通讯系统传输效率的提升对滤波器带宽的要求越来越高，如果使用常规声表面波(SAW)滤波器设计技术，则将面临损耗大或带宽达不到要求的问题。该文根据系列宽带SAW滤波器产品开发结果，总结了采用特殊技术用LiTaO3压电基片实现相对带宽8%以上的宽带SAW滤波器设计方法，其包括利用外围电感、电容增加SAW谐振器的谐振频率和反谐振频率的间隔，提高阻抗元滤波器带宽；利用多模式纵向耦合谐振滤波器结构增加滤波器带宽；利用双通带滤波器并联结构获得大带宽滤波器。上述方法各有优缺点，其均能获得约为9%的带宽。

With the increase of the transmission efficiency of the communication system, the bandwidth of the filter is required to be wider and wider. If the conventional SAW filter design technology is used, it will face the problem of high loss or insufficient bandwidth. Based on the development of a series of wideband SAW filters, this paper summarizes the design methods of wideband SAW filters with a relative bandwidth of more than 8% by using LiTaO3 piezoelectric substrate with special technology. These methods include using peripheral inductance and capacitance to increase the difference between the resonant frequency and the anti-resonant frequency of the SAW resonator to improve the bandwidth of the impedance element filter, using multi-mode longitudinal couple resonance structure to increase filter bandwidth, and using dual-pass filter parallel structure to obtain large-bandwidth filter. Each of the described methods has advantages and disadvantages, and the achievable bandwidth is about 9%.