A uni-planar fed 2D slot array for digital beamforming

A compact design of 2D antenna array for digital beamforming is proposed in this paper. The essential idea is based on switchable microstrip slot antennas in conjunction with spatial multiplexing of local elements (SMILE) techniques. The SMILE technique makes it possible to realize a series-fed digital-beamforming (DBF) antenna array in one dimension and leaves room for parallel element in the other dimension. This provides a simple way of constructing 2D DBF arrays with a simple and uni-planar feed network. It also offers other advantages such as low cost and compatibility with MMICs for the receiver system. A 4×4 receiving array test-bed at 5.5GHz operating frequency is fabricated and digital beamforming on this test-bed is successfully demonstrated in the E- and H- planes.