An Enhanced $Ka$ -Band Reflector Focal-Plane Array Using a Multifeed EBG Structure

This letter presents a first step toward the design of an enhanced multifeed EBG structure that serves as a focal-plane array for a Ka-band reflector for space applications in the 29.5-30-GHz band. The desired Earth coverage is the starting point for the antenna design. As shown in this letter, significant coupling can deteriorate the performance of the multifeed EBG antenna. In order to demonstrate this, the results are compared to those of the single-feed reflector antenna. Filters are then connected to the multifeed antenna ports to control the coupling in a constructive way and obtain good radiation characteristics. Finally, the global feed architecture (EBG structure + filters) is used to illuminate a reflector antenna in order to characterize the antenna performance (C/I ratio, EoC gain).