Simulation and Design of a Bandpass Filter Based on Substrate Integrated E-Plane Waveguide

Abstract This paper presents a bandpass filter based on a substrate integrated E-plane waveguide (SIEW) structure for wireless applications, at X-band. The SIEW geometry allows the development of new horizontally polarized filter topologies, unlike filter structures based on substrate integrated waveguide (SIW), which present vertical polarization (perpendicular to the ground plane). The simulation of the proposed SIEW filter is carried out using Ansoft HFSS software. To evaluate the performance of the proposed structure, the frequency behaviors of the scattering parameters are obtained for a horizontally polarized excitation. In the simulation, analyses are performed for the lossless and lossy (dielectric and metallic) cases, in order to compare the obtained results. The SIEW filter is fabricated and measured using a vector network analyzer (VNA). Measurement results are in agreement with simulation ones, validating the proposed filter design and topology. The fabricated prototype resonates at 10.54 GHz, with a bandwidth of 1.20 GHz, defined for a -3 dB transmission coefficient reference level. The SIEW filter structure is easy to design and manufacture and can be used in wireless communications systems that require components with ease integration into other planar structures.

摘要 本文面向X波段无线应用场景，提出一种基于衬底集成E面波导（substrate integrated E-plane waveguide, SIEW）结构的带通滤波器。与传统基于衬底集成波导（substrate integrated waveguide, SIW）的滤波器结构（其极化方向垂直于接地面，为垂直极化）不同，SIEW结构可实现新型水平极化滤波器拓扑的研发。本文采用Ansoft HFSS软件对所提SIEW滤波器开展仿真分析。为评估所提结构的性能，本文针对水平极化激励条件，获取了散射参数的频率响应特性。仿真环节分别针对无损、有损（包含介质损耗与金属损耗）两种工况展开分析，以对比不同条件下的仿真结果。本文采用矢量网络分析仪（vector network analyzer, VNA）对制备的SIEW滤波器进行测试。测试结果与仿真结果吻合度良好，验证了所提滤波器设计方案与拓扑结构的有效性。所制备的样机谐振频率为10.54 GHz，带宽达1.20 GHz，该带宽以-3 dB传输系数作为参考阈值。SIEW滤波器结构设计与制造流程简便，可应用于要求组件可便捷集成至其他平面结构的无线通信系统中。