Analysis of SFIT saw filters using coupling of modes model

This paper presents a study on using the coupling‐of‐model (COM) model to analyze wide‐band SAW filters with slanted finger interdigital transducers (SFIT). In contrast to other design methods, the COM model is more convenient and more simple to use for designing different types of electrodes by just changing the elements of a P‐matrix. In this paper, we give a complete description of how to use the COM approach to analyze SFIT SAW filters and show a comparison of simulated and experimental frequency responses of the SFIT SAW filter. Two SFIT SAW filters with 30% bandwidth, 60 MHz center frequency, and different numbers of SFIT pairs were designed. On the experimental side, SFIT SAW filters using YZ‐LiNbO3 as the substrate material were fabricated and the on‐wafer frequency responses were measured. Comparisons made between the simulated and measured frequency responses showed good agreement.