Last week at ExCeL London, DSEI brought together over 30,000 participants in the global defence and security industry to view a variety of land, sea and air defence and security products and technologies. The exhibition featured almost 1400 exhibiting companies representing 46 countries and included over 35 national pavilions.
The increasing use of solid-state technologies for defense applications was in evidence with companies such as Kelvin Hughes espousing the benefits of the company’s SharpEye radar. Solid-state GaN technology underpins the transmitter of the SharpEye radar and the range of variants, providing additional flexibility to the systems in terms of size and weight as well as power, accuracy and reliability. The company was highlighting both existing capabilities and the extension to other applications including land-based solutions using the company’s radars in conjunction with cameras for uses such as perimeter control.
Solid-state technologies such as GaAs and GaN are most commonly associated with AESA radars where multiple transmit/receive modules provide the flexibility for multiple beams as well as operational advantages of graceful degradation, coupled with resolution, range and networking advantages. Cassidian was highlighting its AESA-based solutions with the GaN-based TRS-4D naval radar underpinning the company’s capabilities in this area. The AESA-based radar is offered in a format that offers four fixed arrays or combines the AESA array with a rotating antenna depending on customer cost and performance requirements.
There were a number of companies exhibiting at DSEI demonstrating products and solutions that underscored the trends towards AESA radar and solid-state technologies. API Technologies was demonstrating the company’s ability to support this trend with the company’s Quad Transmit/Receive Module designed to offer customers a standard building block for radar or communication applications using either GaAs or GaN technologies. For radar applications, the solutions envisages the use of GaN as the primary technology for the transmit side coupled with GaAs used on the receive side. The four-channel module – the Active Antenna Array Unit (AAAU) - is offered as a fully calibrated modular solution that can be used as a standard building block or as a line replaceable unit (LRU), offering a quicker route to deploying a radar or communication system as well as offering lower through life costs.
Other companies such as Amplifier Technology and Diamond Microwave were showcasing their solid-state based modules, but perhaps the presence of Fujitsu was the most interesting from a GaN technology perspective. The company has been supplying GaN technologies for the Japanese military for several years but was highlighting its GaN technology at DSEI for the first time. The company is now able to engage in soliciting business for its GaN technology on the international market from allied and friendly nations subject to clearance from the Japanese MoD and Fujitsu’s GaN HEMT single-chip transceiver, offering 20W of output power with 50% efficiency and capable of supporting frequencies from X through to Ku-band was the showpiece. The company was also displaying other GaN products suitable for radar and electronic warfare applications. A major US prime is reportedly trialling the company’s GaN technology for a naval platform.
Electronic warfare is another area in which broadband high power RF technologies are needed. As radars become more complex as a result of advances in technology, e.g. a move towards AESA, they are able to operate at lower transmit powers and offer better LPI (Low Probability of Intercept) capabilities making it more difficult for traditional ECM (Electronic Counter Measures) equipment to pick up their presence. While jamming which has been the primary emphasis over the past several years as a result of C-IED operations in theatres such as Iraq and Afghanistan, there is a growing shift in emphasis towards ensuring ESM (Electronic Support Measures) systems will be able to operate effectively and enable assets to detect and avoid these next generation radars in more conventional warfare scenarios.
Such ESM applications need broadband performance coupled with better signal processing capabilities and Teledyne Defence was demonstrating the company’s GaAs-based radar warning receiver (RWR) solution offering instantaneous bandwidth covering 2GHz to 18GHz and combined with FPGA-based digital processing to enable a solution that is optimised for size, weight and power (SWaP) requirements. It is targeted at both rotary/fixed wing and UAV platforms, as well as offshore patrol vehicles and small vehicles (with the possibility of extending the capability to individual soldiers) looking to detect and avoid radar scrutiny.
Off course, solid state solutions are not necessarily the panacea for all radar and EW systems. e2v Technologies and TMD Technologies and others were on-hand to show how TWT-based systems can offer solutions that are flexible and meet the power, broadband, and SWaP requirements for both radar and ECM needs, but avoid the potential pitfalls of ITAR-type export restrictions that may befall solutions reliant on GaN technologies.
From a radar and EW perspective, DSEI 2013 demonstrated the strides that solid state technologies, with GaN in particular, have made in terms of performance, reliability and cost to become established enabling technologies for next generation systems. By being able to combine these technologies in modular solutions, we may see faster development and deployment of systems, coupled with lower through life costs. However, there will continue to be a need for TWT-based solutions to support existing systems as well as platforms requiring high voltage RF power. What will be the future for military RF technologies? Diamond was mentioned a couple of times but whether the performance gains over GaN will be enough to justify the additional cost in what will undoubtedly be a budget constrained environment for a number of years to come remains to be seen.