rf hybrid couplerPIN tube has switching effect on microwave signal under the action of positive and negative low frequency signal. The attenuation of microwave signal is small in forward bias (0.5dB) and large in reverse bias (25dB).

The principle of BJT and FET switches is the same as that of low-frequency triode switches, where the control signal of the base (grid) determines the on-off of the collector (drain) and emitter (source). Amplifier has gain, high reverse isolation, especially suitable for MMIC switching.

MEMS micromechanical circuit is a new device developed in recent years. It can also be used as switching device.

The combination of the microwave switching circuit switch device and the microwave transmission line constitutes the microwave switching module. The equivalent circuit of the connection form of the various switching devices is the same as the microwave circuit. Switches are defined according to the number of interfaces, code #P#T, such as single pole single throw (SPST), single pole double throw (SPDT), double pole double throw (DPDT), single pole six throw (SP6T), etc.

The microwave design of these circuits should consider the parasitic parameters of the switch and the matching network, as well as the installation size of the device.

Any rf hybrid coupler has a corresponding drive circuit. The driver circuit is actually a pulse amplifier that amplifies the control signal (usually a TTL level) to output a sufficiently large current or a sufficiently high voltage. In practice, PIN tube can be reversely added to the circuit, using positive high voltage -5V to reduce the requirements on power supply.

rf hybrid coupler https://www.cenrf.com/Hybrid-Coupler