Hypersonic weapons, unlike ballistic missiles, take unpredictable paths and can evade missile defense systems. To counter hypersonic technology, radar engineers need to build systems that have no holes in the coating and can track such high-speed vehicles. The obstacles facing radar developers require comprehensive cooperation and strategic methods to adapt to evolving developments.
The modern technological threat offers an opportunity to design new solutions and testing will be especially important for the successful development and implementation of these types of systems.
When we talk about hypersonic technology, we are talking about vehicles that can travel at speeds greater than five times the speed of sound (5 Mach). At this speed, you are essentially traveling over a mile per second. With the development of hypersonic technologies, speeds for these vehicles have shifted from relatively slow to supersonic (up to Mach 5) to hypersonic, which can reach speeds of up to Mach 10. This means that these vehicles can cover huge distances in minutes, so the need for more sophisticated missile defense systems is before us.
One of the key challenges facing radar developers is that S-Band radar, which detects a hypersonic threat moving at Mach 10, will see a Doppler shift of approximately 35 MHz. Narrowband equipment will not be enough to measure this change in frequency, nor to emulate targets at hypersonic speeds in a test system with loop hardware.
Test strategies must then be adapted to accurately mimic hypersonic threats. Relying on technologies such as broadband, modular multichannel field programmable ports (FPGA) based tools will be crucial to emulate realistically high Doppler shift and real-time response with low latency FPGAs. This technology is crucial for prototyping and testing these types of systems.
The dynamic nature of hypersonic means that detection radars must be distributed between different land and sea platforms. Remote and mobile radar systems will need significant power to operate, for example, a giant military truck running on a generator. So the game is how to best get the most out of your available power. For this we need gallium nitride (GaN) amplification technology for radio frequency (RF) transmitters.
The use of GaN means that radars can increase the transmission power and extend the detection range needed to detect hypersonic missiles without significantly increasing the power supplied. This amplifier technology is still relatively young and significant improvements in energy efficiency are expected in the coming years. The GaN supply chain currently has a low volume and high prices, which makes it unbearable to implement in a distributed radar configuration with a large number of channels. In order to lead to higher production volumes and lower prices, this technology needs to be more widely accepted in industries.
For test engineers, using GaN is an exercise with extreme precision. Requires more capable test equipment than previous power amplifier technology. As GaN has a lower leakage compared to other power amplifiers, measuring instruments must be careful. High bandwidth and high sensitivity are essential. There is an increased need for testing for safety-critical reliability requirements.
Hypersonic vehicle technologies are difficult to detect by radar because they have a low radar cross section (RCS), which measures how detectable a radar object is. There are several approaches that radar developers can take to overcome this challenge.
The first is to include additional GaN technology to increase radar transmission power to improve the probability of detection. To detect a low RCS object as one of these hidden objects, you need higher power, as these hypersonic ones are designed with sharp edges in such a way that it will reflect very little power back to the radar trying to follow him.
In this context, GaN can act as a more efficient technology that will extract more from the semiconductor for these applications. Another way to overcome stealth is to apply improved algorithms to detect targets and distinguish these targets from other objects. Radar developers will then need to experiment with new waveforms and system architectures to adapt quickly to the development of threats. For example, this might look like moving from a mechanically controlled radar to a phased array prototype or an electronically scanned radar (ESA) radar. Ultimately, the rapid prototyping of new algorithms with software-defined radios could allow researchers and systems engineers to provide critical new capabilities more quickly.
Unlike traditional ballistic missile delivery systems, hypersonic vehicles can be significantly more agile and thus a tracking challenge. This requires radars to use ESA technology instead of relying on systems with mechanically controlled single-beam antennas, which adds a layer of complexity.
ESA testing poses several challenges due to its multi-channel nature, requiring precise synchronized, phase-coherent measurements. Although they offer unprecedented performance and broadband multifunctionality, radar developers are expected to quickly adapt and demonstrate new capabilities in the real world, placing the demand for reliable test solutions, especially when it comes to moving from simulation to test base to field system.
While rapidly deploying advanced capabilities will not be an easy task, it is crucial that you be able to test systems in realistic scenarios to assess system-level performance. Supporting radar developers and engineers while working for spectrum superiority, NA’s scalable RF ESA test solution offers a single set of tools to perform the most common parametric RF tests and perform advanced radar pulse measurements for ESA systems.
Because hypersonic vehicles can be extremely complex in their movement and speed, radars that can track them are very expensive. To obtain final approval of the system, defense teams often require an open-range live-fire test to assess the radar’s ability to cope with speed, stealth and range. Launching a hypersonic vehicle against radar in the open range is quite expensive. Not only that, but it is also not practical to do many repetitions of this test.
Fortunately, innovations in radar testing are on the way to development and implementation. These improvements work together with the new technology in a cost-effective way. Creating a simulated radar environment with reactive, realistic signals in the real world would allow engineers to test more in-depth at reduced cost. By applying the principles of digital transformation in radar design and testing, engineers can create a variety of virtual environments and conditions, as well as increase the chances of success and limit the number of air tests. This not only saves the cost of live fire testing, but also helps produce more reliable radars.
Dealing with hypersonic challenges
The development of hypersonic vehicle technologies is evolving rapidly and the ability not only to maintain productivity but also to adapt when threats are developed in a cost-effective way is a major challenge. As with any rapidly evolving technology, hypersonic technology enables Engineering Ambitiously ™ while collaborating to make the world a safer place.
This article was written by Haydn Nelson, General Solutions Manager, Radar / EW / Wireless and EOIR Test Solutions at National Instruments (Austin, Texas). For more information visit here .