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

Recent advancements in the communicationarena demand small-size devices with better transmission and minimum losses. Switches are the basic buildingblocks for any communication system. MEMS switches offer better performance in terms of size and losses thantheir mechanical and solid-state counterparts. Out of different MEMS switch types, ohmic switches are preferred overcapacitive switches in terms of large bandwidth. Ohmicswitches work over the entire frequency range starting fromdc, whereas capacitive switches only operate in a particu-lar frequency band. Hence, ohmic switches are preferredto cover multibands. However, the insertion loss of theusual series ohmic switches is higher than the capacitiveswitches due to contact resistance. In this article, a newconcept for a shunt ohmic switch with low insertion losshas been designed and characterized. The contact resis-tance term is removed from the switch in the ON state.The insertion loss of the proposed shunt ohmic switch isless than-0.3 dB, and isolation is better than-17 dB overthe frequency range of dc-6 GHz. The proposed switch issuitable for all the communication bands from 2G to 6G tillsub-6-GHz technology