High-efficiency phased array using sequential over-the-air combining

This paper presents a novel sequential transmitter phased array architecture for efficiency boosting of the transmitter-receiver link. The boost in efficiency is achieved by transmitting the signal peaks and the remaining data through different chains, each of which optimized for specific power, and recombining the signal over-the-air. Experimental results verified the over-the-air combining concept in actual environment. An 80 MHz bandwidth 802.11ac OFDM signal with 9.7dB PAPR at 5GHz was transmitted through an array of 4 patch antennas. The received EVM was lower than -38dB, similar to a uniform excited array. Simulations show that this transmitter can boost the efficiency by 31% and 54% for -8dB and -10dB power back-off from the array maximum power respectively, without any penalty in die area nor antenna size compared to a uniform array.