PARALLEL-COUPLED BANDPASS FILTERS WITH BROAD REJECTION BAND USING INTERDIGITAL FINGERS AND DGS

摘要

A novel parallel-coupled bandpass filter (PC-BPF) with a fundamental frequency of 2.4 GHz is presented in this paper, This proposed filter achieves a broad rejection bandwidth and a sufficient attenuation level by using the distributed interdigital fingers to attenuate the spurious even harmonics of 2f{sub}0 and 4f{sub}0, and employing a defected ground structure (DGS) resonator to suppress the 3f{sub}0 spurious response, The measured results show a satisfactory rejection bandwidth of 8.6 GHz with a rejection level of -30 dB at 2f{sub}0. The improved performance will be very attractive for application in many communication systems.