A Beamforming Receiver Using a Time-Modulated LO-Path Vector Modulator Achieving Amplitude and Phase Control with 0.2 dB RMS Gain Error and 1.4 Degree RMS Phase Error

Beamforming receivers use the spatial domain to increase sensitivity, reject spatial interferers, and increase communication to multiple users simultaneously with multiple beams. Conventional vector modulators (VM) consisting of multiple gain slices are used for phase and amplitude control. The number of slices grows as a product of each additional beam, antenna element, and bit of resolution, resulting in significant area and power consumption. We use time-modulation techniques to break the area and VM-resolution tradeoff and have implemented a proof-of-concept prototype of our time-modulated LO (TM-LO) architecture in 65nm. Existing spatio-temporal techniques employ fast-beam switching implemented at the system level [1]. The TM-LO uses time-modulated techniques at the circuit level to enable amplitude and phase control for beam steering.