Patent attributes
A power amplifier for generating a sinusoidal high-frequency signal to be supplied to a load includes a current source adapted to supply a constant electrical current during a portion of a period of a fundamental wave, a first driver circuit that generates a first current wave, and a second driver circuit that generates a second current wave, and a filter network. The first driver circuit includes a first switching element adapted to switch at a fundamental frequency of the fundamental wave between a high ohmic state and a low ohmic state to draw current from the current source, a first capacitance connected in parallel to the first switching element, and a first reactive element to phase shift a first periodic signal. The first driver circuit has a first internal resistance. The second driver includes a second switching element adapted to switch at the fundamental frequency of the fundamental wave between a high ohmic state and a low ohmic state to draw current from the current source, a second capacitance connected in parallel to the second switching element, and a second reactive element to phase shift a second periodic signal. The second driver circuit has a second internal resistance. The filter network includes an oscillating circuit that has a capacitor connected in parallel with the load and a first inductor connected in series with the first internal resistance and a second inductor in series with the second internal resistance. The oscillating circuit is tuned to the fundamental frequency of the fundamental wave, and the oscillating circuit is adapted to perform a resistance transformation from the first and second internal resistances of the driver circuits to the load. At least one resistor is arranged between the first driver circuit and the second driver circuit, and a resistance of the resistor is selected to cause a phase correction between the first current wave and the second current wave.