An efficiency optimized controlling scheme for dynamic load modulation of power amplifiers

Paper i proceeding, 2008

An efficiency optimized controlling scheme for dynamic load modulation (DLM) of power amplifiers (PAs) is proposed. In this scheme, both the input signal and load impedance are controlled to allow high efficiency operation of PAs for a desired output signal modulation. The proposed technique is demonstrated by two 1 GHz, LDMOS, switched mode power amplifiers (SMPAs) which are characterized by varying the input power during load-pull measurements. It is shown that the power-added efficiency (PAE) of the PAs in back-off operation can significantly be improved by the optimum controlling scheme.