Antenna Device Conductor Portion Interference Reduction

Solution Overview

Problem

In vehicle antenna devices, the close proximity of multiple antennas within a limited space leads to interference, compromising antenna performance and making it challenging to maintain excellent electrical characteristics while reducing the device's size.

Innovation Solution

The integration of additional conductor portions extending from the main body of one antenna to correspond with high electric field regions of another antenna, with lengths corresponding to a quarter of the effective wavelength of the respective frequency band, to minimize interference and maintain omnidirectional performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If multiple antennas are arranged in a limited space of a case, then the device size is reduced, but interference between antennas occurs and antenna performance deteriorates

Engineering Contradiction:

Improvedevice sizeVSAvoidinterference between antennas

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by adding conductor portions specifically to the capacitively loaded plate at locations corresponding to high electric field regions of adjacent antennas. This localized modification creates frequency-selective interference cancellation only in the necessary areas, rather than requiring uniform separation of all antennas. The conductor portions are strategically positioned to counteract interference from specific frequency bands while maintaining omnidirectional characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent converts the harmful electric field interference from adjacent antennas into a beneficial effect by adding conductor portions that generate counteracting electric fields. The conductor portions, when excited by the adjacent antenna's electromagnetic field, produce fields that cancel the interference in high electric field regions, thereby transforming the harmful interference into a mechanism for interference reduction.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If antennas are separated by a certain distance to avoid interference, then antenna performance is maintained, but the device size increases

Engineering Contradiction:

Improveantenna interferenceVSAvoiddevice length

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The patent changes the electrical parameters of the capacitively loaded plate by adding conductor portions, which modifies the plate's capacitance and resonant characteristics. This parameter modification enables the antenna system to maintain proper electrical characteristics even when antennas are placed closer together than conventional designs, effectively decoupling the relationship between physical separation distance and interference levels.

Inventive Principle:

Principle #35Parameter changes

3Volume of moving object

If a shark fin-shaped antenna device integrates multiple antennas, then the device becomes compact, but size reduction is limited by interference constraints

Engineering Contradiction:

Improveantenna device volumeVSAvoidinternal configuration complexity

Core Design Contradiction:

Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent applies local quality by adding conductor portions specifically to the capacitively loaded plate at locations corresponding to high electric field regions of adjacent antennas. This localized modification creates frequency-selective interference cancellation only in the necessary areas, rather than requiring uniform separation of all antennas. The conductor portions are strategically positioned to counteract interference from specific frequency bands while maintaining omnidirectional characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent converts the harmful electric field interference from adjacent antennas into a beneficial effect by adding conductor portions that generate counteracting electric fields. The conductor portions, when excited by the adjacent antenna's electromagnetic field, produce fields that cancel the interference in high electric field regions, thereby transforming the harmful interference into a mechanism for interference reduction.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 reduces interference between antennas, allowing for closer spacing while maintaining excellent directional characteristics and gain, thereby reducing the overall size of the antenna device.

Implementation Method 1

an additional conductor portion extends out from a conductor main body portion of the first antenna, and the additional conductor portion includes a predetermined-length portion extending at a distance along an edge of the conductor main body portion and having a predetermined length corresponding to a frequency band of the second antenna

Methodology Applied

Scientific EffectElectric field: Electric Field

Data Source

PatentUS11196154B2Antenna device

Publication Date: 2021.12.07 YOKOWO CO LTD

AI summary

In an antenna device, when an AM/FM antenna as a first antenna and an SDARS antenna or a GPS antenna as a second antenna that have different frequency bands are provided in a common case, an additional conductor portion extends out from a conductor main body portion of a capacitive element, and the additional conductor portion includes a parallel strip-shaped portion having a length that is ¼ of an effective wavelength in a frequency band of the second antenna, and extending parallel to the conductor main body portion.