Electrical performance of rigid ground radomes

The main purpose of a radome is to protect an antenna from the weather. Many designs of radomes can be evolved which will meet the mechanical requirements dictated by such factors as wind and snow load; however, these requirements are not sufficient. The radome must also have certain electrical characteristics in order that operation of the enclosed antennas is not degraded. This paper summarizes the many electrical measurements made on rigid ground radomes to date at the National Research Council to study the effect of the radomes on the performance of radar antennas. Ground radomes made of thin single-skin, sandwich, and thick foam walls have been studied. Performance of single-skin radomes was found to be adequate for wavelengths of about ten centimeters and longer. In order to obtain maximum transmission, the skins must be thin and the panel joints must be small, few in number, and randomly spaced. Sandwich radomes provide a good design for wavelengths of five to ten centimeters. At wavelengths of three centimeters and shorter, the thick foam wall is believed to be the best solution, because in this construction joints between panels can be made practically invisible to the radiation, Transmission losses as low as one per cent have been measured.