Couplings of microstrip square open-loop resonators for cross-coupled planar microwave filters

A new type of cross-coupled planar microwave filter using coupled microstrip square open-loop resonators is proposed. A method for the rigorous calculation of the coupling coefficients of three basic coupling structures encountered in this type of filter is developed. Simple empirical models are derived for estimation of the coupling coefficients. Experiments are performed to verify the theory. A four-pole elliptic function filter of this type is designed and fabricated. Both the theoretical and experimental performance is presented.

[1]  S. Darlington,et al.  Synthesis of Reactance 4-Poles Which Produce Prescribed Insertion Loss Characteristics: Including Special Applications To Filter Design , 1939 .

[2]  A. Atia,et al.  Narrow-Bandpass Waveguide Filters , 1972 .

[3]  A. E. Atia,et al.  Narrow-band multiple-coupled cavity synthesis , 1974 .

[4]  J. Wong,et al.  Microstrip Tapped-Line Filter Design , 1979 .

[5]  S. B. Cohn,et al.  A History of Microwave Filter Research, Design, and Development , 1984 .

[6]  M. Makimoto,et al.  Miniaturized hairpin resonator filters and their application to receiver front-end MICs , 1989 .

[7]  S. J. Fiedziuszko,et al.  Miniature dual mode microstrip filters , 1991, 1991 IEEE MTT-S International Microwave Symposium Digest.

[8]  S. J. Fiedziuszko,et al.  Multi-layered planar filters based on aperture coupled, dual mode microstrip or stripline resonators , 1992, 1992 IEEE Microwave Symposium Digest MTT-S.

[9]  R. R. Bonetti,et al.  Generalized dual-plane multicoupled line filters , 1993 .

[10]  R. R. Bonetti,et al.  New design techniques for coupled-line filters with transmission zeros , 1993, 1993 23rd European Microwave Conference.

[11]  G.L. Hey-Shipton,et al.  Novel staggered resonator array superconducting 2.3-GHz bandpass filter , 1993, 1993 IEEE MTT-S International Microwave Symposium Digest.

[13]  Michael J. Lancaster,et al.  Realisation of quasielliptic function filter using dual-mode microstrip square loop resonators , 1995 .

[14]  Michael J. Lancaster,et al.  Canonical microstrip filter using square open-loop resonators , 1995 .

[15]  Jia-Sheng Hong,et al.  Microstrip bandpass filter using degenerate modes of a novel meander loop resonator , 1995 .

[16]  C. Rauscher,et al.  Microwave channelized active filters-a new modular approach to achieving compactness and high selectivity , 1996 .