Title: Wideband open stub BPF for cognitive radio system applications

Authors: Bhanu Shrestha; Jeong Hyun Yi; Seongsoo Cho

Addresses: Department of Electronics Engineering, Kwangwoon Univerversity, Seoul, 01897, South Korea ' School of Software, Soongsil University, Seoul, 06978, South Korea ' School of Software, Soongsil University, Seoul, 06978, South Korea

Abstract: In this paper, a compact wideband open stub bandpass filter (BPF) is designed, fabricated and characterised for cognitive radio system (CRS) application, which is an emerging technology in the wireless communication system. The designed BPF can be implemented to a front end of CRS system that can pass the desired signal rejecting all other signals and noise. We fabricated on Teflon substrate with dielectric constant of 2.54 and thickness of 0.54 mm and characterised using vector network analyser. The experimental results of wideband BPF are found in good agreement with simulated results, showing fractional bandwidth from 4.4-8.0 GHz (≈59%), insertion loss (S₂₁) of 33.6 dB, and minimum return loss (S₁₁) of 0.10 dB at 6.2 GHz. The group delay of wide BPF is below 0.19 ns. The features of the design are size reduction, wideband, higher insertion loss, feasibility in implementing to CRS. The designed wide BPF occupied the size of 0.394 × 0.601 λg.

Keywords: wireless cognitive radio system; CRS; cognitive radio system; wideband BPF; microstrip BPF; open stub BPF; UWB.

DOI: 10.1504/IJSNET.2017.087725

International Journal of Sensor Networks, 2017 Vol.25 No.3, pp.198 - 205

Received: 04 Mar 2017
Accepted: 04 Mar 2017
Published online: 31 Oct 2017 *

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