An Equivalent Circuit Model for Rectangular Waveguide Performance Analysis Considering Rough Flanges’ Contact

In order to investigate the rough flanges’ impact on the electrical performance of rectangular waveguides in the high-power-microwave and high-frequency-microwave communications, a new equivalent circuit model for the contact problem in waveguide flanges is established. Different from the present method that expresses the contact resistance with the contact radius, this method expresses the contact resistance with the incremental stiffness. The equivalent circuit of the waveguide connection is deduced by combining the mechanical contact model with the contact resistance model. Both metal–insulator–metal contacts and metal–metal contacts are considered. The relationship between electrical characteristics and mechanical characteristics is finally established with the transmission line theory of waveguides. The experimental results are given to demonstrate the proposed methodology.