A dual-band band-pass filter with overlap step-impedance and capacitively loaded hairpin resonators for wireless LAN systems

Abstract

This paper presents a dual-band band-pass filter using modified cross-coupled step-impedance and capacitively loaded hairpin resonators for WLAN systems. The proposed filter has been designed to operate at a fundamental frequency of 2.4GHz and the first harmonics frequency of 5.2GHz. The techniques of step impedance and load capacitor are combined in the design of the proposed filter. In particular, the techniques of modified cross-coupling and overlap resonators are applied to improve the response of insertion losses S 21 at the first harmonic frequency of 5.2GHz. The simulated and experimental results of insertion losses and return losses are better than 3dB and 20dB, respectively, at the operating frequencies. Copyright © 2011 P. Chomtong et al.