A π Small-Signal Model of MEMS Series Switches Based on the Parameter- Extraction Method

A novel π small-signal model of MEMS series switches is presented based on a parameter-extraction method, which can determine a fringing capacitance (C_f) in the end of each signal line as well as a contact resistance (R_c). For an on-state modeling, the average error of S₁₁ for the π model is 5.1% in the range of 5~35 GHz, whereas that of the conventional model of two-port series-impedance without C_f is 167.2 %. It is noted that the conventional model is not valid anymore for the on-state model and C_f should be taken into account. The small-signal modeling by the proposed π model demonstrates the validity of the approach.