Vehicle Window Glass DAB Antenna Standing Wave Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reception performance of DAB antenna elements on vehicle window glass is decreased due to radio waves being excited as standing waves by the horizontal heating wires of defoggers.
Innovation Solution
A vehicle window glass design that includes a glass plate with a defogger having horizontal heating wires, a DAB antenna element, and a standing wave canceller positioned between the DAB antenna and the defogger, where the distance and wavelength relationships are optimized to minimize the impact of standing waves on antenna reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a defogger with horizontal heating wires is provided on the window glass, then the defogging function is improved, but the reception performance of the DAB antenna element decreases due to standing wave excitation
Solution Approach 1:
A vertical antenna element is introduced as an intermediary component between the horizontal heating wires of the defogger and the DAB antenna element. This vertical element intersects the horizontal wires at specific positions and serves as a mediator to prevent the excitation of standing waves that would otherwise directly affect the DAB antenna reception performance
Solution Approach 2:
The vertical antenna element is positioned to intersect the horizontal heating wires at specific locations rather than uniformly across the entire defogger structure. This localized intervention is sufficient to disrupt the standing wave pattern without requiring modification of the entire defogger system
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 effectively suppresses the decrease in DAB antenna reception performance by mitigating the influence of standing waves, ensuring consistent and improved radio wave reception even with a defogger present.
Implementation Method 1
radio waves in the frequency band that should be received by the DAB antenna element being excited as a standing wave in the horizontal heating wires
Data Source
Figure 1~2
Figure 3(a)~3(c)
Figure 4
AI summary
A vehicle window glass according to the present invention includes a glass plate, a pair of bus bars formed on the glass plate, a defogger having a plurality of horizontal heating wires that connect the pair of bus bars, at least one vertical antenna element provided in the defogger and intersecting at least one of the horizontal heating wires, a DAB antenna element formed on the glass plate and disposed on an upper side or a lower side of the defogger, and a standing wave canceller disposed further on the defogger side than the DAB antenna element, and a distance L between the bus bars and the vertical antenna elements or a distance L between the vertical antenna elements, a wavelength λ of a reception wave and a wavelength shortening rate γ of the glass plate satisfy (λ·γ/3)·n≤L≤(λ·γ/1.5)·n (where n is an integer).