On-Board Antenna Layout With Metal Block for Surface Wave Suppression
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Solution Overview
Problem
Traditional radar antennas suffer from pattern jitter and imbalance between transceiving channels due to surface waves excited by high RF frequencies, affecting angle resolution accuracy.
Innovation Solution
An onboard antenna design featuring a dielectric substrate with a metal block positioned to avoid overlapping projections and maintain a coupling threshold distance from the antenna, suppressing surface wave influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an antenna radiation unit is directly placed on a substrate for traditional radar antenna structure, then the device complexity is reduced, but surface waves are excited on the substrate at high RF frequencies, causing antenna pattern jitter and deterioration
Solution Approach 1:
A metal block is introduced as an intermediary element between the antenna radiation unit and the substrate. This metal block acts as a mediator that suppresses surface wave excitation while maintaining the antenna's radiation performance. The metal block is positioned at a specific distance from the antenna (greater than a coupling threshold) to effectively block surface waves without causing harmful coupling effects.
Solution Approach 2:
The harmful surface wave excitation is extracted and isolated from the antenna system by introducing the metal block. The metal block specifically targets and suppresses the surface waves that would otherwise propagate along the substrate, separating the harmful electromagnetic effect from the useful antenna radiation function.
2Reliability
If the metal block is placed close to the antenna to suppress surface waves, then the antenna pattern stability is improved, but the coupling between the metal block and antenna increases, affecting performance
Solution Approach 1:
The distance parameter between the metal block and the antenna is optimized to be greater than a coupling threshold. This parameter change ensures that the metal block is close enough to suppress surface waves effectively, while maintaining sufficient separation to avoid harmful coupling effects. The specific distance parameter balances the competing requirements of surface wave suppression and coupling minimization.
3Measurement precision
If the antenna operates at high RF frequencies for better radar performance, then the detection precision is improved, but surface waves are easily excited, causing pattern jitter and channel imbalance
Solution Approach 1:
The metal block serves as a frequency-selective intermediary that specifically addresses surface wave issues at high RF frequencies. By positioning the metal block at an appropriate distance, it suppresses surface wave excitation that occurs at high frequencies while allowing the antenna to operate at these frequencies for improved radar detection precision.
Solution Approach 2:
The metal block provides localized electromagnetic field control in the region between the antenna and the substrate. This local modification of the electromagnetic environment suppresses surface waves in the critical near-field region, allowing the antenna to maintain stable radiation patterns at high frequencies without affecting the overall radar system performance.
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 design reduces antenna pattern jitter and maintains performance by minimizing surface wave impact, improving angle resolution and channel balance.
Implementation Method 1
due to high RF frequency (such as millimeter wave radar), it is easy to excite surface waves on the substrate. In a polarization direction of the antenna, a pattern is easily affected by the surface waves to jitter greatly
Data Source
AI summary
An onboard antenna, a radio equipment and an electronic device. The onboard antenna includes a dielectric substrate, an antenna and a metal block, wherein the antenna is located on the dielectric substrate, a projection of the metal block on a plane where the dielectric substrate is located is not overlapped with a projection of the antenna on the plane where the dielectric substrate is located, the metal block is located on the dielectric substrate in a polarization direction of the antenna, and a distance between a metal edge of the metal block on a side close to the antenna and the antenna is greater than a coupling threshold. Using this onboard antenna, an influence of surface waves on the pattern can be suppressed to a certain extent by arranging the metal block, and a jitter of the antenna pattern can be reduced.