The NGJ is being designed to break the acquisition cycle of radar installations in the search or early-warning phase of detection. S-band radar installations are the threat most often considered, as they are used in most surface-to-air (SAM) missile systems and other anti-access/area denial (A2/AD) systems. “As that would be your queen on the board, you would want to protect those high-value assets. If you remove the Growlers, you remove the cover and everyone is exposed,” says Andy Lowery, the NGJ chief engineer for Raytheon
To provide these features, the current AN/ALQ-99 Tactical Jamming System (TJS) required replacement. The ALQ-99 is a ram-air, turbine-powered mid-band jamming array that uses mechanically steered technology. It comprises mostly analog technology and delivers turbine power to roughly 27 kW. The power conversion and RF-transmission electronics in the ALQ-99 were designed with older technology. As a result, it cannot use the turbine-generated power in a highly efficient manner. This limits both range and target suppression abilities.
To cover the ultra-high-frequency (UHF) to X-band range, the band-appropriate, mechanically steered antenna arrays require time-consuming installation. This missionization structure only allows a Growler to offer EW capability for a single narrow-frequency range. The NGJ program is designed to reinvent the methods used for jamming technology to eliminate these drawbacks.
“This particular program is completely on the other end of the spectrum. It taps into state-of-the-art technologies from tip to tail. It has a very advanced set of technologies and leverages brand new designs and developments,” notes Lowery.
Several global factors are contributing to the drive to improve the jamming systems of modern warfighters. For instance, the power and sensitivity of potentially hostile radar systems is allowing for much longer range as a byproduct of their increased signal-to-noise ratio (SNR). Today, more countries are producing large numbers of radar installations in dense configurations. The technological sophistication of these radar systems mitigates traditional stealth technology, due to improved signal-processing techniques and jamming avoidance.
To counter these feature enhancements, the NGJ upgrades the jamming capability of the EA-18G with GaN power/thermal-management systems. It uses the electronic scan nature of the AESAs to contend with numerous radar systems. At the same time, it increases back-end system capability with highly sophisticated computer control along with rapid reprogrammability.
The Components
Physically, the NGJ is composed of two pods attached to the port and starboard modular attachments of the Growler (Fig. 2). Each pod houses four AESA arrays with a full-bandwidth pair of arrays in both the front and back of each pod. One array in each pair covers the higher range of the bandwidth. The other array covers the lower end of the threat-band frequency range. This structure eliminates the need for missionization and costly reconfiguration.
The internal computer contains processors, technique generators, and a scope of receiver capabilities. A major advancement of the NGJ is that each of the AESAs can receive and transmit through the whole range of its frequency operation. Additionally, the arbitrary NGJ signal generation offers a wide range of signals that can be transmitted through the apertures and arrays.
Polarization is another control method that the signal generators can perform. It enables the NGJ to perform smart jamming functions. In those scenarios, the NGJ can receive signals from a specified threat and respond to information gathered from those signals with counter-jamming action (Fig. 3). Such actions do not rely on control from the EA-18G techniques generator or electronic support measures (ESMs).
The array modules include electronics that use GaN high-power amplifiers (HPAs). Those amplifiers drive the power signals through the circulators and apertures to the array elements. The AESAs can therefore form high-energy RF beams with advanced signal capability that can be steered by a highly advanced and rapidly reprogrammable computer.
“Due to the nature of it being an AESA, you can form many beams or a super beam with a lot of energy. It is agile, so you can dart from one system to another system on the ground almost instantaneously,” says Lowery.
The computers driving the NGJ system also communicate with the Growler’s common electronics unit (CEU), which has the enhanced ability to link with military-communications networks. In essence, this makes the NGJ system an extremely mobile, high-power, wideband, networked, and steerable long-range software-defined radio (SDR). There are many potential applications for the NGJ system, although currently the NGJ is geared specifically for jamming.
In addition, each pod is a fully self-sustaining system capable of generating its own highly efficient power, cooling, and transmission. The pods require no ship-generated power or resources other than instructions. An edge in efficiency is acquired by using a submerged ram-air turbine technique that enables air power to be extracted. The articulating cores can be completely enclosed during flight, which creates an extremely streamlined pod design for lower drag.
“When they are ready for a jamming mission, it can deploy taking in air and produce an excess of three times more power from the airstream than the ALQ-99,” Lowery says.
Once this air-based mechanical energy is converted to AC electrical energy, it is converted into high-voltage DC. Another conversion produces low-voltage DC power primarily for the GaN-based electronics driving the four arrays and the intelligent subsystems.
