恒定绝对带宽的紧凑型可重构双频带通滤波器

Compact Reconfigurable Dual-Band Bandpass Filter with Constant Absolute Bandwidth

本文研究了一种基于阶梯阻抗谐振器(SIR)和缺陷馈电结构的小型双频带通滤波器(BPF).具有T型中央加载的SIR可以更自由地调整双频谐振频率,SIR和缺陷馈电结构组合,并进行阶数调整,可以很容易控制绝对带宽,仿真得到传输零点.最后,仿真结果显示,恒定绝对带宽在230MHz±5.6%的情况下,第二通带可以在1.55GHz,1.75GHz和2.05GHz之间切换,恒定绝对带宽为32MHz的情况下,第一通带稳定在0.90GHz.实际加工的滤波器测量结果与仿真结果吻合较好.

A compact dual-band bandpass filter( BPF) based on stepped impedance resonator( SIR) and defectedfeeding structure is investigated in this paper. The SIR with T-stub centrally loaded provides more degrees of freedom to adjust the dual-band resonant frequencies. By combining the SIR with the defected-feeding structure and adjusting their dimensions,the absolute bandwidth can be easily controlled. Transmission zero is derived through simulation due to the combination of SIR and defected-feeding structure. Finally,simulation results show the second passband switched among 1. 55 GHz,1. 75 GHz and 2. 05 GHz with a constant absolute bandwidth of 230 MHz± 5. 6%,and the first passband fixed at 0. 90 GHz with a constant absolute bandwidth of 32 MHz. The measurement of the fabricated example shows good agreement with the simulation.