9.8 A 28GHz 20.3%-Transmitter-Efficiency 1.5°-Phase-Error Beamforming Front-End IC with Embedded Switches and Dual-Vector Variable-Gain Phase Shifters

Millimeter-wave beamforming front-end ICs have been studied intensively as the service of 5G wireless communication is scheduled to begin in the near future [1–4]. The ICs include circuit elements such as PAs, LNAs, phase shifters, variable gain blocks, and switches to support antenna arrays for RF/hybrid beamforming. Due to the large number of antennas required for beamforming, the beamforming IC should include as many circuit elements as possible in a chip. The IC also needs high phase- and gain-control resolutions not only for controlling the beams precisely but also for error corrections and calibrations [1]. However, higher-bit controls of the phase and gain as well as high transmitting power increase the chip size in conventional structures, posing a trade-off between them. The front-end IC structure proposed here increases both transmitting power and gain/phase resolutions without increasing either the chip size or the power consumption.