Can GaN displace the Si LDMOS monopoly in the RF market?

The need for high power, high frequency transistors is increasing steadily, commensurate with the huge demand for wireless telecommunications. More power, more frequency bands, better linearity and improved efficiency are driving the current development of RF semiconductor devices capable of handling all these specifications at a reasonable price.

Up to 2005, Si LDMOS covered about 90 percent of the high power RF amplification applications in the 2GHz and higher frequency range; the 10 percent remaining market share was addressed by GaAs pHEMT technology.According to Dr. Roussel, project manager, Compound Semiconductors & Avanced Materials, “This equilibrium is soon to be upset considerably by the introduction of Gallium Nitride (GaN) HEMT technology. These GaN devices are now challenging the dominant position of silicon in an industrial playground in which a power amplifier (PA) market size of ~$900 million is forecasted for 2008.”

Military applications were the first to use WBG devices, especially with the SiC MESFET being developed through broadly financed DARPA and DoD programs in the US. Then in 2006, Eudyna jointly announced with NTT that a first 3G network using GaN HEMT had been deployed in Tokyo for test purposes. New commercial offerings from CREE, RFMD and Nitronex followed, targeting both base-station (3G, WiMAX, etc.) and general-purpose applications. In parallel, R&D for space applications remains very strong and the first products are expected to be implemented in the next few years.

Recent announcements show that key players are more and more focusing on WiMAX/LTE markets, defocusing on the current 3G/3G+ market for which they claim the time-to-market for WBG devices is now over. With strong penetration of WiMAX/LTE applications, Yole Développement forecasts that the market size for GaN RF transistors could reach a level of about $100 million by 2010. The duality between WiMAX and LTE technologies should not widely impact this growth. The battle will take place not only at a performance and reliability level but also at the cost level. Thus, innovative GaN-based substrate makers have a great role to play to help decrease device prices.

Courtesy: Philippe Roussel, Yole Développement