Segmented Dipole Antenna Layout for Low-Interference Co-Location

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Solution Overview

Problem

Co-located antennas operating at different frequency bands often experience performance disturbances, particularly when a low-frequency antenna is placed in front of a high-frequency antenna, leading to issues with sidelobe performance and compactness in radar systems.

Innovation Solution

The implementation of a 'chopped dipole' antenna arrangement where the second antenna is segmented into electrically small pieces with reactive loading between them, making it 'invisible' to the first antenna, thereby minimizing disturbance and allowing for a compact, cost-effective co-location without affecting the primary antenna's performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the second antenna is placed in front of the first antenna to optimize space and minimize overall size, then the compactness and area efficiency are improved, but the performance of the first antenna is disturbed due to the presence of the second antenna

Engineering Contradiction:
Improveoverall antenna arrangement sizeVSAvoidfirst antenna performance
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The second antenna is divided into multiple electrically small segments or elements along its structure. This segmentation allows the antenna to maintain its low-frequency operational capability while reducing its effective radar cross-section and disturbance to the first antenna. The segmented structure creates multiple smaller scattering centers instead of one large disturbance source.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the second antenna are designed with different electrical characteristics. Specifically, certain sections are made electrically small or are positioned in regions where they have minimal impact on the first antenna's illumination field. This local optimization allows the second antenna to function at its operating frequency while being substantially invisible to the first antenna.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the second antenna operates at a lower frequency band than the first antenna, then the frequency band separation is achieved, but the second antenna causes severe disturbance to the antenna pattern and sidelobe performance

Engineering Contradiction:
Improvefrequency band operationVSAvoidantenna sidelobe performance
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The second antenna is divided into multiple electrically small segments or elements along its structure. This segmentation allows the antenna to maintain its low-frequency operational capability while reducing its effective radar cross-section and disturbance to the first antenna. The segmented structure creates multiple smaller scattering centers instead of one large disturbance source.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrical parameters of the second antenna are modified by making its segments electrically small relative to the wavelength of the first antenna's operating frequency. This parameter change ensures that the second antenna presents a minimal electromagnetic profile to the first antenna while maintaining its own low-frequency resonance characteristics.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If active electronically scanned antennas are used to enhance radar capabilities, then the detection and measurement capabilities are improved, but the requirement for low disturbance secondary antennas becomes more stringent

Engineering Contradiction:
Improvetarget detection precisionVSAvoidantenna disturbance sensitivity
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The second antenna is divided into multiple electrically small segments or elements along its structure. This segmentation allows the antenna to maintain its low-frequency operational capability while reducing its effective radar cross-section and disturbance to the first antenna. The segmented structure creates multiple smaller scattering centers instead of one large disturbance source.

Inventive Principle:
Principle #1Segmentation

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 maximizes power transfer and maintains operational capability for both antennas, reducing radar cross-section values and ensuring the second antenna does not disturb the first antenna's operation, while being efficient in manufacturing and size constraints.

Implementation Method 1

Each reactive load section is an inductive load section

Methodology Applied
Scientific EffectReactive loading: Capacitance

Implementation Method 2

Each reactive load section couples an adjacent first and second electrically conductive sections

Methodology Applied
Scientific EffectElectromagnetic coupling: Electromagnetic Induction

Implementation Method 3

the second antenna is segmented into a plurality of electrically small pieces with reactive loading between them, making it 'invisible' to the first antenna

Methodology Applied
Scientific EffectElectromagnetic scattering reduction: Scattering

Data Source

PatentEP4252317B1Antenna arrangement
Publication Date: 2024.11.20 SAAB AB
  • EP4252317B1 patent drawingFigure 1
  • EP4252317B1 patent drawingFigure 2
  • EP4252317B1 patent drawingFigure 3a~3b

AI summary

The present disclosure relates to an antenna arrangement (1) comprising a first antenna (2) configured to operate within a first frequency band and a second antenna (3) configured to operate within a second frequency band. The first frequency band is higher than the second frequency band. Further, the second antenna (3) is at least partly arranged within an illumination-field of the first antenna (2). Furthermore, the second antenna (3) comprises a dipole structure (4) segmented into a plurality of electrically conductive sections (5), wherein each electrically conductive section (5) is coupled to an adjacent electrically conductive section by a reactive load section (6).