It is shown that the reduction of the scattering effect from the seams in large sandwich radomes can be obtained by minimizing the scattering level from the individual seams and optimizing the radome geometry. The scattering from an untuned seam increases with frequency and is related to the polarization current induced in the seam. This effect can be characterized by the induced field ratio (IFR) and the seam scattering pattern. The seam effect on the insertion phase delay (IPD) and the transmission losses (TLs) of the panel for vertical and horizontal polarization is shown. It is observed that for normal incidence the IPD caused by the panel is 26° and the untuned seam causes an additional IPD of 13°. To reduce the IPD caused by the seam, tuning techniques, such as insertion of conductive strips in the seam, are used. The total scattering effect from all the seams in front of the antenna aperture is computed by superposition of all scattering effects from the individual seams. Optimization of the radome geometry takes into consideration factors such as minimization of the total seam length, increase in panel dimensions, minimization of the total number of parallel seams, and uniform seam density throughout the antenna scan angles.
|Number of pages||4|
|Journal||IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)|
|State||Published - 1 Dec 1990|
|Event||1990 Antennas and Propagation Symposium Digest - Dallas, TX, USA|
Duration: 7 May 1990 → 11 May 1990