{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T11:19:42Z","timestamp":1770722382325,"version":"3.49.0"},"reference-count":80,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2016,7,26]],"date-time":"2016-07-26T00:00:00Z","timestamp":1469491200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Short-range noncontact sensors are capable of remotely detecting the precise movements of the subjects or wirelessly estimating the distance from the sensor to the subject. They find wide applications in our day lives such as noncontact vital sign detection of heart beat and respiration, sleep monitoring, occupancy sensing, and gesture sensing. In recent years, short-range noncontact sensors are attracting more and more efforts from both academia and industry due to their vast applications. Compared to other radar architectures such as pulse radar and frequency-modulated continuous-wave (FMCW) radar, Doppler radar is gaining more popularity in terms of system integration and low-power operation. This paper reviews the recent technical advances in Doppler radars for healthcare applications, including system hardware improvement, digital signal processing, and chip integration. This paper also discusses the hybrid FMCW-interferometry radars and the emerging applications and the future trends.<\/jats:p>","DOI":"10.3390\/s16081169","type":"journal-article","created":{"date-parts":[[2016,7,26]],"date-time":"2016-07-26T05:34:42Z","timestamp":1469511282000},"page":"1169","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":105,"title":["Short-Range Noncontact Sensors for Healthcare and Other Emerging Applications: A Review"],"prefix":"10.3390","volume":"16","author":[{"given":"Changzhan","family":"Gu","sequence":"first","affiliation":[{"name":"Google Inc., Mountain View, CA 94043, USA"}]}],"member":"1968","published-online":{"date-parts":[[2016,7,26]]},"reference":[{"key":"ref_1","first-page":"319","article-title":"Radar in War and in Peace","volume":"155","year":"1945","journal-title":"Nature"},{"key":"ref_2","unstructured":"Skolnik, M.I. (1962). Radar Handbook 2, McGraw-Hill Company."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1530","DOI":"10.1109\/PROC.1975.9992","article-title":"Non-invasive microwave measurement of respiration","volume":"63","author":"Lin","year":"1975","journal-title":"IEEE Proc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6383","DOI":"10.3390\/s150306383","article-title":"Assessment of Human Respiration Patterns via Noncontact Sensing Using Doppler Multi-Radar System","volume":"15","author":"Gu","year":"2015","journal-title":"Sensors"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"14830","DOI":"10.3390\/s150714830","article-title":"A Method for Remotely Sensing Vital Signs of Human Subjects Outdoors","volume":"15","author":"Li","year":"2015","journal-title":"Sensors"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1109\/TBME.1986.325760","article-title":"An X-band microwave life-detection system","volume":"7","author":"Chen","year":"1986","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2542","DOI":"10.1109\/TMTT.2009.2029716","article-title":"Assessment of Heart Rate Variability and Respiratory Sinus Arrhythmia via Doppler Radar","volume":"57","author":"Massagram","year":"2009","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"838","DOI":"10.1109\/TMTT.2004.823552","article-title":"Range correlation and I\/Q performance benefits in single-chip silicon Doppler radars for noncontact cardiopulmonary monitoring","volume":"52","author":"Droitcour","year":"2004","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4464","DOI":"10.1109\/TMTT.2006.884652","article-title":"Experiment and spectral analysis of a low-power -band heartbeat detector measuring from four sides of a human body","volume":"54","author":"Li","year":"2006","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3577","DOI":"10.1109\/TMTT.2011.2171712","article-title":"Single-antenna Doppler radars using self and mutual injection locking for vital sign detection with random body movement cancellation","volume":"59","author":"Wang","year":"2011","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_11","unstructured":"Li, C., Lin, J., and Xiao, Y. (September, January 31). Robust overnight monitoring of human vital signs by a non-contact respiration and heartbeat detector. Engineering in Medicine and Biology Society, Proceedings of the 28th Annual International Conference of the IEEE, New York, NY, USA."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1002\/bem.2250130610","article-title":"Microwave sensing of physiological movement and volume change: A review","volume":"13","author":"Lin","year":"1992","journal-title":"Bioelectromagnetics"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1109\/10.817625","article-title":"Microwave life-detection systems for searching human subjects under earthquake rubble or behind barrier","volume":"27","author":"Chen","year":"2000","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"10837","DOI":"10.3390\/s101210837","article-title":"Detecting Vital Signs with Wearable Wireless Sensors","volume":"10","author":"Yilmaz","year":"2010","journal-title":"Sensors"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1724","DOI":"10.1109\/TMTT.2003.812575","article-title":"A displacement measurement technique using millimeter-wave interferometry","volume":"51","author":"Kim","year":"2003","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"8992","DOI":"10.3390\/s110908992","article-title":"Integrating Millimeter Wave Radar with a Monocular Vision Sensor for On-Road Obstacle Detection Applications","volume":"11","author":"Wang","year":"2011","journal-title":"Sensors"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3111","DOI":"10.1109\/TIM.2014.2317298","article-title":"Advanced DC Offset Calibration Strategy for Structural Health Monitoring Based on Portable CW Radar Sensor","volume":"63","author":"Guan","year":"2014","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Yavari, E., Jou, H., Lubecke, V., and Boric-Lubecke, O. (2013, January 20\u201323). Doppler radar sensor for occupancy monitoring. Biomedical Wireless Technologies, Networks, and Sensing Systems (BioWireleSS), Proceedings of the 2013 IEEE Topical Conference, Austin, TX, USA.","DOI":"10.1109\/BioWireleSS.2013.6613701"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1109\/MMM.2013.2296210","article-title":"Is There Anybody in There?: Intelligent Radar Occupancy Sensors","volume":"15","author":"Yavari","year":"2014","journal-title":"IEEE Microw. Mag."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4592","DOI":"10.1109\/TMTT.2015.2495298","article-title":"Gesture Sensing Using Retransmitted Wireless Communication Signals Based on Doppler Radar Technology","volume":"63","author":"Wang","year":"2015","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Liu, C., Gu, C., and Li, C. (2015, January 25\u201328). Non-contact Hand Interaction with Smart Phones Using the Wireless Power Transfer Features. Proceedings of the IEEE Radio and Wireless Symposium (RWS), San Diego, CA, USA.","DOI":"10.1109\/RWS.2015.7129750"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2503","DOI":"10.1109\/TMTT.2004.837153","article-title":"On the development of a multifunction millimeter-wave sensor for displacement sensing and low-velocity measurement","volume":"52","author":"Kim","year":"2004","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_23","unstructured":"Droitcour, A., Lubecke, V., Lin, J., and Boric-Lubecke, O. (2001, January 20\u201325). A microwave radio for Doppler radar sensing of vital signs. Microwave Symposium Digest, Proceedings of the 2001 IEEE MTT-S International, Phoenix, AZ, USA."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1580","DOI":"10.1109\/TIM.2009.2028208","article-title":"Instrument-based noncontact Doppler radar vital sign detection system using heterodyne digital quadrature demodulation architecture","volume":"59","author":"Gu","year":"2010","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"4527","DOI":"10.3390\/s130404527","article-title":"Localization and Mapping Using Only a Rotating FMCW Radar Sensor","volume":"13","author":"Vivet","year":"2013","journal-title":"Sensors"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2995","DOI":"10.1109\/TMTT.2002.805162","article-title":"Compact single-chip W-band FMCW radar modules for commercial high-resolution sensor applications","volume":"50","author":"Tessmann","year":"2002","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Li, Y.-A., Hung, M.-H., Huang, S.-J., and Lee, J. (2010, January 7\u201311). A fully integrated 77 GHz FMCW radar system in 65nm CMOS. Proceedings of the 2010 IEEE International Solid-State Circuits Conference\u2014(ISSCC), San Francisco, CA, USA.","DOI":"10.1109\/ISSCC.2010.5433951"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1109\/TMTT.2007.914363","article-title":"24-GHz frequency-modulation continuous-wave radar front-end system-on-substrate","volume":"56","author":"Li","year":"2008","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1109\/TMTT.2009.2035945","article-title":"Real-time noncoherent UWB positioning radar with millimeter range accuracy: Theory and experiment","volume":"58","author":"Zhang","year":"2010","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_30","first-page":"699","article-title":"Comparison of Impulse Radar and Spread-Spectrum Radar in Through-Wall Imaging","volume":"64","author":"Zhang","year":"2016","journal-title":"IEEE Trans. Microw. Theo. Tech."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1109\/PROC.1978.10952","article-title":"A nanosecond impulse X-band radar","volume":"66","author":"Chudobiak","year":"1978","journal-title":"IEEE Proc."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Wang, Y., Yang, Y., and Fathy, A.E. (2009, January 1\u20135). Reconfigurable ultra-wide band see-through-wall imaging radar system. Proceedings of the 2009 IEEE Antennas and Propagation Society International Symposium, North Charleston, SC, USA.","DOI":"10.1109\/APS.2009.5171851"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1109\/MMM.2014.2308763","article-title":"From Tumor Targeting to Speech Monitoring: Accurate Respiratory Monitoring Using Medical Continuous-Wave Radar Sensors","volume":"15","author":"Gu","year":"2014","journal-title":"IEEE Microw. Mag."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2046","DOI":"10.1109\/TMTT.2013.2256924","article-title":"A Review on Recent Advances in Doppler Radar Sensors for Noncontact Healthcare Monitoring","volume":"61","author":"Li","year":"2013","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1109\/LMWC.2008.925112","article-title":"A 5 GHz double-sideband radar sensor chip in 0.18 m CMOS for non-contact vital sign detection","volume":"18","author":"Li","year":"2008","journal-title":"IEEE Microw. Wire. Compon. Lett."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Yan, Y., Li, C., Rice, J.A., and Lin, J. (2011, January 5\u201310). Wavelength division sensing RF vibrometer. Microwave Symposium Digest (MTT), Proceedings of the 2011 IEEE\/MTT-S International Microwave Symposium, Baltimore, MD, USA.","DOI":"10.1109\/MWSYM.2011.5972827"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"5633","DOI":"10.1109\/TGRS.2013.2291573","article-title":"Short-Range Wideband FMCW Radar for Millimetric Displacement Measurements","volume":"52","author":"Anghel","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"933","DOI":"10.1049\/el.2015.0309","article-title":"Method of doubling range resolution without increasing bandwidth in FMCW radar","volume":"51","author":"Li","year":"2015","journal-title":"Electron. Lett."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Lu, L., Li, C., and Rice, J.A. (2011, January 16\u201319). A software-defined multifunctional radar sensor for linear and reciprocal displacement measurement. Wireless Sensors and Sensor Networks (WiSNet), Proceedings of the 2011 IEEE Topical Conference, Phoenix, AZ, USA.","DOI":"10.1109\/WISNET.2011.5725027"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Gu, C., Li, R., Li, C., and Jiang, S.-B. (2011, January 16\u201319). Doppler radar respiration measurement for gated lung cancer radiotherapy. Biomedical Wireless Technologies, Networks, and Sensing Systems (BioWireleSS), Proceedings of the 2011 IEEE Topical Conference, Phoenix, AZ, USA.","DOI":"10.1109\/BIOWIRELESS.2011.5724348"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1109\/TBCAS.2015.2411732","article-title":"A Self-Calibrating Radar Sensor System Design for Measuring Vital Signs","volume":"10","author":"Huang","year":"2016","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3556","DOI":"10.1109\/TMTT.2011.2172624","article-title":"Analysis of Detection Methods and Realization of a Real-time Monitoring RF Vibrometer","volume":"59","author":"Yan","year":"2011","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Gu, C., Wang, G., Rice, J.A., and Li, C. (2012, January 17\u201322). Interferometric Radar Sensor with Active Transponders for Signal Boosting and Clutter Rejection in Structural Health Monitoring. Microwave Symposium Digest (MTT), Proceedings of the 2012 IEEE\/MTT-S International Microwave Symposium, Montreal, QC, Canada.","DOI":"10.1109\/MWSYM.2012.6259700"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Wang, G., Gu, C., Inoue, T., and Li, C. (2013, January 2). Hybrid FMCW-interferometry radar system in the 5.8 GHz ISM band for indoor precise position and motion detection. Microwave Symposium Digest (IMS), Proceedings of the 2013 IEEE MTT-S International Microwave Symposium, Seattle, WA, USA.","DOI":"10.1109\/MWSYM.2013.6697623"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"2812","DOI":"10.1109\/TMTT.2014.2358572","article-title":"A Hybrid FMCW-Interferometry Radar for Indoor Precise Positioning and Versatile Life Activity Monitoring","volume":"62","author":"Wang","year":"2014","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Nasr, I., Karagozler, E., Poupyrev, I., and Trotta, S. (2015, January 11\u201314). A Highly Integrated 60-GHz 6-Channel Transceiver Chip in 0.35 \u03bcm SiGe Technology for Smart Sensing and Short-Range Communications. Proceedings of the 2015 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS), New Orleans, LA, USA.","DOI":"10.1109\/CSICS.2015.7314475"},{"key":"ref_47","unstructured":"Google\u2019s Project Soli. Available online: https:\/\/atap.google.com\/soli\/."},{"key":"ref_48","unstructured":"Droitcour, A.-D., Boric-Lubecke, O., Lubecke, V.-M., and Lin, J. (2002, January 7). 0.25\/spl mu\/m CMOS and BiCMOS single-chip direct-conversion Doppler radar for remote sensing of vital signs. Solid-State Circuits Conference, 2002. Digest of Technical Papers. ISSCC. In Proceedings of the 2002 IEEE International, San Francisco, CA, USA."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Yavari, E., and Boric-Lubecke, O. (2014, January 1). Low IF demodulation for physiological pulse Doppler radar. Proceedings of the 2014 IEEE MTT-S International Microwave Symposium, Tampa, FL, USA.","DOI":"10.1109\/MWSYM.2014.6848564"},{"key":"ref_50","first-page":"2931","article-title":"Chest-Worn Health Monitor Based on a Bistatic Self-Injection-Locked Radar","volume":"62","author":"Wang","year":"2015","journal-title":"IEEE Trans. Microwave Theory Tech."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Horng, T.-S. (2013, January 5\u20138). Self-injection-locked radar: An advance in continuous-wave technology for emerging radar systems. Proceedings of the 2013 Asia-Pacific Microwave Conference Proceedings, Seoul, South Korea.","DOI":"10.1109\/APMC.2013.6694866"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"2093","DOI":"10.1109\/TMTT.2013.2247055","article-title":"Six-port radar sensor for remote respiration rate and heartbeat vital-sign monitoring","volume":"61","author":"Gabor","year":"2013","journal-title":"IEEE Trans. Microwa. Theory Tech."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1649","DOI":"10.1109\/TMTT.2013.2247620","article-title":"Design and Analysis of a 60-GHz CMOS Doppler Micro-Radar System-in-Package for Vital-Sign and Vibration Detection","volume":"61","author":"Kao","year":"2013","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_54","unstructured":"Li, C., and Lin, J. (2008, January 15\u201318). Complex signal demodulation and random body movement cancellation techniques for non-contact vital sign detection. Microwave Symposium Digest, Proceedings of the 2008 IEEE MTT-S International Microwave Symposium, Atlanta, GA, USA."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1109\/TMTT.2007.895653","article-title":"Arctangent demodulation with DC offset compensation in quadrature Doppler radar receiver systems","volume":"55","author":"Park","year":"2007","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1428","DOI":"10.1049\/el.2012.3130","article-title":"Robust Doppler radar demodulation via compressed sensing","volume":"48","author":"Xu","year":"2012","journal-title":"IET Electron. Lett."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"3143","DOI":"10.1109\/TMTT.2008.2007139","article-title":"Random body movement cancellation in Doppler radar vital sign detection","volume":"56","author":"Li","year":"2008","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_58","first-page":"961","article-title":"High-Precision Motion Detection Using Low-Complexity Doppler Radar with Digital Post-Distortion Technique","volume":"64","author":"Gu","year":"2016","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1718","DOI":"10.1109\/TMTT.2013.2249525","article-title":"Data-based quadrature imbalance compensationfor a CW Doppler radar system","volume":"61","author":"Singh","year":"2013","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"1400","DOI":"10.1109\/TMTT.2014.2321738","article-title":"Quadrature Imbalance Compensation With Ellipse-Fitting Methods for Microwave Radar Physiological Sensing","volume":"62","author":"Zakrzewski","year":"2013","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"3117","DOI":"10.1109\/TBME.2012.2206591","article-title":"Accurate respiration measurement using DC-coupled continuous-wave radar sensor for motion-adaptive cancer radiotherapy","volume":"59","author":"Gu","year":"2012","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"566","DOI":"10.1109\/LMWC.2013.2250269","article-title":"Analysis and Experiment on the Modulation Sensitivity of Doppler Radar Vibration Measurement","volume":"23","author":"Gu","year":"2013","journal-title":"IEEE Microw. Wirel. Compon. Lett."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"830","DOI":"10.1109\/TIM.2011.2171589","article-title":"Compact millimeter-wave sensor for remote monitoring of vital signs","volume":"61","author":"Bakhtiari","year":"2012","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_64","doi-asserted-by":"crossref","unstructured":"Gatesman, A.J., Danylov, A., Goyette, T.M., Dickinson, J.C., Giles, R.H., Goodhue, W., Waldman, J., Nixon, W.E., and Hoen, W. (2006). Terahertz behavior of optical components and common materials\u2014Art. no. 62120E. Terahertz Military Security Appl. IV, 6212.","DOI":"10.21236\/ADA461642"},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"2023","DOI":"10.1109\/TMTT.2006.873625","article-title":"Frequency-tuning technique for remote detection of heartbeat and respiration using low-power double-sideband transmission in the Ka-band","volume":"54","author":"Xiao","year":"2006","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1049\/el.2012.0071","article-title":"DC coupled CW radar sensor using fine-tuning adaptive feedback loop","volume":"48","author":"Gu","year":"2012","journal-title":"IET Electron. Lett."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"1495","DOI":"10.1049\/el.2012.2451","article-title":"Frequency-Selective Distortion in Continuous-Wave Radar Displacement Sensor","volume":"48","author":"Gu","year":"2012","journal-title":"IET Electron. Lett."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1109\/TIM.2013.2277530","article-title":"Non-contact Distance and Amplitude Independent Vibration Measurement Based on an Extended DACM Algorithm","volume":"63","author":"Wang","year":"2014","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_69","doi-asserted-by":"crossref","unstructured":"Gu, C., Wang, G., Inoue, T., and Li, C. (2013, January 2\u20137). Doppler radar vital sign detection with random body movement cancellation based on adaptive phase compensation. Microwave Symposium Digest (IMS), Proceedings of the 2013 IEEE MTT-S International Microwave Symposium, Seattle, WA, USA.","DOI":"10.1109\/MWSYM.2013.6697618"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"4678","DOI":"10.1109\/TMTT.2013.2288226","article-title":"A Hybrid Radar-Camera Sensing System with Phase Compensation for Random Body Movement Cancellation in Doppler Vital Sign Detection","volume":"61","author":"Gu","year":"2013","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"3034","DOI":"10.1109\/TMTT.2015.2471998","article-title":"A Low-IF Tag-Based Motion Compensation Technique for Mobile Doppler Radar Life Signs Monitoring","volume":"63","author":"Rahman","year":"2015","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_72","doi-asserted-by":"crossref","unstructured":"Gao, X., and Boric-Lubecke, O. (2015, January 17\u201322). AC Coupled Quadrature Doppler Radar Displacement Estimation. Microwave Symposium Digest (IMS), Proceedings of the 2015 IEEE MTT-S International Microwave Symposium, Phoenix, AZ, USA.","DOI":"10.1109\/MWSYM.2015.7167039"},{"key":"ref_73","unstructured":"Gao, X., Singh, A., Yavari, E., Lubecke, V., and Boric-Lubecke, O. (Septembre, January 28). Non-contact Displacement Estimation Using Doppler Radar. Proceedings of the 2012 34th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, San Diego, CA, USA."},{"key":"ref_74","doi-asserted-by":"crossref","unstructured":"Yan, Y., Li, C., and Lin, J. (2010, January 10\u201314). Effects of I\/Q mismatch on measurement of periodic movement using a Doppler radar sensor. Proceedings of the 2010 IEEE Radio and Wireless Symposium (RWS), New Orleans, LA, USA.","DOI":"10.1109\/RWS.2010.5434180"},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"1410","DOI":"10.1109\/TMTT.2010.2042856","article-title":"High-sensitivity software-configurable 5.8-GHz radar sensor receiver chip in 0.13-m CMOS for noncontact vital sign detection","volume":"58","author":"Li","year":"2010","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"2069","DOI":"10.1109\/TMTT.2015.2422692","article-title":"Concurrent Detection of Vibration and Distance Using Unmodulated CW Doppler Vibration Radar with an Adaptive Beam-Steering Antenna","volume":"63","author":"Nieh","year":"2015","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"899","DOI":"10.1109\/LMWC.2014.2352852","article-title":"Noncontact Large-Scale Displacement Tracking: Doppler Radar for Water Level Gauging","volume":"24","author":"Gu","year":"2014","journal-title":"IEEE Microw. Wire. Componen. Lett."},{"key":"ref_78","doi-asserted-by":"crossref","unstructured":"Li, C., and Lin, J. (2013). Microwave Noncontact Motion Sensing and Analysis, John Wiley & Sons. [1st ed.].","DOI":"10.1002\/9781118742556"},{"key":"ref_79","doi-asserted-by":"crossref","unstructured":"Boric-Lubecke, O., Lubecke, V.M., Droitcour, A.D., Park, B.K., and Singh, A. (2015). Doppler Radar Physiological Sensing, John Wiley & Sons. [1st ed.].","DOI":"10.1002\/9781119078418"},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1145\/2897824.2925953","article-title":"Soli: Ubiquitous Gesture Sensing with Millimeter Wave Radar","volume":"35","author":"Lien","year":"2016","journal-title":"ACM Trans. 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