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

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.