Active Reflection Coefficients Optimization for Antenna Arrays
conference paper
This paper addresses the challenge of enhancing the power radiated by Active Electronically Scanned Array (AESA) radars, in particular at large scan angles, where performance degradation arises from both the cosine-dependent reduction in antenna effective area and suboptimal active impedance matching. Traditional methods to improve directivity—such as increasing the number of elements, employing asymmetric element designs, or integrating bulky lens systems—present various trade-offs that can compromise overall system efficiency. Here, we explore an approach that increases the radiated power by optimizing the active reflection coefficients (ARCs) of the antenna through the synthesis of array element excitations. Focusing on a planar dipole array, we compare stochastic differential evolution and convex optimization techniques, under the constraint of a uniform amplitude taper, which is critical to limit the loss in output power. Furthermore, we combine this with a quasibalanced Doherty power amplifier architecture that compensates for the remaining scan-angle-induced variations in output load impedance. The study includes a detailed analysis of the effects of phase and amplitude errors on ARC control and demonstrates, through numerical results, the improved performance of the integrated system over conventional designs.
Topics
TNO Identifier
1025915
Source title
IEEE Transactions on Antennas and Propagation - IEEE International Symposium on Phased Array Systems and Technology, Boston, MA USA, 15-18 October 2024
Place of publication
Den Haag
Pages
1-14