Filip Demuynck

Current antenna research at K. U. Leuven

Four antenna research projects at the Katholieke Universiteit Leuven are described. In the first project, four different methods for the transformation of plane-polar near-field data to far-field antenna characteristics have been compared, and the method with the best performance (accuracy versus computer time) has been implemented on an HP 1000 and on a VAX under VMS. In the second project, a test method has been developed to detect faulty columns in three-dimensional array antennas. The method is based on a reconstruction technique, and has been implemented in an air-surveillance secondary radar system. In the third project, the transmission-line model developed for rectangular microstrip antennas has been implemented and verified for linear and planar arrays. The software package runs on a PC, as well as on VAX workstations. In the fourth project, a software package, running on a VAX under VMS, has been developed based on a moment-method approach for the analysis of multiprobe, multipatch configurations in stratified-dielectric media. The procedure developed contains features to improve the convergence, accuracy and efficiency of the moment method.<<ETX>>

Analytical treatment of the Green's function singularities in a stratified dielectric medium

Recently, simple and efficient method of moments procedures have been developed for the solution of the mixed-potential electric field integral equations (MPIE) involved in electromagnetic scattering and radiation problems in stratified media. An important step prior to these procedures is the determination of the spatial Greens functions for the stratified medium. In the spectral domain, these Greens functions can be calculated in a very efficient recursive way. The inverse Fourier transform integrals are of the Sommerfeld type. In this paper, a new procedure is proposed which treats the singularities of the spectral Greens functions in an analytical way. This leads to a very efficient and fast implementation in a software package.