Annual Report 2007

TRI researchers have patented a discovery that could significantly increase the reliability and reduce the cost of equipment that helps protect U.S. military aircraft from attack. The patent covers a device called a digital crystal video receiver, a vital part of the radar warning receiver system that alerts an aircraft crew to enemy ground-radar activity. GTRI researchers Michael Willis and Michael McGuire, working with Air Force scientist Charlie Clark, have patented a way to use digital circuitry to perform many functions formerly allotted to more problematic analog chips. Specifically, the researchers have moved a critical operation – the logarithmic transfer function – from the analog to digital domain. The logarithmic transfer function coordinates the input and output of a radar warning receiver’s signal processing system. G Improving Reliability of Radar Warning Receivers “Electronic analog technologies have a number of error sources and limitations when subjected to the extended temperature range that our military requires,” said Willis, a GTRI principal research engineer. “By moving the logarithmic transfer function into the digital signal processing domain, we’ve improved the stability of the circuit.” Analog circuits, traditionally used to detect realworld 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. In radar warning receivers, Willis explained, the continuous-scale analog implementation has been difficult to calibrate and maintain. By contrast, the digital domain needs no calibration and is more robust. The digital version is also far less expensive to manufacture. “Moving 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,” he said. “The cost of the digital video portion could become nearly insignificant in comparison to the cost of the remainder of the system.” The new digital crystal video receiver is composed of an analog-to-digital converter and programmable logic component. Together, they’re able to transfer most received analog signals to the more reliable digital domain. Commercial applications are also possible for the technology. The discovery could be applied to any receiver that requires a logarithmic transfer function, including many types of radios and other devices that involve signal receiving and processing capabilities. GTRI is currently studying how to implement the new technology, Willis added. In collaboration with the Air Force, GTRI researchers have patented a digital crystal video receiver to improve operation of radar warning systems. 1 www.gtri.gatech.edu http://www.gtri.gatech.edu

Table of Contents Feed for the Digital Edition of Annual Report 2007

Annual Report 2007 Contents From the Director Research at GTRI Defense and Security Health and Human Systems Energy and Environment Manufacturing Technologies Information and Communication Technologies GTRI Around the World Interdisciplinary Research Centers The Laboratories of GTRI Georgia Tech Ireland GTRI by the Numbers GTRI and Georgia Tech Supporting Breakthrough Research GTRI Professional Education The People of GTRI

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