HOW IT WORKS: Radar Defense Systems

Revealed: Pentagon’s Plan to Defeat Russian and Chinese Radar With A.I.

Dave Majumdar,
February 29, 2016

The Pentagon’s Defense Advanced Research Projects Agency (DARPA) is working on a new generation of electronic warfare systems that are based on artificial intelligence (AI). If the program were to prove a success, the new A.I.-driven systems would provide the United States military a way to counter evermore-capable Russian and Chinese radars.

“One of our programs at DARPA is taking a whole new approach to this problem, this is an effort we refer to as cognitive electronic warfare,” DARPA director, Dr. Arati Prabhakar, told the House Armed Services Committee’s Subcommittee on Emerging Threats and Capabilities on February 24. “We’re using artificial intelligence to learn in real-time what the adversaries’ radar is doing and then on-the-fly create a new jamming profile. That whole process of sensing, learning and adapting is going on continually.”

Current generation aircraft—including the stealthy Lockheed Martin F-22 and F-35—have a preprogrammed databank of enemy radar signals and jamming profiles stored in a threat library. But if those warplanes encounter a signal that has not previously been encountered, the system registers the threat as unknown—which means the aircraft is vulnerable to that threat.

“Today, when out aircraft go out on their missions, they’re loaded up with a set of jamming profiles—these are specific frequencies and waveforms that they can transmit in order to jam and disrupt an adversaries’ radar to protect themselves,” Prabhakar said. “Sometimes when they go out today, they encounter a new kind of frequency or different waveform—one that they’re not programmed for, that’s not in their library, and in a time of conflict, that would leave them exposed.”

During peacetime, the Pentagon usually deploys a signals intelligence aircraft like the RC-135V/W Rivet Joint to collect data on a new waveform. That data is then sent to a laboratory to be analyzed so that a new jamming profile can be created. Those new jamming profiles are then incorporated into a jet’s—F-22, F-35, F/A-18 or any other fighter—operational flight program updates. “Eventually, months—sometimes years—later our aircraft finally get the protection that they need against this new kind of radar signal,” Prabhakar said.

In the years prior to the digital revolution when radar waveforms were rarely altered, that slow process might have been adequate. In the current era where a new waveform can be created very quickly with minor software tweaks, the current process leaves American forces vulnerable. “That slow moving world is now gone,” Prabhakar said. “It’s not that hard to modify a radar system today. If you think about, the same technologies that have brought communications and the Internet to billions of people around the world, those are the same technologies that people are now using to modify radars.”

It’s a problem that has cropped up in many different regions around the world, Pabhakar said. Right now, the only U.S. combat aircraft that have some capacity to analyze enemy waveforms in real time are the Northrop Grumman EA-6B Prowler—which is still serving with the Marines—and the Navy’s Boeing EA-18G Growler. While both the Growler and Prowler have pre-programmed onboard threat libraries, both jets carry electronic warfare officers (EWO). Those EWOs can recognize and analyze the unknown enemy waveforms and—based on their experience—figure out a way to jam them in real time to an extent. However, it’s far from perfect because it relies purely on the skills of an individual EWO.

If DARPA’s new AI-based electronic warfare system works, it would save the Pentagon time, money and potentially even save the lives of aircrew if they encounter a new enemy surface-to-air missile system or fighter radar. “So what all of that means is that our aircraft in the future won’t have to wait weeks, months to years, but in real time, in the battlespace, they’ll be able to adapt and jam this new radar threat that they get.”

Dave Majumdar is the new Defense Editor for the National Interest. You can follow him on Twitter: @DaveMajumdar.

Image: Wikimedia Commons/U.S. Navy.
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Phase-Coded CW MIMO Radar Using ZCZ Sequence Sets

Millimeter-Wave Phase-Coded CW MIMO Radar Using Zero-Correlation-Zone Sequence Sets Heinz Haderer, Reinhard Feger, Clemens Pfeffer, and Andreas Stelzer Institute for Communications Engineering and RF-Systems, Johannes Kepler University Linz Altenberger Str. 69, 4040 Linz, Austria Email: h.haderer, r.feger, c.pfeffer, a.stelzerg@nthfs.jku.at

Abstract —We present a phase-coded continuous-wave (CW) multiple-input multiple-output (MIMO) radar approach based on code-division multiplexing. We use zero-correlation-zone (ZCZ) sequence sets to separate at the receivers signals from multiple transmitters. In particular, our approach uses equidistantly shifted almost-perfect autocorrelation sequences for efficient implementation. We carried out measurements using a software-defined radar platform with 16 MIMO channels to demonstrate the capability of the proposed approach.
IndexTerms—phase-coded CW radar, zero correlation sequence sets, APAS, MIMO, beamforming

Haderer, H.; Feger, R.; Stelzer, A., "A comparison of phase-coded CW radar modulation schemes for integrated radar sensors," Microwave Conference (EuMC), 2014 44th European , vol., no., pp.1896,1899, 6-9 Oct. 2014 doi: 10.1109/EuMC.2014.6986832

Abstract: For radar sensors, for example, automotive radar sensors based on integrated circuits, taking advantage of the growing capabilities of digital circuits is becoming of increasing interest. Currently used linear frequency-modulated continuous wave (FMCW) signals could be replaced with phase-coded ones. As a consequence, the codes used would become a significant design parameter. In our investigation, we applied three binary codes (binary m-sequence, almost perfect autocorrelation sequence, and Golay-complementary sequence), one two-valued code (Golomb's code), and one ternary sequence (Ipatov's ternary sequence) and used a linear FMCW signal for comparison. The codes were selected with a future realization of the radar system based on integrated circuits in mind. We provide brief instructions for generating each sequence. Finally, we demonstrate the performance of the phase-coded signals by means of measurements carried out with a SiGe-based RF IQ-transceiver.
keywords: {CW radar;Golay codes;sensors;FMCW signals;Golay complementary sequence;Golomb code;Ipatov ternary sequence;autocorrelation sequence;automotive radar sensors;binary m-sequence;digital circuits;integrated circuits;integrated radar sensors;linear FMCW signal;linear frequency modulated continuous wave;phase coded CW radar modulation scheme comparison;radar system;Correlation;Integrated circuits;Phase measurement;Polynomials;Radar cross-sections;Sensors},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6986832&isnumber=6986339

Lei Xu; Qilian Liang, "Zero Correlation Zone Sequence Pair Sets for MIMO Radar," Aerospace and Electronic Systems, IEEE Transactions on, vol.48, no.3, pp.2100,2113, JULY 2012 doi: 10.1109/TAES.2012.6237581

Abstract: Inspired by recent advances in multiple-input multiple-output (MIMO) radar, we apply orthogonal phase coded waveforms to MIMO radar system in order to gain better range resolution and target direction finding performance. We provide and investigate a generalized MIMO radar system model using orthogonal phase coded waveforms. In addition, we slightly modify the system model to improve the system performance. Accordingly, we propose the concept and the design methodology for a set of ternary phase coded waveforms that is the optimized punctured zero correlation zone (ZCZ) sequence-pair set (ZCZPS). We also study the MIMO radar ambiguity function of the system using phase coded waveforms, based on which we analyze the properties of our proposed phase coded waveforms which show that better range resolution could be achieved. In the end, we apply our proposed codes to the two MIMO radar system models and simulate their target direction finding performances. The simulation results show that the first MIMO radar system model could obtain ideal target direction finding performance when the number of transmit antennas is equal to the number of receive antennas. The second MIMO radar system model is more complicated but could improve the direction finding performance of the system.
keywords: {MIMO radar;antenna arrays;orthogonal codes;phase coding;receiving antennas;ZCZ-ZCZPS;direction finding performance;generalized MIMO radar system model;multiple-input multiple-output radar;orthogonal phase coded waveforms;receive antennas;ternary phase coded waveforms;zero correlation zone sequence pair sets;zero correlation zone sequence-pair set;Correlation;MIMO;MIMO radar;Radar antennas;Receiving antennas;Transmitting antennas},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6237581&isnumber=6237562

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Imec and Panasonic Present breakthrough in CMOS-based Transceivers for mm-Wave Radar Systems

SAN FRANCISCO (ISSCC 2015, International Solid State Circuits Conference) – Feb. 25, 2015 — Today, at the 2015 International Solid State Circuits Conference (ISSCC), imec and Panasonic presented a transceiver chip for phase-modulated continuous-wave radar at 79GHz. This achievement demonstrates the potential of downscaled CMOS for cheap millimeter-wave (mm-wave) radar systems that can be used for accurate presence and motion detection.

Mm-wave radar technology is used in advanced driver assistance systems (ADAS) to improve safety in blurry conditions such as dust, fog and darkness, where image-based driver assistance systems lack robustness. It also offers longer range, higher precision and invisible mounting capabilities compared to ultrasound sensors. Imec’s 79GHz radar solution is based on advanced (28nm) CMOS technology, and it is an attractive alternative to the current SiGe-based technology as it offers a path to a low-power, compact and integrated solution. Moreover, at the expected high manufacturing volumes, CMOS technology is intrinsically low-cost.

Imec’s and Panasonic’s transceiver chip contains a control loop to suppress the spillover from the transmitter into the receiver without affecting the RF performance. With a power consumption of 260mW, the output power of the transmitter is 11dBm, while the RX gain is 35dB with a noise figure below 7dB and a TX-to-RX spillover suppression of 15dB. Thanks to the wide modulation bandwidth, the achievable depth resolution is 7.5cm.

“We are pleased with these excellent performance results on 28nm CMOS technology, and excited about the new opportunities they present for mm-wave radar systems, not only for automotive radar, but also for other applications such as smart homes, unmanned aerial vehicles (UAVs), robotics and others.” stated Wim Van Thillo, program director Perceptive Systems for the Internet of Things at imec. “This transceiver chip is an important milestone we have realized in our pursuit of a complete high-performance radar system fully integrated onto a single chip”.

Interested companies have access to imec’s CMOS-based 79GHz radar technology by joining imec’s industrial affiliation program or through IP licensing.

Caption: 28nm CMOS 79GHz Transceiver Chip for Phase-Modulated Continuous-Wave Radar.
Click on the picture to download the high-res version.

About Panasonic
Panasonic Corporation is a worldwide leader in the development and engineering of electronic technologies and solutions for customers in residential, non-residential, mobility and personal applications. Since its founding in 1918, the company has expanded globally and now operates around 500 consolidated companies worldwide, recording consolidated net sales of 7.74 trillion yen for the year ended March 31, 2014. Committed to pursuing new value through innovation across divisional lines, the company strives to create a better life and a better world for its customers.
For more information about Panasonic, please visit the company's website at http://panasonic.net/.
About imec
Imec performs world-leading research in nanoelectronics and photovoltaics. Imec leverages its scientific knowledge with the innovative power of its global partnerships in ICT, healthcare and energy. Imec delivers industry-relevant technology solutions. In a unique high-tech environment, its international top talent is committed to providing the building blocks for a better life in a sustainable society. Imec is headquartered in Leuven, Belgium, and has offices in the Netherlands, Taiwan, US, China, India and Japan. Its staff of over 2,080 people includes more than 670 industrial residents and guest researchers. In 2013, imec's revenue (P&L) totaled 332 million euro. Further information on imec can be found at www.imec.be. Stay up to date about what’s happening at imec with the monthly imec magazine, available for tablets and smartphones (as an app for iOS and Android), or via the website www.imec.be/imecmagazine
Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a "stichting van openbaar nut”), imec Belgium (IMEC vzw supported by the Flemish Government), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government), imec Taiwan (IMEC Taiwan Co.)and imec China (IMEC Microelectronics (Shanghai) Co. Ltd.) and imec India (Imec India Private Limited).

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Mikros gets Navy contract for radar gear

Mikros Systems Corporation announced it has received a $5 million production contract from the U.S. Navy for its ADEPT radar maintenance equipment.

The electronic systems technology company, headquartered in Princeton, said in a news release that the Navy will purchase 54 ADEPT units over the next year, deploying them on Aegis destroyers and cruisers in support of the AN/SPY-1 radar on air defense and ballistic missile defense missions.

“We have been looking forward to this award for some time,” Mikros President Tom Meaney said in the release. “It’s a major corporate milestone and validates all of the hard work we’ve done on ADEPT development. We are delighted that the Navy has chosen to move forward with ADEPT production.”

Mikros said the contract increases its engineering backlog to an all-time high of approximately $8 million in work. It added that the systems will be assembled at Mikros’ Largo, Florida, facility.

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US Air Force Could Award Long-Range Radar Contract Next Week

The U.S. Air Force is close to naming the winner of a contract to produce long-range, ground-based sensors for tracking hostile aircraft and missiles, Defense News reported Wednesday.

Aaron Mehta writes that Lockheed Martin (NYSE: LMT), Northrop Grumman (NYSE: NOC) and Raytheon (NYSE: RTN) are competing for the Air Force’s Three Dimensional Expeditionary Long-Range Radar development program.

The 3DELRR contract could be awarded next week and the selected contractor will work to build 35 air defense radars for the service, according to Defense News.

Mehta reports the branch plans a critical design review of the system by the end of the first quarter of 2015.

The Air Force also expects the technology to enter low-rate initial production in early fiscal 2018 and achieve initial operational capability by fiscal 2020.

3DELRRs will be built to replace the branch’s legacy AN/TPS-75 field radars, according to Mehta’s article.

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