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Electronic Warfare and Military Communications Riding the Millimeter-wave

by Asif Anwar | Apr 22, 2016

Electronic Warfare and military communications will continue to be a pivotal resource in-theatre with future architectural designs dictated by factors such as the need to optimise SWaP-C (size, weight, power, cost), changing demands from in-theatre and the ability to make effective use of spectrum which is an increasingly limited resource.

For military communications, the use of millimetre-wave technologies has been driven by satellite communications. Conventional frequencies used for military satellite communications have traditionally been segmented along UHF, L-band and C-band with X-band frequencies and Ku-band representing the highest frequencies of operation for military satellite communications.

In 2014-2015, Strategy Analytics estimated that these traditional frequency bands accounted for 77% of military satellite terminal communications across the land, air and sea domains. As use across these frequencies has increased over the past 20 years, the available spectrum has shrunk and the resulting cost of military satellite communications has increased in line with increasing capacity constraints. As a result, defense departments have increasingly relied on leasing or sharing commercial spectrum to keep up with the demand for connectivity.

The demand for spectrum continued to increase especially in asymmetric theatres where intelligence enable through ISR missions enabled using UAS platforms also rose, driving additional demand for BLOS datalinks. Consequently, military satellite communications have had to use expensive high functionality solutions over X-band as well as Ku-band.

Millimeter-wave frequencies at Ka-band started to underpin usage providing another avenue to meet the demand for military satellite connectivity, bringing a number of benefits including:

  • Higher upload and download data rates
  • Better spectral efficiencies
  • Less congestion in the spectrum band
  • Lower bandwidth costs for the user

This focus on millimetre-wave frequencies will increase over the next ten years with Ka-band forecast to account for almost 30% of the military satellite communications by 2024.

However, the move to Ka-band will not translate into a move away from existing infrastructure so future military satellite terminals will increasingly focus on being able to support multiple bands, usually by having interchangeable BUCs and LNBs to allow the user to take advantage of the respective satellite signal frequency available at a given location. This will translate into multi-band terminals that house multiple RF chains designed to handle the respective signals. At the same time, the emphasis on enabling the warfighter to have COTM capabilities will maintain pressures to have systems that support portability in terms of both size and power consumption.

This has already translated into moves by companies such as Advantech Wireless towards GaAs-based solutions, and this is now being supplemented by trends towards GaN-based SSPB/BUC products that enable higher power, wider bandwidth and higher frequency performance while also allowing terminal sizes to shrink. Moving forwards, it is conceivable that the capabilities of GaN-based RF will enable wideband solutions to cover a range of frequencies without compromising on performance and thus enable satellite communication terminals to shrink even further.

Off course, as millimetre-wave frequency use at Ka-band becomes more prolific (especially as the commercial market also looks to take advantage), congestion in this spectrum will also increase. We can expect moves towards higher frequencies to be initiated with Q- and V-bands being the next primary targets for consideration. Northrop Grumman introduced the Q-band APN167 GaN MMIC in 2012 offering 3.5W of output power and 20 dB of linear gain for the military SatCom sector, as well as other applications.

The need for wideband performance across the spectrum including millimetre-wave frequencies is a core requirement for electronic warfare. US senators recently introduced the Electronic Warfare Enhancement Act to refocus US EW efforts, finally recognizing the fact that the ability to control and make effective use of spectrum is essential to enable operations in a spectrum environment that is increasingly congested and contested.

Traditionally, the role of the EW system has been segmented with the Electronic Attack (EA) or Electronic Warfare Support (EWS) system designed to monitor, protect and mitigate specific RF operations, e.g. communications or radar. With communications jamming and COMINT/DF requirements typically not extending beyond S-band, while radar jammers could be required to go as high as Ka-band if designed to disable missile threats that featured radar seekers.

Trends driving spending on the Electronic Warfare (EW) sector will be underpinned by the need to control an ever increasing complex spectrum environment, countering modern frequency agile radar systems and network-based IP-centric communications in conventional symmetric warfare scenarios, as well as combatting asymmetric threats from improvised explosive devices. In both cases, the frequencies that need to be combatted are expanding and in the case of radar systems, the frequency agility will negate the traditional use of threat libraries, so future systems will need to employ flexible wideband materials that can enable cognitive analysis of the threat environment to effectively control the electromagnetic spectrum.

RF-based Electronic Attack (EA) system design for applications such as radar, communications and RCIED (radio controlled improvised explosive device) jamming see an increasing emphasis towards systems that can support multi-band and/or wideband operation to combat the increasingly complex spectrum environment. While the need for high power RF transmitters for applications such as long-range jamming will mean vacuum tube-based solutions will continue to dominate, programs such as the US-based Next Generation Jammer (NGJ) and Surface Electronic Warfare Improvement Program (SEWIP) will point to a future direction of architectural design that will be underpinned by AESAs and leverage the advantages of wideband materials such as GaN and digital RF memory (DRFM) capabilities.

For RF-based EWS systems such as RWRs (Radar Warning Receivers), DF/COMINT (Direction Finding and Communications Intelligence) and ESM/ELINT (Electronic Support Measures and Electronic Signals Intelligence) this will be underpinned by an emphasis on direct and fast digital synthesis of the RF signals across the full breadth of the frequency spectrum, effectively digitizing the RF as close to the antenna signal as possible. This will drive demand for wideband solid state RF component technologies that can be coupled with higher performing wider bandwidth digital receivers.

Strategy Analytics will be in San Francisco where we will host our annual analyst event at IMS 2016 to share more insights into how the next generation of military (as well as commercial) systems will “ride the millimeter-wave”. Before that, we’ll be attending the AOC Electronic Warfare Europe 2016 conference taking place on May 10-12 in Rotterdam, The Netherlands, where I look forward to discussing the challenges that will shape the future outlook for electronic warfare markets.
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