RF-Transparent Solar Reflector for Vehicle Roof Antenna Cooling

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Solution Overview

Problem

Electronic equipment, such as telematics control units (TCUs) in vehicles are exposed to solar radiation and suffer from thermal inefficiencies in the existing technologies have not addressed or effectively solved the issue of solar radiation absorption, leading to increased operating temperatures and potential failure due to thermal stress.

Innovation Solution

A multi-layered RF transparent, IR reflective body comprising conductive and nonconductive coatings, thermally insulating layers, and dielectric layers are used to reflect incident solar and thermal flux while allowing RF signals to pass through, integrated with the electronic equipment to reduce operating temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If electronic equipment is placed inside the vehicle cabin for easy access, then ease of operation is improved, but the equipment is exposed to solar radiation and heat accumulation, worsening temperature control

Engineering Contradiction:
Improveaccess to electronic equipmentVSAvoidoperating temperature of electronic equipment
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The vehicle roof is segmented into multiple sections: an exterior portion, an interior compartment, and a RF transparent portion. The electronic equipment is placed in the interior compartment, separated from direct solar exposure by the exterior roof portion, while maintaining RF signal transmission through the transparent section.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A solar reflector is introduced as an intermediary component between the solar radiation and the electronic equipment. This reflector redirects solar energy away from the equipment, mediating the thermal environment while allowing the equipment to remain in the cabin for easy access.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If exterior antennas are used to improve signal transmission, then RF signal quality is improved, but the aesthetic appearance and vehicle integrity are compromised

Engineering Contradiction:
ImproveRF signal transmission qualityVSAvoidaesthetic appearance and vehicle integrity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The antenna system is nested within the vehicle roof structure. The antenna is housed inside the interior compartment of the roof, concealed from external view, while still maintaining its RF transmission function through the RF transparent portion of the roof.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The roof incorporates an RF transparent portion that acts as a flexible shell allowing RF signals to pass through. This transparent section enables the antenna to be positioned inside the cabin while maintaining external signal transmission capability without visible exterior antennas.

Inventive Principle:
Principle #30Flexible shells and thin films

3Temperature

If a solid reflective barrier is used to block solar radiation, then temperature control is improved, but RF signal transmission is blocked

Engineering Contradiction:
Improveheat blocking capabilityVSAvoidRF signal transmission
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The solar reflector is positioned specifically at the exterior portion of the roof where solar radiation first contacts the vehicle. This localized placement allows the reflector to block solar heat while the RF transparent portion at a different location enables signal transmission without interference.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The solution separates the thermal management function and RF transmission function into different spatial dimensions. The solar reflector operates in the thermal dimension at the exterior roof, while the RF transparent portion operates in the electromagnetic dimension, allowing both functions to coexist without interference.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Reliability

If the roof is made completely transparent for RF signals, then RF transmission is improved, but solar heat penetration increases

Engineering Contradiction:
ImproveRF signal transmissionVSAvoidsolar heat penetration
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The roof is divided into functionally distinct sections: an exterior portion with solar reflector for thermal management, an interior compartment for housing equipment, and an RF transparent portion for signal transmission. This segmentation allows each section to optimize its specific function without compromising the others.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solar reflector serves as an intermediary that intercepts solar radiation before it can penetrate into the vehicle interior. This mediator protects the electronic equipment in the interior compartment from heat accumulation while allowing the RF transparent portion to transmit signals without thermal interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively reduces solar energy absorption and thermal stress on electronic equipment, maintaining optimal operating temperatures and enhancing performance and reliability.

Implementation Method 1

a patterned radio frequency transparent solar reflector including a pattern of reflectors spaced apart from each other by areas devoid of the reflectors

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

configured for reflecting and/or blocking solar energy and associated infrared energy while allowing radio frequency signals to pass through

Methodology Applied
Scientific EffectRadio frequency transparency:

Implementation Method 3

a thermally-insulating layer

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 4

one or more dielectric layers comprising one or more low-emissivity materials

Methodology Applied
Scientific EffectInfrared reflection: Infrared Radiation

Implementation Method 5

configured for reflecting incident waves having wavelengths within the solar and/or infrared spectrum and their associated energy flux while remaining transparent for passage of radio frequency signals

Methodology Applied
Scientific EffectRadio frequency transparency:

Data Source

PatentEP4123824B1Solar mitigation solutions for electronic equipment, system comprising the same, vehicle, and antenna assembly
Publication Date: 2026.04.29 MOLEX INC
  • EP4123824B1 patent drawingFigure 1
  • EP4123824B1 patent drawingFigure 2
  • EP4123824B1 patent drawingFigure 3

AI summary

Exemplary embodiments are disclosed of solar mitigation solutions for electronic equipment, such as electronic control modules (ECMs) or electronic control units (ECUs) (e.g., automotive telematics control unit (TCU), TCU antenna module, etc.), antennas, antenna arrays, vehicular antenna assemblies, radomes, cellular towers, other electronic equipment that is exposed to solar radiation and suffers from the external energy impact, etc.