Research And Design Of RF MEMS Switches

In a communication system switch applications for example, used in the design of the communication system of the two SPST MEMS switches and four SPDT Switch, the switch is made of silicon substrate, processing technology can be integrated with microelectronics other, switch design not only can be used for this communication system, also can be transplanted to other communication systems is very good.Derivation and Simulation of microwave equivalent circuit of MEMS switch and its formula based on, through the design of microwave simulation software Ansoft software HFSS series resistive SPST switch and shunt capacitive SPST switch. Design and Simulation of two kinds of switch is the result of the electromagnetic characteristics of good, shunt capacitive switch with high isolation in the frequency range of20-40GHz, the advantages of low insertion loss, series resistance type switch in the0-20GHz frequency range showed high isolation, low insertion loss.In this paper, based on the design of MEMS SPST switch on the design, four kinds of single pole double throw switch, on the basis of SPDT Switch on theory study, by means of microwave simulation software Ansoft HFSS software on four kinds of single pole double throw switch, simulation and optimization, parallel SPDT switch in the20-40GHz frequency range the return loss and isolation are greater than25dB, and the insertion loss is less than or equal to0.6dB. Series SPDT switch in the1～20GHz frequency band. The return loss and isolation is more than18dB, the insertion loss is less than0.3dB. The series-parallel hybrid switch in the frequency range of20-40GHz return loss and isolation are higher than20dB, the insertion loss is less than0.65dB. Parallel SPDT Switch has good electromagnetic properties in the20GHz-40GH band; series connection SPDT Switch has excellent electromagnetic properties in0-20GHz; series-parallel mixed SPDT Switch for output ports required frequency is not also has extensive application. In the design of the initial3D model, using microwave simulation software was used to optimize the geometry of each switch, by changing the switch insertion loss, isolation, return loss is to optimize the parameters, to meet the design requirements.