Device technologies for future mobile wireless applications

The trends for future mobile handsets or any equivalent devices are small in size, light in weight, and longer talk and standby time. Because a battery is the largest component in a handset, it is obvious that reducing battery size is the key; that means the current 3V operation need to be reduced to 2V or even 1V. This low voltage operation presents a great challenge for electronic components, especially the power amplifier. In this paper, we will present double-heterojunction pseudomorphic high electron mobility transistor (DH-PHEMT) devices with InGaP/InGaAs and InAlGaP/InGaAs, which show promising results for low voltage operation. Under 1.2V bias, output power of 21.5dBm and PAE of 57.4% has been obtained at 850MHz with 1cm gate width.