A GAN ON SIC HFET DEVICE TECHNOLOGY FOR WIRELESS INFRASTRUCTURE APPLICATIONS
This paper presents Freescale's baseline GaN device technology for wireless infrastructure applications. At 48 V drain bias and 2.1 GHz operating frequency 10-11 W/mm, 62-67% power-added efficiency (PAE) is realized on 0.3 mm devices and 74 W (5.9 W/mm), 55% PAE is demonstrated for 12.6 mm devices. A simple thermal model shows that a more than twofold increase in channel temperature is responsible for limiting the CW power density on the 12.6 mm compared to 0.3 mm devices. The addition of through wafer source vias to improve gain and tuning the device in a fixture optimized for efficiency yield an output power of 57W (4.7 W/mm), PAE of 66%, and a calculated channel temperature of approximately 137°C at a 28 V bias.