Design of coils inductively-tuned RF MEMS shunt switches using novel modeling method

In this paper, the design of inductively-tuned coil RF MEMS shunt switches, using a novel modeling method, is presented. In this model, both lumped elements and coplanar waveguides (CPW) are used in the electrical equivalent circuit due to the fact that the up-state capacitance is usually very small, and the CPW loss is a main contribution to the up-state insertion loss. The CPW loss is estimated to be less than 0.2 dB at 0-10 GHz in most case. The modeling method allows us to simulate the RF switch more efficiently compare to commercial FEM CAD tools. Using this model, optimized switches with tuning coils operation at S-band are obtained. The isolation of the switches is 23 dB at 4 GHz and 16 dB at 2.4 GHz, respectively. The modeling results are verified by using HFSS simulation.