High-efficiency 0.1 cc power amplifier module for 900 MHz personal digitalcellular telephones

A new harmonic termination that controls the waveform of the drain current to be rectangular is developed for high-efficiency power amplifier modules. Tts harmonic termination is a short circuit at the third harmonic and a no n-short circuit at the second harmonic. It is found experimentally and conf irmed by simulation that the load-matching condition at the third-order har monic improves the efficiency of a transistor by more than 13%. By using th is tuning, 57.7% power-added efficiency of the module is achieved at the ou tput gower of 29.9 dBm with ACP of -50 dBc, NACP of -65 dBc at 925 MHz and V-dd of 3.5 V.