Low RCS Antenna with Embedded Lossy Lightweight Structure
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Solution Overview
Problem
Existing Active Electrically Scanned Antennas (AESA) for aircraft and missiles have high Radar Cross Section (RCS) values, leading to high complexity and cost, and limited performance due to difficulties in achieving wide-band matching, mechanical stability, and scattering issues, which hinder their ability to reduce passive signature effectively.
Innovation Solution
An AESA structure with a lightweight, rigid enclosure embedded with antenna elements and covered by a thin laminate doped with lossy materials for dielectric, magnetic, and resistive losses, providing improved mechanical stability and reduced RCS by minimizing reflections and maintaining scanning capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional AESA is used, then scanning capability is provided, but the Radar Cross Section (RCS) is too high for low-RCS aircraft
Solution Approach 1:
The antenna elements are segmented and embedded within a lightweight structure rather than using a conventional flat-plate design. This segmentation allows each element to be positioned and oriented to minimize RCS while maintaining scanning capability through electronic beam steering.
Solution Approach 2:
The patent applies different material properties to different parts of the antenna structure. Lossy materials are strategically placed in specific regions to absorb radar waves and reduce RCS, while other regions maintain structural integrity and scanning functionality.
2Object-affected harmful factors
If absorbers are introduced to reduce RCS, then RCS is reduced, but complexity and cost increase
Solution Approach 1:
The patent merges the absorber materials directly into the lightweight structure that supports the antenna elements. This integration eliminates the need for separate absorber components and their associated mounting structures, reducing overall complexity while maintaining RCS reduction benefits.
Solution Approach 2:
The lightweight structure serves multiple functions: it provides mechanical support for the antenna elements, reduces RCS through embedded lossy materials, and enables scanning capability. This multi-functionality reduces the need for separate components and simplifies the overall design.
3Reliability
If a laminate cover is used for hermeticity, then sealing is provided, but thickness increases limiting scannability and bandwidth
Solution Approach 1:
The patent employs a thin laminate cover that provides hermetic sealing without the thickness constraints of conventional covers. This thin film approach maintains the required sealing while allowing the antenna elements to scan through larger angular ranges and support wider bandwidth operations.
4Stability of the object's composition
If the antenna structure is made rigid for mechanical stability, then stability is improved, but weight increases
Solution Approach 1:
The patent uses composite materials that provide high mechanical stability with low weight. The lightweight structure incorporating lossy materials achieves the required rigidity and stability without the weight penalty of conventional rigid structures, enabling stable operation during aircraft maneuvers.
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 achieves a low RCS while maintaining mechanical stability and scanning performance, reducing the complexity and cost associated with existing stealth AESA designs, allowing for missions that were previously out of reach for standard AESA-equipped aircraft.
Implementation Method 1
Parts of the lightweight structure is further arranged to be doped with a lossy material having dielectric, magnetic and/or resistive losses, thus making these parts of the lightweight structure absorbing for electromagnetic radiation
Implementation Method 2
Parts of the lightweight structure is further arranged to be doped with a lossy material having dielectric, magnetic and/or resistive losses, thus making these parts of the lightweight structure absorbing for electromagnetic radiation
Implementation Method 3
Parts of the lightweight structure is further arranged to be doped with a lossy material having dielectric, magnetic and/or resistive losses, thus making these parts of the lightweight structure absorbing for electromagnetic radiation
Data Source
AI summary
A low-radar cross section antenna structure for an active electrically scanned antenna including an active electrically scanned antenna enclosure and at least two antenna elements. The antenna elements are arranged to be mounted on a front surface of the active electrically scanned antenna enclosure and embedded in a lightweight structure. The front surface and side surfaces of the active electrically scanned antenna enclosure and the antenna elements are arranged to be covered with the lightweight structure. A thin laminate is arranged to cover an outer top surface and an outer side surface of the lightweight structure. Parts of the lightweight structure are arranged to be doped with a lossy material having dielectric, magnetic and/or resistive losses, thus making these parts of the lightweight structure absorbing for electromagnetic radiation.