Domain Decomposition Method Based on Generalized Scattering Matrix for Installed Performance of Antennas on Aircraft

Abstract

We describe the factorization (FACTOPO) domain decomposition method based on the boundary element method (BEM) and the finite element method (FEM) applied to the analysis of antenna performance on aircraft. The benefits of the subdomain method are mainly the ability to deal with collaborative studies involving several companies, and the reduction of the computation costs by one or more orders of magnitude, especially in the context of parametric studies. Furthermore, this paper proposes global functions defined on fictitious surfaces surrounding radiating elements, to deal with the computation of antenna far field patterns in a multidomain mode. By masking the complexity of the antenna (wires, thin surfaces, materials, feeding network) the external domain of the aircraft can be closed so that the combined field integral equation can be used, which is better conditioned than the electric field integral equation and converges much faster. The accuracy and efficiency of this technique is assessed by directivity computations of VHF monopole antennas mounted on Fokker 100 and ATR42 scaled mock-up. Domain decomposition results obtained by combining two sets of subdomains are compared with measurements and the FEKO commercial method of moments code.