Miniaturized bandpass filter using coupled lines for wireless applications

Abstract

Abstract In this paper, a bandpass filter (BPF) has been designed using bent and coupled-line structure. The design process of the filter to achieve a BPF with good characteristics is completely explained. Therefore the LC equivalent circuit of The BPF is presented as the analytical description. The proposed filter can pass frequencies between 2.2 and 3.6 GHz with an insertion loss <0.4 dB, which is suitable for wireless applications. The fractional bandwidths (FBW) of the filter is about 48%. Some characteristics such as small size, low insertion loss, high return loss wide upper stopband bandwidth, and good suppression level in stopband are among the advantages of this study to be mentioned. Finally, the presented filter was fabricated, and the measured results have a proper agreement with the simulation results.