E-PHEMT for single supply, no drain switch, and high efficiency cellular telephone power amplifiers

Performance of a newly developed enhancement mode power PHEMT technology is demonstrated for single supply, no drain switch, high efficiency cellular telephone power amplifier applications. The E-PHEMT features Idss=0.5 /spl mu/A/mm, Imax=190 mA/mm, V/sub p/=+0.3 V, Gm=340 mS/mm, and Vbdg=20 V. When matched on-wafer for a compromise between power and efficiency at 900 MHz, the E-PHEMT achieves Pout=100-140 mW/mm with associated PAE=70 % at 3.2 V and Pout=35 mW/mm and PAE=71% at 1.5 V. The new E-PHEMT has high gain, excellent efficiency under linear and 1 dB compressed gain conditions, making it attractive for high efficiency linear power amplifiers. A 10 mm E-PHEMT achieves remarkably similar saturated power and efficiency performance over 0 to 400 mA quiescent bias current range, which allows low power dissipation operation for high reliability.