A Sparse Phased Array and Its Fast Multibeam Measurement

In this paper, we design a sparse phased array and use a fast multibeam measurement method to test its beam scanning capability. Specifically, to enable the scanning performance of the sparse phased array with a reduced number of radio frequency channels, a reconfigurable beamforming network is designed and integrated to the sparse array. The network can change the radiation beam of the 1×6 subarray in three modes. The phased array composed of four subarrays (with an inter-subarray spacing of 3.4 λ0) still can scan its beam from -10° to 10° (i.e., the vertical scanning range of access point arrays) without grating lobes. Meanwhile, a fast multibeam measurement method is employed here to attain the radiation patterns of the proposed sparse phased array. For fast test of its beam scanning capability, the multiple beam patterns are reconstructed synchronously by utilizing subarray patterns with a few sparse measurement samples, enabling quick and efficient measurement of all possible steered beams.