Frequency-Selective Glazing Coating for RF Signal Transmission
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Solution Overview
Problem
Conventional glazing units with solar control coatings are highly reflective for RF radiation, impeding the transmission and reception of radio frequency signals, which is a challenge for indoor and outdoor coverage, especially with the increasing demand for high-frequency wireless communication systems like 5G and IoT devices.
Innovation Solution
A glazing unit with a frequency selective coating system that includes a decoated portion with a regular grid pattern and additional decoated elements, where segments and sub-segments are designed to minimize RF reflection and maximize transmission across various frequency bands, including those below 6 GHz and above 15 GHz, by creating a dual band bandpass filter effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a solar control coating system is applied to the glazing unit to reduce heat accumulation, then energy saving and heat reduction are improved, but RF radiation transmission is worsened due to high reflectance
Solution Approach 1:
The coating system is segmented into multiple functional layers including a solar control coating layer and a frequency selective surface layer. The FSS layer is further segmented into conductive elements arranged in specific patterns that selectively transmit certain RF frequencies while maintaining solar control functionality. This segmentation allows independent optimization of thermal and RF performance.
Solution Approach 2:
Different regions of the coating system have different properties: the solar control coating provides heat rejection, while the FSS layer provides frequency-selective RF transmission. The conductive elements in the FSS are strategically positioned and sized to create local electromagnetic properties that allow RF signals to pass through specific frequency bands while blocking others, thus achieving local quality differentiation for dual functionality.
2Loss of energy
If the coating system is made highly reflective for RF radiation to improve solar control performance, then heat reduction is improved, but antenna reception and transmission are worsened
Solution Approach 1:
The electromagnetic parameters of the coating system are changed by introducing the FSS layer with specific geometric patterns and conductive element configurations. By adjusting the size, shape, spacing, and arrangement of the conductive elements, the system achieves frequency-selective transmission characteristics that allow certain RF bands to pass through while maintaining high reflectance for solar control, thus changing the parameter of RF transmission selectivity without sacrificing solar control performance.
3Use of energy by stationary object
If conventional coating systems are used to maintain energy conserving properties, then thermal performance is improved, but RF signal penetration into buildings is worsened
Solution Approach 1:
The coating system uses a composite structure combining solar control coating materials with frequency selective surface materials. The FSS layer comprises conductive elements (such as metallic patterns or transparent conductive oxides) arranged in specific geometries on top of or integrated with the solar control coating. This composite material approach allows the system to simultaneously provide thermal energy conservation through the solar control layer and RF signal penetration through the frequency-selective FSS layer for designated frequency bands.
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 solution reduces RF signal attenuation to at most -10 decibels, enhancing the transmission of RF waves through the glazing unit while maintaining the energy conserving properties of the coating, thus improving indoor and outdoor coverage for wireless communication systems.
Implementation Method 1
A glazing unit with a frequency selective coating system that includes a decoated portion with a regular grid pattern and additional decoated elements, where segments and sub-segments are designed to minimize RF reflection and maximize transmission across various frequency bands
Implementation Method 2
frequency selective transmission characteristics... minimize RF reflection and maximize transmission
Implementation Method 3
a glazing unit may be coated with a coating system, for example a solar control coating system, that absorbs or reflects solar energy
Implementation Method 4
coating system, for example a solar control coating system, that absorbs or reflects solar energy
Implementation Method 5
removing a portion of the coating by laser ablation
Data Source
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AI summary
The present invention discloses an improved a glazing unit comprising a glass panel which is low in reflectance for RF radiation, a coating system which is high in reflectance for RF radiation disposed on the said glass panel and creating onto the glazing unit a dual band bandpass filter. The glazing unit further comprises at least one frequencies selective decoated portion of the coating system extending along a plane, P, defined by a longitudinal axis, X, and a vertical axis, Z; having a width, DW, measured along the longitudinal axis, X, and a length, DL, measured along the vertical axis, Z. The at least one frequencies selective decoated portion comprises a first decoated element comprising a plurality of unit cells forming a regular grid. The at least one frequencies selective decoated portion further comprises a plurality of second decoated elements wherein a second decoated element is placed in each unit cell of the first decoated element and wherein no second decoated element is in contact with the first decoated element.