{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T11:18:44Z","timestamp":1780053524605,"version":"3.54.0"},"reference-count":38,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2022,1,11]],"date-time":"2022-01-11T00:00:00Z","timestamp":1641859200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["1955805"],"award-info":[{"award-number":["1955805"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["2030859"],"award-info":[{"award-number":["2030859"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Data about users is collected constantly by phones, cameras, Internet websites, and others. The advent of so-called \u2018Smart Things\u2019 now enable ever-more sensitive data to be collected inside that most private of spaces: the home. The first step in helping users regain control of their information (inside their home) is to alert them to the presence of potentially unwanted electronics. In this paper, we present a system that could help homeowners (or home dwellers) find electronic devices in their living space. Specifically, we demonstrate the use of harmonic radars (sometimes called nonlinear junction detectors), which have also been used in applications ranging from explosives detection to insect tracking. We adapt this radar technology to detect consumer electronics in a home setting and show that we can indeed accurately detect the presence of even \u2018simple\u2019 electronic devices like a smart lightbulb. We evaluate the performance of our radar in both wired and over-the-air transmission scenarios.<\/jats:p>","DOI":"10.3390\/rs14020327","type":"journal-article","created":{"date-parts":[[2022,1,11]],"date-time":"2022-01-11T20:33:04Z","timestamp":1641933184000},"page":"327","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Detecting the Presence of Electronic Devices in Smart Homes Using Harmonic Radar Technology"],"prefix":"10.3390","volume":"14","author":[{"given":"Beatrice","family":"Perez","sequence":"first","affiliation":[{"name":"Department of Computer Science, Dartmouth College, Hanover, NH 03755, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5814-7425","authenticated-orcid":false,"given":"Gregory","family":"Mazzaro","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, The Citadel, The Military College of South Carolina, Charleston, SC 29409, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Timothy J.","family":"Pierson","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Dartmouth College, Hanover, NH 03755, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7411-2783","authenticated-orcid":false,"given":"David","family":"Kotz","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Dartmouth College, Hanover, NH 03755, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,11]]},"reference":[{"key":"ref_1","unstructured":"Wikipedia (2021, October 25). Amazon Echo. Available online: https:\/\/en.wikipedia.org\/wiki\/Amazon_Echo."},{"key":"ref_2","unstructured":"Wikipedia (2021, October 25). Google Home. Available online: https:\/\/en.wikipedia.org\/wiki\/Google_Home."},{"key":"ref_3","unstructured":"Signify Holding (2021, October 25). Smart Mood Lighting. Available online: https:\/\/www.philips-hue.com\/en-us\/explore-hue\/propositions\/personal-mood-lighting."},{"key":"ref_4","unstructured":"Yale, ASSA ABLOY Residential Group (2021). Smart Door Locks, Yale, ASSA ABLOY Residential Group."},{"key":"ref_5","unstructured":"Samsung (2021, October 25). Smart Refrigerator. Available online: https:\/\/www.samsung.com\/us\/explore\/family-hub-refrigerator\/overview\/."},{"key":"ref_6","unstructured":"McKinsey & Company (2021). Growing Opportunities in the Internet of Things, McKinsey & Company."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"081001","DOI":"10.1088\/1748-9326\/ab3761","article-title":"Smart urban water systems: What Could possibly go wrong?","volume":"14","author":"Schneider","year":"2019","journal-title":"Environ. Res. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Sami, S., Dai, Y., Tan, S.R.X., Roy, N., and Han, J. (2020, January 16\u201319). Spying with your robot vacuum cleaner: Eavesdropping via lidar sensors. Proceedings of the ACM Conference on Embedded Networked Sensor Systems (Sensys), Virtual.","DOI":"10.1145\/3384419.3430781"},{"key":"ref_9","first-page":"114080E","article-title":"Nonlinear radar: A historical overview and a summary of recent advancements","volume":"11408","author":"Mazzaro","year":"2020","journal-title":"Proc. SPIE"},{"key":"ref_10","unstructured":"Pedro, J.C., and Carvalho, N.B. (2003). Intermodulation Distortion in Microwave and Wireless Circuits, Artech House."},{"key":"ref_11","unstructured":"Gallagher, K. (2015). Harmonic Radar: Theory and Applications to Nonlinear Target Detection, Tracking, Imaging and Classification. [Ph.D. Thesis, Pennsylvania State University]."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Martone, A.F., Ranney, K.I., Sherbondy, K.D., Gallagher, K.A., Mazzaro, G.J., and Narayanan, R.M. (July, January 30). An overview of spectrum sensing for harmonic radar. Proceedings of the 2016 International Symposium on Fundamentals of Electrical Engineering (ISFEE), Bucharest, Romania.","DOI":"10.1109\/ISFEE.2016.7803226"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Viikari, V., Kantanen, M., Varpula, T., Lamminen, A., Alastalo, A., Mattila, T., Seppa, H., Pursula, P., Saebboe, J., and Cheng, S. (2009, January 26\u201329). Technical solutions for automotive intermodulation radar for detecting vulnerable road users. Proceedings of the VTC Spring 2009-IEEE 69th Vehicular Technology Conference, Barcelona, Spain.","DOI":"10.1109\/VETECS.2009.5073875"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Aumann, H.M., and Emanetoglu, N.W. (2014, January 19\u201323). A wideband harmonic radar for tracking small wood frogs. Proceedings of the 2014 IEEE Radar Conference, Cincinnati, OH, USA.","DOI":"10.1109\/RADAR.2014.6875565"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"666","DOI":"10.1109\/TMTT.2012.2230020","article-title":"A high-range-accuracy and high-sensitivity harmonic radar using pulse pseudorandom code for bee searching","volume":"61","author":"Tsai","year":"2012","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1016\/j.aspen.2016.03.013","article-title":"Potential of harmonic radar system for use on five economically important insects: Radar tag attachment on insects and its impact on flight capacity","volume":"19","author":"Kim","year":"2016","journal-title":"J. Asia-Pac. Entomol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Aballo, T., Cabria, L., Garcia, J., Fernandez, T., and Marante, F. (2006, January 10\u201315). Taking advantage of a Schottky junction nonlinear characteristic for radiofrequency temperature sensing. Proceedings of the 2006 European Microwave Conference, Manchester, UK.","DOI":"10.1109\/EUMC.2006.281320"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Kubina, B., Romeu, J., Mandel, C., Sch\u00fc\u00dfler, M., and Jakoby, R. (2014, January 2\u20135). Design of a quasi-chipless harmonic radar sensor for ambient temperature sensing. Proceedings of the 2014 IEEE SENSORS, Valencia, Spain.","DOI":"10.1109\/ICSENS.2014.6985316"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1017\/S1759078721000520","article-title":"A SFCW harmonic radar system for maritime search and rescue using passive and active tags","volume":"13","author":"Harzheim","year":"2021","journal-title":"Int. J. Microw. Wirel. Technol."},{"key":"ref_20","unstructured":"Fussell, S. (2021, October 25). Airbnb Has a Hidden Camera Problem. Available online: https:\/\/www.theatlantic.com\/technology\/archive\/2019\/03\/what-happens-when-you-find-cameras-your-airbnb\/585007\/."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2621","DOI":"10.1109\/ACCESS.2016.2572730","article-title":"Wireless Chaos-Based Communication Systems: A Comprehensive Survey","volume":"4","author":"Kaddoum","year":"2016","journal-title":"IEEE Access"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Cabrera, C., Palade, A., and Clarke, S. (2017, January 4\u20136). An Evaluation of Service Discovery Protocols in the Internet of Things. Proceedings of the Symposium on Applied Computing (SAC), Marrakech, Morocco.","DOI":"10.1145\/3019612.3019698"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1109\/MMM.2015.2465591","article-title":"Getting the bugs out: A portable harmonic radar system for electronic countersurveillance applications","volume":"16","author":"Aniktar","year":"2015","journal-title":"IEEE Microw. Mag."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Mazzaro, G.J., and Sherbondy, K.D. (2019, January 11\u201314). Filter Selection for Wideband Harmonic Radar. Proceedings of the 2019 SoutheastCon, Huntsville, AL, USA.","DOI":"10.1109\/SoutheastCon42311.2019.9020651"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2825","DOI":"10.1109\/TAP.2004.835166","article-title":"Harmonic radar transceiver design: Miniature tags for insect tracking","volume":"52","author":"Colpitts","year":"2004","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Kiriazi, J., Nakakura, J., Hall, K., Hafner, N., and Lubecke, V. (2007, January 22\u201326). Low Profile Harmonic Radar Transponder for Tracking Small Endangered Species. Proceedings of the 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Lyon, France.","DOI":"10.1109\/IEMBS.2007.4352795"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Kim, I.H., Min, K.S., Jeong, J.H., and Kim, S.M. (2013, January 5\u20138). Circularly polarized tripleband patch antenna for non-linear junction detector. Proceedings of the 2013 Asia-Pacific Microwave Conference Proceedings (APMC), Seoul, Korea.","DOI":"10.1109\/APMC.2013.6695217"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"98290P","DOI":"10.1117\/12.2224478","article-title":"Derivation and validation of the nonlinear radar range equation","volume":"9829","author":"Gallagher","year":"2016","journal-title":"Proc. SPIE"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Gallagher, K.A., Narayanan, R.M., Mazzaro, G.J., Ranney, K.I., Martone, A.F., and Sherbondy, K.D. (2015, January 10\u201315). Moving target indication with non-linear radar. Proceedings of the 2015 IEEE Radar Conference (RadarCon), Arlington, VA, USA.","DOI":"10.1109\/RADAR.2015.7131219"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Ilbegi, H., Hayvaci, H.T., Yetik, I.S., and Yilmaz, A.E. (2017, January 8\u201312). Distinguishing electronic devices using harmonic radar. Proceedings of the 2017 IEEE Radar Conference (RadarConf), Seattle, WA, USA.","DOI":"10.1109\/RADAR.2017.7944449"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Mazzaro, G., Gallagher, K., Sherbondy, K., and Salik, K. (2021, January 10\u201313). Detecting Nonlinear Junctions Using Harmonic Cross-Modulation. Proceedings of the SoutheastCon 2021, Atlanta, GA, USA.","DOI":"10.1109\/SoutheastCon45413.2021.9401890"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"558","DOI":"10.1109\/JSEN.2011.2134083","article-title":"Respiratory monitoring and clutter rejection using a CW Doppler radar with passive RF tags","volume":"12","author":"Singh","year":"2011","journal-title":"IEEE Sens. J."},{"key":"ref_33","first-page":"91","article-title":"Harmonic nonlinear radar: From benchtop experimentation to short-range wireless data collection","volume":"Volume 11003","author":"Ranney","year":"2019","journal-title":"Radar Sensor Technology XXIII"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Gorbatenko, N.N., and Semenikhina, D.V. (February, January 29). A radiation characteristic of perfect conducted cylinder with non-linear loads covered with a layer of metematerial. Proceedings of the 2018 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus), Moscow and St. Petersburg, Russia.","DOI":"10.1109\/EIConRus.2018.8317135"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Mazzaro, G.J., Martone, A.F., Sherbondy, K.D., Gallagher, K.A., and Narayanan, R.M. (April, January 30). Maximizing harmonic-radar target response: Duty cycle vs. peak power. Proceedings of the SoutheastCon 2016, Norfolk, VA, USA.","DOI":"10.1109\/SECON.2016.7506726"},{"key":"ref_36","unstructured":"Signal Hound (2021, October 25). VSG60A\u20146 GHz Vector Signal Generator. Available online: https:\/\/signalhound.com\/products\/vsg60a-6-ghz-vector-signal-generator\/."},{"key":"ref_37","unstructured":"Signal Hound (2021, October 25). BB60C\u20146 GHz Real-time Spectrum Analyzer. Available online: https:\/\/signalhound.com\/products\/bb60c\/."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"477","DOI":"10.1109\/TAES.2013.120798","article-title":"Detection of RF electronics by multitone harmonic radar","volume":"50","author":"Mazzaro","year":"2014","journal-title":"IEEE Trans. Aerosp. Electron. 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