W-band CPW RF MEMS circuits on quartz substrates

This paper presents W-band coplanar waveguide RF microelectromechanical system (MEMS) capacitive shunt switches with very low insertion loss (-0.2 to -0.5 dB) and high-isolation (< -30 dB) over the entire W-band frequency range. It is shown that full-wave electromagnetic modeling using Sonnet can predict the performance of RF MEMS switches up to 120 GHz. Also presented are W-band 0(degree)/90(degree) and 0(degree)/180(degree) switched-line phase shifters with very good insertion loss (1.75 dB/bit at 90 GHz) and a wide bandwidth of operation (75100 GHz). These circuits are the first demonstration of RF MEMS digital-type phase shifters at W-band frequencies and they outperform their solid-state counterparts by a large margin.