A 256-Element Phased-Array Relay Transceiver for 5G Network Using 24-GHz Wireless Power Transfer With Discrete ICs

This letter introduces a 256-array wirelessly powered phased-array transceiver with 24-GHz wireless power transfer (WPT) for 28-GHz millimeter-wave 5G communication. The 256-element rectifier arrays are configured with discrete ICs, including GaAs diodes, baluns, DPDT switches, and digital ICs. The rectifier can convert a 24-GHz WPT signal to dc while providing the frequency conversion between 28-and 4-GHz IF signal by using a 24-GHz WPT as an LO signal. The phases of 4-GHz IF signals are changed by the 180 $^{\circ}$ phase shifters, configured with two baluns and a DPDT switch, resulting in Tx and Rx beamforming. According to the over-the-air (OTA) measurement with the 256-array prototype module, it can achieve 54% of PCE with 10-dBm input power and $-$ 19-dB conversion gain for Tx mode. The error vector magnitude (EVM) is also measured with the orthogonal frequency-division multiple access (OFDMA)-mode modulated signal, compliant with 5G new radio (NR), and the proposed transceiver can transmit and receive a 64 QAM modulated signal with 400-MHz bandwidth with 28-GHz beamforming.