Rotating Aperture Radar for Clutter Suppression

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Solution Overview

Problem

Current radar systems with stationary aperture surfaces struggle to effectively suppress cluttering, jamming, and Bragg lobe, and are limited in beam scanning capabilities, particularly in narrow spaces, due to fixed polarization and mechanical constraints.

Innovation Solution

A radar device with a controllable aperture surface featuring element antennas, phase shifters, and a rotational mechanism that adjusts the aperture surface's orientation and polarization to suppress cluttering, jamming, and Bragg lobe, while expanding coverage without compromising antenna gain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a stationary aperture surface is used in a phased array antenna, then the radar system structure is simple and stable, but cluttering cannot be suppressed and jamming cannot be removed

Engineering Contradiction:
Improvecluttering suppression capabilityVSAvoidaperture surface control mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The aperture surface is transformed from a stationary structure to a dynamically controllable one. The patent introduces a rotation mechanism that allows the aperture surface to rotate about the beam axis, enabling real-time adjustment of the aperture orientation to suppress cluttering and remove jamming signals through spatial filtering

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the orientation parameter of the aperture surface by rotating it to different angles. This parameter change allows the radar to adaptively adjust the aperture orientation relative to the beam direction, creating nulls in directions of cluttering and jamming signals while maintaining gain in the target direction

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If mechanical driving is combined to expand coverage, then the coverage area is increased, but the space requirement increases and the platform becomes incompatible with narrow spaces

Engineering Contradiction:
Improvecoverage areaVSAvoidinstallation space
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

Instead of expanding coverage through mechanical rotation in the azimuth plane (traditional approach requiring large space), the patent utilizes the dimension of aperture orientation adjustment. By rotating the aperture surface about the beam axis and electronically steering the beam, the system achieves enhanced coverage and clutter suppression without requiring additional physical space

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

3Reliability

If the aperture surface is rotated to suppress cluttering, then cluttering suppression is achieved, but the system complexity and failure risk increase

Engineering Contradiction:
Improvecluttering suppressionVSAvoidrotational mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical rotational mechanisms with a simpler design where the aperture surface rotates about the beam axis. This simplification reduces the mechanical complexity and potential failure points while achieving the same cluttering suppression effect through controlled aperture orientation changes

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 solution enables precise target detection by dynamically controlling the aperture surface to reduce cluttering and jamming, expand coverage, and minimize the radar's reflection sectional area, making it suitable for narrow platforms like airplanes.

Implementation Method 1

phase shifters configured to set phases of signals to be transmitted to and received from the element antennas

Methodology Applied
Scientific EffectPhase shifting:

Implementation Method 2

a gear configured to rotate the aperture surface; a motor configured to drive the gear to rotate the aperture surface

Methodology Applied
Scientific EffectMechanical rotation:

Implementation Method 3

element antennas configured to emit and receive electromagnetic waves

Methodology Applied
Scientific EffectElectromagnetic radiation and reflection: Reflection

Data Source

PatentEP3812789A1Radar device
Publication Date: 2021.04.28 MITSUBISHI ELECTRIC CORP
  • EP3812789A1 patent drawingFigure 1
  • EP3812789A1 patent drawingFigure 2
  • EP3812789A1 patent drawingFigure 3(a)~3(b)(3)

AI summary

A radar device includes: an aperture surface, which includes element antennas and phase shifters; an antenna phase control unit configured to set phases to the phase shifters and calculate phase amounts based on a beam orientation direction and on a rotation angle of the aperture surface; a rotation mechanism configured to rotate the aperture surface; an antenna driving control unit configured to set a rotation angle to the rotation mechanism; a resolver configured to detect the rotation angle of the aperture surface; an exciter configured to generate transmission signals; a radar receiver configured to process reception signals; a signal processing unit configured to detect a target with the use of the radar receiver, set at least one of the rotation angle of the aperture surface or the beam orientation direction in the antenna driving control unit and the antenna phase control unit, and calculate the level of competing cluttering with the use of an antenna pattern, to thereby determine propriety of the rotation angle; and a pattern calculating unit configured to calculate the antenna pattern from the rotation angle of the aperture surface and from the beam orientation direction.