Accuracy-Enhanced Angle-of-Arrival Finding System Using Switched Six-Port Network

In this letter, a switched six-port (SP) receiver is proposed for an accurate angle-of-arrival (AoA) finding system. The proposed switched six-port network consists of four antennas, two hybrid couplers, two dual-pole-dual-throw switches, and four power detectors. The proposed switched six-port receiver periodically selects two different antennas from four antennas, providing four different antenna spacings for a more accurate AoA detection. As a result, a smaller and more accurate AoA finding system has been achieved than a conventional dual six-port receiver that uses two different antenna spacings from four antennas. For validation, the proposed method was simulated, implemented, and measured. In the measurement, the averaged root-mean-square error of the estimated angle over the range of -90° to 90° was 3.16° with 20 sample numbers and a signal-to-noise ratio (SNR) of 15 dB.