Compact tri-band bandpass filter using asymmetric square ring loaded resonator

Abstract

A triple-band bandpass filter with good selectivity based on asymmetric square ring loaded resonator (ASRLR) is proposed in this paper. The even- and odd-mode method is applied to investigate the resonant characteristic of the proposed triple-mode ASRLR. The 50-Ω tapped line is applied to design the I/O ports. The operating bands of the designed tri-band BPF are located at 1.57 GHz (GPS application), 3.5 GHz (WiMAX application) and 5.2 GHz (WLAN application), respectively. To verify the proposed approach, the filter is designed and analyzed by using EM simulator, the obtained results are agree well with the theory analysis?