Full-Wave Numerical Modeling of Near-Field Beam Profiles at 200 and 700 GHz
Authors:
M.T. Chen, C.E. Tong, L. Chen, S. Paine, R. Blundell
Abstract:
A full-wave numerical method has been implemented to examine near-field beam profiles of antenna feeds at sub-millimeter wavelengths. Using a vectorial Green's function formulation, we have calculated the electromagnetic field distribution at the aperture of feed horns of 200 and 700 GHz. Beam pattern measurements in the near-field have been compared with the theoretical data projected to the measured plane. The calculated results agree well in both amplitude and phase, with the measured data from feed horns used with SIS receivers developed for the Smithsonian Institution's Sub-Millimeter Array (SMA). We have also used this method to examine cross-polarization and beam distortion introduced by an off-axis parabolic mirror.