학술논문

Physical Mechanisms and Design Principles in Mode Filters for Oversized Rectangular Waveguides
Document Type
Periodical
Source
IEEE Transactions on Microwave Theory and Techniques IEEE Trans. Microwave Theory Techn. Microwave Theory and Techniques, IEEE Transactions on. 65(8):2726-2733 Aug, 2017
Subject
Fields, Waves and Electromagnetics
Couplings
Rectangular waveguides
Waveguide junctions
Microwave filters
Absorption
Optical waveguides
Guided-wave structures
high-power microwaves
modal coupling and interaction
passive microwave components
waveguide filters
Language
ISSN
0018-9480
1557-9670
Abstract
Mode filters, based on oversized rectangular waveguides with periodic symmetrical junctions, are addressed through analytical models under a small coupling approximation to explain the physical mechanisms of their behavior, and provide guidelines for their design. In the junctions, which are partially filled with a lossy dielectric, both propagating and evanescent modes play a role. Filter parameters are studied with respect to their impact on the excitation, propagation, and absorption of such modes in the junctions. Particular attention is paid to practical choices a designer has to face in real applications. The performance of single versus multiple lengthwise slots with the same total length is compared, and high-power matters such as voltage and thermal breakdown are discussed. A novel junction with two absorbing layers is proposed to help designers in maximizing absorption, while fulfilling thermal constraints.