General Microwave switches cover the frequency range from 100 MHz to 40 GHz and are available in various topologies ranging from single-pole single throw (SPST) to single-pole eight-throw (SP8T) in both reflective and non-reflective configurations, and a Non- reflective SP16T unit.
SWITCH TOPOLOGY
There are two fundamental methods of connecting PIN diodes to a transmission line to provide a switching function: in series with the transmission line so that RF power is conducted when the PIN diode is forward biased and reflected when reverse biased; or in shunt with the transmission line so that the RF power is conducted when the diode is reverse biased and reflected when forward biased. A simple reflective SPST switch can be designed utilizing one or more PIN diodes in either configuration as shown in Fig. 1.
A multi-throw switch essentially consists of combination of SPST switches connected to a common junction and biased so that each switch port can be enabled individually. The common junction of the switch must be designed to minimize the resistive and reactive loading presented by the OFF ports in order to obtain low insertion loss and VSWR for the ON port. There are two basic methods of realizing a multi-throw switch common junction for optimum performance over a broad frequency range. The first employs series mounted PIN diodes connected to the common junction. A path is selected by forward biasing its series diode and simultaneously reverse biasing all the other diodes. This provides the desired low-loss path for the ON port with a minimum of loading from the OFF ports. The second method utilizes shunt mounted PIN diodes located a quarter wavelength from the junction. The diode(s) of the selected ON port is reverse biased while the OFF ports are forward biased to create a short circuit across the transmission line. As a result of the quarter wavelength spacing, the short circuits are transformed to open circuits at the junction. By proper choice of transmission line impedances and minimization of stray reactance it is possible to construct a switch of this type with low insertion loss and VSWR over a three to one bandwidth.
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Herley – General Microwave specializes in developing and producing customized microwave components and millimeter wave products for the defense and aerospace industries as well as for non-defense applications such as communication systems. Herley General Microwave produces the industry standard General Microwave line of off-the-shelf catalog RF componentד. If you are looking for a Solid State Power Amplifier, Microwave Synthesizers or other microwave oscillators, Microwave Receiver, RF Switches, Microwave attenuator, Microwave Limiter, Microwave Phase Shifter, or Microwave IQ Vector Modulator we can produce components meeting your requirements at a very competitive price. We also produce high quality customized Integrated Microwave Assemblies such as Up and Down Converters, DLVAs, Beam Forming Networks, Front Ends, or Switched Bank Filters, that can be used in a wide variety of demanding applications. Herley General Microwave (HGMI), a subsidiary of Herley Industries provides solutions for electronic warfare systems, Phased Array Radar systems, electronic warfare simulators, test Equipment and test Systems and other defense and non-defense systems. We look forward to working with you, so please contact us today.