Gain limits of phase compensated conformal antenna arrays on non-conducting spherical surfaces using the projection method

Abstract

Previously, it has been shown that the projection method can be used as an effective tool to compute the appropriate phase compensation of a conformal antenna array on a spherical surface. In this paper, the projection method is used to study the gain limitations of a phase-compensated six-element conformal microstrip antenna array on non-conducting spherical surfaces. As a metric for comparison, the computed gain of the phase-compensated conformal array is compared to the gain of a six-element reference antenna on a flat surface with the same inter-element spacing and operating frequency. To validate these computations, a conformal phased-array antenna consisting of six individual microstrip patches, voltage controlled phase shifters and a power divider was assembled and tested at 2.22 GHz. Overall, it is shown how much less the gain of the phase-compensated antenna is than the reference antenna for various radius values of the sphere.