Up-state and Down-state Capacitance Measurement in RF MEMS One-bit Switch Designed at Microwave Frequency Range

Insertion loss, isolation factor and return loss of one-bit RF MEMS switch designed at higher microwave frequency ranges is numerically measured for computation of up-state and down-state capacitance. SiO2 is the material considered for design purpose and simulation is performed over the entire microwave frequency range in order to investigate the position of maximum loss (peak point). Overlap cross-sectional area is varied over the possible fabrication range, and losses are measured for both actuated as well as unactuated states of the device over the varying overlap region. Both up and down state capacitances are measured which are higher with increase of active area. Return loss of −50 dB is observed for unactuated state whereas it becomes very low (~ −7.5 dB) for actuated device. Also for down state capacitance measurement, isolation increases upto −40 dB. Results are very useful for phase-shifter design at microwave spectrum.