Antenna Mounting Base Grooves Reduce Wind Noise
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Solution Overview
Problem
Rod-shaped antennas mounted on vehicles generate whistling sounds due to airflow at high speeds, which can be distracting and irritating to drivers and occupants.
Innovation Solution
The design of an antenna assembly with a mounting base featuring a tapered shaft portion and asymmetrical cross-sectional area, including grooves and a spiral element, which generates turbulence to reduce wind noise by scattering low-pressure regions and suppressing vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a rod-shaped antenna is mounted on a vehicle, then the antenna can provide wireless communication functionality, but it generates whistling sounds due to airflow at high speeds
Solution Approach 1:
The patent applies asymmetry by introducing grooves and a spiral element to the otherwise symmetrical cylindrical antenna structure. These asymmetric features disrupt the symmetrical airflow pattern that causes whistling, creating turbulence instead. The grooves are positioned at specific angles and depths to optimize the disruption of airflow while maintaining the antenna's functional shape.
Solution Approach 2:
The patent applies local quality by modifying only specific portions of the antenna structure rather than changing the entire shape. The grooves are located on the shaft portion, and the spiral element is positioned on the antenna rod, leaving other portions intact. This localized modification approach maintains the overall cylindrical shape for functional purposes while introducing turbulence-generating features only where needed to reduce whistling.
2Object-affected harmful factors
If the antenna shaft is given an asymmetrical cross-sectional area with grooves, then wind noise is reduced through turbulence generation, but the manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the antenna structure into distinct components: the shaft portion with grooves, the antenna rod, and the spiral element. This segmentation allows each component to be manufactured separately using standard techniques, then assembled together. The grooves can be molded into the shaft, while the spiral element can be separately formed and attached, simplifying the overall manufacturing process compared to creating a fully complex integrated structure.
Solution Approach 2:
The patent applies curvature through the spiral element that wraps around the antenna rod and the curved grooves in the shaft. These curved features are designed to optimize turbulence generation while being manufacturable using conventional molding and forming techniques. The spiral geometry, while complex in function, can be produced efficiently through rotational molding or wrapping processes.
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
Significantly reduces wind noise generated by airflow across the antenna assembly, providing a more comfortable driving experience by minimizing whistling sounds.
Implementation Method 1
cause air flowing across peripheries of the mounting base and the antenna element to generate significant degrees of turbulence
Implementation Method 2
scattering low-pressure regions and suppressing vibrations
Data Source
AI summary
An antenna assembly is provided that includes an antenna element depending from an antenna mounting base. The mounting base includes a shaft portion that uniformly tapers from a mounting end portion to a projecting end portion. The shaft portion includes grooves, or flutes, that each extends from the mounting end portion toward the projecting end portion, and that each has a curvature about an axis of the shaft portion. The grooves provide the shaft portion with an asymmetrical cross-sectional area that causes airflow impinging on the shaft portion to generate turbulence and scatter low air pressure regions that tend to form locally around the shaft portion. As a result, small vibrations generated by the low pressure regions are suppressed, and whistling sounds, noises, etc. associated with the vibrations may be reduced.