基于双同轴阶梯阻抗谐振单元的平衡带通滤波器

Balanced Bandpass Filter Based on Twin Coaxial Stepped Impedance Resonator

本文介绍了一种基于阶梯阻抗谐振器(SIR)的双同轴谐振单元(TCR),并基于此构建了一个具有宽阻带和高共模抑制能力的二阶平衡带通滤波器。双同轴谐振器的单腔由两个阶梯阻抗谐振器构成。在这种情况下,基模用于构建差分通带,而第二个模式则用作共模抑制。本文主要提出了一个二阶带通平衡滤波器,该滤波器中心频率为1.17GHz,插入损耗为0.18 dB,3-dB相对带宽为6.3%,共模抑制超过65 dB。此外,谐波出现的位置约为基模频率的3.7倍,优于普通同轴谐振器的谐波水平。

In this paper,a twin coaxial resonator(TCR)based on stepped impedance resonators(SIR)is proposed and utilized to construct a second-order balanced bandpass filter with a wide stopband and high common mode rejection.The single cavity of the dual coaxial resonator consists of two stepped impedance resonators.In this case,the fundamental mode is used to construct the differential passband,while the second mode is used for the common mode rejection.A second-order balanced bandpass filter is proposed with a center frequency of 1.17 GHz,an insertion loss of 0.18 dB,a 3-dB relative bandwidth of 6.3%,and a common-mode rejection of more than 65 dB.In addition,the simulated results show a spurious-free response of the order of 3.7 times,which is better than the ordinary coaxial resonators.