A 28/39-GHz Reconfigurable Phased-Array Transmitter Front-End for 5G New Radio in a 65-nm CMOS

This article presents a reconfigurable phased-array transmitter (TX) front-end for 5G new radio (NR) in 65-nm CMOS. A reconfigurable up-converter is implemented to support dual-band operation around K-/Ka-bands without increasing LO or intermediate frequency (IF) bandwidth. The circuit moves image signals and spurs outside the passband of the RF channels, achieving a high image rejection ratio (IRR). Measured results show the chip covers both bands of 24–30 GHz and 36–40 GHz with 10–12 GHz LO and 4–6 GHz IF bands, with an IRR over 44 dB. Utilizing a PCB-based Vivaldi antenna array, a four-element phased-array TX front-end system is designed. The beam scanning ranges are ±30° and ±15° at 28 and 39 GHz, respectively. In addition, TX-to-RX wireless communication is demonstrated with the TX system and a K-/Ka-band receiver front-end. The over-the-air (OTA) tests reveal that the data rate is up to 1.2 Gbps/800 Mbps at 27/34.6 GHz over a 1-m distance.