Back-to-Back Slotted Waveguide Radar Arrays for False Reflection Shielding
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Solution Overview
Problem
Existing cavity slotted-waveguide antenna systems suffer from false reflections from the radiating antenna to the receiving antenna, which degrade the signal-to-noise ratio and hinder accurate detection of small targets like birds or UAVs in cluttered environments.
Innovation Solution
A radar system with two back-to-back positioned planar slotted waveguide antenna arrays, where the radiating and receiving arrays are offset in a perpendicular direction, and shielded by electromagnetic plates to minimize false reflections, allowing for increased signal exposure time and improved signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If radiating and receiving antenna arrays are positioned close together in a compact configuration, then device size is reduced, but false reflections from radiating antenna to receiving antenna increase, degrading signal-to-noise ratio
Solution Approach 1:
An electromagnetic shield plate is positioned between the radiating antenna array and the receiving antenna array to block false reflections. The shield plate acts as an intermediary element that prevents direct electromagnetic coupling between transmit and receive arrays, thereby improving signal-to-noise ratio while allowing compact overall system configuration.
Solution Approach 2:
The radiating and receiving antenna arrays are offset in a direction perpendicular to their facing direction, creating a three-dimensional separation rather than simple lateral displacement. This vertical offset combined with lateral spacing optimizes the balance between compact footprint and false reflection reduction.
2Reliability
If radiating and receiving antenna arrays are separated by large distance to reduce false reflections, then signal-to-noise ratio improves, but device size increases
Solution Approach 1:
The electromagnetic shield plate enables compact array spacing by actively blocking false reflections, eliminating the need for large separation distances that would otherwise be required to achieve the same signal-to-noise ratio performance.
3Reliability
If shield plate is added between radiating and receiving arrays to block false reflections, then signal-to-noise ratio improves, but device complexity increases
Solution Approach 1:
The electromagnetic shield plate is constructed from the same conductive material as the antenna arrays themselves, creating a homogeneous structure that simplifies manufacturing and assembly. This material uniformity reduces complexity compared to using dissimilar materials or complex composite structures.
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 system reduces false reflections, enhances signal-to-noise ratio, and enables accurate classification of detected objects by increasing radar signal exposure time, particularly useful for detecting small targets like UAVs and birds.
Implementation Method 1
These slots introduce discontinuities in the conductor and interrupt the flow of current along the waveguide. Instead, the current must flow around the edges of the slots, causing them to act as dipole antennas.
Implementation Method 2
the radar system holds two back-to-back positioned antenna modules, each antenna module holding a radiating array and a receiving array with an electromagnetic shield plate positioned between the radiating array and the receiving array
Data Source
Figure 1a
Figure 1b~1c
Figure 2a
AI summary
There is provided a radar system comprising a first radar antenna module, which radar module comprises a first planar slotted waveguide antenna array configured for radiating electromagnetic waves, and a second planar slotted waveguide antenna array configured for receiving electromagnetic waves, where each of the planar slotted waveguide antenna arrays comprises several longitudinal extending waveguide columns, where the waveguide columns have a front side and a rear side with a plurality of cavity slots on the front side. The front side of the columns holding the cavity slots of the first planar antenna array are positioned in a first plane and the front side of the columns holding the cavity slots of the second planar antenna array are positioned in a second plane parallel to the first plane. The first and second parallel planes may be offset with a minimum perpendicular array distance to each other in a direction perpendicular to the planes. The first and second antenna arrays may also or alternatively be positioned at a distance to each other in a direction parallel to the first and second planes.