摘要

This paper presents a triple-band bandpass filter for applications of GSM, WiMAX, and WLAN systems. The proposed filter comprises of the tri-section step-impedance and capacitively loaded step-impedance resonators, which are combined using the cross coupling technique. Additionally, tapered lines are used to connect at both ports of the filter in order to enhance matching for the tri-band resonant frequencies. The filter can operate at the resonant frequencies of 1.8 GHz, 3.7 GHz, and 5.5 GHz. At resonant frequencies, the measured values of S-11 are -17.2 dB, -33.6 dB, and -17.9 dB, while the measured values of S-21 are -2.23 dB, -2.98 dB, and -3.31 dB, respectively. Moreover, the presented filter has compact size compared with the conventional open-loop cross coupling triple band bandpass filters.

  • 出版日期2014-5