Power amplifier
First Claim
1. 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.
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Accused Products
Abstract
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.
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Citations
15 Claims
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1. A power amplifier for generating a sinusoidal high-frequency signal to be supplied to a load, the power amplifier comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 14)
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10. A method of generating a sinusoidal high-frequency signal for operating a load, the method comprising:
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providing a current source to supply constant electrical current during a portion of a period of a fundamental wave;
switching a first switching element switching at a fundamental frequency of the fundamental wave between a high ohmic state and a low ohmic state to generate a first current wave;
phase-shifting the first current wave with a first reactive element;
switching a second switching element at a fundamental frequency of the fundamental wave between a high ohmic state and a low ohmic state to generate a second current wave;
phase-shifting the second current wave with a second reactive element;
matching a first internal resistance of the first switching element and the first reactive element and a second internal resistance of the second switching element and the second reactive element to a resistance of the load with a matching filter network comprising an oscillating circuit having a capacitor connected in parallel with the load and a first inductor connected in series with the first internal resistance and a second inductor connected in series with the second internal resistance, wherein the oscillating circuit is tuned to the fundamental frequency; and
aligning the phases of the first current wave and the second current wave. - View Dependent Claims (11, 12, 13)
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15. A power generator for driving a load, the power generator comprising:
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an input stage;
at least two driver stages downstream from the input stage, wherein each driver stage comprises a power amplifier having a downstream final stage circuit that is interconnected with the other final stage circuits at a star point, and wherein an output terminal of each driver stage is connected in a current node, at which current is fed via a choke or a parallel oscillating circuit and at which a ground capacitor is connected.
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Specification