A 256-Element 28GHz 5G NR Wirelessly-Powered Active Relay Transceiver with TDD Synchronization Free Bidirectional Amplifiers

In this paper, we propose a millimeter-wave relay system powered entirely by energy harvested by wireless power transfer, eliminating the need for TDD synchronization. The relay transceiver uses a TDD synchronization free bidirectional amplifier, allowing the system to continuously receive and transmit signals without T/R switches or TDD synchronization signals. This combined with the transceiver being fully powered by received WPT signals, which removes the need for external power supply units, reduces the system installation complexity. The bidirectional amplifier consists of two Wilkinson dividers and amplifiers that perform simultaneous two-way amplification. The prototype IC integrates an unequal bidirectional amplifier that uses unequal Wilkinson dividers to improve the noise figure. The prototype IC has 16 paths per chip, and the prototype board is a 256-element transceiver. The proposed relay transceiver supports 256QAM for the Rx and 64QAM for the Tx with a 400MHz bandwidth, standard compliant 5G NR OFDMA-mode modulated signals.