ABSTRACT
Microwave switches are control elements required in a variety of systems applications. They are used to control and direct, under stimulus from externally applied signals, the flow of radio frequency energy from one part of a circuit to another. Phased-array radars generally use semiconductor transmit/receive modules and use large numbers of switches. The rate at which the pin diode can be switched from a low-impedance, forward biased condition to a high-impedance, reverse biased condition, is determined by the speed at which the free charge can be extracted from the diode. A Metal Semiconductor Field-Effect Transistors (MESFET) can be used in two different modes as passive or active elements. In the passive mode of operation, the MESFET is configured to function as a passive two-terminal device, with the gate terminal acting as a port for only the control signal. Insertion Loss and isolation are important parameters that are used to characterize the performance of microwave switches.
