P波段窄带高抑制选频组件性能优化的研究

Research on Performance Optimization of P-Band Narrowband High Suppression Frequency-Selecting Module

摘要:

直插封装（SC04-06）滤波器装配工艺复杂，引脚修剪长度和装配过孔等影响端口阻抗，导致产品一致性差，不利于选频组件批量生产。表面贴装封装（SMD0705B）滤波器的体积小，装配工艺简单，但存在阻带抑制不佳问题。利用三维电磁软件对选频组件的核心声表面波（SAW）滤波器进行仿真，通过仿真结果和实物对比，验证了滤波器封装对阻带抑制的影响。提出对 SMD0705B 封装滤波器增加屏蔽罩的方法，实现了 P 波段窄带选频组件的高阻带抑制。结果表明，选频组件阻带抑制大于 40 dBc，带内波纹小于 1 dB，幅度一致性小于 1 dB，可批量生产。

Abstract:

The assembly process of the direct insertion package （SC04-06） filter is complex， and the trimming length of the pins and assembly vias affects the port impedance. This results in poor product consistency and hinders mass production of the frequency-selecting module. The surface mount package （SMD0705B） filter has a small size and a simple assembly process， but it suffers from poor stop-band suppression. This paper uses three-dimensional electromagnetic software to simulate the core surface acoustic wave （SAW） filter of the frequency-selective component. Through comparison of simulation results and physical measurements， the influence of filter packaging on stop-band suppression is verified. A method is proposed to add a shielding cover to the SMD0705B packaged filter， achieving high stop-band suppression in the P-band narrowband frequency-selecting module. The results indicate that the frequency-selecting module achieves stop-band suppression greater than 40 dBc， in-band ripple less than 1 dB， and amplitude consistency within 1 dB， making it suitable for mass production.