A 10-GHz Localized-LO-Phase-Shifting Phased-Array Transmitter

This work presents a phased-array architecture based on the localized LO phase-shifting technique. Each LO element consists of a digital PLL with direct phase control, which allows inherently-linear high-resolution phase shifting, in spite of the nonlinearity of the analog components. A 10−GHz quadelement beamformer circuit, adopting the LO phase-shifting architecture, is implemented in a 28−nm CMOS process. The measured radiation pattern, when the beamformer drives an onboard patch antenna, demonstrates beam-steering capabilities and phase noise of the combined beam scaling down with the number of LO elements.