A Phased-Array Transceiver With 2-Dimension Continuously Auto Link-Tracking Operation and Time Division Modulator

This work presents an eight-element 23–40 GHz continuously auto link-tracking phased-array transceiver (TRX) with a time division modulator in a conventional 40-nm CMOS technology. Such a TRX array can support fast auto-beam-steering in both receiver (RX) and transmitter (TX) arrays. The link-tracking loop is introduced to generate the phase and amplitude control codes of the RX array, which can automatically steer the RX beam to the unknown target direction to establish the RX link. After the RX link is located, the link-tracking loop provides a phase control code to steer the TX beam toward the target. Meanwhile, the time division modulator consists of four digital power amplifiers (DPAs), a quadrature signal generator, and a sign-map circuit. The time division modulator can not only tune the LO power for RX gain flatness improvement but also provide a baseband-to-RF direct conversion in TX mode. The measured link-tracking time and peak TX system efficiency are
$7~\mu \text{s}$
and 25.3%, respectively, while the proposed TRX array can support 4.8 Gb/s 64-QAM and 8 Gb/s 16-QAM transmission.