Just Under the Radar
By Bob Pinato, MPD Editorial Advisor

Where but from the innovation masters of advanced semiconductor technology would we find such diverse uses for new, exciting and advanced GaN devices? GaN, a semiconductor platform that was developed over many years through DARPA funding by many small and large commercial and defense industry technology firms. We are finding that GaN, only a few years ago relegated to the ones who could afford the premiums which the exotic small wafer technology demanded, is finding its way into other moderate volume commercial and government projects. Once thought of, and by many still is, as a replacement for high power amplifiers in base stations due to its higher efficiencies and optimal operation for the new 4G, LTE, WiMAX (and beyond) frequency bands, GaN is now being identified with new products and market parameters due more to its broadband and efficiency characteristics than its cost advantages.

As evidenced at U.S. and international mobile communications, CATV, RADAR, technology and defense conferences, GaN is getting a lot of well-deserved attention from the designer and end user communities. GaN is more efficient, very green messages here, has wider bandwidth and can attain higher frequencies with high power outputs than most of its contemporaries in GaAs and Silicon.

This quarter, there are numerous shows, conferences and symposia across the industry in many countries around the world that are all going to have elements of GaN being proposed for the systems key to their industries. There is the CATV show in China; CCBN, a defense RADAR and aerospace show in Bangalore; CommunicAsia in Singapore; and MTT and CTIA in the USA. Each in a different and very specific segment of the industry; each has its own unique characteristics, frequency and technology requirements. Something which GaN, in each segment, can support the system requirements, at a price point key to each industry.

Take, for example, CCBN in Beijing, the biggest CATV conference in Asia, servicing the largest new CATV market in the world. With China committing tens of billions to communications infrastructure to build out the network in tier 2 & 3 cities in the current new five year plan, companies are falling over each other to be participants in the planning, design and execution of a new “from the ground up” system. A system that is capable of supporting the “tripleplay” over their bi-directional broadband networks. U.S. powerhouses such as Motorola, Cisco, Arris (C-Cor), among others, who are touting their new “green” power amplifiers, line amps, power doublers and sub-systems, are working to gain recognition for their new “greener” approaches in an industry driven by price, quality, up-time and a system design which goes back almost 40 years. Also, at the same time, both designing into new systems with other international firms (who act as the main contractors and brokers), SARFTA (China Broadcasters forum, akin to the FCC), and competing with the local firms, while at the same time working with those who have secured some of the in-country state and prefecture contracts to develop the systems.

In the middle of all this newness and excitement defining the network architecture and requirements is a technology known as GaN (Gallium Nitride). GaN is quickly becoming a major focus due to its greener footprint, as it allows for designs which can use fewer amplifiers in the network, but again at a price. It becomes a device versus systems cost tradeoff, something which puts the primarily American driven technology (Europe and Japan have GaN also) in a very solid position when competing against the older Silicon power amplifiers supplied by NXP, Freescale and others for systems requiring efficient, flat, broad band (5 MHz to 1.2 GHz), highly reliable operation up to 1.2 GHz. A revolution in CATV systems deployment is taking place in the international realm and is driving the need for “green” in Europe and Asia, even making GaN a preferred technology in some contract proposals. Again the USA is leading in innovation and technology that is leading to systems innovation, but challenging our ability to manufacture and export a slightly exotic technology to the world for use in the higher end products.

In Bangalore, the defense industry is touting the latest in avionics systems, RADAR systems and aeronautics and satellite systems, which are being driven by a new focus to upgrade systems for the country. Every major name one can think of from around the world is in Bangalore for the defense and RADAR show this year (see Microwave Product Digest story on the India Aeronautics Show, June 2011) and defense show later in 2012. India is committing over $15 billion USD to developing and purchasing new systems for upgrading the air force, navy and army for future systems deployments. In RADAR systems, the key power amplifier technologies are still silicon based bi-polar and LDMOS amplifiers. However, for the wider band RADAR applications, it is clear that the new technology of choice for the future is in GaN. Again, a technology developed in the USA, manufactured in the USA and which can be supplied by the USA (if regulations are loosened for key partners) to address potentially hundreds of millions of dollars in sales in the next five to eight years. Israel and some European firms are now using some of the U.S. technology and their own as well, aggressively pursuing this business and, with the limitations we place on our own exports, at an advantage over our U.S. companies.

Our USA technology and systems developments are among the best in the world. While we could sell to some of our systems, there are potential billions to be made if U.S. firms step up and (like aircraft manufacturers do) partner with local in-country firms to co-manufacture the final assemblies in the home country, giving the USA firm a lever to use their own technology and at the same time sell a U.S. (even partially manufactured) product.

The RADAR industry can consume very large quantities of GaN and Silicon amplifier products for the unique frequency bands needed for avionics, naval radar systems and airport ground systems. Frequency bands which can be as high as S-band, C-band and X-band for GaN as new efficient amplifiers competing with GaAs, and at S-band and lower frequencies for the silicon bi-polar amplifiers which have proven operation over the past 30 or so years. The opportunities are out there; markets driven by security concerns from unstable regions are defining the system needs and these all need a technology such as GaN to be fully successful.

CTIA (as well as MTT) is the big show with all the latest in mobile systems, test equipment, platforms and gadgets and the technologies driving these systems. This year is no exception. With 4G making the big push and LTE as the new advanced fast platform, there is a plethora of new exciting approaches demonstrated this year at CTIA. Some of which can benefit, with the right approach, from the use of GaN and integration of functions into one multi-chip device (many chips in a package, emulating a MMIC approach, but more flexible), smaller than MCM approaches currently used in many systems. GaN devices, including high power switches along with the higher power amplifiers, make the products even more tantalizing to the designer.

Which eventually leads us to the perceived big market for GaN; the Big Kahuna, and any technology for that matter, is mobile base station systems. GaN, just as GaAs and now a more refined higher frequency (ft) SiGe, all have a place in these new systems. Creative minds come up with systems and product design approaches we at the device level could not have conceived, but we must support them so that we can supply more advanced developments in the future.

There was a time when some in the industry had the vision that GaN would compete with Si-LDMOS for base station platforms and that due to its efficiency, linearity and broadband characteristics, GaN would eat away at LDMOS’ lead position. Price, as a matter of course, would drop in step with demand. A similar story to what happened with GaAs HBT in the mid-90s, when many thought the technology could not be reliable enough or come down the cost curve enough to satisfy the masses, but it did eat away at existing technologies to become the dominant technology in higher frequency, efficient and cost-effective RF systems. Can history repeat itself with yet another new and nascent technology such as GaN?

One glitch: LDMOS is a cheap wafer platform available in very large wafer diameters with a mature semiconductor industry backing it up. Well, maybe two glitches. Base-station designers design for specific frequencies and bands for each base-station platform, negating the broadband power advantage which GaN brings to the designer. However, in time, the cost of multiple amplifiers in a multiplatform base-station will be leveraged, once costs drop in production, towards a one GaN amplifier solution.

GaN will define its space very soon for those who need a more efficient, “green”-er technology for a multitude of applications which will drive the markets for RADAR, CATV, broadband multi-platform BTS and repeaters as well as photonics and avionics communications systems.

Key investments in GaN technology are continuing at greater levels due to the success of GaN in previous years’ developments sponsored by industry and government. With this success come even more challenges to push the technology, in different flavors if you will, into new realms. GaN for CATV requires a broadband, on the lower frequency side of the spectrum (50 MHz to 1.5 GHz), very low distortion, power efficient, at a moderate power output and thermally efficient devices. While GaN for higher frequency (in avionics, for example) will necessitate not only thermal and power efficiency at microwave frequencies, but also a stable high power output. The requirements for RADAR systems are not too different, but again the broadband characteristics of GaN not only make them a most efficient solution, it also makes them attractive as the power output of GaN per mm2 of device real estate is nearly unmatched by any other available technology. Which brings us to the biggest potential market, telecom.

In the end, it is the continuous investments into the commercialization of GaN that will determine its ability to compete in the future into new systems. It will be the government’s willingness to allow the technology to be fielded around the world openly in commercial and ground systems applications which will also benefit the USA firms who drive the systems and technology. It, like HBT before it, will be the technology which opens the spectrum of opportunity for the USA to take leadership in the high technology world of RF and microwave communications and security systems. New gadgets will be developed by leveraging the GaN advantages and the consumers will pay for these faster, smaller and more slick products, just as we have done with early versions of smartphones and the more powerful systems driving the faster and faster connections.

The counter to this position is the erosion of high technology, challenging positions in the future for our young, up and coming talent in the engineering, device physics and technical worlds. Without the investments in the technology, advances in developments in physics and material sciences, we will leave the future of technology and product development (something we in the USA need to pick up pace with again) to those who are funded outside of our country. We educate many from abroad and are very fortunate to keep a very large percentage working in the USA after graduation. It is less fortunate that we do not yet have programs to foster the growth of our youth to have the desire to enter into the sciences. Fields that require critical thinking skills, a balance of short attention and creativity with that of a persistence to pursue to the end a dream to make something happen. We must begin to make the sciences something that creates dreams, much like the space program did for many of our generation, and desires for something better. Not just the financial markets and stock markets which have drained us of so many of our potential talent to enter into the sciences. Finances are necessary for us all to invest and grow, however, we must also keep in mind that without the dreamers and drivers of products and technology, there will be less to invest into in our future.

We need these dreamers who are not afraid not only to spur innovation, but also to spur re-innovation and not be afraid to build upon what others have tried to do. To be creative where those have feared to tread and pursue what they thought, and not just that others before them, the customers and markets would want. Great re-innovators in our time include the likes of Edison, who pursued the challenge of finding the right combination of filaments, even though others before him had failed. Then, in more recent times, Steve Jobs and his team at Apple. Ready to throw in the proverbial towel (or so some suspected), but then took an exciting technology known as MP3, players which had already existed, and created a cleaner, smoother interface with an even slicker software interface than what had existed previously (at least legally) in industry, creating the ground-breaking iPod.

It is a key time for us all to reflect on what we in America do best. Innovate! Don’t be shy about innovation — become the team who is pushing innovation out to the world, even re-learning how to manufacture high value products where it makes sense to do so. Our predecessors taught us a lot about ourselves: That the financial nerds who invest in our technology and innovation nerds create some of the most fascinating technology and systems that the world demands from us. Let’s get it out there and make some money for the USA!

Bob Pinato
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