RF Screen Assembly for Microwave UV Lamps

Solution Overview

Problem

Conventional RF screens in microwave powered UV lamp systems are prone to manufacturing difficulties due to their wavy and flexible nature, leading to alignment and welding challenges, and are susceptible to damage and arcing, resulting in reduced light output and potential component damage.

Innovation Solution

An improved RF screen assembly formed from a single sheet of conductive material with a photo-chemically etched mesh pattern, allowing for increased flexibility in mesh design and improved conductivity, including non-traditional patterns with 3 or more nodes, which enhances light transmission while maintaining RF energy containment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fine mesh screen is used to contain RF energy, then RF energy containment is improved, but manufacturing precision deteriorates due to alignment and welding difficulties

Engineering Contradiction:

ImproveRF energy containmentVSAvoidalignment precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The screen is divided into multiple panels that can be separately manufactured and then assembled together using frame members. This segmentation allows each panel to be handled more easily during manufacturing while maintaining the overall fine mesh structure needed for RF containment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Frame members are introduced as intermediary elements that connect the screen panels to each other and to the support structure. These frame members provide stable attachment points and facilitate precise alignment during assembly, solving the manufacturing precision problem while preserving the fine mesh design.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a fine mesh screen is used to contain RF energy, then RF energy containment is improved, but ease of manufacture deteriorates due to handling and welding challenges

Engineering Contradiction:

ImproveRF energy containmentVSAvoidassembly ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The screen is divided into multiple panels that can be separately manufactured and then assembled together using frame members. This segmentation allows each panel to be handled more easily during manufacturing while maintaining the overall fine mesh structure needed for RF containment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Frame members are introduced as intermediary elements that connect the screen panels to each other and to the support structure. These frame members provide stable attachment points and facilitate precise alignment during assembly, solving the manufacturing precision problem while preserving the fine mesh design.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Illumination intensity

If a single sheet with etched mesh pattern is used, then light transmission is improved, but manufacturing complexity increases due to photo-chemical etching process

Engineering Contradiction:

Improvelight transmissionVSAvoidmanufacturing process complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The traditional mechanical process of weaving fine wires into a mesh is replaced with a photo-chemical etching process applied to a metal sheet. This substitution enables the creation of precise mesh patterns with controlled opening sizes and shapes that optimize light transmission while maintaining RF containment properties.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The manufacturing approach changes from mechanical wire weaving to chemical etching, allowing for precise control of mesh parameters such as opening size, shape, and distribution. This parameter control optimizes both light transmission and RF containment performance.

Inventive Principle:

Principle #35Parameter changes

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

The improved RF screen assembly achieves higher light transmission and reduced RF leakage, maintaining electrical integrity and extending the screen's lifespan by preventing arcing and erosion, with light transmission exceeding 80% and RF leakage within safe limits.

Implementation Method 1

The mesh pattern in the sheet of conductive material can be formed from processes such as photo-chemical etching

Methodology Applied

Scientific EffectPhoto-chemical etching: Photo-oxidation

Implementation Method 2

The RF screen acts as a 'faraday cage' as the openings in the screen are constructed to be smaller than the RF radiation wavelength preventing the RF energy from escaping

Methodology Applied

Scientific EffectElectromagnetic reflection: Reflection

Implementation Method 3

An improved RF screen assembly formed from a single sheet of conductive material with a photo-chemically etched mesh pattern, allowing for increased flexibility in mesh design and improved conductivity

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS8101931B2RF screen assembly for microwave powered UV lamps

Publication Date: 2012.01.24 MILTEC CORP

AI summary

An RF screen for microwave powered UV lamp systems is provided. The RF screen is formed of a single sheet of conductive material in which a mesh pattern has been formed. The screen includes a non-traditional mesh pattern including individual openings with 3 or more nodes. The RF screen is generally configured to optimize the balance between light transmission and RF energy leakage desired for the particular application. Generally, it is desired that the RF screen has an open area percentage greater than about 80% while limiting RF energy leakage from the microwave powered lamp system to acceptable levels.