Shared-Case Antenna Layout to Avoid Standing-Wave Interference
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Solution Overview
Problem
In vehicle-mounted antenna devices, maintaining sufficient distance between multiple antennas within a limited space is challenging, leading to decreased antenna gain, while increasing distance results in a larger case size, making downsizing difficult.
Innovation Solution
The antenna device incorporates a second plate-shaped antenna above a first antenna, with the first antenna positioned to avoid voltage maximum points of the second antenna's standing waves, and uses a helical element and filter components to optimize antenna placement and size without compromising gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple antennas are provided within a limited space in a case, then the antenna device can be downsized, but the distance between antennas cannot be sufficiently maintained and antenna gain decreases
Solution Approach 1:
The patent positions the second plate-shaped antenna above the first antenna in the vertical direction, utilizing three-dimensional space arrangement. This vertical stacking allows multiple antennas to coexist within a compact horizontal footprint while maintaining sufficient vertical separation to preserve antenna gain and reduce mutual interference.
Solution Approach 2:
The patent strategically positions the first antenna to avoid voltage maximum points of standing waves generated by the second antenna. By selecting specific locations where electromagnetic field interference is minimized, the arrangement maintains antenna gain despite the close proximity required for downsizing.
2Reliability
If the distance between antennas is increased inside a case, then antenna gain is maintained, but the case becomes large and cannot be downsized
Solution Approach 1:
The patent transitions from horizontal to vertical spatial arrangement, stacking antennas in the vertical dimension. This allows the antennas to be positioned close together horizontally for compact case size while maintaining adequate vertical distance to preserve antenna gain and reduce interference.
Solution Approach 2:
The patent implements a nested arrangement where the first antenna is positioned within the electromagnetic field region of the second antenna, specifically at locations of minimal interference (voltage minimum points). This nested configuration allows compact integration while maintaining 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
This configuration allows for a downsized antenna device with maintained or improved antenna gain by strategically positioning antennas to minimize interference and maximize space efficiency.
Implementation Method 1
the first antenna is arranged so as to avoid a voltage maximum point of a standing wave, of a frequency band of the first antenna, generated in the second antenna
Data Source
AI summary
An antenna device which includes a plurality of antennas in a common case and is capable of achieving downsizing while suppressing a decrease of an antenna gain, is provided. An antenna device includes a TEL antenna and a capacity loaded element in a common case. The capacity loaded element is located above the TEL antenna. A length of the capacity loaded element is a positive integer multiple of one-half a wavelength of a PCS band. The TEL antenna is arranged so as to avoid a voltage maximum point of a standing wave, of the PCS band, generated in the capacity loaded element.