Synthesizing Microstrip Dual-Band Bandpass Filters Using Frequency Transformation and Circuit Conversion Technique

A novel method is proposed to synthesize dual-band bandpass filters (BPFs) from a prototype lowpass filter. By implementing successive frequency transformations and circuit conversions, a new filter topology is obtained which consists of only admittance inverters and series or shunt resonators, and is thereby easy to be realized by using conventional distributed elements. A microstrip dual-band BPF with central frequencies of 1.8 GHz and 2.4 GHz is designed and fabricated using microstrip lines and stubs. The simulated and measured results show a good agreement and validate thereby the proposed theory.

[1]  Zhewang Ma,et al.  A dual-band bandpass filter synthesized by using frequency transformation and circuit conversion technique , 2005, 2005 Asia-Pacific Microwave Conference Proceedings.

[2]  Kouji Wada,et al.  Fundamentals of Open-Ended Resonators and Their Application to Microwave Filters , 2000 .

[3]  Lin-Chuan Tsai,et al.  Dual-band bandpass filters using equal-length coupled-serial-shunted lines and Z-transform technique , 2004, IEEE Transactions on Microwave Theory and Techniques.

[4]  Jhin-Fang Huang,et al.  Annealing Algorithm Applied in Optimum Design of 2.4 GHz and 5.2 GHz Dual-Wideband Microstrip Line Filters , 2005, IEICE Trans. Electron..

[5]  Kin‐Lu Wong,et al.  Printed double-T monopole antenna for 2.4/5.2 GHz dual-band WLAN operations , 2003 .

[6]  T. Ishizaki,et al.  A miniaturized monolithic dual band filter using ceramic lamination technique for dual mode portable telephones , 1997, 1997 IEEE MTT-S International Microwave Symposium Digest.

[7]  Hossein Hashemi,et al.  Concurrent multiband low-noise amplifiers-theory, design, and applications , 2002 .

[8]  K.-K.M. Cheng,et al.  Novel dual-band planar resonator and admittance inverter for filter design and applications , 2005, IEEE MTT-S International Microwave Symposium Digest, 2005..

[9]  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).

[10]  C. Hsue,et al.  Dual-band bandpass filters using equal-length coupled-serial-shunted lines and Z-transform technique , 2004 .

[11]  Zhewang Ma,et al.  Design and realization of bandpass filters using composite resonators to obtain transmission zeros , 2005, 2005 European Microwave Conference.

[12]  E. M. Jones,et al.  Microwave Filters, Impedance-Matching Networks, and Coupling Structures , 1980 .

[13]  Hong-Ming Lee,et al.  Transmission-line filter design with fully controllable second passband , 2005, IEEE MTT-S International Microwave Symposium Digest, 2005..

[14]  Sheng-Fuh Chang,et al.  Dual-band step-impedance bandpass filter for multimode wireless LANs , 2004 .

[15]  C. Quendo,et al.  An original topology of dual-band filter with transmission zeros , 2003, IEEE MTT-S International Microwave Symposium Digest, 2003.