Design of a compact wide-bandwidth band-pass filter using a parallel-coupled structure

Abstract

In this article, a broad bandpass filter (BPF) with a parallel-coupled line (PCL) structure is proposed. In general, a BPF with a PCL structure has a limited bandwidth of 20%. A broader range of bandwidth than this requires a very narrow coupling-gap that can hardly be realized. In this research, a new smaller-sized broad-BPF using a new type of PCL is presented. The new broad BPF shows a measured insertion loss of less than 0.31 dB and a return loss of better than 19.2 dB at the center frequency of 5.8 GHz with a 70% broad bandwidth. (c) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2581-2584, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27157