GaN tech driving radar and electronic warfare designs

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November 30, 2017

Gallium Nitride (GaN) technology continues to be a game changer for military radar, electronic warfare (EW), and communications applications. In the following Q & A with Roger Hall, General Manager, Defense & Aerospace for Qorvo he discusses GaN's impact on these applications, reduced size, weight, and power (SWaP) requirements, how automotive radar innovation is influencing military designs, as well as the buzz on the International Microwave Symposium (IMS) show floor this summer.

Edited excerpts follow.

MCHALE REPORT: Please provide a brief description of your responsibility within Qorvo and your group’s role within the company.

HALL: I lead the High Performance Solutions group within Qorvo, a team that focuses on driving technology, products, and solutions for defense, aerospace and wireless infrastructure applications. We develop cutting-edge products for radar, electronic warfare, defense communications, and base station markets, and help our customers to integrate them into program-winning systems.

MCHALE REPORT: What trends did you see emerging at the International Microwave Symposium and European Microwave Week (EuMW) this summer? What was the buzz?

HALL: GaN-on-SiC [silicon] is clearly the focus, impacting both commercial and defense applications. The defense market has relied on GaN-on-SiC for AESAs [active electronically scanned arrays] for many years to increase system performance and reliability. Now, commercial applications are drawing on these technologies from the defense market to better solve some of the new complexities they’re experiencing in preparation for the roll out of 5G. Wireless infrastructure is utilizing Massive MIMO [multiple-input multiple-output] in base stations to increase modulation rates and data speeds in densely populated areas. We expect this trend to continue as commercial applications adopt technologies pioneered in defense.

MCHALE REPORT: GaN continues to be the hottest tech in the industry, but there also seems to be more education needed for the customer base on its benefits and where and when to use it?

HALL: As the industry continues to focus on size, weight, power, and cost (SWaP-C) constraints, engineers will further understand how GaN-on-SiC and its variety of features help meet power consumption demands while improving the capabilities of new and legacy systems. As with any new technology, there is a learning curve, but Qorvo’s applications engineers have many years of experience to help customers integrate GaN-on-SiC into their systems as needed.

MCHALE REPORT: What military applications are most benefitting from GaN and why?

HALL: It’s been an exciting few years in the defense industry with the increased focus on applying GaN-based electronically scanned arrays for EW, radar, and communications applications. Many new technologies rely on the power of GaN-on-SiC, which holds many well-known advantages to previous solutions, including increased RF [radio-frequency] reliability at a higher channel temperature, frequency availability and extended product lifetime. We also see the transition of tube-based systems to solid state GaAs [Gallium Arsenide] and GaN amplifiers, which increases reliability significantly. Finally, GaN-on-SiC’s true advantages shine as you go up in frequency and bandwidth which support the growing needs of both EW and [communications] systems.

MCHALE REPORT: How do GaN and LDMOS (laterally diffused metal oxide semiconductor) compare? Could they ever be used in the same solution? When do you choose one over the other?

HALL: GaN-on-SiC is the solution of choice over LDMOS because it provides increased RF performance and system efficiency. Qorvo has designed GaN from DC to over 250GHz whereas the performance of LDMOS rolls off over 2.5GHz. GaN-on-SiC also has higher efficiency, especially over the wider bandwidths that systems demand now.

The superior RF performance of GaN-on-SiC also leads to overall lower system operating costs and a broader bandwidth in a similar footprint to LDMOS. For example, you can replace two or three LDMOS parts with one GaN component and get equivalent efficiency and lower costs while increasing bandwidth.

MCHALE REPORT: Is GaN gaining popularity in commercial markets as well? Will the cost come down as more high-volume markets adapt the technology?

HALL: We are already seeing GaN-on-SiC in commercial markets. It has been used for several years in cable TV and base station applications due to GaN’s highly efficient broadband performance for customers. The costs of GaN-on-SiC are already down significantly, which is why we are seeing continued adoption in consumer markets, including wireless infrastructure. We’ll soon see GaN-on-SiC consistently replace LDMOS in all frequency bands. Next-gen network demands resulting from 5G will require the power efficiency, bandwidth and performance that only GaN-on-SiC can provide.

MCHALE REPORT: RF and microwave technology fuel much of the radar technology 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?

HALL: The market roadmaps for military radar and automotive radar are aligned and tracking in terms of long-term reliability and consistency in their supply chains, as well as the requirements for innovative packaging that improve SWaP-C. We see the commercial markets helping defense by driving down costs and powering RF packaging innovation.

At Qorvo, we are strategically positioned to address the defense markets as well as the commercial markets like IoT [Internet of Things] and autonomous cars. We have a broad-range of products from a market-leading high-power RF portfolio to innovative ultra-low power, short-range wireless personal area network (WPAN) SoCs, as well as 802.11p, automotive Wi-Fi, SDARS [Satellite Digital Audio Radio System], GPS, and LTE [Long-Term Evolution] automotive solutions.

MCHALE REPORT: Do you see continued growth for RF technology in military applications with the recent increases in the Department of Defense’s (DoD) budget or will this market remain flat like others?

HALL: There will continue to be growth in RF segments for military applications. We have seen GaN-on-SiC growth double year-over-year, and it will continue to grow, driven mainly by defense along with substantial growth across all our major sub-markets: radar, [electronic warfare], and military [communications]. We also expect to see growth in other market areas in the next year, in both macro and Massive MIMO base stations, as 5G moves into production. As was highlighted in our recent earnings release, we are very positive on the defense market.

MCHALE REPORT: It seems every piece of electronic equipment today is getting smaller -- GPS systems, radios, etc. How have reduced size, weight, and power (SWaP) requirements affected your radar product designs? What are the tradeoffs with smaller tech?

HALL: At Qorvo, we are innovating packaging design and device technology to accelerate higher levels of integration in our solutions. Our defense and commercial solutions enable system designers to lower system level costs, increase bandwidth and reduce board space, and improve thermal performance. Our experience in the commercial market enables us to innovate small, low-cost plastic packaging for our defense customers’ needs. For example, we have high power plastic packaging for S-band radar with industry leading performance. In some cases, we can reduce board space by thirty to fifty percent, which significantly lowers SWaP-C and improve the cost structure.

MCHALE REPORT: How do you manage obsolescence and how does obsolescence management differ in the military and automotive markets?

HALL: Qorvo has been executing long lifecycle programs for the defense and automotive markets since the mid-80s. There are commonalities in both markets which leverage high tech, rigorous quality requirements and a long-life cycle. Our decades of expertise make us the perfect partner when developing similar programs in the automotive industry.

It’s key to effectively manage product life cycles while also understanding the market and your customers. We know what our customers needs and we work closely with them to choose technologies that complement their product life cycles. Qorvo’s advantage of having its own fabs allows us to effectively approach this while also better understanding and controlling our destiny.

MCHALE REPORT: When one attends a trade show such as IMS or the Consumer Electronics Show (CES), one can’t help but notice there is a lot less gray hair at these events than at military technology events such as the large Army and Navy events. Does the military electronics industry have a recruitment challenge on its hands? If so how can they mitigate it?

HALL: Diversity is a great thing when solving complex problems. The younger generation of engineers is bringing lots of new ideas to the solution space for our customers. At Qorvo we start partnering with students in junior high and high school through STEM [Science, Technology, Engineering, and Math] programs. These students are much more likely to go to college to get a technical degree and might someday end up working at Qorvo. In addition, we also have a robust college program to ensure that we attract top talent to Qorvo.

MCHALE REPORT: Looking forward, what disruptive technology/innovation will be a game changer in the military RF & microwave world and why? Predict the future.

HALL: All eyes will continue to be on GaN-on-SiC in 2018. It’s the technology of choice in the defense industry as contractors look to develop smaller, more powerful radar and EW solutions. This trend is primarily driven by packaging updates made to GaN-on-SiC. Our move to plastic packaging is significantly cutting the cost of manufacturing, making products more attainable in the commercial market. More affordable pricing of GaN-on-Sic power amplifiers (PAs) will certainly be an early adopter in the commercial space.

RF filters will also be another disruptor in the military RF and microwave industries. The number of mobile devices is growing. As it does, frequency and bandwidth will continue to be limited. This significantly impacts everything from commercial applications like smartphones, Wi-Fi, and base stations to defense technologies like radar and [communications] systems. The industry will have to rely on RF filters such as BAW [bulk acoustic wave] and SAW [surface acoustic wave] to solve this issue, which will ultimately improve user experience and connectivity.

Finally, as we look for high power, smaller footprint options with better packaging that considers thermals. We’re always looking at how to take the heat out, because circuit designers can be limited by thermals.

Roger Hall is general manager of Qorvo’s High Performance Solutions group, which uses years of technology expertise and product development to shape Qorvo’s next-generation solutions for defense and infrastructure systems. Prior to joining Qorvo, Hall held senior positions within TriQuint (now Qorvo), Raytheon, and Honeywell International/Allied Signal.