Perturbation method for near-elliptical Half-Mode cavity antennas

Abstract

In this paper, the analysis of the resonance frequency for a Half-Mode Substrate-Integrated Waveguide (HMSIW) cavity realized with circular segments is presented. The analysis is based on the perturbation method applied on an elliptical waveguide using Mathieu functions. The results show an excellent agreement between simulation and analysis for an ideal model of HMSIW where the open aperture is approximated as perfect magnetic conductor (PMC) wall. To enhance the method applicability to a practical HMSIW, a well-known empirical formula for the HMSIW effective width is utilized, which yields a good prediction on the resonance frequency for this type of cavity antenna. The presented analysis further demonstrates the application of the perturbation method on waveguides with arbitrary shapes.