High-Accuracy, High-Gain Phased Array Utilizing Matrix-Sum and Tunable Amplifier Techniques

This paper presents an 8-element phased array system and proposes a novel beam control method—namely, matrix-sum method—that can achieve beam steering and beam-width control. The system architecture comprises an
$8\times 8$
phase matrix network and a 1-to-8 real number weighting network. The 1-to-8 real number weighting network simultaneously supplies the required weighting value to all input ports of the phase matrix network, enabling the adjustment of the phase difference and power ratio between adjacent output signals and thereby generating the desired beam. According to the equations used to calculate the weighting values, the matrix-sum method requires only real number weighting to achieve beam synthesis with steering and tapering functions if used with a suitable phase matrix. Comparison results revealed that for the same number of control bits, the proposed method system exhibited higher beam-steering accuracy and system gain in different beam pattern cases than phased array systems that use conventional and vector-sum phase shifters. The proposed phased array system was fabricated and experimentally investigated at 3.5 GHz. The results indicated that it achieved fully controllable beam steering with a fine beam resolution of 1° steps. Additionally, the system’s sum, difference, and tapering beam patterns were accurate compared with ideal beam patterns.