Design and Realization of a Fully Differential SAW Filter Architecture for Bandwidth Enhancement

This paper proposes a S-Band lattice topology filter using 6% Aluminum Scandium Nitride (AlScN)-based Surface Acoustic Wave (SAW) resonators. The lattice filter consists of a differential configuration of series and parallel resonators with Figure of Merit (FoM) 4.89 and 5.52, respectively. The resonant frequencies are set lithographically in a single mask itself. We successfully demonstrated the lattice filter with a center frequency of 2.295 GHz and a 3 dB fractional bandwidth of 1.52 %. Along with a good Stop Band Rejection characteristic, this filter exhibited 1.45 times the bandwidth of the ladder configuration possible with the same number of resonators.