Large Bandwidth Low-Spurious SAW Filter for N78 Band

Abstract

With the rapid development of 5G technology, key components like Surface Acoustic Wave Filters (SAWF) face challenges in bandwidth, spurious, and leakage. This paper optimizes the materials, thickness, and metallization ratio (MR) of IDT to propose a high-frequency, low-spurious, wide-bandwidth filter for the N78 band. Firstly, simulations show Au outperforms Al and Cu in reducing spurious and leakage. Secondly, by analyzing impact of MR, the optimal MR for series and parallel resonant units is 0.4 and 0.6, respectively. Eventually, A filter with 642 MHz bandwidth, 3.52 GHz center frequency, and 1.22 dB in-band spurious was obtained for N78 band.