The Design Of225MHz~400MHz High Speed Power T/R Switch

Microwave switch is widely used in communication, radar and electronic countersystems. T/R switch is a single-pole double-throw switch (SPDT) which connected intransmitter output, antenna and receiver. Now PIN diode and GaAs MESFET arecommonly used in T/R switch. Because the Pin diode has good characteristics that arelarge controlled power, low loss, high speed and cost-effective, it applies to the controlcircuit such as the Modulating, the Phase Shifter, the Amplitude Limiting, the attenuatorsand microwave switches.After Thesis details the PIN diode and basic theory of switch, proposes designmethod of broadband switch. It also details the process of switch circuit and uses ADSsimulation software to simulate and optimize the broadband switch and assemble and testthe circuit. The test results are given suggestions for improvement measures. The thesis isalso focus on the development of a novel SP4T T/R switch. The thesis complete awideband SP4T switch simulation design and test it. Because of the influence of someparasitic parameter in PIN diode and circuits, a lot of simulation and optimization must betaken to compensate the circuits. Measured results show that the insertion loss of all thechannels are less than0.6dB over225MHz-400MHz, the isolation is more than60dB andthe VSWR is less than1.5.Measured results show that the test results are consistent withthe simulation curve on the whole. The thesis also proposes the further work required andit has a certain reference value to the design of the switch circuit.