5G NR Transceiver and 24GHz Wireless Power Receiver Utilizing a Low Insertion Loss Differential Output Butler Matrix for Long-Range Wireless Transmission

This paper presents a wirelessly power-fed relay transceiver for expanding millimeter-wave (mmW) 5G coverage. The prototype of the proposed relay transceiver consists of inverted antenna pairs and two differential output Butler matrixes (B-matrix) implemented on PCB and rectifiers fabricated in a Si CMOS 65nm process. The relay reduces insertion loss and RF-DC conversion efficiency is improved even over long distances. The proposed relay transceiver achieves -45° to 45° beam steering angles even without an external power source. Wireless power transmission (WPT) generates 1.7mW at 24GHz while achieving an RF-DC conversion efficiency of 34.0%. When the WPT base station operates with an EIRP set to 65 dBm, it exhibits three times improvement in RF-DC conversion efficiency compared to other works. The 28GHz communication performance in both RX and TX modes is measured with a 400MHz 64QAM OFDMA-mode signal (5G NR, MSC 17).