Internal Radome Lightning Strip Layout for Low-Distortion Antenna Signals

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Solution Overview

Problem

Existing lightning protection systems for aircraft radomes either cause aerodynamic issues or disrupt antenna radiation patterns, as metal strips positioned externally or internally interfere with the radome's functionality.

Innovation Solution

The lightning protection system consists of metal strips arranged on the internal wall of the radome, with curves substantially perpendicular to the direction of the antenna's electric field polarization, connected to an electrical mass beyond the radome's contour, minimizing interference with antenna radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal strips are positioned externally on the radome, then lightning protection is provided, but aerodynamic problems occur

Engineering Contradiction:
Improvelightning protectionVSAvoidaerodynamic problems
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The lightning protection strips are nested inside the radome structure, positioned on the internal wall rather than externally. This nesting approach allows the protective function to be integrated within the existing structure, eliminating the aerodynamic interference that would occur with external positioning while maintaining the lightning guidance capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Object-generated harmful factors

If metal strips are positioned internally on the radome, then aerodynamic problems are eliminated, but antenna radiation pattern is distorted

Engineering Contradiction:
Improveaerodynamic problemsVSAvoidantenna radiation pattern
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The lightning protection strips are positioned selectively on specific zones of the internal radome wall, rather than uniformly across the entire surface. The strips are arranged in curved configurations that follow specific geometric patterns perpendicular to the antenna's radiation beams, creating localized protection zones that avoid interfering with the main radiation lobes while still providing comprehensive lightning protection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention transitions from traditional straight radial strip arrangements to curved three-dimensional configurations. The strips follow curved paths that are perpendicular to the projection of antenna radiation beams on the radome inner surface, creating a spatial arrangement that guides lightning away from the antenna while maintaining aerodynamic smoothness. This dimensional transformation from simple radial lines to complex curved surfaces optimizes both protection and radiation performance.

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

3Device complexity

If metal strips are arranged radially on the inner face of the radome, then connection to aircraft fuselage is simplified, but total energy emitted is reduced

Engineering Contradiction:
Improveconnection complexityVSAvoidtotal energy emitted
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The invention transforms the traditional two-dimensional radial strip arrangement into a three-dimensional curved configuration. The strips follow curved paths that are perpendicular to the antenna radiation beam projections, creating a spatial distribution that maintains electrical connectivity while minimizing interference with the electromagnetic energy distribution. This dimensional transformation allows the strips to guide lightning away from high-energy radiation zones.

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

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 configuration reduces transparency loss and beam deformation, enhancing detection range and sensitivity, reducing secondary lobe reflections, and improving signal quality by minimizing ground echoes and axis deviations.

Implementation Method 1

When lightning strikes the radome, the metal strips guide the lightning to the aircraft's ground

Methodology Applied
Scientific EffectLightning conduction: Conduction (electrical)

Implementation Method 2

the curve defined by each of said at least one lightning protection strip is substantially perpendicular to the direction of the antenna's electric field polarization

Methodology Applied
Scientific EffectElectromagnetic field interaction: Electric Field

Data Source

PatentEP2744041B1Lightning protection system for radome and related installation method
Publication Date: 2023.11.22 AIRBUS OPERATIONS (SAS)
  • EP2744041B1 patent drawingFigure 1~2
  • EP2744041B1 patent drawingFigure 3
  • EP2744041B1 patent drawingFigure 4a~5b

AI summary

The system has lightning protection strips (b1-b6) positioned on an inner wall of a radome. The lightning protection strips define, on an inner wall of the radome, a curve (E) that is perpendicular, at each of its points, to a predetermined rectilinear polarization direction of an electrical field vector. The curve defined by the lightning protection strips is perpendicular to a set of segments (S1-SN), where each segment corresponds, for a misalignment of the antenna, to a projection on the inner wall of the radome. Independent claims are also included for the following: (1) a device including a radome and an antenna (2) a method for assembling a lightning protection system on an inner wall of a radome.