Generalized Synthesis of Double-Mode SAW Filters: A Systematic and Automated Approach

This paper presents a generalized and automated synthesis methodology for Double-Mode Surface Acoustic Wave (DMS) filters. While DMS filters offer superior out-of-band rejection, their design has traditionally relied on empirical tuning and iterative optimization. The lack of a systematic synthesis process has limited their efficient and scalable deployment. The proposed method integrates the Coupling-of-Modes (COM) model with extracted-pole and trisection topologies, enabling a direct link between coupling matrix elements and physical geometry. The design flow is validated through the synthesis, fabrication, and measurement of a 368 MHz DMS filter on 42^◦Y-cut LiTaO3, showing excellent agreement across synthesis, simulation, and experiment. This methodology enables accurate and predictable design of compact, high-performance DMS filters for future RF front-end applications.