Microstrip dual-band bandpass filter for ISM band applications

This paper presents a development of microstrip dual-band bandpass filter for Industrial, Scientific and Medical (ISM) band application. The proposed bandpass filter which can operate at 2.4 GHz and 5 GHz band is implemented based on parallel coupled line technique. The parallel coupled line filter allows tuning two bands at desired frequencies apart for minimizing the return losses within both dual passband. The Advanced Design System (ADS) simulator has been used during simulation and optimization. For the design verification, the prototype of the proposed microstrip filter has been fabricated and measured. The simulated return loss S11 and insertion loss S21 of the proposed microstrip filter are -25.092 dB and -0.013 dB at 2.4 GHz respectively, while -22.373 dB and -0.025 dB at 5 GHz respectively. For the design verification, the prototype of the proposed antenna was fabricated and measured. The result shows that the proposed design can be realized in any communication system applications.