Optimization of Coplanar Waveguide Integrated PCM Switches

This paper presents the optimization of coplanar waveguide integrated PCM switches. PCM switches isolation efficiency is directly affected by distance between ground planes above and below the transmission line. Reducing this distance from 160 μm to 26 μm, while keeping exactly the same PCM switch core, dramatically improves measured isolation from -22.2 dB to —31.1 dB at 40 GHz using a single device. Without changing the switch geometry, its figure of merit is enhanced from 14.9 fsec to 5.9 fsec. The design technique presented in this paper can be reused for designing CMOS integrated PCM switches.