Parallel‐coupled bandpass filters with broad rejection band using interdigital fingers and DGS

Abstract

AbstractA 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 2f0 and 4f0, and employing a defected ground structure (DGS) resonator to suppress the 3f0 spurious response. The measured results show a satisfactory rejection bandwidth of 8.6 GHz with a rejection level of −30 dB at 2f0. The improved performance will be very attractive for application in many communication systems. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 705–707, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21449