Third-Order Intermodulation of an MEMS Clamped-Clamped Beam Capacitive Power Sensor Based on GaAs Technology

This letter presents a comprehensive theoretical and experimental study of the third-order intermodulation (IM3) in a microelectromechanical system capacitive power sensor with clamped-clamped beam at
$X$
-band. A simple model is developed to analyze the origin of IM3. High linearity of the sensor is demonstrated by dual-tone signal measurements both in frequency interval (
$\Delta f$
) dependence and input power dependence. The worst IM3 product for different
$\Delta f$
remains less than −39 dBm at an input of
$P_{1} = P_{2}=6$
dBm. Third-order intercept points of 29.3 dBm at
$\Delta f=100$
Hz and 33.2 dBm at
$\Delta f=10$
kHz are derived by measurements.