A 533µW Fast Duty-Cycled Pulsed-LO Beam-Steering Receiver

This work presents a mixer-first zero-IF pulsed-LO beam-steering receiver operating at 2.4 GHz. The receiver leverages a pulsed LO delay-locked to an external reference (XO). The delay-chain and pulse-combining architecture settles quickly and eliminates the need for PLL, thereby saving power while maintaining phase coherence. Beam steering is implemented entirely in the LO domain through quadrature LO rotation and fine delay tuning. Receiver power and performance scale with the pulsed-LO duty-cycle (D0), controlled by XO frequency, enabling a single-knob power-performance trade-off. At a D0 of 93.5 %, the receiver consumes 533 µW and achieves an EVM of −33.4 dB, while at 11.4 % it reduces to 65 µW with an EVM of −18.1 dB. The chip is implemented in 65-nm CMOS and measured in an anechoic chamber with an array of patch antennas. The receiver achieves a per-element noise figure of 13 dB and a phase resolution of 9°