GaN: The Technology Of The FutureSource: RFMD
Gallium nitride (GaN) has turned into the new industry buzzword. We hear of new products and application breakthroughs using GaN on a regular basis. GaN is unique compared to other technologies because it can not only be used to emit bright light via its form of a light emitting diode (LED), it can also be used in next-generation semiconductor material with high power, high frequency, wide bandwidth, and at high-temperature operation.
When GaN technology was just beginning to show promise in university trials and government-funded success stories, commercial semiconductor organizations took notice and looked at ways to incorporate this technology into new or existing products. Looking at the early history of GaN takes us as far back as the 1930s. The first GaN crystal was synthesized in 1932, the first p-type GaN was developed in 1961, and the first GaN LED was created in 1971. Key historical evolutions of GaN came in the early 1990s, when research scientists made remarkable advancements in GaN-based LED materials by developing high bright blue LEDs and then, later, white LEDs. Today, we see developments using GaN in cellular applications, military radar, and even non-RF applications in high-power conversion devices.
One of GaN’s unique properties is its device physics properties, which enable it to perform in existing and new applications of wide-bandgap, high breakdown voltage, high power density, and high-gain performance. Using GaN for microwave devices provides 10 to 30 times more power and insulated gate advantages over competing technologies, such as silicon.
Although the GaN adoption rate has been slow in the RF realm, markets such as radar, military, and CATV have jumped to the forefront of using GaN. Another new opportunity in RF microwave applications beyond the high-power RF amplifiers includes RF switches used to create a more broadband switch. Using GaN technology for switches allows for low insertion loss, higher breakdown voltage, and higher-bandwidth switches. These switches can be used in automotive applications, such as hybrid vehicles, as well as solutions for energy conservation and power conversion. GaN also has received the industry’s green technology label because of its ability to provide lower product current consumption and improved thermal management while maintaining performance levels equal to or superior to competing semiconductor technologies. For example, today’s new CATV GaN-based amplifier products have lower current consumption and better linearity for improved video and data amplification compared to competing legacy technology solutions. This allows carriers to reduce the number of repeaters and driver amplifiers in their networks, further reducing the current consumption and operating costs of the overall network.
Other markets and applications are just beginning to explore GaN for new industries and devices. As with all emerging technologies, original, interesting applications continue to surface, such as the use of GaN in medical research. Recently, researchers discovered GaN is much different from other semiconductor materials in that it can be used safely in biomedical implants and it is nontoxic, which minimizes the risk to both the environment and the patient. This property alone leads scientists to believe this semiconductor material can be used for implants such as electrodes in neurostimulation therapies or for monitoring blood chemistry. Researchers also have created flexible GaN LEDs that can be implanted and used to detect various cancers, such as prostate cancer. These bio-integrated GaN devices have the potential for great innovations in the healthcare industry and hold the probability of expanding into unknown areas for GaN semiconductor designers.
Another of the largest and fastest-growing markets for GaN technology is the power management, or power conversion, industry. The advantage of using GaN in these applications is that GaN-based devices can be switched at high frequencies, well beyond current technology offerings, which means dramatic size reductions in passive components (such as transformers) and output filter components in power management and power conversion designs. Not only do GaN-based designs offer a five-time increase in switching frequencies, they also offer significant reductions of size and weight in the final product design. This reduction in weight and size generates benefits in automotive and UPS (uninterruptable power supply) applications, providing consumer benefits such as increased gas mileage in cars, increased office space, or building space in building or industrial settings.
Apart from LED production, the GaN semiconductor market will initially grow by taking market share from existing applications in the silicon materials arena. Moving into larger wafers, product yield improvements, as well as improved production costs eventually will make GaN more comparable to existing silicon solutions. Nevertheless, for now, prices do remain high for GaN devices, and semiconductor suppliers are migrating toward markets such as military, radar, or CATV, where customers are willing to pay a premium for a performance edge that will have a greater return on investment. For now, GaN’s market penetration is limited, but its potential for adoption and growth is evident in myriad applications. No other technology has the high-breakdown, wide-bandwidth, high power density, and biomedical attributes GaN offers, not to mention its cost and energy-saving benefits. It is very apparent that GaN will continue to be the buzzword for many industries in the near and distant future.
We want to know what you think. Currently due to cost, the best solution for high-power RF in base station designs is LDMOS. When do you see GaN being adopted at a higher rate in this market area? When will GaN adoption begin in the commercial market areas such as CATV, infrastructure, or medical? Please post your thoughts in the comments section below.
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