Multi-Band Vehicular Antenna Layout for Compact Size and Gain

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Solution Overview

Problem

There is a demand for miniaturizing vehicular antenna devices while maintaining antenna gains, as existing multi-antenna configurations face challenges in securing gains during size reduction.

Innovation Solution

The antenna device incorporates a base with a first antenna for a first frequency band and a second antenna for a second frequency band, both equipped with capacitance loading elements, where the second frequency band antenna is positioned above the first, with specific geometrical configurations to minimize overlap and maximize gain, including the use of helical elements and LC circuits to manage impedance and coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple antennas are installed in a common case, then multi-frequency band reception capability is improved, but device size increases

Engineering Contradiction:
Improvemulti-frequency band reception capabilityVSAvoidantenna device size
Core Design Contradiction:
Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The patent applies nesting by placing the second antenna (for higher frequency band) above the first capacitance loading element of the first antenna (for lower frequency band) in the vertical direction. This allows multiple antennas to occupy overlapping or adjacent spatial regions, enabling multi-frequency band reception while minimizing the overall device volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from horizontal arrangement to vertical stacking by positioning antennas in the vertical direction. The second antenna is disposed above the base at a front side of the first capacitance loading element, utilizing the vertical dimension to pack multiple antennas into a compact footprint, thereby reducing the device's planar area while maintaining multi-band functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of stationary object

If antenna size is reduced for miniaturization, then device compactness is improved, but antenna gain decreases

Engineering Contradiction:
Improveantenna device sizeVSAvoidantenna gain
Core Design Contradiction:
Volume of stationary objectVSPower

Solution Approach 1:

The patent applies local quality by giving the second antenna an asymmetric configuration where one side portion extends further than the other. This localized extension optimizes the current distribution and radiation pattern in specific directions, maintaining antenna gain despite the overall compact size. The asymmetric design allows the antenna to achieve adequate gain performance within a reduced volume by concentrating effective radiating elements in critical regions.

Inventive Principle:
Principle #3Local quality

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 miniaturization of the antenna device while suppressing the reduction of antenna gains, ensuring effective reception across multiple frequency bands without the need for wave separation circuits and maintaining sensitivity by adjusting inductances to avoid resonance frequency overlap.

Implementation Method 1

a first antenna (for a first frequency band) includes a first capacitance loading element, the second antenna (for a second frequency band) includes a second capacitance loading element

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

maintaining sensitivity by adjusting inductances to avoid resonance frequency overlap

Methodology Applied
Scientific EffectInductance: Inductor

Implementation Method 3

the first antenna includes a first helical element between the first capacitance loading element and a first feeding point, and the second antenna includes a second helical element between the second capacitance loading element and a second feeding point

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3605735B1Antenna device
Publication Date: 2023.12.27 YOKOWO CO LTD
  • EP3605735B1 patent drawingFigure 1~2
  • EP3605735B1 patent drawingFigure 3
  • EP3605735B1 patent drawingFigure 4~5

AI summary

The present invention provides an antenna device that can be miniaturized while suppressing a drop in antenna gain. A band III capacity loaded element 8 is made up of one metal sheet component and has a side part 8a and a top part 8b. The side part 8a is a flat surface perpendicular to a base. The side part 8a is shaped so that the height with respect to the base increases from the front toward the rear. The top part 8b is a portion that is bent from the upper end of the side part 8a. The upper edge of the side part 8a and the left edge of the top part 8b come in contact with each other. The top part 8b is perpendicular to the side part 8a. The top part 8b has a smaller angle with respect to the base than the side part 8a. The right edge of the top part 8b is the outer edge of the band III capacity loaded element 8.