基于阶跃阻抗谐振器的新型双频宽带带通滤波器

在传统1/4波长阶跃阻抗谐振器（step impedance resonator,SIR）的基础上,提出一种新型双频宽带带通滤波器（bandpass filter,BPF）的结构及其设计方法,其中心频率为1.90/5.65 GHz,可工作于GSM等无线通信系统中.该滤波器频率覆盖范围广,带宽宽,其第一频段的绝对带宽为980 MHz,第二频段的绝对带宽为960 MHz.该滤波器在基频1.90 GHz的回波损耗低于-25 dB,插入损耗为-0.012 dB.同时,滤波器的两通带隔离度好,结构简单,易于加工.频率响应特性S₁₁和S₂₁的电磁仿真和实测结果非常吻合.

Wide Bandwidth Dual-band Bandpass Filter Based on Step Impedance Resonator

Based on the traditional quarter wavelength step impedance resonator（SIR）,a new dual-band bandpass filter（BPF） with wide bandwidth is proposed.Its center frequencies are 1.90/5.65 GHz, which can be used in wireless communication systems such as GSM.The filter has a wide frequency range,with the absolute bandwidth of the first and second center frequencies being 980 and 960 MHz respectively.At 1.90 GHz,the proposed BPF has return loss less than-25 dB and insertion-loss less than -0.012 dB.The BPF has better isolation between the two passband and a simple structure for easy manufacturing.Simulated frequency responses S₁₁and 5₂₁ of the filter agree with the measured results.