In this paper, we propose a reflector antenna with a microstrip-patch-array offset feed. The proposed antenna offers several advantages in design flexibility, especially to determine the horizontal and vertical beam patterns by the modular feed and the reflector curvature design, respectively. Moreover, it provides an internal tuning mechanism in the form of a tuning strip which is relatively simple to apply. The paper describes the steps in a parametric study carried out to minimize the antenna dimensions. The resulting optimized design is found to be around 50% smaller in dimension than the initial design of the proposed antenna. A demonstrator for experimental analysis, consisting of a transmit and a receive antenna, has been constructed, and the isolation between the antennas is found to be better than 70 dB. The antenna demonstrator has been integrated with an FMCW radar transceiver and satisfactorily tested to operate as a coastal surveillance radar.
