Coherent RF Feed Control for Uniform Microwave Heating
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Solution Overview
Problem
Conventional microwave ovens using a single, non-coherent magnetron source for electromagnetic cooking result in non-uniform heating of food due to the lack of control over electromagnetic energy distribution within the cooking cavity.
Innovation Solution
A system with multiple coherent radio frequency feeds, each with independently controlled phase, frequency, and amplitude, is used to generate dynamic electromagnetic wave patterns within the cooking cavity, ensuring coherent interference patterns for uniform heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single magnetron source is used to generate microwave radiation, then the device complexity is reduced, but the heating uniformity deteriorates
Solution Approach 1:
The single magnetron source is segmented into multiple independent feed channels (at least two), each with its own phase shifter and amplitude controller. This segmentation allows independent control of each channel's electromagnetic radiation, enabling precise manipulation of the overall energy distribution pattern within the cooking cavity to achieve uniform heating across different food regions.
Solution Approach 2:
The system implements dynamic control by allowing the phase and amplitude of each feed channel to be adjusted in real-time based on the desired heating pattern. The phase shifters and amplitude controllers enable the system to dynamically reshape the electromagnetic field distribution within the cavity, adapting to different food types, sizes, and positions to maintain heating uniformity.
2Manufacturing precision
If mechanical stirrers and turntables are added to improve heating uniformity, then the heating uniformity is improved, but the device complexity increases
Solution Approach 1:
The patent replaces mechanical stirring and rotating components with an electronic control system. Instead of using physical stirrers to redistribute microwave energy or turntables to rotate food, the invention uses electronically controlled phase shifters and amplitude modulators to dynamically reshape the electromagnetic field patterns, achieving uniform heating through field manipulation rather than mechanical motion.
Solution Approach 2:
The system achieves heating uniformity by changing the electromagnetic parameters (phase and amplitude) of the radiation from each feed channel. By independently adjusting these parameters for each channel, the system can create optimized energy distribution patterns that adapt to different cooking scenarios, replacing the need for mechanical intervention.
3Manufacturing precision
If multiple coherent feeds with independent phase control are used, then the electromagnetic energy distribution control is improved, but the device complexity increases
Solution Approach 1:
The phase shifters and amplitude controllers serve multiple functions: they control the phase and amplitude of each individual feed channel, enable the formation of different electromagnetic field patterns, and facilitate adaptive heating for various food types and configurations. This multi-functionality justifies the added complexity by providing comprehensive control over energy distribution.
Solution Approach 2:
The system achieves precise energy distribution control by independently varying the phase and amplitude parameters of each feed channel. The phase shifters provide continuous or discrete phase adjustment capability, while amplitude controllers modulate the power level of each channel, allowing the system to create optimized heating patterns for different cooking requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for precise control of electromagnetic energy distribution, achieving uniform heating and maximizing the coupling of RF power with the food, leading to more efficient and consistent cooking results.
Implementation Method 1
each high-power radio frequency amplifier including at least one amplifying component configured to output a periodic signal that is amplified in power with respect to an input radio frequency common reference signal
Implementation Method 2
a phase-shifting component configured to modulate the phase of the output periodic signal with respect to the input radio frequency signal
Implementation Method 3
A conventional microwave oven cooks food by a process of dielectric heating in which a high-frequency alternating electromagnetic field is distributed throughout an enclosed cavity
Implementation Method 4
microwave frequencies at or around 2.45 GHz cause dielectric heating primarily by absorption of energy in water
Implementation Method 5
microwave frequencies at or around 2.45 GHz cause dielectric heating primarily by absorption of energy in water
Data Source
AI summary
An electromagnetic energy delivery system includes a set of radio frequency channels. Each channel includes a radio frequency feed, at least one high-power amplifier and a phase-shifting component. Each high-power radio frequency amplifier includes at least one amplifying component configured to output a periodic signal that is amplified in power with respect to an input radio frequency common reference signal. The phase-shifting component is configured to modulate the phase of the output periodic signal with respect to the input radio frequency signal. A controller coupled to the set of radio frequency channels can be configured to cause the output periodic signals from each of the radio frequency channels is to have a time-varying phase difference relative to the common reference signal and a phase difference relative to the other output periodic signals that is constant when averaged over time.