High Isolation RF MEMS Series-Shunt SPST Switch at W Band

In this paper individual series and shunt switches have been optimized for the best RF performance. The width of the beam of the shunt switch, gap between the signal line and bottom of the beam in shunt switch, gap between the signal line and bottom of the dimple in series switch and the distance between the shunt and the series switch have been parametrically simulated. The insertion loss of -0.7dB, return better than -8dB and isolation greater than 25dB in W-band have been achieved in shunt switches. The width of the metallic contact strip has been varied to achieve an insertion loss of -1.2 dB, return loss of -7dB and isolation of 10dB achieved in case of series switch. Both the switch are then cascaded and the distance between the two switches optimized for the best RF output performances. An insertion loss of -1dB up to 95GHz and better than -1.5dB in the range from 95GHz to 110 GHz, return loss better than -6dB have been achieved. Isolation of 40 dB up to 95 GHz and 32dB in the range from 95GHz to 110GHz have been achieved.