A comparison of numerical methods for the full-wave analysis of flange mounted rectangular apertures

The analysis and design of small- and medium-sized aperture antenna arrays is an important task in the development of many microwave systems, and is computationally heavy due to the typical requirements for efficiency and accuracy. Several approaches have already been proposed in the literature, but they have not been compared so far in terms of their computational efficiency. In this paper, we compare different methods, either based on rectangular waveguide modes to expand the field over the aperture, or based on Gegenbauer's polynomials for singular fields representation. Their numerical properties are studied, and their performance compared. It is concluded that similar accuracies are achieved, whilst the approach using the spectral-domain rectangular waveguide mode formulation is the more robust, and should be considered for the development of general purpose software packages. Copyright © 2000 John Wiley & Sons, Ltd.