High-Performance Wideband SAW Filter With Parallel DMS on LiTaO 3 /SiO 2 / α -Si/Si Substrate

This letter presents a high-performance wideband surface acoustic wave (SAW) filter using a parallel longitudinally coupled double-mode SAW (DMS) structure on LiTaO3/SiO2/$\alpha $-Si/Si multilayer substrate. The proposed DMS filter, designed and optimized using the finite element method (FEM), successfully achieves a combined passband with twice the bandwidth of a conventional single DMS filter. Experimental results demonstrate a fractional bandwidth (FBW) of 12.6%, confirming its enhanced broadband performance. Moreover, it exhibits temperature coefficients of frequency as low as 3.17 ppm/°C at the upper sidebands within the −3 dB bandwidth, together with a power handling capability of 25.5 dBm, indicating good temperature stability and high power durability. These superior characteristics make the proposed filter a promising candidate for next-generation radio frequency (RF) front-end systems.