Abstract:
RF MEMS devices are competitive for handling high frequency microwave signals. In comparison to semiconductor devices, the performance of RF MEMS devices is highly linear, minimizing signal distortion. A contactless piezoelectric RF MEMS switch has been designed and simulated. Due to the use of a contactless design based on variable capacitance the reliability issues affecting contacting-type MEMS switches are avoided. The structure is piezoelectrically actuated using a sputtered lead zirconate titanate (PZT) layer. Finite element simulation has been conducted to optimize the structure. Electrical simulation predicts that, by achieving an on-off capacitance ratio greater than 10, isolation will exceed 15 dB over the frequency range from 4 to 15 GHz. Preliminary isolation measurements on fabricated devices without the actuating layer showed 26 dB isolation at 4 GHz, similar to that modeled, although isolation did not decrease by the modeled trend at high frequencies approaching 15 GHz.
