Active Shielding Screen Control for Transparent Microwave Protection

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Solution Overview

Problem

Current electromagnetic shielding systems require human intervention to switch between transparent and blocking states, and there is a need for automatic switching based on microwave radiation intensity.

Innovation Solution

A control system using an electromagnetic sensor and detector-rectifier to autonomously activate or deactivate an electromagnetic shielding screen based on the intensity of microwave radiation, harnessing the energy of the incident electromagnetic field to power the switching mechanism without an external power source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the shielding screen is made opaque to microwave radiation, then electromagnetic protection is improved, but optical transparency deteriorates

Engineering Contradiction:
Improveelectromagnetic radiation protectionVSAvoidoptical transparency
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The shielding screen transitions from a static structure to a dynamic one by incorporating switchable elements (PIN diodes or metal/insulator transition materials) that can change their electromagnetic properties in real-time. When microwave radiation is detected, the screen dynamically switches from transparent to opaque state, providing protection only when needed while maintaining optical transparency during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the electromagnetic parameters of the shielding material by using controllable components whose electrical conductivity can be switched. The PIN diodes or VO2 materials alter their electrical properties based on control signals or temperature changes, thereby modifying the screen's microwave attenuation characteristics while preserving optical transparency in the off state.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the shielding screen is made adaptive to block high-energy microwaves, then electromagnetic protection is improved, but device complexity increases

Engineering Contradiction:
Improvemicrowave radiation protectionVSAvoidshielding system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The shielding system incorporates self-detection and self-activation capabilities. The electromagnetic sensor detects microwave radiation and automatically triggers the switching mechanism without requiring external control systems. This self-service approach reduces the need for complex external control electronics while achieving adaptive shielding functionality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention merges multiple functions into the shielding screen structure itself: the micrometric metallic mesh provides both the optical transparency and the microwave blocking capability when activated. The switching elements are integrated directly into the mesh structure, combining the shielding function with the control mechanism in a single unified component rather than separate systems.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If external power source is used to control shielding activation, then switching reliability is improved, but system complexity and power requirements increase

Engineering Contradiction:
Improveswitching reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system converts the harmful microwave radiation into a useful resource by using it to power the switching mechanism. The electromagnetic sensor and detector-rectifier capture energy from the incident microwave fields and use this energy to activate the PIN diodes or heat the VO2 materials, eliminating the need for external power sources while maintaining switching reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention replaces the traditional electrical power-based switching mechanism with an energy-harvesting approach. Instead of using external electrical power to control the shielding, the system uses the electromagnetic energy itself to drive the switching process, substituting a passive energy capture mechanism for an active power supply system.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 system automatically adjusts the shielding effectiveness between transparent and blocking states in response to electromagnetic interference, optimizing optical transparency and protection without requiring external power, thus enhancing system reliability and efficiency.

Implementation Method 1

an electromagnetic sensor for receiving radio-frequency electromagnetic fields, connected to a detector-rectifier with a sensitivity greater than a minimum value of the power of an electromagnetic field to be blocked

Methodology Applied
Scientific EffectElectromagnetic detection and rectification: Rectenna

Implementation Method 2

a shielding screen (11a, 11b, 11c, 11d) comprising a two-dimensional structure electrically conductive in the microwave frequency range

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP4305392B1Control system for an active shielding screen
Publication Date: 2026.01.28 SAFRAN ELECTRONICS & DEFENSE (FR)
  • EP4305392B1 patent drawingFigure 1~2
  • EP4305392B1 patent drawingFigure 3~4

AI summary

Control system for activating/deactivating an electromagnetic shielding screen (11a, 11b, 11c, 11d) of a porthole or of a window for protecting optoelectronic equipment, which comprises, a radiofrequency electromagnetic sensor (1), of passband matched to a blocking band of said shielding screen corresponding to a range of electromagnetic fields to be blocked, which is connected to a detector-rectifier (2) of sensitivity higher than a minimum value of the power of an electromagnetic field to be blocked by means of said shielding screen and a device (13, 14, 15, 16) for activating/deactivating said electromagnetic shielding screen, said detector-rectifier being configured to, in the presence of electromagnetic fields of power exceeding said minimum value, activate said device (13, 14, 15, 16) for activating/deactivating the electromagnetic shielding screen by capturing electromagnetic energy delivered by said electromagnetic fields of power exceeding said minimum value.