A 4-Element Baseband Charge-Domain Beamformer Integrated into 9-bit SAR ADC Achieving 32dB Spatial Notch with 52.1mW

This work presents a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4\times 4$</tex> fully passive charge-domain configurable beamformer integrated into 9-bit SAR ADCs in Intel 16 process, which operates up to 500MHz, achieving over 33dB spatial notch with 52.1mW per RX element. 1-degree resolution, energy-efficient switched-capacitor phase shifters with on-chip calibration ability are implemented using existing circuits in SAR ADC, realizing beamforming with only 15% area and 5% power overhead.