Journal of South China University of Technology(Natural Science Edition) ›› 2012, Vol. 40 ›› Issue (6): 11-15,21.

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

Design of Hairpin-Comb Dual-Band Bandpass Filter with Source-Load Coupling

Chu Qing-xin1  Ouyang Xiao1,2  Li Zhi-hui1   

  1. 1. School of Electronic and Information Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China; 2. National Key Laboratory of Science and Technology on Space Microwave Technology,Xi’an 710100,Shaanxi,China
  • Received:2011-12-13 Revised:2012-03-18 Online:2012-06-25 Published:2012-05-03
  • Contact: 褚庆昕(1958-) ，男，教授，博士生导师，主要从事射频电路及天线研究． E-mail:qxchu@ scut.edu.cn
  • About author:褚庆昕(1958-) ，男，教授，博士生导师，主要从事射频电路及天线研究．
  • Supported by:

    国家自然科学基金资助项目( 61171029) ; 重点实验室基金资助项目( 9140C5306021008)

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Abstract:

In order to develop dual-band bandpass filters with high selectivity,small size and low cost,a novel method to design the filter with quasi-elliptic response is presented. In this method,two sets of hairpin-comb resonators working at different frequencies are utilized,which provides enough freedom for the independent control of two passbands. The mixed electromagnetic coupling of hiarpin-comb resonators can generate a controllable out-ofband transmission zero,and the source-load coupling can also introduce additional transsmission zeros in the stopband. Therefore,the selectivity and the stopband-restricting ability of the filter are both improved by the transmission zeros caused as much as possible by the combination of these two couplings. A dual-band bandpass filter operating at 2.4 and 5.2GHz is finally designed and fabricated,and the measured results accord well with the simulated ones,which means that the proposed design method is effective.

Key words: bandpass filter, dual band, hairpin-comb resonator, mixed electromagnetic coupling, source-load coupling

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