In this paper we present the optimization of photoswitches constituted of a coplanar line introducing interdigitated MSM photodetectors in the central strip. The reflection and the transmission coefficients are studied with the aim of highlighting the influence of different geometrical parameters on the photoswitch microwave behavior. In pursuance of improving the performances, new topologies of coplanar lines introducing tapers of linear shapes, as well as tightening of ground planes around the central strip are proposed and studied. The outcomes showed that it is possible to achieve high insulation (−52.3 dB) at the Off state. As for as the On/Off ratio is concerned, a value of 48.8 dB is reached.
