In this paper, a microstrip filter using a modified stepped impedance resonator with high return loss, low insertion loss, and ultra-wide stopband is presented. The frequency response of the filter based on the layout and LC model is presented. The presented LPF consists of stepped impedance resonators to achieve a − 20 dB suppression level from 3.26 GHz up to 30 GHz. Using stepped impedance resonators results in multiple transmission zeros in the stopband. The proposed filter has an insertion loss of 0.1 dB, return loss of 26 dB, and cut-off frequency of 3 GHz. The transition band of the filter (with attenuation levels of − 3 dB and − 20 dB) is 0.26 GHz. The simulated results are close to the measured results, which shows the accuracy of our design.

本文提出了一种采用改进型步进阻抗谐振器的微带滤波器，该滤波器具有高回波损耗，低插入损耗和超宽阻带。提出了基于布局和LC模型的滤波器频率响应。提出的LPF由步进阻抗谐振器组成，以实现从3.26 GHz到30 GHz的− 20 dB抑制水平。使用步进阻抗谐振器会在阻带中导致多个传输零点。所提出的滤波器的插入损耗为0.1 dB，回波损耗为26 dB，截止频率为3 GHz。滤波器的过渡带（衰减水平为− 3 dB和− 20 dB）为0.26 GHz。仿真结果与实测结果接近，表明了我们设计的准确性。