Semi-circular microstrip array on a planar reflector with extended beam-scanning range

For wide-angle scanning applications, we investigate a semi-circular microstrip array on a planar metallic reflector. The array elements lie on the semi-circular surface of a cylinder bisected axially by the plane of the reflector. To assess its beam scanning properties, the achievable directivity is determined for different main-lobe directions. For this particular array configuration, the main lobe can be scanned in an angular range of /spl plusmn/82/spl deg/ with a slightly reduced directivity compared to a corresponding planar linear array, indicating an angular scan range of /spl plusmn/50/spl deg/. As a proof of this concept, two array antennas with fixed main-beam directions are realized at an operating frequency of 10 GHz. The experimental results are compared with our simple analytical model using Matlab and simulations using the commercial tool Clementine.