A Comparative Analysis of UWB Phased Arrays With Combining Network for Wireless-Power-Transfer Applications

This article presents the theory, design, and demonstration of the performance of multiple ultrawideband and low-profile modified microstrip line-based phased array antennas with 4 x 4 and 6 x 6 quadrants. A comparative analysis of the performance between the novel combining network-based 4 x 4 and 6 x 6 phased antenna arrays is demonstrated in terms of dimension, gain, half-power beamwidth (HPBW), and beam steering capability. The proposed combining network is an attractive solution for wide-angle scanning phased array antennas because the diagonally connected elements of the network have achieved an additional 45 degrees phase difference. The measured peak gains for the 4 x 4 and 6 x 6 antenna arrays are 15.5 and 24.39 dBi, respectively, while achieving an S-11 <-35 dB. The 4 x 4 array achieves a bandwidth (BW) of 0.69 GHz (6.42-7.11 GHz, fractional BW (FBW) of 10.19%), while the 6 x 6 array achieves 1.67 GHz BW (8.93-10.60 GHz, 17.10% FBW). The measured radiation patterns of the 4 x 4 and 6 x 6 antenna arrays show the beam steering range of -13 degrees to 99 degrees and -9 degrees to -81 degrees, and -150 degrees to 30 degrees and -15 degrees to 45 degrees along the phi- and theta-axes at 6.69 GHz and -52 degrees to 31 degrees and -36 degrees to 45 degrees along the phi-axis at 10.34 GHz, respectively. The results demonstrate that the suggested antenna arrays are promising candidates for unmanned aerial system (UAS)-based wireless-power-transfer (WPT) applications.