Abstract
An active load-pull measurement technique is exploited to test the performance of novel high-efficiency power amplifier (PA) concepts based on non-reciprocity. This technique allows new PA architectures, including its load-modulation, to be evaluated before any construction is necessary. Merely active load -pull measurements of a single representative device or PA, in combination with knowledge of the S-parameters of the output combiner, are needed. As a result of the technique, the load modulation on the branch PAs are exposed, thereby allowing PA designers to optimize PA performance. The technique is demonstrated by emulating a load-modulation PA, consisting of two branch PAs with their outputs combined using a non-reciprocal circulator. The resulting PA concept is designed and evaluated at 2.14 GHz.