Electromagnetic Full-Wave Modelling of Conformal Array Antennas and Scatterers

摘要

In this contribution we address the topic of antenna modelling in the context of conformal arrays. We deal with waveguide-fed aperture arrays on arbitrarily shaped and perfectly electrical conducting surfaces. Issues concerning antenna as well as network properties like embedded element patterns, antenna RCS, mutual coupling and insertion loss can be treated with the method which has been developed. The numerical modelling method applied here is a so-called Hybrid Boundary Element Method / Mode-Matching (BEM/MM) method. It is a full-wave method, which does not make use of any physically equivalent models but rigorously solves an electromagnetic boundary value problem. The model of the antenna structures is exact up to a truncation error. The boundary value problem is solved via a numerical solution of an integral equation in the spatial domain at certain frequencies. The waveguide fields represented by modal series expansions are coupled to the boundary value problem at the elements' apertures. The scattering parameters of an array antenna are calculated by successively exciting one element and calculating the received and reflected modes within all apertures. In addition to antenna problems our method is also capable of modelling the electromagnetic scattering from arbitrarily shaped metal bodies. Thus exact RCS calculations may also be performed. Numerical results will be compared to both analytically generated and measured data concerning both antenna and scattering problems. A numerical investigation on a small array will be presented at the end of this contribution.