Rigorous hybridmode analysis of the transition from rectangular waveguide to shielded dielectric image guide
Abstract
The transition waveguide to shielded and dielectric image guide is analyzed by the rigorous hybridmode field expansion technique where higher order mode coupling effects are taken into account directly, also below the corresponding cutoff frequency. The solution of the related eigenvalue problem includes waves with a complex propagation constant although the guide is assumed to be lossless. Calculated diagrams of the propagation constant as a function of frequency, as well as of the permittivity, illustrate the complicated mode conversion between evanescent modes, complex waves, backward waves, and propagating waves. For the threedimensional scattering problem, the calculated magnitude of the input reflection coefficient agrees well with measurements, whereas the transmissionline theory applied to this structure leads to wrong results.
 Publication:

IEEE Transactions on Microwave Theory Techniques
 Pub Date:
 May 1985
 DOI:
 10.1109/TMTT.1985.1133010
 Bibcode:
 1985ITMTT..33..391S
 Keywords:

 Dielectrics;
 Electromagnetic Shielding;
 Image Tubes;
 Propagation Modes;
 Rectangular Waveguides;
 Waveguide Windows;
 Backward Waves;
 Coupled Modes;
 Field Mode Theory;
 Frequency Response;
 Microwave Transmission;
 Mode Transformers;
 Permittivity;
 Spectral Reflectance;
 Wave Dispersion;
 Electronics and Electrical Engineering