There are many possible applications, including lighting, medical, cooking, heating, drying, defrosting and automotive. The decisive factor in the early adoption and later mass adoption of solid-state power transistors in this RF energy market is the latest progress in the design of highly efficient, low-cost solid-state power amplifiers, made possible by key improvements in LDMOS and GaN technologies on the semiconductor component side. Looking at both these semiconductor technologies available in the market, end users might want to know which is the best technology to adopt at this moment in time for the emerging RF energy market. This article looks at the pros and cons of each.
Maturity and reliability
LDMOS has been and still is the dominant RF power device technology in the cellular communications infrastructure market, having successfully displaced the silicon bipolar transistors in the nineties and held out against other technologies such as GaAs. The same trend has been seen in adjacent RF power markets such as broadcast, radar and ISM, where it has dominated for the past twenty years. The RF energy market has similar requirements, and for the same reasons will also be drawn to LDMOS. On the other hand, GaN technology began and is continuing to progress in markets ranging from cellular base stations to two-way communications and radar. However, even though GaN is now considered a proven technology, it still needs to prove its long-term performance and reliability in the mass market. The widespread adoption of LDMOS in these other RF power applications has happened thanks to the continuous improvement of application-specific reliability and customization of LDMOS device structures within its different series of development and node generations (see figure 1), but also thanks to the ongoing ability to leverage low-cost silicon manufacturing technologies.