Performance improvement of a reconfigurable series-shunt switch via asymmetric structure based RF-MEMS capacitive switch

This paper presents a series combination of metal to metal contact and capacitive RF-MEMS switches for multi-band wireless applications. For performance improvement a novel capacitive shunt switch is used and the response has been compared with a conventional shunt device. The proposed design shows the insertion loss better than 0.35 dB and return loss below 13.96 dB up to 30 GHz as compared to 1.64 dB insertion loss and 6.14 dB of return loss with conventional device. Isolation peaks of 75.33, 71.58 and 72.98 dB has been observed at 8.2, 7.3 and 15.5 GHz when left, right or both cantilevers are electro-statically actuated in the down-state respectively, whereas conventional device has peak only at 7.3 GHz. Further, a reduction of about 60 % in the pull-in voltage of capacitive switch and 17.5 % in device area has also been observed. The proposed design can be used as a building block for multiple throw switches and switch matrices for the future reconfigurable RF front end applications.