Beamforming experiment with a DBF multibeam antenna in a mobile satellite environment

This paper describes a digital beamforming (DBF) multibeam antenna that incorporates a compact digital signal processor (DSP) engine, and the results of using it in a beamforming experiment receiving a satellite signal in a land-mobile environment, A considerable reduction in the scale of the DSP engine has been achieved by using field programmable gate arrays (FPGA's), To capture a satellite signal arriving from an unknown direction, a two-dimensional (2-D) spatial FFT signal processing provides orthogonal multibeam patterns on the broad side of a planar array antenna, The experimental results demonstrated the features of coarse acquisition and tracking of a signal arrival by selecting the strongest of the beams without assistance from direction finding sensors or microwave phase shifters, The DBF multibeam antenna will provide high-quality communications and increase traffic capacity if it is applied to a high-gain mobile antennas or a multispot-beam base station antennas in cellular or satellite mobile communications.