A 28 GHz Highly Accurate Phase- and Gain-Steering Transmitter Frontend for 5G Phased-Array Applications.

This paper presents a 28 GHz highly accurate phase-and gain-steering transmitter frontend for 5G phased-array repeater applications. It is designed in a 130 nm SiGe BiCMOS technology. The transmitter chain consists of a highly accurate 7-bit phase shifter, a 5-bit variable gain amplifier and an exceedingly linear analog predistorted power amplifier. The frontend provides up to 31.9 dB gain at 28 GHz and offers steering ranges of 9 dB for gain and 360° for phase. The root mean square (RMS) phase error of the transmitter frontend is less than 3.1 °, the RMS gain error results to 0.5 dB. An output-referred 1 dB-compression point (P 1 dB) of 9.9 dBm is achieved with a DC power consumption of 127.9 mW at voltage levels of 3.3/4.0 V.