Gaas If Switch Design And Development,

With the great development of radar and microwave technology , it's necessary to increase switching time of MID frequency switch under the condition of high isolation and low insertion loss. GaAs MID frequency switch has small cubage and above advantages, can meet our expectations. In order to exert the speed performance of GaAs MID frequency switch and improve the agility to be compatible with TTL control electric level of most present system, we studied the GaAs MID frequency switch with TTL driver.In this paper,GaAs MIDF switch's design and fabrication programme are described in details.First of all,GaAs MESFET's principle is analysed and a switch circuitry design methodology is supposed and,in the meanwhile,the transient parameters are discussed.Based on above ones,a switch circuit topology is finished,which is designed and optimized by modern CAD technology.Large signal model of GaAs MESFET is built and,in the light of advanced PSPICE circuit simulation programme,the circuit transient and DC operation analyse and speed performances are calculated.And also,the inserted loss and isolation are optimized by microwave circuit software TOUCHSTN of EESOF Company.In order to improve process quality and increase probability,we optimize ohm contact resistance and breakdown voltage of devices by adjusting process conditions.Finally,DC-500MHz MIDF switch is fabricated,in which some important conclusions and suggestions are introduced.