Design of an Active Tunable Bandpass Filter for Spectrum Sensing Application in the TVWS Band

Kim, Dong-Su; Kim, Do-Hyun; Yun, Sang-Won

doi:2017.17.1.34

J. Electromagn. Eng. Sci > Volume 17(1); 2017 > Article

Journal of Electromagnetic Engineering and Science 2017;17(1):34-38.
DOI: https://doi.org/10.5515/JKIEES.2017.17.1.34

Design of an Active Tunable Bandpass Filter for Spectrum Sensing Application in the TVWS Band

Dong-Su Kim, Do-Hyun Kim, Sang-Won Yun

Department of Electronic Engineering, Sogang University

Correspondence: Sang-Won Yun,Email: swyun@sogang.ac.kr

Abstract

In this paper, we propose an active tunable bandpass filter (BPF) for efficient spectrum sensing in the TV White Space (TVWS) band. By designing a narrow bandwidth, it is possible to improve the sensing probability. The basic circuit configuration involves switching the PIN diode compromising capacitor bank to change the capacitance of the LC resonant circuit. To cover the whole TVWS band effectively, we add a varactor diode, and the bandwidth is set to 25-MHz. We improve the insertion loss by using the active capacitance circuit. The tunable BPF in the TVWS band with a 20-MHz interval is designed to have 11 channels with a bandwidth of 25 MHz and a low insertion loss of 1.7-2.0 dB.

Key words: Active Filter, Negative Resistance, Tunable Bandpass Filter (BPF), TV White Space