{"72267":{"#nid":"72267","#data":{"type":"news","title":"Digital Process Provides Better Aircraft Warnings","body":[{"value":"\u003Cp\u003EResearchers at the Georgia Tech Research Institute (GTRI) have patented a discovery that could significantly increase reliability and reduce cost in equipment that helps protect U.S. military aircraft from attack.  \u003C\/p\u003E\n\u003Cp\u003EThe patent covers a device called a digital crystal video receiver (DCVR), a vital part of the radar warning receiver (RWR) system that alerts an aircraft crew to enemy ground-radar activity.  GTRI researchers Michael J. Willis and Michael L. McGuire, working with Air Force scientist Charlie W. Clark, have patented a way to use digital circuitry to perform many functions formerly allotted to more-problematic analog chips. \n\u003C\/p\u003E\n\u003Cp\u003ESpecifically, the researchers have moved a critical operation -- the logarithmic transfer function -- from the analog to the digital domain. The logarithmic transfer function coordinates the input and output of a radar warning receiver\u0027s signal-processing system. \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Electronic analog technologies have a number of error sources and limitations when subjected to the extended temperature range that our military requires,\u0022 said Willis, a principal research engineer with GTRI\u0027s Electronic Systems Laboratory (ELSYS).  \u0022By moving the logarithmic transfer function into the digital signal-processing domain, we\u0027ve improved the stability of the circuit.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EAnalog circuits, traditionally used to detect real-world phenomena such as sound or temperature, hold a multitude of continuous values across any given range.  By contrast, digital circuits process information in discrete steps governed by the binary code that computers use.  \n\u003C\/p\u003E\n\u003Cp\u003EIn radar warning receivers, Willis explains, the continuous-scale analog implementation has been difficult to calibrate and maintain. By contrast, the digital domain needs no calibration and is more robust.\n\u003C\/p\u003E\n\u003Cp\u003EThe digital version is also far less expensive to manufacture.  \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Moving the logarithmic transfer function from analog to digital probably reduces production costs of a radar warning receiver by a factor of between five and 10,\u0022 he said. \u0022The cost of the digital video portion could become nearly insignificant in comparison to the cost of the remainder of the RWR system.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EThe new digital crystal video receiver is comprised of an analog-to-digital converter and a programmable logic component.  Together, they\u0027re able to transfer most received analog signals to the more-reliable digital domain. \n\u003C\/p\u003E\n\u003Cp\u003EEarlier crystal video receiver architectures, Willis explains, detected radio-frequency (RF) signals immediately, without intermediate processing.  Such analog \u0022direct-conversion\u0022 receivers often needed multiple receivers to detect radar signals over a range of frequencies.\n\u003C\/p\u003E\n\u003Cp\u003EBy contrast, the DCVR\u0027s improvements include a capacity to readily detect RF signals through a wide range of frequencies using up-to-date broadband receiver techniques.  \n\u003C\/p\u003E\n\u003Cp\u003EScientists use the word \u0022video\u0022 to describe this technology because the receiver demodulates received radar signals into video waveforms.  The new digital crystal video receiver approach subjects those video waveforms to digital signal processing, producing a digital equivalent with a logarithmic function applied to it to make processing easier.\n\u003C\/p\u003E\n\u003Cp\u003E\u0022Adding the word \u0022digital\u0022 to the older term \u0022crystal video receiver\u0022 emphasizes that technology advances have allowed us to overcome many limitations of the older-generation, crystal-based, direct-conversion receivers,\u0022 Willis said. \n\u003C\/p\u003E\n\u003Cp\u003EThe initial sponsored research involved a radar warning receiver used on a number of U.S. military aircraft, Willis said.  The discovery may have other military applications as well.\n\u003C\/p\u003E\n\u003Cp\u003ECommercial applications are also possible, he said. The discovery could be applied not only to radar warning receivers but to any receiver that requires a logarithmic transfer function.  Thus, it could be used in many types of radios or in other devices that involve signal receiving and processing capabilities. \n\u003C\/p\u003E\n\u003Cp\u003EThe recent patent, shared by GTRI and the U.S. government, is significant because it protects the technology.  Still, Willis said, the patent is only another step in an ongoing process leading to field deployment.  \n\u003C\/p\u003E\n\u003Cp\u003ECurrently, he said, GTRI is studying how to implement the new technology.   He expects it will take two years to complete the design process and transition the final implementation into production.\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 100\u003Cbr \/\u003E\nAtlanta, Georgia  30308  USA\u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Assistance\u003C\/strong\u003E: John Toon (404-894-6986); E-mail: (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Kirk Englehardt (404-407-7280); E-mail: (\u003Ca href=\u0022mailto:kirk.englehardt@gtri.gatech.edu\u0022\u003Ekirk.englehardt@gtri.gatech.edu\u003C\/a\u003E).\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: Rick Robinson\n\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"GTRI researchers receive patent for radar warning receiver improvement"}],"field_summary":[{"value":"Researchers at the Georgia Tech Research Institute (GTRI) have patented a discovery that could significantly increase reliability and reduce cost in equipment that helps protect U.S. military aircraft from attack.","format":"limited_html"}],"field_summary_sentence":[{"value":"GTRI researchers patent an improved receiver"}],"uid":"27303","created_gmt":"2007-03-08 01:00:00","changed_gmt":"2016-10-08 03:03:29","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2007-03-08T00:00:00-05:00","iso_date":"2007-03-08T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"72268":{"id":"72268","type":"image","title":"Mike Willis","body":null,"created":"1449177446","gmt_created":"2015-12-03 21:17:26","changed":"1475894653","gmt_changed":"2016-10-08 02:44:13"},"72269":{"id":"72269","type":"image","title":"Mike Willis","body":null,"created":"1449177446","gmt_created":"2015-12-03 21:17:26","changed":"1475894653","gmt_changed":"2016-10-08 02:44:13"}},"media_ids":["72268","72269"],"related_links":[{"url":"http:\/\/www.gtri.gatech.edu\/elsys\/index.html","title":"Electronic Systems Laboratory"},{"url":"http:\/\/www.gtri.gatech.edu\/","title":"Georgia Tech Research Institute"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"136","name":"Aerospace"},{"id":"145","name":"Engineering"},{"id":"135","name":"Research"}],"keywords":[{"id":"7569","name":"analog"},{"id":"525","name":"military"},{"id":"2621","name":"radar"},{"id":"2027","name":"warning"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}