compatible with BNC connectors. They are used in applications for frequencies up to 50 MHz. The locking system allows for quick engagement and disengagement. Center contacts for each mating pair are in deep recesses so that it avoids shorting at the center when not connected. To connect, the outer couplings must be engaged first before the center can be shorted.
Sidelobes	Undesirable gain response of an antenna in a direction not with the main beam.
Signal Generator	Can generate repeating and non-repeating signals based on a given setting. A signal generator can provide adjustable wavelength, frequency, waveform, load, and magnitude.
Signal-to-noise ratio (SNR)	Signal power to noise power ratio which is related to bit error rate performance.
Sine Wave	The classic example of a "wave." A sine wave is a function whose value oscillates about some zero value equally in both the positive and negative directions with respect to time.
Single-mode Fiber	An optical fiber whose diameter is so small that light can only travel on one path. This dimension must be under 10 microns.
Skin Effect	The tendency for an AC signal to be present at the surface of a conductor rather than in the interior. This property is due to the natural gathering of charge at the edges of a conductor.
SMA Connector	Uses a 4.2mm diameter outer coax filled with PTFE dielectric. The upper frequency limit is between 18 to 26 GHz depending on the quality of manufacturing. Similar to many other coax connectors, a 5/16 inch wrench can be used to tighten the screw-coupling mechanism. These connectors are compatible with 3.5mm and 2.92mm connectors. There should be a careful inspection before mixing of SMA connectors that are more expensive.
SMA Reverse Polarity	Sub-Miniature coaxial connector with a center contact with reversed gender. They perform up to 18 GHz and are often used for connections between W-LAN components, and have optimum electrical properties, such as low VSWR, high durability, long life, and high mechanical stability.
SMB (Subminiature B) Connector	A coaxial connector capable of frequencies from DC to 4 GHz. Uses snap on coupling.
SMB Connector	A subminiature connector with a simple snap-on mechanism, and a maximum operating frequency of up to 4 GHz.
SMC Connector	A connector with a screw-on attachment, usable up to 10 GHz. These connectors can be coupled with a shared nut.
Smith Chart	Used to calculate resistance transformations on transmission lines, as well as the corresponding matching circuits. A Smith Chart represents the reflection coefficient as a complex plane within the restrictions of the unit circle. It contains lines of complex resistances that are normalized respectively to the characteristic impedance, consisting of constant real components and constant imaginary components.
SMP Connector	A micro-miniature connector most commonly used in board-to-board applications. They operate up to 40 GHz and are available in a variety of mounting styles.
SMS Connector	A subminiature connector with a slide-on coupling mechanism and has a frequency range of DC - 4 GHz
Snap N Connector	A quick-lock connector that can be mated with an N connector. It can be connected very quickly and in tight places without the need of any tools.
Snap-on	The ability to easily assemble or remove one part to or from another
Solder Contact	A contact terminal that accepts a wire for soldering ends by using a cup, hollow cylinder, eyelet or hook.
Solder Paste	A combination of several components including, solder powder, flux, solvent, and binder. It is printed onto PCB's and used to form solder joints.
Soldering	The process of connecting many components by melting a metal which holds them together.
Spectrum Analyzer	An instrument that measures the amplitude of a signal along a range of frequencies.
Splice	A splice is a permanent junction, either applied mechanically or fused thermally, located between optical fibers.
Spread Spectrum	Spread-spectrum techniques give a signal a wider bandwidth by spreading its original bandwidth in the frequency domain.
Spring-Finger Action	A contact locking mechanism that uses a small protrusion, angled away from the direction of connection, to lock a connector into place.
Spurious Free Dynamic Range	The ratio between the RMS power of the fundamental signal and the RMS power of the resulting noise or distortion.
SSMB Connector	Micro-miniature coaxial connector with snap-on coupling mechanism uses a tongue and groove design to hold the plugged connectors together. The design permits fast engagement/disengagement in small and hard to access locations.
SSMC Connector	A micro miniature coaxial connector capable of 6 GHz frequencies and has low voltage standing wave ratios. The connector uses screw on coupling.
Standing-Wave	When two sets of waves travel in opposite directions, the resulting distribution of voltage and current on a transmission line is called standing-wave.
Star Coupler	A passive electrical component which takes multiple optical inputs and spreads their power along multiple outputs.
Step Function	A signal with instantaneous change in amplitude, shaped like a step. Typically, step functions are used to test transient responses for systems.
Step-index Fiber	A fiber designed with an uniform refractive index core. This profile allows the abrupt changes at boundaries between core and cladding.
Stimulated Emission	Radiation that is emitted due to the internal energy of a quantum mechanical system which drops from an excited to lower level. This drop is induced by the presence of radiant energy at the same frequency. See also: Spontaneous emission; Injection Laser Diode.
Stopband	A range of frequencies that are rejected - typically by a filter.
Stripline	A type of transmission line with a conducting strip either on top of or between two conducting surfaces (typically, stripline refers to the latter). It is generally favored in higher frequencies and broadband applications.
SUCOPLATE®	Plating made out of copper, tin, and zinc. Provides good corrosion and abrasion resistance and is not magnetic. Registered mark of HUBER+SUHNER AG.
SUCOPRO®	It is a plating material with Nickel-Phosphorus-Alloy under a layer of gold. Provides protection from wear and excellent solder-ability.
SUCOREX®	Plating with an inner material made from SUCOPLATE and a thin outer layer of gold. Provides good corrosion and wear resistance. Easy to solder due to the gold layer.
Super Conductor	Has a bulk resistivity of zero.
Surface Mount Device (SMD)	A passive or active device that is made to be soldered onto a PCB surface.
Surface Mount Technology (SMT)	A way of mounting components to the surface of a printed surface board as opposed to plated through-holes.
Switch	A device that works like a light switch. It either turns on or off the signal or redirects it to an adjacent port.
T
T Adapter	A 3-port device in the shape of a 'T' that divides one RF signal into multiples.
TDU	Time Delay Unit. This is a structure similar to a phase shifter and allows specific or programmable time delay using a multi-path structure. Unlike a phase shifter, TDUs do not provide a fixed insertion phase difference between two states. A TDU can provide a large number of wavelengths of phase shift which is exactly proportional to frequency such that the difference between group delays is flat over required bandwidth.
TEM Wave	TEM waves, or Transverse Electro-Magnetic waves have magnetic and electrical field parts that lie on a plane that is vertical to the direction of propagation. These waves can propagate on coaxial lines.
Temperature	A temperature range (minimum through maximum) at which a component can function while still meeting all its required specifications.
Termination (RF Load)	A component that absorbs the remainder of a signal, ideally with little to no reflection.
Test Voltage	The maximum voltage in which a circuit component can be used for a specific amount of time, and under specific environmental conditions, without getting damaged.
Thermal Shock	A drastic change in temperature causing non-uniform expansion or contractor within a material or a combination of materials that can cause internal parts to separate from each other.
Time Delay	For a signal to pass through a filter, it will take a certain amount of time. This is known as time delay.
TNC (50 Ohms) Connector	Coaxial connectors with electrical properties and dimensions similar to a BMC connector, but with a screw-on mating mechanism for quick connections. It generally usable up to 4 GHz.
TNC Reverse Polarity Connector	A type of threaded coaxial connector that contains the opposite sex center contact. This is know as reverse center contact. Optimum results are achieved up to 4 GHz, and is often used for connections between W-LAN components, much like SMA reverse polarity connectors.
Torque	Torque is defined as the tendency of an object to twist around an axis due to a force. Although the actual calculation of torque is a vector cross-product, it can generally be thought of as the amount of force applied times the distance from the axis of rotation. Because of the sensitivity of building materials, industry standards for the tightness of connectors are established. Examples: 1. SMA - 7 to 10 in-lbs; 2. Type-N – 12 to 15 in-lbs; 3. TNC – 12 to 15 in-lbs; 4. 7/16 DIN – 220 to 300 in-lbs.
Total Internal Reflection	The confinement of light by means of reflection within a substance. This is the property that allows optical fibers to transmit light with no loss.
TPX® (Polymethylpentene)	A 4-methylpentene-1 based polyolefin manufactured by Mitsui Chemicals, Inc. TPX is is used as a jacketing material on coaxial cables.
Transceiver	A component capable of both transmitting and receiving signals. In the RF sphere, it's implementation is used to tighten the gap between digital signals and antennas.
Transducer	Converts energy from one form to another. For example, electrical energy (audio-frequency) into sound.
Transfer Impedance	A value relating the current in the outer conductor of a coaxial cable to the voltage drop between the outer and inner sides of that conductor. The impermeability of the outer conductor of coaxial cables is represented by the transfer impedance.
Transformer	Used to achieve maximum power transfer by matching impedance, as well as for separating DC from two circuits while keeping AC continuous, and voltage step-down or step-up. These processes take place in low-power electronic circuits.
Transition Band	The frequency range between the passband and the stopband. This could be thought of as the "downward slope" between these two areas.
Transmission Coefficient	The measurement of the degree of a signal's transmission that goes through a network with two ports. In other words, it is the ratio of the amplitude of the transmitted wave to the wave at the two port network input.
Transmission Line	Refers to the group signal carrying components, like a waveguide, a stripline, or a coax, in a circuit.
Transmission Line Constants	The characteristic parameters of a transmission line
Transmission Loss	The loss of power from on point to another during propagation.
Transmittance	The ratio of the radiant power let through to the total radiant power.
Transmitter	A device that transmits an electrical signal over a fiber cable by first converting it into an optical wave.
Triaxial Cable	A type of cable similar to the coaxial cable, but has two outer concentric conductors, an insulating layer between them, and a center conductor.
Triplexer	A passive device that will split a complex signal into three pre-defined frequency bands.
TTL Control Circuit	A Transistor-Transistor Logic Control Circuit allows the user to control switch operations with a 5 volt control circuit.
Twinax BNC	Di-Pole symmetrical connectors with a bayonet coupling mechanism, applicable for shielded twin-wire cables with different characteristic impedance. It is not mateable with standard BNC connectors.
Twinaxial Cable	A twinaxial cable (Twinax) has two-pole symmetrical connectors which are polarized and locked. It also has a screw-locking system and gaskets that make it weatherproof. Twinaxial cable has impedances between 75 and 95 Ohms.
Twinaxial Connector	A connector with 2 center conductors.
Twist-On	A method use to attach the connector to the coax by twisting them together.
Two-Wire Line	A two-wire line has two separate conductors that are mutually insulated. It is the most common type of electrical cable.
U
UCA	An acronym for Uniform Circular Array, which is an arrangement of antennas in a circular formation, equally spaced apart.
UGA	An arrangement of antennas in a grid pattern, where they are spaced equally apart in both dimensions
UHF	Ultra High Frequency. Contains the range of 300 to 3000 MHz.
ULA	A Uniform Linear Array is a collection of transmitters aligned with equal spacing in a linear fashion.
Ultra Wideband (UWB)	Useful at low energy levels and short ranges for high bandwidth communications. This technology uses a large frequency range.
Ultraviolet	A spectrum of light that is outside the visible spectrum that ranges from 20 to 380nm and is damaging to human eyes and skin.
Unilateral Device	Unilateral devices usually refer to ideal amplifiers and other active devices where the parameter S12 = 0. This is an idyllic concept.
V
V band	A frequency band between 40-75 GHz. IEEE Standard 521-1984.
Vapor Phase Soldering	A soldering process, during which the heating method uses of latent heat of vaporized liquid.
Vector Network Analyzer (VNA)	An instrument that measures an electrical network's parameters, such as S, Y, Z, and H parameters.
Vector Signal Analyzer	A electromagnetic analysis device which measures of the magnitude and phase of an input signal to produce data such as spectral flatness and error vector magnitude.
Velocity of light	In a vacuum, the speed of light is approximately 300,000 km/s (186,000 miles/sec)
Velocity of propagation (VoP)	The possible speed of an electrical signal in a medium relative to it's speed in free space. Velocity of Propagation is usually expressed as a percentage.
VHF	An acronym for Very High Frequency, which is from 30-300 MHz
Viterbi Algorithm	A dynamic programming algorithm that is used in decoding convolution codes.
Voltage Controlled Oscillator (VCO)	An oscillator that can change the frequency by supplying a voltage to it.
Voltage Standing Wave Ratio (VSWR)	The measurement of how efficiently radio frequency is transmitted from a power source to a load through a transmission line. A VSWR of 1 is ideal. From VSWR, Return Loss and Reflection Coefficient can be calculated.
VoP (Velocity of propagation)	The speed of an electrical signal, expressed as a percentage, when it travels through a cable in comparison to speed in free space.
VSWR (Voltage Standing Wave Ratio)	VSWR is a measurement of signal reflection in devices, with a VSWR of 1 being ideal (no signal reflected. VSWR can be converted to return loss or the reflection coefficient.
W
W band	Frequency band between 75 and 110 GHz, from IEEE Standard 521-1984.
Wave Soldering	A largely used process for through -hole boards, solder is applied to the bottom of the board and connects the metal surfaces.
Waveguide	Hollow tubes with conductive walls which transmit signals along its axis. Waveguides can be rectangular, circular, or elliptical, and the operating frequencies are dependent on its shape and dimensions.
Wavelength	The distance from the beginning of an electromagnetic wave's complete cycle to the end of the cycle. The distance over which the wave's shape repeats.
Welding	The process of joining to metals through a very high temperature procedure.
Wetting	The mechanical bonds formed when liquid solder is attached to other metallic surfaces.
Wetting and sweating	Wetting is the wet-like appearance of a well soldered joint that was brought up to proper temperature levels. Sweating is slang for soldering.
Wilkinson Power Divider	A passive device that either combines input signals to a common port or divides an input signal between its outputs. However, power dissipation limits the power divider when it is used as a combiner. Power dissipation occurs when signals are non-coherent, out of phase, or have amplitude imbalance.
X
X band	Frequency range between 8 GHz to 12 GHz. IEEE Standard 521-1984
Y
Yagi	A directional, shortwave antenna containing a group of dipoles that are equally insulated and are parallel with a horizontal conductor. Yagi's contain one or two dipoles that are connected with the receiver.
Z
ZigBee	A method of short range data transmission used to create personal-use networks for connecting devices.

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