Back-to-Back Slotted-Waveguide Radar Antennas for False Reflection Isolation
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Solution Overview
Problem
Existing radar systems face challenges in reducing false reflections from radiating antennas to receiving antennas, which affects the signal-to-noise ratio and accurate classification of small targets in cluttered environments.
Innovation Solution
A cavity slotted-waveguide antenna system with two back-to-back positioned antenna modules, where each module has a planar slotted waveguide array for radiating and receiving electromagnetic waves, is designed to minimize false reflections by using a rotating system, electromagnetic shields, and optimized antenna array configurations to increase signal exposure time and reduce cross-polarization radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single antenna module is used for radiating and receiving radar signals, then the device complexity is reduced, but false reflections from the radiating antenna reach the receiving antenna, decreasing the signal-to-noise ratio
Solution Approach 1:
The antenna system is segmented into separate radiating and receiving antenna modules. The radiating antenna transmits radar signals while the receiving antenna detects reflected signals from targets. This segmentation prevents false reflections from the radiating antenna from reaching the receiving antenna, thereby improving the signal-to-noise ratio for detecting small targets in cluttered environments.
2Productivity
If the radar system rotates at high speed, then the productivity of target detection is increased, but the signal exposure time on the target is reduced, decreasing the signal-to-noise ratio
Solution Approach 1:
The radar system performs preliminary scanning at higher speeds to quickly identify potential targets. Once a target is detected, the system then focuses on that specific target with extended signal exposure time, allowing for improved signal-to-noise ratio and accurate classification without sacrificing overall detection productivity.
3Measurement precision
If the antenna arrays are positioned close to each other, then the device complexity and size are reduced, but false reflections increase, affecting target classification accuracy
Solution Approach 1:
The system employs electromagnetic shields positioned between the radiating and receiving antenna arrays. These shields create localized electromagnetic isolation, preventing false reflections from reaching the receiving antenna while maintaining a compact overall structure. This allows the antenna arrays to be positioned relatively close together without compromising target classification accuracy.
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 achieves a higher signal-to-noise ratio and improved target classification by reducing false reflections and increasing signal exposure time, allowing for more accurate detection of small targets like birds or UAVs.
Implementation Method 1
slotted-waveguide antennas consist of lengths of waveguides with a multiple number of slots formed in the conducting walls of the waveguides. 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
a rotation system configured for supporting and rotating the first and second antenna modules around a vertical axis
Data Source
AI summary
A radar system includes antenna modules that have 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. A rotation system is configured for supporting and rotating the antenna modules around a vertical axis, with the antenna modules arranged in a back-to-back position on opposite sides of a plane intersecting the vertical axis of rotation. There is also provided another radar system comprising a first radar antenna module that has 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 have several longitudinal extending waveguide columns. The waveguide columns have a front side and a rear side with a plurality of cavity slots on the front side.