It’s easy to forget that Gallium Nitride (GaN) technology was just getting started less than two decades ago. The lure of potentially exponential power gains over large frequency ranges captured the imaginations of ambitious design engineers.
Predictably, though, early results tended to cast doubts on the new technology.
The idea of using other materials to overcome the limitations of the properties of silicon was not new. For example, chips made with Gallium Arsenide (GaAs) and Silicon Carbide (SiC) could withstand higher voltages than silicon but lacked the ruggedness and power density designers, primarily in the military and space industry, needed for the applications they were developing.
Radar equipment was one early benefactor of the increased power density of amplifiers designed with GaN technology. More power density meant miniaturized transmitters could achieve the same radiated power as larger ones. In addition, these smaller, higher power designs could transmit greater distances at higher resolutions.
The increased power density achieved through GaN allowed radar systems designers to create more sensitive surveillance equipment with a smaller footprint.
But early GaN designs suffered from reliability issues. The problems stemmed from the fact that GaN was still new and primarily untried.
Problems With the Promise
Many unknowns existed with GaN. As a novel technology, the failure mechanisms that drive product lifetime had not been characterized. As is the case with many significant advancements in technology, a large initial investment in infrastructure was necessary to begin the process of integrating GaN into regular use.
The military and space industries helped drive the initial efforts to establish the intrinsic reliability properties of GaN. Government programs brought commercial investors into the fold, as private enterprise saw the technological benefits of GaN for a wide array of wireless and power applications.
GaN attracted designers of 5G networks and a host of other applications with its ability to operate at high power over wide frequency ranges. Serendipitously, or perhaps because the wide-bandgap properties of GaN helped drive the demand, the material contained the exact capabilities for RF transmission and power load needed for the exploding wave of new applications.
In addition, commercial chip manufacturers built upon the work with GaN that came before their involvement. In the beginning phases of commercial development, GaN was expensive to process and prone to problems.
Then, engineers discovered peculiarities with the manufacturing process unique to GaN and developed improved processing methods with the material. Finally, due to widespread efforts to improve designs through reliability testing, GaN is now an industry success story still early in its telling. As a result, device developers learned that GaN-based devices were coming to represent outstanding performance, high customer demand, and the expected standard for RF amplifier and transmitter designs.
Reliability Testing’s Role in the Success of GaN
Transitioning GaN from a new, unproven material to a position as the industry standard for RF amplifier designs took time and significant investment in reliability testing from government and industry contributors. Starting with the most basic transistor test structure, reliability engineers collected and fed back data to the process engineers to create a robust technology from scratch. This feedback loop continued for each new device application, each new layer of circuit complexity, slowly, over nearly two decades, to build the complete characterization picture of GaN. Finally, reliability testing programs built into the structure of device development made the widespread use of GaN possible.
The story continues today as designers exploit GaN’s unique power amplification characteristics to create a bevy of new devices and applications primarily for the 5G infrastructure market but already spilling into consumer markets as well.
Overcoming Obstacles to GaN Development
Qualifying a new material slated to play an intricate part in developing technologies requires scientists and engineers from different disciplines.
However, as everyone plays their roles in various phases of the overall GaN development process, one factor unites all the efforts. That element of cohesion is flexible testing solutions that can help manufacturers keep up with the development needs of a rapidly evolving technology.
So, starting from the earliest reliability studies of the gallium nitride material’s innate characteristics through accelerated life testing of a population of devices to testing a finished product for a particular application, the flexibility of the testing platform is crucial to the process. Furthermore, the ability of a test platform to evolve and expand with testing needs prevents companies from having to reinvent the wheel and continually start their testing programs over from scratch.
GaN is starting to reach the potential first promised early in its use. As it moves toward complete maturation, the different benefits for designs based on the material seem almost limitless.
Companies continue to research GaN device designs for new and more strenuous applications. Engineers have solved the early ruggedness issues that device manufacturers faced, and GaN can now support applications in all types of environmental conditions. Manufacturing processes have also matured to enable foundries to utilize GaN wafers more efficiently, resulting in higher yields and more profitability.
Accel-RF Testing Solutions for Growth
As GaN has moved through its various development stages from promising newcomer to newly established monolith, Accel-RF engineers met the industry’s requirements for testing equipment that could expand by adding components.
We design our RF equipment to be modular so manufacturers can set up a base testing system capable of testing a population of devices over a particular range of frequencies and power levels. Later, when a new product requires reliability testing at a different frequency band, the engineers can add a component enabling testing at that frequency to the base system and begin performing the new test.
Over time, the device manufacturer that pursues a strategy of integrating a fully flexible reliability testing program from Accel-RF into their company philosophy will enjoy the benefits of remaining nimble in a fluid market.
Accel-RF played a vital role in developing GaN technology by providing a means to test the new material to assess its fit for use. However, we are not GaN-specific. Our modular approach to testing solutions began evolving early in our history, before the introduction of GaN, and it will continue long after some new material comes along to replace it.