Multi-band Antenna Using Capacitor Assembly for Size Reduction

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Solution Overview

Problem

Conventional antennas for terminal devices require larger space due to increased cabling and parasitic elements to achieve multiple bands, conflicting with the trend of miniaturization and portability demands.

Innovation Solution

A multi-band antenna design utilizing a capacitor assembly and matching network between the feedpoint and radiation portion, enabling two resonance frequencies in a CRLH mode to reduce antenna size without increasing space, thereby adapting to miniaturized terminal devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple branches or parasitic elements are added to achieve multiple bands, then the antenna can cover more frequency bands, but the antenna occupies larger space

Engineering Contradiction:
Improvemulti-band coverageVSAvoidantenna space
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent changes the electrical parameters of the antenna by introducing a capacitor assembly and matching network, transforming the antenna's resonance characteristics to achieve multiple bands without adding physical branches or parasitic elements. The capacitor assembly modifies the impedance and resonance frequency of the radiating element, enabling multi-band operation within the same physical structure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The capacitor assembly acts as an intermediary component between the feedpoint and the radiating element, mediating the electrical connection to achieve multi-band resonance. This intermediary component enables the antenna to support multiple frequency bands by introducing additional resonance paths without requiring additional radiating structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If conventional antenna structures are used to achieve multiple bands, then the antenna can provide multiple resonance frequencies, but the cabling space increases

Engineering Contradiction:
Improvemultiple resonance frequenciesVSAvoidcabling space
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The patent merges the matching network and capacitor assembly into a compact integrated structure that is directly coupled to the radiating element. This integration eliminates the need for separate cabling and connecting structures, reducing the overall cabling space while maintaining the multiple resonance frequency capability through the combined electrical structure.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If the quantity of branches is increased to achieve more bands, then the antenna can cover more frequency ranges, but larger space is occupied

Engineering Contradiction:
Improvefrequency band coverageVSAvoidantenna volume
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The single radiating element with the capacitor assembly and matching network performs multiple functions by supporting multiple resonance frequencies. Instead of requiring separate branches for different bands, this universal structure achieves multi-band coverage through electrical tuning and resonance manipulation, significantly reducing the antenna volume.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution allows for multiple resonance frequencies while significantly reducing antenna size, accommodating the miniaturization trend and enhancing portability without the need for additional branches or parasitic elements.

Implementation Method 1

A first resonant circuit is formed from the feedpoint to the grounding portion, and the first resonant circuit generates a first resonance frequency and a second resonance frequency

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 2

one resonance frequency is used in a CRLH mode, so that two resonance frequencies can be provided on the basis of reducing an antenna size

Methodology Applied
Scientific EffectCRLH mode:

Data Source

PatentEP3258539B1Multi-frequency antenna and terminal device
Publication Date: 2019.07.24 HUAWEI TECH CO LTD
  • EP3258539B1 patent drawingFigure 1A~2B
  • EP3258539B1 patent drawingFigure 3A~5B
  • EP3258539B1 patent drawingFigure 5C~6

AI summary

Embodiments of the present invention provide a multi-band antenna and a terminal device. The multi-band antenna includes: a feedpoint, a matching network, a capacitor assembly, a radiation portion, and a grounding portion. The feedpoint, the matching network, the capacitor assembly, the radiation portion, and the grounding portion are connected in sequence. The matching network includes at least a serially-connected inductor and a grounded capacitor or inductor. The grounding portion is electrically connected to a ground plane. A first resonant circuit is formed from the feedpoint to the grounding portion. The first resonant circuit generates a first resonance frequency and a second resonance frequency. The first resonance frequency is used in a CRLH mode, and the second resonance frequency is used in a half-wavelength loop mode.