Jammer and Countermeasure Systems Ride RF and Compute Advances

No longer aimed at simply disrupting enemy electronic systems, jamming and ECM platforms are using integrated RF and computing technologies to misdirect electronic detection systems.


Nearing the end of COTS Journal’s year-long “Signal Chain” series, this month looks at technologies and platforms focused on the stage of the signal chain where sensor data stream signals are modified to be sent out for radar jamming or as an electronic countermeasure (ECM) to confuse enemy systems. This is stage where electronics and computer are used not passively to detect signals, but rather to send them toward the enemy as an attack.

Gone now are the days with electronic warfare was simply about denying an enemy’s use of electronic systems aimed at detecting your warfighters and their assets. Today it’s more about gaining an edge by deceptive jamming designed to cause an adversary’s systems to misinterpreting the electronic environment. A number of RF and computing technologies enable this evolution of capability such as Digital RF Memory (DRFM) technology.

DRFM Technology in Use

For its part, Mercury Defense Systems, a subsidiary of Mercury Systems, has expertise in Digital RF Memory (DRFM) technology. It has made use of smaller packages, faster responses and vast volumes of low-latency compute power define modern DRFM evolution. According to Mercury, its our latest generation DRFM technology produces modules as thin as 0.44inches (standard modules are 0.8 inches wide, typical peer solutions are double width or 1.6 inches wide) and leverage the advantages of Direct Digital Synthesizer (DDS) Local Oscillator (LO) technology. DDS enables sub-microsecond tuning speeds over a wide bandwidth. That however is only beneficial if their associated digital noise is compensated for or eliminated. To address that the company uses advanced circuit design and materials, IMA topology and construction and especially, detailed design simulation to achieve excellent spurious, inter-module and phase noise performance. It that way DDS noise is completely negated.

Mercury Defense Systems has receive numerous offers from the U.S. Navy in the past couple years for its DRFM jammers. Most recently in June, Mercury received a $7.6 million follow-on order against its 5 year sole source basic ordering agreement (BOA) to deliver advanced Digital RF Memory (DRFM) jammers to the U.S. Navy. The order was received in the Company’s fiscal 2015 fourth quarter and is expected to be shipped by the end of its fiscal 2017 second quarter.

Board Level Solutions

An example board-level product offering direct digital synthesizer (DDS) capabilities is Mercury’s OpenRFM Ensemble RFM-1RS18 single-channel tuner family (Figure 1). It is available in four configurations that cover 2 to 18 GHz. Two down-converter tuners convert signals to a lower frequency IF for processing, and two transmit up-converter tuners convert an IF to a user-selectable frequency between 2 and 18 GHz. All four are composed of up to three OpenRFM modules and require only a single 6U VXS slot. They can be used as stand-alone units or paired, dramatically reducing the time required to configure application-specific subsystems.

Figure 1 Offering direct digital synthesizer (DDS) capabilities, the OpenRFM Ensemble RFM-1RS18 is a single-channel tuner available in four configurations that cover 2 to 18 GHz.

One of the two down-converter tuners has an instantaneous bandwidth of 1.5 GHz; its output is split into four IF outputs, each with a 375 MHz bandwidth centered at 745 MHz. The other has a single 1 GHz wide output centered at 1.875 GHz. Both down-converter tuners include a fast switching direct digital synthesizer (DDS). Both tuner up-converters have single outputs, a tunable range of 2 to 18 GHz and can accept 1 GHz of bandwidth centered at 1.875 GHz. One model also has a DDS. The up-converter tuner without a DDS can be paired with the down-converter model with a DDS, sharing the down-converter tuner’s synthesizer to provide locked tune frequencies. The up-converter tuner with a DDS can be used as a stand-alone unit, or it can be paired with the single output down-converter tuner to provide an RF transmit/receive solution with independent tuning capabilities in both transmit and receive paths.

Upgrading Aircraft Jammer

At the platform level, one of the most advanced radar jamming systems is the Navy’s EA-18G Prowler aircraft. The Navy has both short term upgrade and long term replacement plans to the sophisticated jamming systems aboard the Growler. Earlier this year Exelis received a U.S. Naval Surface Warfare Center contract valued at $15.3 million to perform essential sustainment work on the ALQ-99 tactical jamming system. The ALQ-99 is used on the Navy’s EA-6B Prowler and EA-18G Growler electronic attack aircraft (Figure 2). Under the contract, Exelis was tasked to redesign three modules-components of the ALQ-99’s universal exciter upgrade shop-replaceable assembly-to extend the service life of the Navy’s principal standoff jammer.

Figure 2 The ALQ-99 tactical jamming system is used on the Navy’s EA-6B Prowler and EA-18G Growler (shown) electronic attack aircraft.

As part of the redesign, Exelis replacing legacy application-specific electronic components (ASICs) with modern field-programmable technology (FPGAs), enhancing reliability and the system’s ability to adapt to changing mission needs. The work will also include extensive qualification testing to ensure that the aircraft can operate successfully in challenging environments. According Exelis, the ALQ-99 is expected to continue supporting the Navy’s electronic attack mission for several years until a next-generation solution is fielded.

Exelis was acquired by Harris this summer. In August Harries announced it has received a $97 million order to provide the U.S. Naval Air Systems Command (NAVAIR) with self-protection jammers for the integrated defensive electronic countermeasures (IDECM) program. Harris will provide its ALQ-214 radio frequency integrated countermeasure system, which is already used by the Navy to protect carrier-based F/A-18s, including both Hornets and Super Hornets, from sophisticated RF threats such as hostile radars and air defense systems. Under the latest order, Harris will begin producing the twelfth full-rate production lot of the system, with an option for the thirteenth lot to be exercised in 2016. The 46 systems plus spare weapons replaceable assemblies will equip new aircraft as well as modernize the existing fleet. The order also includes field support and assembly repairs.

Next Gen Jammer Program

Meanwhile,  in collaboration with the U.S. Navy, Raytheon recently completed Effective Isotropic Radiated Power (EIRP) testing for its Next Generation Jammer (NGJ) array prototypes at the Benefield Anechoic Facility at Edwards Air Force Base, California. The prototype testing, conducted over a six week period, indicated that the NGJ will fulfill the U.S. Navy’s stringent requirements for EIRP, a prime indicator of the system’s range and capacity for reaching and affecting multiple targets simultaneously.

The NGJ is built on a combination of high-powered, agile, beam-jamming techniques and cutting-edge solid-state electronics to achieve two goals: meet the U.S. Navy’s electronic warfare mission requirements and provide a cost-effective open systems architecture for future upgrades. It is scheduled to replace legacy ALQ-99 tactical jamming pods, delivering new capabilities for the Navy’s EA-18G Growler.

Earlier this month Raytheon announced it-along with the U.S. Navy-completed the Preliminary Design Review (PDR) for the NGJ program, a key milestone in the acquisition process. The Navy plans to declare Initial Operating Capability for the Jammer in 2021. According to Raytheon the jammer’s open architecture design, coupled with high-powered, solid state electronics and agile jamming techniques, will enable us to meet U.S. Navy electronic warfare mission requirements while ensuring the affordability of future upgrades.

Shipboard Electronic Warfare

As for shipboard electronic warfare systems, the most advanced on-going is the Navy’s Surface Electronic Warfare Improvement Program (SEWIP). For the past 17 years Navy’s Surface Electronic Warfare Improvement Program (SEWIP), a spiral-block development program, has provided a common/open and scalable architecture to leverage emerging technologies. In Block 2 of the Navy’s SEWIP initiative employed the first sensor to be fully compliant with the Navy’s Product Line Architecture strategy (Figure 3). By using COTS components, it provides additional cost savings and ease of maintenance for sailors. Called the AN/SLQ-32(V)2, the system found on all U.S. aircraft carriers, cruisers, destroyers and other warships is upgraded with key capabilities that determine if the electronic sensors of potential foes are stalking the ship.

Figure 3 Block 2 of the Navy’s SEWIP initiative is upgraded with key capabilities that determine if the electronic sensors of potential foes are stalking the ship.

Mercury Systems provided Lockheed Martin with advanced radio frequency (RF) microwave tuner and intermediate frequency (IF) products as part of the SEWIP Block 2 upgrade. In July the Navy awarded Lockheed Martin a $154 million low-rate initial production contract for Block 2 of t provide additional systems to upgrade the AN/SLQ-32 systems on U.S. aircraft carriers, cruisers, destroyers and other warships. Block 2 is the latest in an evolutionary succession of improvement “blocks” the Navy is pursuing for its shipboard electronic warfare system. In 2013 and 2014, Lockheed Martin was awarded 24 systems as part of low-rate initial production, the first 10 of which have been delivered to the Navy on schedule.

EMC2 Aims and RF Integration

In another interesting recent electronic warfare technology announcement, earlier this month the Office of Naval Research issued a solicitation for the Electromagnetic Command and Control (EMC2) project. The effort is aimed at close integration of disparate RF system electronics and antennas to reduce costs and RF interference. The effort is leveraging work underway in the Integrated Topside (InTop) shipboard antenna program.

According to the solicitation synopses, the EMC2 effort is for the study, design, fabrication, integration, and test & evaluation (T&E) tasks anticipated for the development and demonstration of a set of prototypes, and their component subsystems, that integrate RF functionality (Electronic Warfare (EW), Radar, Communications (Comms), Information Operations (IO)) into a common set of multi-function apertures, electronics and software/firmware through an architecture that is modular, scalable across platforms and open at the RF, electronics and software/firmware levels.