External Resonator Capacitive Coupling for Electrode-less Plasma Lamp
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Solution Overview
Problem
Existing plasma lamps with internal electrodes suffer from electrode deterioration and limited lifetime, while electrode-less lamps using dielectric waveguides face issues with wasted light, size constraints, and manufacturing complexities due to resonance requirements.
Innovation Solution
An external resonator or cavity structure is used to drive the plasma lamp capacitively, allowing operation at lower frequencies, reducing lamp size, and enhancing light harvesting by decoupling the lamp from the dielectric waveguide body, using an RF source and a lumped or distributed resonator to sustain the plasma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If internal electrodes are used in plasma lamps, then plasma excitation is achieved, but electrode deterioration occurs and lifetime is limited
Solution Approach 1:
The invention removes electrodes entirely from the plasma lamp system and replaces them with an external resonant circuit that generates electromagnetic fields to excite the plasma. This extraction of the problematic electrode component eliminates sputtering and electrode deterioration while maintaining plasma excitation capability through capacitive coupling between the external resonator and the gas fill.
Solution Approach 2:
The invention introduces a dielectric resonator as an intermediary component that couples electromagnetic energy from an external RF source to the plasma without requiring direct contact or internal electrodes. The resonator acts as a mediator that transforms RF energy into the appropriate field configuration for plasma excitation, eliminating the need for internal electrodes while maintaining effective power transfer.
2Reliability
If dielectric waveguide bodies are used to encase the plasma, then electrode-less operation is achieved, but light is wasted and lamp size increases
Solution Approach 1:
The invention separates the resonant circuit function from the light emission function by using an external resonator rather than enclosing the plasma in a dielectric waveguide body. This segmentation allows the plasma to be excited electromagnetically without being embedded in a large dielectric structure, thereby improving light harvesting efficiency while maintaining electrode-less operation.
Solution Approach 2:
The invention transitions from a three-dimensional dielectric waveguide enclosure to a two-dimensional external resonant circuit configuration. By moving the resonant structure to an external plane rather than embedding it within the plasma container, the design reduces material usage and improves light extraction while maintaining the electrode-less operational mode.
3Power
If dielectric waveguide bodies form resonant cavities, then microwave excitation is achieved, but manufacturing complexity increases and costs rise
Solution Approach 1:
The invention extracts the resonant circuit from the plasma lamp assembly and places it externally. This separation eliminates the need for complex integrated dielectric waveguide structures with precise resonant cavity geometries, significantly simplifying manufacturing while maintaining microwave or RF excitation capability through the external resonator.
Solution Approach 2:
Instead of embedding the resonant structure within the plasma lamp as in conventional designs, the invention inverts the architecture by placing the resonator externally and coupling it to the plasma through capacitive coupling. This inverted configuration reduces manufacturing complexity by eliminating the need for precision-machined dielectric waveguides and integrated resonant cavities.
4Power
If the lamp is incorporated into a microwave resonator or cavity, then plasma excitation is achieved, but light harvesting is reduced
Solution Approach 1:
The invention segments the system into an external resonant circuit and a separate plasma emission chamber. This segmentation allows the resonator to be optimized for electromagnetic coupling while the plasma chamber is optimized for light emission and extraction, eliminating the trade-off between excitation efficiency and light harvesting that exists in integrated designs.
Solution Approach 2:
The invention uses capacitive coupling as an intermediary mechanism to transfer energy from the external resonator to the plasma without requiring the plasma to be embedded in a resonant cavity. This intermediary coupling method maintains efficient plasma excitation while allowing maximum light extraction from the plasma chamber, resolving the contradiction between excitation efficiency and light output.
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 results in cost-effective, spectrally stable, energy-efficient plasma lamps with prolonged lifetimes and expanded application range, as the lamp can operate at frequencies below 1 GHz, reducing size constraints and manufacturing obstacles.
Implementation Method 1
a gas-fill vessel not contiguous with (detached from) any RF/microwave cavities or resonators... The gas transitions into a plasma state under the presence of the RF energy
Implementation Method 2
Gas ionization resulting in plasma formation is accomplished by passing a high-current through closely-spaced electrodes... Plasma interaction with the trace substance gives rise to light
Implementation Method 3
Plasma interaction with the trace substance (Selenium or other) gives rise to light in the UV, visible, and near infrared portions of the electromagnetic spectrum
Data Source
AI summary
Described is a plasma electrode-less lamp. The device comprises an electromagnetic resonator and an electromagnetic radiation source conductively connected with the electromagnetic resonator. The device further comprises a pair of field probes, the field probes conductively connected with the electromagnetic resonator. A gas-fill vessel is formed from a closed, transparent body, forming a cavity. The gas-fill vessel is not contiguous with (detached from) the electromagnetic resonator and is capacitively coupled with the field probes. The gas-fill vessel further contains a gas within the cavity, whereby the gas is induced to emit light when electromagnetic radiation from the electromagnetic radiation source resonates inside the electromagnetic resonator, the electromagnetic resonator capacitively coupling the electromagnetic radiation to the gas, which becomes a plasma and emits light.