Abstract
To address the effects of surface roughness on wave propagation in the microwave and millimeter-wave bands, this paper studies electromagnetic wave propagation and focuses on the propagation loss within an inner environment featuring surface roughness of the metallic waveguide structures. The conductivity gradient model is first developed to treat surface roughness with inhomogeneous conductivity, and then the concept of a frequency-dependent effective conductivity is introduced to model the effects of surface roughness in waveguide structures. With the effective conductivity used in the commercial 3D field solver, High Frequency Structure Simulator (HFSS™), a surface impedance boundary condition strategy is applied on ideally smooth surfaces to model the actual behavior of rough metallic waveguide surfaces. Finally, the propagation performance is predicted by comparing the effects of surface roughness in metallic waveguide structures and the results from the models with ideally smooth surfaces, using rectangular waveguide, cylindrical resonator and coupling cavity filters models. Overall, this effective conductive concept can be applied using various commercial field solvers to handle surface roughness effects accurately and efficiently in any work involving conducting microwave structures.
Highlights
Waveguides are a basic component in radar and communication applications [1,2,3]
Advances in accurately modeling practical or realistic waveguide structures with finite conductivity and inner surface roughness are needed in engineering problems; this is especially important for several applications, such as in microwave measurement devices, to improve the measurement accuracy and extend the measurement range, and in high power space communication components, to improve electromagnetic reliability and operation life
From the analysis presented earlier, field solutions have been obtained for conductor surface roughness in space using a gradient conductivity model
Summary
Waveguides are a basic component in radar and communication applications [1,2,3]. The accurate modeling of electromagnetic wave propagation is an important problem, especially as majority of present and future radar and communication systems operate at higher frequencies in the millimeter-wave bands. Advances in accurately modeling practical or realistic waveguide structures with finite conductivity and inner surface roughness are needed in engineering problems; this is especially important for several applications, such as in microwave measurement devices, to improve the measurement accuracy and extend the measurement range, and in high power space communication components, to improve electromagnetic reliability and operation life. The models of the rough interface between the dielectric and conductive mediums and the rough parallel plate waveguide were investigated using an analytical second-order small perturbation method (SPM2), as well as numerical methods, such as the method of moments (MoM) and the transfer matrix (T-matrix) method These models cannot be extended straightforwardly for the models of non-TEM waveguide structures with inner surface roughness.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
