A Finite Element Method (FEM) is presented to determine reflection and transmission coefficients of rectangular waveguide junction discontinuities. An H-plane discontinuity, an E-plane ridge discontinuity, and a step discontinuity in a concentric rectangular waveguide junction are analyzed using the FEM procedure. Also, reflection and transmission coefficients due to presence of a gap between two sections of a rectangular waveguide are determined using the FEM. The numerical results obtained by the present method are in excellent agreement with the earlier published results. The numerical results obtained by the FEM are compared with the numerical results obtained using the Mode Matching Method (MMM) and also with the measured data. Deshpande, Manohar D. Langley Research Center NAS1-19341; RTOP 522-33-11-02...

An integral equation has been developed for the reflection coefficient from an arbitrary perturbation in the complex dielectric constant of a dielectric plug inside a rectangular waveguide. Using the variational approximation the integral equation for the reflection coefficient is solved when the perturbation is small. (Author).

Transitions from rectangular waveguide to layered ridge dielectric waveguide are studied both experimentally and theoretically. In addition, a design procedure is given for each transition. The analysis and design procedures are valid for transitions between rectangular waveguide and other open dielectric waveguides such as Image Guide, Insulated Image Guide, Dielectric Ridge Guide, and Inverted Strip Dielectric Waveguide. It is shown that for small dielectric waveguides such as a Layered Ridge Dielectric Waveguide, a transition which is comprised of a tapered ridge waveguide reduces the radiation loss by at least 1 dB.

Waveguides, Communication equipment, Electrical wave measurement, Wave properties and phenomena, Rectangular shape, Flanges, Interfaces, Optical measurement, Reflection, Symbols, Dimensional changes, Angular, Test equipment

This book collects much of Helszajn's work (formerly, Heriot-Watt University) and includes closed-form and finite element calculations of the propagation constant, attenuation and mode spectrum for the ridge waveguide, and power-current and power-voltage definitions of impedance. Circular polarization is also treated. Propagation properties where the waveguide has a dielectric filler are calculated. The treatment is then extended to more complex designs, including quadruple ridge waveguides with and without a gyromagnetic filler. The text includes descriptions of many of the passive devices which can be realized using these waveguides, including isolators, phase shifters, and circulators. c. Book News Inc.