Microwave Output Device Pulse-Modulated Power Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microwave output devices for plasma processing struggle to accurately control the power of pulse-modulated microwaves with multi-carrier bandwidths, leading to fluctuations in power levels and reduced precision in maintaining set power levels.
Innovation Solution
A microwave output device comprising a microwave generator, an output unit, a first directional coupler, and a measurer, which pulse-modulates the microwave power based on set parameters and averages measurement values to control the High and Low levels, ensuring the power of the microwave is maintained within precise limits by satisfying specific conditions related to carrier pitch and duty ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pulse modulation is applied to control microwave power levels, then power control capability is improved, but power fluctuation increases
Solution Approach 1:
The patent implements feedback control by measuring the actual microwave power levels during pulse modulation and using this information to adjust control parameters. The system monitors power fluctuations and dynamically adjusts the pulse modulation parameters to maintain stable power delivery, resolving the contradiction between power control capability and power stability.
Solution Approach 2:
The system dynamically adjusts pulse modulation parameters (duty cycle, pulse width, frequency) in real-time based on measured power levels and plasma conditions. This dynamic adaptation allows the system to maintain precise power control while compensating for fluctuations, thereby achieving both ease of operation and stability.
2Adaptability or versatility
If multi-carrier bandwidth is used for microwave generation, then processing versatility is improved, but measurement precision deteriorates
Solution Approach 1:
The patent segments the multi-carrier microwave signal into individual frequency components for separate measurement and analysis. By measuring each carrier component independently and then combining the results, the system maintains measurement precision while preserving the versatility benefits of multi-carrier operation.
Solution Approach 2:
The system introduces an intermediary measurement and processing stage that handles multi-carrier signals. This intermediary layer separates, measures, and recombines the carrier components, enabling precise measurement of each component while maintaining the overall multi-carrier signal's versatility for different plasma processing applications.
3Stability of the object's composition
If moving average filtering is applied to measurement values, then power stability is improved, but response time increases
Solution Approach 1:
The system dynamically adjusts the moving average window size and filtering parameters based on the specific operating conditions and required response speed. During stable operation, longer averaging periods provide better stability, while during transient conditions, the system reduces averaging to improve response time, thus balancing both requirements adaptively.
Solution Approach 2:
The patent implements periodic measurement and updating of power levels with strategically chosen intervals. By sampling at optimal periods and applying moving average filtering only to these periodic samples, the system achieves stable power control without excessive time delays, maintaining both stability and acceptable response time.
Data Source
AI summary
A device includes a microwave generator configured to generate a microwave having a bandwidth, an output unit, a directional coupler and a measurer. The microwave generator generates a microwave a power of which is pulse-modulated to be a High level and a Low level. A set carrier pitch is set to satisfy a preset condition. The preset condition includes a condition that a value obtained by dividing a set pulse frequency by the set carrier pitch or a value obtained by dividing the set carrier pitch by the set pulse frequency is not an integer and a condition that an ON-time of the High level is equal to or larger than 50%. The microwave generator averages a first High measurement value and a first Low measurement value in a preset moving average time longer than a sum of the ON-time of the High level at a preset sampling interval.