Novel Topology for a Non-Reciprocal MEMS Filter

Abstract

The paper reports the first prototype of a magnetic-free, non-reciprocal 50Ω matched MEMS filter, based on a spatio-temporal modulation of identical resonators. The proposed approach shows similar performances and at least a 7 times smaller area if compared with a dual ladder filter. For these reasons, the novel topology eliminates all trade offs among performances, area, fabrication complexity and temperature compensation processes which restrict any MEMS filters. Experimental data has shown 12MHz BW3dB with insertion loss of 5.6dB and an isolation peak equal to -20dB, by exploiting 6 1GHz FBARs with 6.5% k <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 320 as quality factor.