Design and Analysis of a 60-GHz CMOS Doppler Micro-Radar System-in-Package for Vital-Sign and Vibration Detection

• Published in: IEEE transactions on microwave theory and techniques Vol. 61; no. 4; pp. 1649 - 1659
• Main Authors: Kao, T-Y J., Yan Yan, Tze-Min Shen, Chen, A. Y-K, Jenshan Lin
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2013; Institute of Electrical and Electronics Engineers
• Subjects: Amplifiers; Antennas; Applied sciences; Circuit properties; CMOS integrated circuits; Design. Technologies. Operation analysis. Testing; Doppler radar; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; flip chip; frequency measurement; Inductors; Integrated circuits; medical signal detection; millimeter-wave integrated circuits; Mixers; Noise; patch antennas; Radar; Radar antennas; Radiocommunications; Radiolocalization and radionavigation; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; sensors; Telecommunications; Telecommunications and information theory; Robust estimation; Frequency measurement; Micromachine; Accuracy; Complementary MOS technology; Intermediate frequency; Optical receiver; Signal reconstruction; millimeter-wave integrated circuits; CMOS integrated circuits; flip chip; patch antennas; Phase modulation; Flip-chip; Printed antenna; Heterodyne receivers; Compact design; Power electronics; Mechanical vibrations; medical signal detection; Algorithm; System in package; Signal restoration; sensors; Portable equipment; Doppler radar; Power amplifier; Gain
• DOI: 10.1109/TMTT.2013.2247620
• ISSN: 0018-9480

This paper presents the first flip-chip-packaged and fully integrated Doppler micro-radar in 90-nm CMOS for noncontact vital-sign and vibration detection. The use of a smaller wavelength compared with previous works achieves the highly compact system for portable devices, and the radar design considerations at 60 GHz are discussed from both system and circuits points of view. The compact 60-GHz core (0.73 mm 2 ) provides a 36-dB peak down-conversion gain and transmits a radar signal around 0 dBm at 55 GHz. Quadrature generation at the intermediate frequency stage of the heterodyne receiver gives a power- and area-efficient solution to the null detection point issue, ensuring robust detection. By using single-patch antennas and without a high-power amplifier, the system demonstrates the first-pass success of human vital-sign detection at 0.3 m. The small mechanical vibration with a displacement of 0.2 mm can be detected up to 2 m away. At 60 GHz, target displacement comparable to wavelength results in strong nonlinear phase modulation and increases detection difficulties. A signal-recovery algorithm is proposed to improve the accuracy of vital-sign detection.