A high power and high efficiency amplifier with controlled second-harmonic source impedance

A novel technology that drastically improves output power and efficiency of amplifiers has been developed. A record high 74% power added efficiency (PAE) with an output power (Pout) of 31.4 dBm (1.4 W) has been achieved from an ion implanted GaAs MESFET at a low supply voltage of 3.5 V and 930 MHz, by optimally terminating second-harmonic source impedance as well as second-harmonic load impedance. By using this technology, a small sized (0.4 cc) power amplifier module for cellular phones has been developed. It has realized a high PAE of 66% with Pout of 31 dBm (1.25 W) under the condition of 3.5 V around 915-945 MHz band.<>