基于LCP基板的宽带滤波器设计

Design of Broadband Filter Based on LCP Substrate

基于50μm厚度的液晶高分子聚合物(LCP)基板,设计了一款宽频带柔性带通滤波器。中心频率为13GHz,带宽6GHz,插入损耗小于1.7dB,回波损耗小于17.5dB,在7.5GHz和19GHz处的带外抑制大于17.5dB。该滤波器结构紧凑,总尺寸为16.570mm×7.620mm×0.086mm。经实际测试,其测试结果与电磁仿真结果吻合。同时,对比了滤波器在物理结构平坦时和其在较小角度的随机弯折状态下的实测结果,结果显示其结构的弯折基本不影响滤波器性能。

Based on a 50 μm thick liquid crystal polymer(LCP) substrate, a broadband bandpass flexible filter was designed. The center frequency of the filter is 13 GHz, the bandwidth is 6 GHz, the insertion loss is less than 1.7 dB and the return loss is less than 17.5 dB, and the out-of-band rejection is greater than 17.5 dB at 7.5 GHz and 19 GHz. The filter is compact in structure, with a total size of 16.570 mm×7.620 mm×0.086 mm. The test results are in agreement with the electromagnetic simulation results through the actual test. Moreover, the actual measurement results of the filter in the conditions of flat physical structure and of the random bending state at a small angle are compared. The results show that the bending of the structure does not affect the performance of the filter basically.