Radar Shielding Element for False Alarm Suppression
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Solution Overview
Problem
Radar systems cause false alarms due to signal reflections from the front wall of their housing, which are mistaken for objects outside the desired field of view, leading to misinterpretation and unreliable intrusion detection.
Innovation Solution
A radar device with a metal shield surrounding the electronic unit, extending from the front end to the level of the unit, absorbs or redirects the reflected signal from the front wall, preventing it from reaching behind the housing and causing unnecessary alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the front wall of the housing is made of plastic to allow signal passage, then the radar can detect objects in the front field of view, but signal reflections occur that cause false alarms from objects behind the radar
Solution Approach 1:
The harmful reflected signal is extracted from the main signal path by using a metallic shield that redirects reflections away from the antenna. The shield creates a separate path for reflected signals, preventing them from returning to the electronic unit and causing false alarms.
Solution Approach 2:
A metallic shield is introduced as an intermediary element between the front wall and the electronic unit. This shield intercepts reflected signals and redirects them, acting as a mediator that prevents harmful reflections from reaching the antenna while allowing the main detection function to continue.
2Object-generated harmful factors
If a metallic shield is added to block reflected signals, then false alarms are reduced, but the device complexity and manufacturing cost increase
Solution Approach 1:
The shield is segmented into multiple parts (first shield portion and second shield portion) that can be independently positioned and adjusted. This segmentation allows for simpler manufacturing and assembly while maintaining the effectiveness of signal blocking.
Solution Approach 2:
The shield portions are made movable relative to each other, allowing dynamic adjustment of the shield configuration. This enables the system to adapt to different installation conditions and maintain optimal performance without requiring a complex fixed structure.
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 suppresses signal reflections, reducing false alarms and enhancing the reliability and accuracy of intrusion detection by ensuring that only intended signals from the front field of view are processed, while maintaining a simple and cost-effective design.
Implementation Method 1
some reflection may still occur. Various shares of the reflected signal, depending on their direction, may be directly incident on the electronic unit and be absorbed thereby
Implementation Method 2
an annular metallic shield extending from a front end portion, proximate to the front wall of the housing, at least to a level of the electronic unit
Data Source
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Figure 5~6
AI summary
A radar device (1) for intrusion detection comprises a housing (2) which delimits a housing seat (24) between front walls (21) and rear walls (23) and a peripheral wall (22). An electronic unit (3) accommodated in the seat (24) of the housing (2) is configured to transmit an electromagnetic signal through the front wall (21). The device (1) comprises a shield (4), for example a metal band, which defines a channel that extends from the front wall (21) at least to the electronic unit (3). The shield (4) prevents part of the signal, reflected from the front wall (21), from detecting objects behind the radar device (1) thereby generating false alarms.