Patent ID: 7046088

Claim:
A power amplifier for generating a sinusoidal high-frequency signal to be supplied to a load, the power amplifier comprising: 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, the circuit comprising: 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, wherein the first driver circuit has a first internal resistance; a second driver circuit for generating a second current wave, the circuit comprising: 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, wherein the second driver circuit has a second internal resistance; a filter network comprising an oscillating circuit comprising 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, wherein the oscillating circuit is tuned to the fundamental frequency of the fundamental wave and wherein the oscillating circuit is adapted to perform a resistance transformation from the first and second internal resistances of the driver circuits to the load; and at least one resistor arranged between the first driver circuit and the second driver circuit, wherein a resistance of the resistor is selected to cause a phase correction between the first current wave and the second current wave.