Multi-beam Conformal Transmitarray Synthesis for Advanced Wireless Systems

Multi-beam conformal transmitarrays with a single feed antenna are synthesized using two different methods for the first time. First, a particle swarm optimization (PSO) algorithm is employed for phase-only optimizations on a cylindrical transmitting surface, producing a two-beam radiation pattern at +/- 30 degrees in the circular cutting plane. Second, a superposition method is investigated to achieve the same objective, showing a higher peak gain and lower sidelobe levels compared to the results from PSO. Third, the superposition method is further analyzed for a single-feed quad-beam conformal transmitarray. As a proof of concept, the prototype designed using the superposition method for two beams is manufactured and tested. Good radiation performance is observed with two beams at +29 degrees and -28 degrees, respectively. The peak measured gain is 18.3 dBi and the gain difference of two beams is only 0.1 dB.