A Two-Beam Eight-Element Direct Digital Beamforming RF Modulator in 40-nm CMOS

Packaging and Antenna Integration for Silicon-Based Millimeter-Wave Phased Arrays: 5G and Beyond

“…Beamforming can be performed in the RF, local oscillator (LO), intermediate frequency (IF), or digital domains [7]. Digital beamforming, with its ability to create simultaneous beams, 1 is becoming an attractive approach for phased arrays with fewer elements and low bandwidth in the FR1 bands below 7 GHz [10], [11]. For the FR2 and FR4 bands, the larger number of antennas (and corresponding frequency chains) and the larger bandwidth, makes digital beamforming expensive [12], [13].…”