Automatic Remote Array Calibration System for Microwave Wireless Power Transmitter

Abstract

A system that can automatically calibrate the Microwave Power Transmitter (MPT) array was developed. The Rotating Element electric-field Vector (REV) method was used, which measures only the amplitudes of signals at the power-receiving location. A Reference Signal Transmitter (RST) capable of fast phase rotation has been manufactured, replacing one of the four channels of an MPT module. In addition, a Calibration Signal Detector (CSD) was fabricated to measure the synthesized waveform of the reference channel and the tested channel signal at the receiving position. In order to check the developed system's operation in the laboratory, the reference and tested outputs of the new MPT module were combined by a Wilkinson power divider and input to CSD. When the reference signal's phase was rotated at a speed of 10 kHz, the calibration signal was synthesized properly and measured well. The hardware of the proposed remote array calibration system was applied to the low-weight version of the wireless power transmission system (5.8 GHz, 96 ch, 50 W/ch, implemented in 2021), and the calibration software was integrated with the control program of the MPT system. The entire MPT array was successfully auto-calibrated using the CDS at 58 m. The whole calibration could be completed within 3 minutes using Ethernet wired communication and 4 minutes using 922 MHz wireless communication. Decreased beam-width and increased power density were confirmed after the calibration. Copyright © 2023 by Korea Electrotechnology Research Institute (KERI). Published by the IAF, with permission and released to the IAF to publish in all forms.