This paper describes the design and evaluation of a highly selective wideband microstrip bandpass filter with a near brick‐shaped transmission response and a very wide stopband characteristic. The proposed filter structure excites multimode resonances that combine to realize a wideband filter response and excited too are transmission zeros that create a highly selective filter with wideband suppression in the upper and lower stopbands. The filter configuration comprises electromagnetically coupled resonators that are stub loaded. The input and output feedlines are interdigitally coupled to the resonators. Measured results confirm the low‐loss and via‐free wideband filter exhibits an elliptical response with a wide stopband with a rejection greater than 30 dB. The selectivity factor and stopband performance of the proposed filter is better than that obtained with the high‐temperature superconductor (HTS) filters. Design of the filter is relatively simple and easy to manufacture using standard PCB technology. There is good correlation between the simulation and measured results. The proposed wideband bandpass filter is suitable for applications in high interference environments and cognitive radio systems.

中文翻译：

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具有非常宽的阻带特性的高选择性宽带BPF

本文介绍了具有接近砖形传输响应和非常宽的阻带特性的高选择性宽带微带通滤波器的设计和评估。所提出的滤波器结构激发了多模谐振，这些谐振相结合以实现宽带滤波器响应，并且由于传输零点而被激发，从而产生了高选择性滤波器，并在上下阻带中实现了宽带抑制。滤波器配置包括短线负载的电磁耦合谐振器。输入和输出馈线以数字方式耦合到谐振器。测量结果证实了该低损耗，无通孔的宽带滤波器呈现出椭圆形响应，并具有宽阻带，其抑制比大于30 dB。所提出的滤波器的选择性因子和阻带性能要优于高温超导体（HTS）滤波器。滤波器的设计相对简单，使用标准PCB技术易于制造。仿真和测量结果之间具有良好的相关性。所提出的宽带带通滤波器适用于高干扰环境和认知无线电系统中的应用。