A 60-GHz Area-efficient Coupled Standing-Wave-Oscillators LO Distribution Network for a 240-GHz 2-D Phased-Array

This paper presents a $\mathbf{6 0 - G H z}$ LO distribution network for a $\mathbf{2 4 0 - G H z}$ 2-D phased-array transceiver in TSMC 28nm CMOS technology. The network couples multiple halfwave-length standing-wave oscillators (C-SWOs) through single-sided transmission-line coupling with layout optimized for area efficiency and unit-element symmetry. The $4 \times 2$ array prototype shows the desired synchronicity from the measured phase noise improvement as well as the observation of the injection-pulling spectrum. The tolerance of array to element mismatches are quantified and the phase skews at $0.33 \sim 3.28^{\circ}$ between pairs of SWOs are measured. Per element power consumption is 15 mW.