28V planar GaAs MESFETs for wireless base-station power amplifiers

This paper reports DC and RF characteristics of a high-voltage planar GaAs MESFET. Its breakdown voltages are over 65V at off state (V/sub gs/ = -1.5V) and 30V at on state (V/sub gs/ = 0.5 V). Under 28 V drain bias and 1.9GHz input, the power density reaches 1.0 W/mm with greater than 14dB linear gain. The third-order intermodulation product is -34dBc with 1dB back off from 1dB gain compression. These results suggest that the planar GaAs MESFET may be used as high-power and high-linearity RF power amplifiers in wireless base stations. The planar structure also makes it highly suitable for low-cost mass production.