Compact dual-band open-stub bandstop filter with suppression of spurious passbands

In this article, by replacing the series quarter-wavelength connecting line of conventional open-stub bandstop filter (BSF) with the equivalent P-shaped line, a compact dual-band BSF is proposed and designed. Furthermore, it suppresses a lot of spurious passbands of the open-stub BSF. Design equations of P-shaped line are achieved by ABCD matrixes. To validate the design concept, two full-wave electromagnetic simulators are used and the proposed filter is fabricated. The simulate results are in excellent agreement with measurement results. The circuit area of the dual-band BSF is only 50% of the conventional open-stub BSF.

[1]  Hwann-Kaeo Chiou,et al.  Dual-band microstrip bandstop filter using dual-mode loop resonator , 2009 .

[2]  Kai Chang,et al.  Compact second harmonic-suppressed bandstop and bandpass filters using open stubs , 2006, IEEE Transactions on Microwave Theory and Techniques.

[3]  K. Chin,et al.  Novel Microstrip Bandstop Filters With Controllable Dual Stopbands , 2007, 2007 Asia-Pacific Microwave Conference.

[4]  Kuo-Sheng Chin,et al.  Compact Dual-Band Bandstop Filters Using Stepped-Impedance Resonators , 2007, IEEE Microwave and Wireless Components Letters.

[5]  A.B. Guntupalli,et al.  Compact high performance microstrip dual-band bandstop filters for GSM mobile bands , 2008, 2008 10th International Conference on Electromagnetic Interference & Compatibility.

[6]  D. Pozar.  Microwave Engineering , 1990 .

[7]  Vamsi Krishna Velidi,et al.  Compact tapped stepped impedance open stub dual‐band bandstop filters with sharp rejection characteristics , 2009 .

[8]  J. Hirokawa,et al.  Dual-band-rejection filter for distortion reduction in RF transmitters , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[9]  Kai Chang,et al.  Microstrip Elliptic-Function Low-Pass Filters Using Distributed Elements or Slotted Ground Structure , 2006, IEEE Transactions on Microwave Theory and Techniques.

[10]  Zhewang Ma,et al.  Novel microstrip dual-band bandstop filter with controllable dual-stopband response , 2006, 2006 Asia-Pacific Microwave Conference.

[11]  Kuo-Sheng Chin,et al.  Tri-section stepped-impedance resonators for design of dual-band bandstop filter , 2009, 2009 European Microwave Conference (EuMC).