Vehicle Window Antenna with Shielding Film for DAB Reception
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Solution Overview
Problem
Conventional vehicle antennas for receiving vertical polarized DAB signals face challenges in achieving high reception gain while maintaining a discreet and aesthetically pleasing design, particularly when mounted near metal vehicle bodies, which can interfere with signal reception and visibility.
Innovation Solution
A vehicle antenna design featuring antenna elements with specific length and orientation configurations on a window plate, including a monopolar antenna with a power-feed part positioned near the upper edge of the vehicle body and a shielding film to minimize visibility and interference, while optimizing conductor lengths for resonance in the DAB frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the glass antenna is mounted proximal to the body of the vehicle to prevent blocking the passenger's view, then the appearance is improved, but the reception gain deteriorates due to interference from metal vehicle body
Solution Approach 1:
A shielding film is introduced as an intermediary layer between the antenna elements and the vehicle body. This shielding film creates an electrical barrier that prevents interference from the metal vehicle body while allowing the antenna to be mounted in the aesthetically preferred location proximal to the body edge.
Solution Approach 2:
The antenna design transitions from traditional vertical patterns to horizontal patterns that extend in the lateral direction. This dimensional change allows the antenna to achieve sufficient reception gain by utilizing the horizontal dimension rather than being constrained by vertical space near the vehicle body.
2Reliability
If the glass antenna is mounted away from the vehicle body to improve reception gain, then the reception gain is improved, but the appearance deteriorates as the antenna becomes more visible and blocks passenger view
Solution Approach 1:
The shielding film is applied selectively at specific locations where the antenna elements are mounted, rather than covering the entire window. This localized application maintains the aesthetic quality of the window while providing interference protection only where needed for the antenna elements.
3Reliability
If long vertical patterns are used for DAB reception, then the reception gain for vertical polarized waves is improved, but the antenna becomes more visible and blocks passenger view
Solution Approach 1:
The antenna design employs asymmetric horizontal patterns that extend laterally rather than vertically. This asymmetric configuration in the horizontal plane provides sufficient reception gain for vertical polarized waves without creating the visual obstruction of long vertical patterns, as the horizontal extension is less noticeable from the passenger perspective.
Solution Approach 2:
The antenna patterns are reoriented from the vertical dimension to the horizontal dimension. By extending the antenna elements in the lateral direction rather than vertically, the design achieves the necessary electrical length for DAB reception while minimizing visual impact on passenger view.
4Reliability
If the antenna elements are positioned to resonate at DAB frequencies, then the reception gain is improved, but the antenna structure becomes more complex
Solution Approach 1:
Multiple antenna elements are combined in a planar configuration on the glass surface, sharing common feed structures and grounding. This merging approach achieves the necessary resonance characteristics for DAB frequency bands while maintaining a unified, relatively simple overall structure rather than using separate complex antenna systems.
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 improves the appearance and reception gain for vertical polarized DAB signals by minimizing interference from the vehicle body and ensuring the antenna elements are optimally positioned to resonate within the desired frequency bands, enhancing signal quality without compromising aesthetics.
Implementation Method 1
a first antenna element, extending in a first direction from the feeding part; a second antenna element, extending in a second direction substantially perpendicular to the first direction from an end of extension of the first antenna element
Data Source
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AI summary
A vehicle antenna included in a window plate mounted to an opening of a vehicle body. The vehicle antenna includes an antenna conductor, a power-feed part including a connection point. The antenna conductor and the power-feed part are positioned in a vicinity of an upper edge and arranged between a side edge of the opening and a center line of the window plate in a width direction. The antenna conductor includes a first linear element extending in a vertical direction and including upper and lower ends, the upper end being directly connected to the connection point or by way of a connection element, and a second linear element extending in a horizontal direction and connected to the first linear element at the lower end or a vicinity of the lower end. A length of the second linear element is greater than a length of the first linear element.