High-isolation CPW MEMS shunt switches - Part 2: Design

In this paper, the second of two parts, the equivalent RLC model of the shu nt switch is used in the design of tuned two- and four-bridge "cross" switc hes from 10 to 40 GHz, The cross switch attained an insertion loss of less than 0.3-0.6 dB, a return loss below -20 dB from 22 to 38 GHz in the up sta te, and a down-state isolation of 45-50 dB with only 1.5 pF of down-state c apacitance (Cd) Also, an X-band microelectromechanical system (MEMS) switch with an insertion loss of less than 0.2 dB and an isolation of 35 dB is pr esented. This is done by inductively tuning the LC series resonance of the shunt switch. The MEMS bridge height is 1.5-2.5 mu m, resulting in a pull-d own voltage of 15-25 V. Application areas are in low-loss high-isolation co mmunication and radar switches.