Implementation of a Compact Dual-Band Bandpass Filter Using Signal Interference Technique on Paper Substrate

Abstract This paper exhibits the design and implementation of a compact dual-band bandpass filter on paper substrate. The proposed filter which works on the principle of signal interference technique has a parallel combination of short-circuited coupled line and an H-shaped network of transmission lines with open stubs. Due to the superposition of signals of the two transmission paths, a second order dual-band bandpass response with four transmission zeroes is achieved. To validate the proposed design, theoretical analysis using the lossless transmission line model is carried out and acknowledged. The developed dual-band filter prototype with center frequencies 1.17 GHz and 4.06 GHz has 3-dB fractional bandwidths of 82.56% (0.69-1.656 GHz) and 20.59% (3.645-4.481 GHz), respectively. The simulated and experimental results are in good congruence with each other. The proposed dual-band bandpass filter can be used in various wireless applications, for example, Global System for Mobile Communications (880-915 MHz), Aircraft surveillance (960-1215 MHz), Indian Regional Navigation Satellite System (1.164-1.188 GHz), Amateur radio (1.24-1.30 GHz), Global Positioning System (1.559-1.61 GHz), Satellite phones (1.616-1.626 GHz), and Satellite communication (3.7-4.2 GHz).