High-Frequency Power Supply Phase Reset for Reflected Wave Reduction
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Solution Overview
Problem
In high-frequency power supply systems, intermodulation distortion (IMD) leads to fluctuating reflected wave power, making it difficult to reduce power values effectively, especially when the second power supply performs pulse modulation, and the difference in clock signals between the first and second power supplies causes timing discrepancies that accumulate and worsen the power matching issue.
Innovation Solution
The system includes a second power supply that outputs a second forward wave voltage with a frequency lower than the first, performing pulse modulation, and a first power supply that frequency-modulates its output with a modulation signal matching the second frequency during the second power supply's ON period, while generating a phase reset signal to synchronize the initial phase of the modulation signal, thereby reducing the reflected wave power and aligning the timing between the two supplies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If frequency modulation control is performed continuously to reduce reflected wave power during IMD, then reflected wave power is reduced during ON period, but reflected wave power increases during OFF period
Solution Approach 1:
The patent applies periodic action by enabling frequency modulation control only during the ON period of the second power supply when IMD occurs, and disabling it during the OFF period. This periodic switching of the control mechanism matches the periodic nature of the pulse modulation, reducing reflected wave power when needed without causing adverse effects when IMD is absent.
2Loss of energy
If matching operation is performed to reduce reflected wave power, then power matching improves, but the operation cannot be completed within the pulse modulation cycle time
Solution Approach 1:
The patent replaces the mechanical matching operation (adjusting variable elements) with frequency modulation control that can respond instantaneously to IMD conditions. This substitution allows the system to reduce reflected wave power without being constrained by the slow response time of mechanical matching adjustments, enabling effective control within the pulse modulation cycle.
3Adaptability or versatility
If different clock signals are used for first and second power supplies, then each power supply operates independently, but timing difference accumulates and increases
Solution Approach 1:
The patent implements feedback by having the first power supply detect the output state of the second power supply and adjust its own output accordingly. This feedback mechanism allows the first power supply to synchronize its frequency modulation with the actual operating state of the second power supply, compensating for timing differences caused by independent clock signals and preventing time difference accumulation.
Data Source
AI summary
A high-frequency power supply system according to the present disclosure includes a first power supply, a second power supply, a first matcher, and a second matcher. The second power supply performs pulse modulation of repeating an ON operation of outputting a second forward wave voltage and an OFF operation of not outputting the second forward wave voltage. The first power supply performs frequency modulation control in a second power supply ON period, and performs frequency offset control of outputting a forward wave voltage VF3 having a fundamental frequency obtained by adding an offset frequency to a fundamental frequency in a second power supply OFF period. The second matcher generates a phase reset signal having a frequency lower than a fundamental frequency based on detection information of a forward wave voltage, and supplies the phase reset signal to the first power supply.