Military Embedded Systems

Gallium Nitride technology hot in military RF and microwave circles and at IMS 2015


June 11, 2015

John McHale

Editorial Director

Military Embedded Systems

Gallium Nitride technology hot in military RF and microwave circles and at IMS 2015

COTS CONFIDENTIAL. Every month the McHale Report will host an online roundtable with experts from the defense electronics industry ? from major prime contractors to defense component suppliers. Each roundtable will explore topics important to the military embedded electronics market. This month we discuss the International Microwave Symposium event held last month in Phoenix and the military market outlook for RF and microwave technology.

This month’s panelists are: David Lewicki, Product Manager RF Military, Freescale; Lorne Graves, Chief Technologist, Embedded Products, Mercury Systems; Darren McCarthy, A&D Technical Marketing Manager, Rohde & Schwarz USA; Gregg Peters, Vice President & General Manager of Keysight’s Component Test Division, and Jon Firth, Marketing Engineer, Discrete Products Group, Microsemi Corp.

MCHALE REPORT: The International Microwave Symposium was held last month in Phoenix, arguably the largest RF & microwave show in the U.S. What trends regarding military designs and applications did you see emerging at the event?

LEWICKI: Gallium Nitride (GaN) technology is becoming ever more pervasive for military RF solutions as defense contractors continue their upgrades of older system designs from vacuum tubes, TWTs, klystrons, and older semiconductor technologies to the latest in solid state power amplifiers.

GRAVES: This event is always a gold mine of information if you take the time to inspect what’s on display – and then ask questions. This year was no exception. Two of the major trends I noticed were how to tackle the size, weight, and power (SWaP) reductions needed for military applications, and the need for interoperable/adaptable subsystems. This was apparent at exhibits from both large and small companies that hadn’t been focusing on this in previous years. To no one’s surprise, GaN was everywhere. For RF power amplifier manufacturers, GaN has become the “Good Housekeeping Seal of Approval” that separates the players from the rest, and it applies to integrated microwave assembly (IMA) manufacturers as well. The rapid advances in this technology seem incredible: only a few years ago GaN was found mostly in the symposium papers, not on the exhibit floor.

In keeping with this, there were – or seemed to be – more packaging, substrate, and microwave materials companies on the floor, most touting their thermal-conductivity benefits. As this parameter is a key enabler of higher-density GaN solutions, that’s not surprising. As has become increasingly evident in recent years, companies from China, South Korea, and Japan are moving more aggressively into the U.S. microwave market. I found it interesting that the frequencies covered by many of their products are occupied only by defense systems.

Test-equipment manufacturers are an excellent bellwether of what’s in store for defense (and of source commercial) applications. This year it appeared to be all about bandwidth and millimeter-wave capability, driven by both DoD and commercial applications like “5G” wireless and automotive radar.

MCCARTHY: Higher frequency is getting commercialized rapidly. While still in the early days, research efforts in wireless communications on 5G at 60 GHz and commercial implementation of automotive radar at 77 GHz are driving forces. The benefit to military designs would be twofold: the use of these commercial technologies for future communications systems and autonomous vehicle operations; and the impact on lower price component technologies resulting from commercial use.

PETERS: There is a considerable push into higher frequencies by military and commercial industries alike. The need to utilize the mmWave spectrum is not limited to commercial 5G wireless applications. The defense industry is also working to use mmWave for higher throughput data links on both space based and terrestrial. Higher frequencies also enable smaller form factors for sensors and their antennas that are ideal for use on UAVs (unmanned aerial vehicles) and other remote systems. The challenge to the industry is to be able to deliver components at a cost effective price.

The expanding availability of small but high-powered GaN devices is enabling a renaissance in array antenna design where the use of AESA (Active Electronically Scanned Array) antennas has become nearly ubiquitous in military applications for their many advantages. Systems using wider and wider bandwidths and multiple antenna apertures are becoming more prevalent with the promise of higher resolution radars and higher throughput communications.

FIRTH: At this year’s show we noticed a higher level of emphasis on GaN devices, including GaN transistors, than in previous years. This is mainly due to the trending of improved performance combined with generally lower prices, which has made the implementation of GaN-based solutions more practical in military systems such as radar, electronic warfare, and communications applications. We also observed more product offerings with RF and digital functionality, higher levels of integration, and reduced power consumption.

MCHALE REPORT: Do you see growth for RF and microwave technology use in military applications with the announced increases in the Department of Defense’s (DoD’s) FY 2016 budget, or will this market remain flat like other military niches?

LEWICKI: Freescale expects healthy growth over the next few years for military equipment modernization, especially in the refreshes of RF technology. Upgrading RF sections to the latest GaN and LDMOS RF technologies offer defense contractors and the DoD the “best bang for their buck” in terms of SWaP improvements, replacement cost, reliability enhancement, and future proofing of defense systems.

GRAVES: Speaking for myself and Mercury, I strongly believe we will see RF and microwave technology as the main growth area in DoD’s budget. The Pacific Pivot brings with it a new type of threat environment, and with that, a need for newer, more advanced RF and microwave capabilities for various systems. DoD has made it clear that spectrum dominance is more than a catchphrase, electronic warfare is coming back in force, and AESA radar will replace legacy systems, to name just a few major drivers. The Pentagon also appears to be committed to multifunction, multiplatform systems, standardizing form factors to reduce the number of “one-off” systems, and tightening the screws on SWaP-C [with C meaning cost]. It’s also becoming clear to even the most stalwart opponents of defense spending that the U.S. is facing greater threats than it has since the end of the Cold War and can ill afford to cut back on RTD&E (research, testing, development, and evaluation) as well as procurement of critical systems. Taken together, these facts make it a good time to be in this industry.

MCCARTHY: Certainly, there is a trend to utilize more [commercial-off-the-shelf] COTS technologies where possible. Communications and radar technologies are among those seeing investment. With a more toward more cost effective and autonomous solutions, like swarm electronic warfare operations, you still link radio links, proximity radars (to avoid collisions), as well as mission critical technologies (Electronic Attack, Electronic Support... etc). For these, OFDM technologies like LTE and LTE-Advanced commercial technologies are being studied.

We have directly seen a large increase in the interest in LTE technologies, both from an operational use enabled by future Release 12 and 13 of 3GPP standards as well as coexistence studies in progress to meet the federal broadband initiatives.

PETERS: Spending for the overall military market, even with the proposed uptick in spending for FY 2016, really belies the opportunities for RF and microwave technologies and applications. In the U.S. and some European countries there is a concerted effort to build smaller, more technologically capable military forces. RF and microwave technologies will clearly play a critical role in this transformation. Even though overall budgets may be flat or shrinking the money earmarked for technology advancement, particularly for RF and microwave applications, will grow significantly.

MCHALE REPORT: What military applications are the best bets for RF and microwave suppliers?

LEWICKI: The upgrade radar applications (HF, VHF, UHF, L, S, C & X-bands) are perfect homes for the latest GaN and LDMOS RF power transistor products. Broadband radios (portable, man-pack, mobile, and base station) demand ever wider operating bandwidths and are incorporating data and video capabilities in addition to two-way voice. Electronic warfare applications also continue to proliferate and can also take advantage of these latest devices.

GRAVES: The need for RF and microwave components, subsystems, and systems designed for defense applications is wide and deep. It transcends the obvious electronic warfare, ELINT (electronic signals intelligence), SIGINT (signal intelligence), radar, and communications applications, reaching even into the cyberworld that most people consider a “wired” threat. It’s anything but, as vulnerabilities are just as ominous when communications are conducted over the air via terrestrial or SATCOM systems. So to more directly answer your question, any system that uses the electromagnetic spectrum for any purpose is a potential market for some sector or sectors of the RF and microwave industry.

MCCARTHY: As mentioned in the previous question, radio technologies such as LTE and radar will be the key application areas.

PETERS: There is considerable attention being given to electronic warfare currently and likely for the next few years to come. Radar technology is advancing as well with new methods emerging from the availability of high performance data conversion products (analog to digital and digital to analog] as well as robust, real-time processing engines in the form of FPGAs and GPUs. These new capabilities in the digital space will open up new opportunities for RF and microwave suppliers to provide components and subsystems supporting wider bandwidths, frequency agility, and high dynamic range.

FIRTH: The best military applications for this technology are electronic warfare, radar, and communications.

MCHALE REPORT: RF and microwave technology fuels much of the radar and electronic warfare development in the military market, but the automotive radar market promises even larger growth. How is innovation in automotive radar driving military RF and microwave designs?

LEWICKI: As a supplier of radar technology to the automotive industry we see future opportunities to apply this technology in military applications such as land vehicles, aircraft, UAVs, and infantry support.

GRAVES: Large-scale development of millimeter-wave systems has been “just around the corner” since I’ve been in this industry. However, thanks in large measure to the huge investments in adaptive cruise control made by the automotive industry, cost-effective radar sensors and subsystems have become a reality. This is just the beginning, as the auto industry is working to make vehicles more and more autonomous. That means more and more radar sensors will be required, which will drive down cost. It’s good news for the defense sector, as we can piggyback on these developments for use in everything from battlefield radar to short-range communication systems at a fraction of what it would have cost in years past.

That said, radar developers will need to stick very closely to an open architecture approach because as automotive radar matures the life cycle of the components will be reduced.

MCCARTHY: The low-cost and low-power applications of millimeter wave automotive radar are largely using FMCW [frequency-modulated continuous wave] technologies at 77 GHz. Not only does this technology have direct relevance in use of autonomous vehicle operation, the waveform development and image recognition technology enabled by the new waveforms have direct interest in modern military radar applications (land, air, and sea). This technology not only provides a tremendous amount of processing gain that reduces size, weight, and power, but it has the distinction of also being LPI (low-probability of intercept).

PETERS: The push for improved automotive safety has driven large investments in short range mmWave radars. The military uses for such radars, in addition to aircraft and vehicle collision warning, include artillery location tracking, missile guidance and tracking, and Imaging/sensing in adverse environments. The innovations achieved with automotive radar that has benefited military applications the most revolve around SWaP-C. The automotive industry has managed to produce units with very small form factors and cost so the technology can be effectively applied to their commercial products. These are definitely useful attributes for military applications as well.

FIRTH: Innovation is leading to higher frequency designs, higher levels of integration, and more advanced packaging.