SU-8 serial MEMS switch for flexible RF applications

Abstract

This paper presents a novel SU-8 micromachining process for MEMS series switch fabrication. The switch is designed with a clamped-clamped SU-8 (5 mu m)/Cu (2 mu m)/SU-8 (3 mu m) beam structure driven by electrostatic force, which is fabricated on a silicon substrate with a resistivity of similar to 5 Omega cm. Experimental results show that the switch can exhibit better than -4.48 dB insertion loss and -28.2 dB isolation up to 12 GHz. Such a large insertion loss is mainly caused by substrate loss which can be further reduced down to -0.75 dB as long as the substrate resistivity is increased up to 100 Omega cm.