The Open Collections website will be undergoing maintenance on Wednesday December 7th from 9pm to 11pm PST. The site may be temporarily unavailable during this time.

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

An investigation of nonreciprocal periodic structures, transverse discontinuities in nonreciprocal waveguides, and in inhomogeneous and magnetized ferrite loaded ridged waveguide Enegren, Terry A.

Abstract

This thesis is mainly concerned with the effects of periodic loading of nonreciprocal waveguides by regular placement of discontinuitie and with the associated problem of the evaluation of a transverse discontinuity in a nonreciprocal ferrite loaded waveguide. The mode-matching technique is used to analyse a transverse discontinuity in a nonreciprocal waveguide. The difficult orthogonality relations are circumvented using a Galerkin approach. The elements of an exact three-element equivalent circuit for an infinitely thin metallic diaphragm are evaluated. Each element has two values, one for each direction of propagation. The numerical results show the same trends as those obtained experimentally in a similar configuration. The properties of a nonreciprocal, ferrite loaded, rectangular waveguide, which is periodically loaded by thin metallic "inductive" diaphragms, are investigated experimentally. The propagation constants of the structures are measured and are compared with predictions based on measured values of the scattering parameters of a single diaphragm in the nonreciprocal waveguide. The agreement between theory and experiment is generally good except for the smaller spacings between the diaphragms. This discrepancy is attributed to the effects of higher mode interaction. An investigation was also made of a magnetized ferrite loaded ridged waveguide. A theoretical and experimental investigation was first made of the preliminary problem of a reciprocal, inhomogeneous ridged waveguide and guided by these results an approximate, theoretical technique was formulated to analyse the nonreciprocal ferrite loaded ridged waveguide problem. It was found that introduction of the ridge had detrimental effects on the differential phase shift characteristics except for a few special cases.

Item Media

Item Citations and Data

Rights

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.