Experimental design method for GHz-band high-efficiency power amplifiers based on MHz-band active harmonics load-pull technique

We propose an experimental design method for GHz-band high-efficiency power amplifiers based on a MHzband active load-pull technique that includes harmonics tuning. By considering reactive parasitic elements in the transistor, an optimum load condition in the GHz-band can be predicted with the MHz-band evaluation method. The active load-pull system is easily constructed by using a commercial arbitrary waveform generator and oscilloscope. Therefore, a load circuit design depending on the specific properties of the transistor can easily be achieved. A load circuit for a 1.9-GHz operation has been experimentally designed based on 20-MHz-band active load-pull measurement.