太赫兹科学与电子信息学报, 2018, 16 (4): 668, 网络出版: 2018-09-12
X波段阶梯阻抗微带带通滤波器设计
Design of multi-mode microstrip bandpass filter using stepped impedance resonator at X-band
多模滤波器 阶梯阻抗 带外抑制 奇偶模 传输零点 multi-mode filters stepped-impedance suppression of stop band odd/even mode transmission zero
摘要
设计了一款X波段的多模带通滤波器, 并给出了仿真与实验结果。采用恒定阻抗枝节加载3个阶梯阻抗枝节的方式, 构成滤波器的主体;利用表面电流分布图获得影响带内极点分布的枝节参数, 通过调整阶梯阻抗枝节参数优化滤波性能。为实现更好的带外抑制能力, 滤波器两端各串联一对平行耦合线, 在14 GHz引入一个传输零点。实验测试结果显示, 所设计滤波器的中心频率为9.76 GHz, 带宽为2.4 GHz, 30 dB/3 dB矩形系数为1.63, 相对带宽为25%, 带内插入损耗大部分小于1 dB, 大部分回波损耗高于15 dB, 与仿真结果较为吻合。
Abstract
A multimode bandpass filter working at X-band is designed and developed, and both the simulated and measured results are presented. A constant-impedance stub loaded with three stepped- impedance stubs constitutes the main structure of this filter. Surface current distribution maps are utilized to acquire parameters which influence the distribution of transmission poles. By regulating the parameters of stepped impedance stubs, the performance of this filter can be optimized. For further enhancing the suppression of stop band, a pair of parallel coupled lines are joined up in series at both sides to introduce a transmission zero at 14 GHz. The measured results show that the designed filter has the center frequency of 9.76 GHz, the bandwidth of 2.4 GHz, the rectangular coefficient at 30 dB/3 dB of 1.63, the relative bandwidth of 25%, and most of the insertion loss and the return loss of the passband are respectively less than 1 dB and higher than 15 dB,which agree well with the simulated results.
张威, 叶龙芳, 许雄, 张勇, 徐锐敏. X波段阶梯阻抗微带带通滤波器设计[J]. 太赫兹科学与电子信息学报, 2018, 16(4): 668. ZHANGWei, YE Longfang, XU Xiong, ZHANG Yong, XU Ruimin. Design of multi-mode microstrip bandpass filter using stepped impedance resonator at X-band[J]. Journal of terahertz science and electronic information technology, 2018, 16(4): 668.