A new evanescent-mode filter for densely packaged waveguide applications

A novel evanescent-mode filter structure based on T-septum waveguide technology is presented for applications in extremely compact designs. The excellent characteristics of the T-septum waveguide are utilized to significantly reduce the resonator cutoff frequency compared with standard ridge waveguide designs. This allows the evanescent-mode guide to have a smaller cross-section, hence considerably reducing the overall length of the filter. The computer-aided design uses a full-wave mode-matching technique which takes into account higher-order mode coupling at all discontinuities involved. Design data are given for X- and Ka-bands. The method was verified by measurements. The manufactured 10-GHz prototype measured only 18.4 mm in length.<<ETX>>

[1]  Jens Bornemann,et al.  Comparison between different formulations of the transverse resonance field‐matching technique for the three‐dimensional analysis of metal‐finned waveguide resonators , 1991 .

[2]  A.M.K. Saad,et al.  Novel Lowpass Harmonic Filters for Satellite Application , 1984 .

[3]  J. Bornemann,et al.  Matrix singular value decomposition for pole-free solutions of homogeneous matrix equations as applied to numerical modeling methods , 1992, IEEE Microwave and Guided Wave Letters.

[4]  F. German,et al.  Bandwidth properties of rectangular T-septum waveguides , 1989 .

[5]  G. Craven,et al.  Waveguide bandpass filters using evanescent modes , 1966 .

[6]  W. Joines,et al.  Some Properties of T-Septum Waveguides , 1987 .

[7]  Jens Bornemann,et al.  Transverse resonance, standing wave, and resonator formulations of the ridge waveguide eigenvalue problem and its application to the design of E-plane finned waveguide filters , 1990 .

[8]  Henri Baudrand,et al.  Multimodel variational analysis of uniaxial waveguide discontinuities , 1991 .

[9]  T. Itoh,et al.  Computer-aided design of evanescent-mode waveguide filter with nontouching E-plane fins , 1988 .

[10]  G. Craven,et al.  The Design of Evanescent Mode Waveguide Bandpass Filters for a Prescribed Insertion Loss Characteristic , 1971 .

[11]  G. Craven.  Tuning techniques for multisection waveguide bandpass filters using evanescent modes , 1966 .

[12]  R. Elliott.  Two-Mode Waveguide for Equal Mode Velocities , 1968 .