一种甚高频中心和带宽可调耦合滤波器设计

A VHFLband tunable bandpass filter with continuous control of central frequency and bandwidth

摘要: 针对两种典型的电调谐耦合滤波器结构，研究了在滤波器中心频率改变时如何保持滤波带宽恒定的问题.采用LC集总元件，考虑实际元件的寄生效应，提出了VHFL频段中心频率和带宽可调的双调谐耦合滤波器结构。仿真结果表明：该滤波器在56.9～165.8 MHz的可调范围内，电路频率选择性能良好，且矩形系数（30 dB/3 dB）小于7，保持接近常数的带宽.实际电路的测试结果验证了设计的有效性.

Abstract: A bandpass filter on FR4 substrate for application in VHFL band is presented.The principle of the circuit is analyzed and the performance is predicted with ADS.Finally，a reconfigurable filter is fabricated and tested to validate the proposed approach.Simulation results show that the absolute passband bandwidth could be maintained constantly in 56.9～165.8MHz， performance of selectivity is high, and the rectangular coefficient is less than 7.Experimental results validate the feasibility of the proposed tunable filter architecture.