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Electronic-warfare (EW) systems rely upon control of the electromagnetic (EM) spectrum to disable or confuse an opponent’s electronic systems. These systems are installed on most large military vehicles for use on land, at sea, and in the air. As they’ve grown more sophisticated through the years, they have come to rely on analog, digital, and RF/microwave technologies to achieve performance levels in smaller, lighter, units that are capable of operating at lower power levels.

Fig. 1

Advances in these technologies extend from semiconductor processes through component and circuit levels, even in improved circuit substrate materials. The improvements may start out small, but they build to enhanced performance in next-generation EW and electronic-countermeasures (ECM) systems.

Digital RF memories (DRFMs) are representative of the types of advanced components employed in EW and ECM systems. A DRFM combines the latest analog and digital circuit technologies—such as wideband analog amplifiers, high-speed field-programmable gate arrays (FPGAs)—and analog-to-digital converters (ADCs), to capture and analyze the complex modulated signals used by modern military systems. Captured waveforms are stored in digital form and often return as part of waveform libraries for identification purposes in EW and ECM systems.

A major, longtime contractor for EW and ECM systems, Raytheon Co., is well versed in available electronic technologies that can serve these systems—both from within the company and from companies working with Raytheon. The firm has been the contractor for the U.S. Navy, for example, on the Next Generation Jammer (NGJ) system, a platform which employs active electronically scanned array (AESA) technology common to many different EW systems. Raytheon’s years of investing in advanced semiconductor technologies such as gallium-nitride (GaN) power transistors and integrated circuits (ICs) contributed a great deal to the selection of Raytheon for the NGJ by the Navy.

In terms of applying advanced technologies such as GaN semiconductors to EW and ECM systems, Travis Slocumb, vice president of Electronic Warfare Systems at Raytheon’s space and airborne systems business, had this to say: “Eight months after award of the NGJ program, we successfully flew the integrated prototype system against representative threat radars…This demonstrates the capability and readiness of the core enabling technologies for the next generation of EW systems, and we did it on our first flight.” Some of the subsystems incorporated in the NGJ system, such as the high-power AESA front end and multiple-channel techniques signal generator, can serve other EW and ECM systems as well, whether on ground, in the air, or at sea.

Fig. 2

Raytheon is also working on a low-cost decoy airframe for the U.S. Air Force’s Miniature Air-Launched Decoy (MALD) program. The MALD work will leverage advanced materials technologies to save weight without sacrificing strength, as well as robotics techniques to provide automatic functionality. The MALD system is being designed with jamming functionality, in addition to the capability to mimic the signatures of energy radar systems.

The firm has produced one of the most widely used EW systems, the AN/SLQ-32(V) shipboard EW system (Fig. 1) with more than 450 systems produced. The different AN/SLQ-32(V) systems provide different functions, including early warning, threat identification, direction-finding (DF) capability, and jamming capabilities for multiple threats. The system employs a sensitive receiver with fast response time and high-power jammer sources and transmitters. It uses a digital library of emitter types for rapid identification of threat signals. Raytheon is also well known for the Advanced Countermeasures Electronic System (ACES), a leading ECM system for aircraft (Fig. 2).

Many other contractors are involved in EW/ECM systems development and the application of advanced technologies, including BAE Systems,  Dynetics, Exelis, Lockheed Martin, Mercury Defense Systems, and Northrop Grumman. Their systems are leveraging currently available technologies—such as high-speed data converters and high-power GaN devicesto achieve performance targets in smaller system sizes.

High-power GaN amplifier modules such as the recently announced model DM-X1K0-01 pulsed GaN amplifier from Diamond Microwave are allowing radar, EW, and ECM system designers to re-think their block diagrams because of the performance possible in such small packages. This amplifier measures just 244 × 134 × 50 mm and weighs 3 kg, but delivers 1 kW pulsed output power at X-band frequencies. It is a compact alternative to traveling-wave-tube amplifiers (TWTAs) with high power-added efficiency (PAE) of better than 20% for a better than 1-GHz bandwidth centered at 9.5 GHz. And this is really just one example of the performance that is possible at high frequencies and high power levels with this device technology.

Of course, older technologies such as TWTs and TWTAs have powered EW and ECM systems for many years, and developers of those technologies are not about to step aside for GaN. As an example, dB Control recently introduced high-power microwave power modules (MPMs) and TWTAs for EW and ECM applications, including the model dB-3907 TWTA with impressive 12-kW pulsed output power from 9 to 10 GHz. The tradeoff with GaN (among other things) is size, with this TWTA measuring 18 × 28 × 36 in. in an enclosure weighing 280 lb. But, for EW and ECM systems (such as land-based systems) with room for this size amplifier, this air-cooled unit can provide reliable pulsed microwave power with high gain and low distortion. 

Modeling Threats

Computer software simulations will have a great deal to do with next-generation EW and ECM systems, allowing system designers the opportunity to explore the impact of such things as environmental conditions and adversary responses on the performance of a system. Recognizing the importance of simulation software on EW/ECM system advancement, the Air Force recently awarded an $84-million, five-year contract to Avariant (Buffalo, N.Y.), which will enable EW system simulations for different aircraft, including the F-22 Raptor and the F-35 Joint Strike Fighter.  

The contract is called the Virtual Integrated Electronic Warfare Simulations (VIEWS) II and will focus on testing and evaluation of advanced sensors for EW and ECM systems. It also enables system developers to keep up with new and different technologies as adversaries develop their own EW and ECM capabilities. The Air Force is also funding an EW-technology-based program called the Spectrum Warfare Assessment Technologies (SWAT) program, which is geared toward evaluating how different EW technologies will perform in real-world environments.

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