Avionic Monopole Antenna Array With Low Radar Cross-Section
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Solution Overview
Problem
Existing antenna arrays have a large radar cross-section (RCS), which is disadvantageous in applications where minimizing radar visibility is desired without significantly affecting antenna gain.
Innovation Solution
The use of monopole antennas connected via coaxial cables, combined with radiation-absorbent material (RAM) and strategically shaped to minimize reflections, and optionally complemented with directional antennas, to reduce RCS while maintaining high gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional antenna arrays are used, then antenna gain is achieved, but radar cross-section is large
Solution Approach 1:
The antenna array is divided into multiple individual antenna elements, each surrounded by its own RAM structure. This segmentation allows each element to independently manage radar wave interaction, reducing the overall RCS while maintaining the collective gain through phased array operation.
Solution Approach 2:
Radiation-absorbent material is used to convert harmful radar reflections into absorbed energy. The RAM structures surrounding each antenna element absorb incident radar waves, transforming the harmful reflective effect into beneficial energy dissipation, thereby reducing RCS without compromising antenna functionality.
2Object-affected harmful factors
If radiation-absorbent material is added to reduce RCS, then radar visibility is minimized, but device complexity increases
Solution Approach 1:
RAM material is applied locally around each antenna element rather than uniformly across the entire array. This localized application allows the RAM to be positioned where it most effectively reduces RCS for each individual element, optimizing radar visibility reduction while minimizing overall structural complexity.
Solution Approach 2:
The antenna array combines conventional conductive antenna elements with radiation-absorbent composite materials. This composite structure integrates the electromagnetic functionality of metal antennas with the radar-absorbing properties of specialized materials, achieving reduced radar visibility without significantly increasing structural complexity.
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 the radar cross-section of the antenna array by absorbing and scattering radar energy, maintaining high gain and reducing radar visibility.
Implementation Method 1
The material can absorb electromagnetic energy, particularly via dielectric relaxation effects (associated with molecular dipoles) or resonance effects (arising from rotations or vibrations of atoms, ions, or electrons)
Implementation Method 2
The material can absorb electromagnetic energy, particularly via dielectric relaxation effects (associated with molecular dipoles) or resonance effects (arising from rotations or vibrations of atoms, ions, or electrons)
Implementation Method 3
Radio waves that have entered the RAM can be reflected multiple times within the material. By providing the RAM in a beneficial shape, the number of reflections within the RAM and thus the energy dissipation can be increased.
Implementation Method 4
The conductive particles promote destructive interference of electromagnetic waves that have entered the RAM. Hence, the RCS of the antenna array can be reduced further.
Data Source
Figure 1~2
Figure 3~4
AI summary
An antenna array (10) for avionic applications is described. The antenna array (10) comprises a base (12) and a plurality of antenna elements (14) attached to a surface (15) of the base (12). The antenna elements (14) are monopole antennas that are spaced from each other and each connected with a single coaxial cable (13).