How The Military Is Using mmWaves
By John Oncea, Editor
Defense invests in mmWave tech for radar, ECM, and communication due to wider capacity, security, and high bandwidth, crucial for modern warfare.
The global rollout of 5G continues and expectations are that more than one-third of the world’s population will be covered by 2025. According to the GSMA, 5G will account for as many as 1.2 billion connections by then as well.
By the end of January 2024, the Global mobile Suppliers Association (GSA) had identified nearly 600 operators in 176 countries and territories investing in 5G. This includes “trials, acquisition of licenses, planning, network deployment, and launches. This number excludes nearly 200 additional companies awarded priority access licenses in the U.S. auction of CBRS spectrum, which could potentially be used for 5G.”
Many factors are responsible for the ongoing success of 5G including millimeter wave (mmWave) technology which, writes ScienceDirect, uses optical heterodyne, which combines light signals from two lasers operating at different wavelengths using an optical combiner and detects them using a photodiode. mmWave systems have frequency ranges between 30 and 300 GHz where a total of around 250 GHz bandwidths are available.
mmWave is used for many applications other than 5G, including:
- Radio astronomy
- Remote sensing
- Automotive radars
- Imaging
- Security screening
- Telecommunications
- High-speed, point-to-point WLANs
- Broadband access
- Short-range personal area networks
The technology is also used by the defense industry due to its wider capacity, secure and survivable communication, higher bandwidth, increased connectivity with many more channels, and faster exchange of data during tactical communication. These attributes help to improve the performance of radar, airborne datalink, and satellite communications.
In 2023, interest in mmWave for defense applications increased, in part due to the resurgence of Electronic Warfare (EW) as a critical tactic during the Ukrainian conflict. “This shift required a significant reassessment of military doctrine and tactics, including a shift from static to mobile formations,” Blu Wireless writes. “Also noteworthy is the recent intensified exploration of mmWave’s role for C4ISR drone communications.”
Why Defense Is Investing In mmWave Technology
“There will always be emerging threats in the defense sector that require the innovation that millimeter-wave technology offers,” writes dB Control. “Radar, EW and countermeasures, airborne datalink, and satellite communications” are in particular need of mmWave products “because next-gen tactical networks and EW are transitioning to higher frequency spectrums to defend against newly discovered threats. With innovations like 5G, 6G, and Satcom backhaul on the rise, connectivity, bandwidth, and speed are hugely important in the commercial and defense sectors.”
In the past, products that operated in C-, X-, and Ku-band frequencies were commonly used in various applications. However, with advancements in military operations and increasing congestion in those bands, defense contractors and original equipment manufacturers have been seeking more bandwidth. This has led to the migration of EW, Satcom, and datalink applications to mmWave frequencies. With the maturation of K-, Q-, and V-band technology, original equipment manufacturers are now modifying their designs to meet the demands of modern military and commercial applications.
“Defense contractors are seeking frequency ranges from 18 to 50 GHz,” dB Control writes. “The specific frequency depends on the application. For EW applications, wideband, and continuous wave (CW) power are required. For datalink and satcom applications, narrow band and CW power are required. For radar applications, narrowband and pulsed power are required.”
To accomplish this, mmWave products will need to operate in all sorts of environments. Any high-power traveling wave tube amplifier (TWTA) or microwave power module (MPM) must be equipped to withstand extremely complex and harsh conditions. The complexity and conditions that the equipment will face should be outlined from the very beginning to ensure that it meets the requirements of its intended use.
For instance, all millimeter-wave high-power amplifiers (HPAs) must be able to endure harsh environments with extreme temperatures, excessive vibration, shock, and altitudes up to 70,000 feet above sea level. HPAs must undergo rigorous testing to ensure that they remain dependable even on the most rugged missions, including potential nuclear events.
mmWaves And ECM
Electronic countermeasures (ECM) are used to protect aircraft from guided missiles and have also been used by military ships and tanks to fool laser/IR-guided missiles. One of the primary applications of mmWaves in ECMs is jamming, or the transmission of powerful signals on the same frequency as the adversary’s radar or communication systems. By doing so, ECMs create interference, making it difficult for the enemy to distinguish real targets from false ones.
mmWaves allow ECMs to rapidly change frequencies. This frequency agility helps counter adaptive radar systems that attempt to avoid jamming by hopping frequencies. Modern ECMs leverage software-defined threats. These threats are generated using advanced digital signal processing (DSP) and machine learning (ML) techniques. By analyzing these threats, writes Keysight, ECMs can evaluate their effectiveness and adapt accordingly.
To evaluate both electronic attacks and countermeasures, ECMs generate a multitude of threats simultaneously. The goal is to gauge the countermeasures’ response. By maintaining control of the electromagnetic spectrum, ECMs safeguard critical capabilities, from communications to mission support.
Historically, ECMs relied on stored databases of threat signatures. However, modern threats evolve dynamically, and ECMs must respond more intelligently using agile techniques like ML and DSP2.
mmWaves And Enhanced Communication
mmWave technology serves as a powerful tool for improving communication, enhancing situational awareness, and ensuring effective military operations. Its unique characteristics make it particularly suitable for military applications, even over extended distances
mmWave’s higher bandwidth compared to lower-frequency communication systems allows for the transmission of large amounts of data at high speeds, essential for modern military operations where real-time data transfer is critical. The high frequency of mmWaves enables low-latency communication which, in military scenarios where split-second decisions can be the difference between success and failure, is crucial for transmitting commands, sensor data, and other critical information rapidly.
Due to their high frequency and directional nature, mmWaves can be utilized for secure and stealthy communication as they are less susceptible to interception and jamming, providing enhanced security for military communications. They can be designed to be compact and lightweight, making them suitable for integration into various military platforms including infantry equipment, vehicles, aircraft, and drones.
While mmWaves primarily operate in line-of-sight scenarios, advancements in technology such as beamforming and relay systems can extend their reach to non-line-of-sight situations, enhancing their versatility for military applications in complex terrain or urban environments.
mmWaves are susceptible to atmospheric absorption and attenuation but advancements in antenna design and signal processing techniques mitigate these challenges, ensuring reliable communication even in adverse weather conditions.
As defense applications continue to evolve and adapt to emerging threats, mmWave technology is poised to remain at the forefront, driving innovation and enabling next-generation tactical networks to defend against increasingly sophisticated adversaries. With its robust performance, reliability, and adaptability to harsh environments, mmWave technology stands as a cornerstone in the modernization of defense systems, ensuring readiness and resilience in an ever-changing global landscape.