基于LCP基板的超宽带滤波器的设计与实现

Design and implementation of a ultra-wide band pass filter based on LCP

高分子液晶聚合物(LCP)以其优异的高频特性,被认为是继低温共烧陶瓷(LTCC)后的下一代微波毫米波的基板和微组装材料。本文基于五层LCP基板设计了一款超宽带(UWB)带通滤波器(BPF),采用四分之一波长线来替换半波长的MMR结构,并且通过折叠传输线的方法进一步缩小BPF滤波器的体积。利用HFSS仿真软件对滤波器进行了建模仿真。通过标准的LCP多层工艺,制备了超宽带滤波器。测试结果表明,在2.5 GHz到10.4 GHz的频带范围内,插入损耗优于-5 dB,回波损耗小于-15 dB,带外抑制高于-30 dB。其测试结果和仿真结果能够较好地吻合。该滤波器的成功设计为超宽带通信系统的小型化提供了一个重要的参考。

Liquid crystal polymer ( LCP) is considered as the next generation microwave andmillimeter wave substrateand microassembled material after low temperature co-fired ceramics ( LTCC). Based on the LCP substrate, an ultra-wideband ( UWB) band-pass filter ( BPF) was designed and simulated with 3D EM HFSS. The quarter-wavelength line was used to replace the half-wavelength MMR structure, and the volume ofthe BPF filter was further reduced by folding the transmission line. The simulation results show that the insertion loss is better than-5dB, the return loss is less than-15 dB, and the out-of-band suppression is higher than-30 dB in the frequency band from 2. 5 GHz to 10. 4 GHz. Through the standard LCP multilayer process, the UWB filter is fabricated, and the test results and simulationresults are in good agreement. The design of the filter provides an important reference for the miniaturization of UWB communication system.