Mismatched Load Operation of Outphasing Transmitters with Switching Generators Direct Summation

The paper considers outphasing power amplifiers (OPPA) with switching generators direct summation under mismatched load conditions operation. Analysis of the total OPPA load mismatch on its energy and quality characteristics effect is carried out. It is shown that the capacitive load mismatch leads to a significant deterioration in energy and quality characteristics. Based on the identified patterns, it is proposed to compensate for the capacitive mismatch using a parallel compensating inductance at the harmonic filter input. A graph-analytical method for calculating the compensating inductance has been developed, ensuring the absence of capacitive conductivity at a given load VSWR. It is shown that at VSWR=1.5, installing an additional corrective inductance increases maximum transistors current by only 6% and does not lead to a noticeable overload of the transistors by current.