Design and Development of a Low Insertion Loss RF MEMS Shunt Ohmic Switch

Recent advancements in the communication arena demand small-size devices with better transmission and minimum losses. Switches are the basic building blocks for any communication system. MEMS switches offer better performance in terms of size and losses than their mechanical and solid-state counterparts. Out of different MEMS switch types, ohmic switches are preferred over capacitive switches in terms of large bandwidth. Ohmic switches work over the entire frequency range starting from dc, whereas capacitive switches only operate in a particular frequency band. Hence, ohmic switches are preferred to cover multibands. However, the insertion loss of the usual series ohmic switches is higher than the capacitive switches due to contact resistance. In this article, a new concept for a shunt ohmic switch with low insertion loss has been designed and characterized. The contact resistance term is removed from the switch in the ON state. The insertion loss of the proposed shunt ohmic switch is less than −0.3 dB, and isolation is better than −17 dB over the frequency range of dc-6 GHz. The proposed switch is suitable for all the communication bands from 2G to 6G till sub-6-GHz technology.