{"id":1288,"date":"2019-07-18T08:00:01","date_gmt":"2019-07-18T12:00:01","guid":{"rendered":"http:\/\/blog.pasternack.com\/?p=1288"},"modified":"2019-07-17T12:04:57","modified_gmt":"2019-07-17T16:04:57","slug":"rf-test-equipment-series-programmable-phase-shifters","status":"publish","type":"post","link":"\/blog\/rf-testing\/rf-test-equipment-series-programmable-phase-shifters\/","title":{"rendered":"RF Test Equipment Series: Programmable Phase Shifters"},"content":{"rendered":"

\"\"Controlling\u00a0the phase of RF\/microwave signals is an essential aspect of most modern communications, radar, and testing applications. Phase adjustments can be used to create a variety of effects, including combining, subtracting, and aligning signals, as well as part of phased-array antenna technology. Moreover, phase variations in a radar response can be used to distinguish important characteristics of a radar target. Hence, there is a need during testing and for deployed systems for phase shifting hardware.<\/p>\n

A key instrument for prototyping, testing, and deployed systems is the programmable phase shifter.<\/p>\n

There are several types of phase shifter technologies. These include mechanically or electrical phase shifting. Mechanical phase shifter is done by physically manipulating structures within the phase shifter to cause a delay, such as changing the length of a transmission line. Electrically controlled phase shifters can be implemented with a variety of electronic technologies, including varactor diodes, Schottky diodes, PIN diodes, switched filters, or other active electronic methods.<\/p>\n

A programmable phase shifter is a phase shifter that can be digitally programmed (via parallel or serial communications) or even computer controlled. Typically, phase shifters are either bench-top instruments, rack-mountable instruments for automated-test equipment (ATE) applications, or connectorized modules that can be integrated inline to a testing or hardware system. Recent advancements have also led to compact surface mount package phase shifters that are more readily integrated into dense and complex devices, such as phased-array antenna transmit-receive (TR) modules. The programming cable for these devices can be as simple as an SPI interconnect, GPIO, RS-232, Ethernet, TTL, or even USB.<\/p>\n

Generally, the critical parameters for a programmable phase shifter, are switching speed, phase control range, frequency range, phase resolution, phase flatness, insertion loss, power-handling, phase noise, VSWR, and noise figure. These factors are largely influenced by the specific phase shifter technology as well as the packaging\/housing for the device.<\/p>\n

As programmable phase shifters may be bench-top, rack-mount, in-line connectorized, or surface mount components, there is a wide range of interconnect, both coaxial and waveguide, that may be used with these devices. This includes coaxial cable assemblies, waveguide interconnect, and coaxial\/waveguide adapters. Moreover, a programmable phase shifter is often used alongside a variable attenuator to either create modulation or to manipulate the antenna pattern of a beam steerable antenna.<\/p>\n

RF\/Microwave Power Meter Compatible Components and Accessories<\/p>\n