Experimental Demonstration of a Dielectric Dome Antenna with Reduced Profile and Wide Scanning Capability

Abstract

A wide scanning dome antenna with reduced profile is presented in this contribution. The minimum height of the dielectric lens is derived from its geometrical configuration and imposed in the design. The antenna is analysed using in-house ray tracing and physical optics tools. Because of the presence of the lens, the phase distribution of the elements is not linear and is derived from the ray distribution over the array using a Zernike polynomial expansion. The maximum scanning angle of the illuminating array is 60° and, due to the combination with the lens, the field of view is enlarged to 70° with similar performance in all planes. A demonstrator of the lens was manufactured and combined with an available phased array working in Ku-band. The active reflection coefficient is not significantly affected by the presence of the lens thanks to the matching layer on both the dielectric surfaces. The measured radiated patterns are in excellent agreement with the theoretical prediction, and they then validate the analysis tools. The active element patterns of the dome antenna are rotationally symmetric, showing how the radiating performance is almost independent on the plane of scanning. Moreover, the gain for scanning wider than 60° is significantly improved compared to the stand-alone array.