60-GHz Two-Dimensionally Scanning Array Employing Wideband Planar Switched Beam Network

A two-dimensionally (2-D) scanning array employing a planar switched beam network (SBN) is proposed for 60-GHz high data rate wireless communication. SBNs offer a number of advantages including low cost, multibeam operation, simple direction finding, and minimal power consumption. Unlike existing switched beam arrays operating at 60 GHz, the proposed array scans in both planes. Also, in contrast to 2-D scanning stacks of Butler matrices and Rotman lenses, the proposed SBN is uniplanar and, hence, leads to low-cost manufacturing and integration with 60-GHz radios. The network produces eight 2-D beam states and demonstrates beamforming capability across the entire band of interest (57-64 GHz) with the aid of dummy crossover structures. It is printed on a Rogers Duroid 5880 substrate along with a 2 × 4 patch array. This letter describes the design, operation, and realization of the beamforming array. Simulated and measured performance results are presented to verify the design.