Full-wave modeling and design of waveguide passive components.

摘要

Waveguide passive components are an integral part of the modern communication systems, particular for space applications which require low loss and high power handling capability. This dissertation is devoted to the full-wave modeling, synthesis, and optimization design of various high performance waveguide filters and couplers.; Full-wave design of waveguide branch couplers by optimization is presented. Approaches used to obtain tight couplings are discussed, and illustrated by two design examples of 3-dB couplers. Tunable dielectric resonators with dielectric tuning disks in cylindrical and rectangular enclosures are investigated. Wide tuning ranges are achieved while other resonator properties are kept well over the tuning ranges. Length reduction of evanescent-mode ridge waveguide bandpass filters is investigated. A generalized filter configuration is proposed. More than 50% length reduction can be achieved by configuring the ridge waveguide properly and enlarging the height of the evanescent waveguide. In addition, a folded filter configuration is modeled. Using the structure, the filter length could be further reduced. Full-wave design of canonical waveguide filters by optimization is presented. Design examples of four- and six-cavity canonical waveguide filters are presented to demonstrate the feasibility of the design approach. Design of rectangular waveguide diplexers using circular-to-rectangular T-junctions and waveguide dividers as diplexing manifold is presented. Measured results are in good agreement with computed results.