Ultralow-Power Radar Sensors for Ambient Sensing in the -Band

• Published in: IEEE transactions on microwave theory and techniques 2017-12, Vol.65 (12), p.5401-5410
• Main Authors: Shopov, Stefan, Girma, Mekdes G., Hasch, Juergen, Cahoon, Ned, Voinigescu, Sorin P.
• Format: Article
• Language: English
• Subjects: Ambient sensing; Antennas; Circuit design; CMOS; Die forming; Dies; Direction of arrival; doppler sensor; Internet of Things (IoT); millimeter wave (mm-wave) radar; MOS devices; MOSFET circuits; multichannel transceiver; Noise levels; Phase noise; Power consumption; Power demand; Sensors; SOI; Topology; Voltage controlled oscillators
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2017.2771261

The design considerations and circuit topologies of a family of ultralow-power fundamental-frequency and second-harmonic 60-GHz radar sensors are described. The single-chip sensor architecture features four lownoise-matched receivers, either a fundamental-frequency 60GHz voltage-controlled oscillator (VCO) or 30-GHz VCO + doubler, and a static divide-by-8192 chain which is turned OFF 95% of the time to save DC power. On-die measurements show a power consumption of 42 mW from a single 1.2-V supply, 10% frequency tuning range, -104 to -108 dBc/Hz phase noise at 10-MHz offset, 10-dB conversion gain per receiver, and -7-dBm transmitter output power at the antenna pads. Several 45-nm SOI-CMOS sensor dies were flip-chip mounted on a 7 × 7 mm 2 flexible interposer which also includes four receiveand two transmit antennas. Doppler and direction of arrival tests were conducted over distances of several tens of centimeters.