Multi-Resonant Antenna with Variable Reactance for Carrier Aggregation

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Solution Overview

Problem

Current antenna structures in mobile devices face efficiency challenges in covering wide frequency ranges, particularly in low frequency bands, due to size constraints and bandwidth requirements, leading to degraded performance in carrier aggregation applications where channels from adjacent low frequency bands are difficult to combine effectively.

Innovation Solution

A multi-resonant antenna structure with a metal frame, featuring two closely spaced low band resonances, where one resonance is adjustable using a MEMS-based variable reactance device, allowing efficient operation across all commercial wireless communication bands with minimal efficiency roll-off, enabling effective carrier aggregation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single antenna structure is used to cover wide frequency ranges, then frequency coverage is improved, but antenna efficiency deteriorates

Engineering Contradiction:
Improvefrequency coverageVSAvoidantenna efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The antenna structure is divided into multiple resonant elements, each optimized for specific frequency bands. The patent employs multiple radiating elements with different lengths and configurations, allowing each segment to resonate at different frequencies, thereby achieving wideband coverage while maintaining high efficiency at each segment's optimal frequency range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent incorporates tunable reactive loading that allows dynamic adjustment of resonant frequencies. By varying the reactance values, the antenna can adapt its resonant characteristics to match different operating bands, maintaining optimal efficiency across wide frequency ranges through real-time parameter adjustment.

Inventive Principle:
Principle #15Dynamics

2Volume of moving object

If antenna size is decreased to fit device constraints, then device integration is improved, but antenna efficiency deteriorates

Engineering Contradiction:
Improveantenna sizeVSAvoidantenna efficiency
Core Design Contradiction:
Volume of moving objectVSLoss of energy

Solution Approach 1:

The patent employs nested resonant structures where smaller resonant elements are positioned within or alongside larger ones. This nesting allows multiple resonant modes to coexist in a compact volume, achieving wide frequency coverage and high efficiency without requiring large physical dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes three-dimensional spatial arrangements and vertical stacking of resonant elements to achieve compact size. By transitioning from planar to volumetric configurations, the antenna maintains sufficient electrical length for efficient resonance while fitting within constrained device volumes.

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

3Adaptability or versatility

If operational bandwidth is increased to cover more frequency bands, then frequency coverage is improved, but antenna efficiency deteriorates

Engineering Contradiction:
Improveoperational bandwidthVSAvoidantenna efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The bandwidth is segmented into multiple resonant peaks, each corresponding to a specific frequency band. Rather than attempting a single broad resonance, the patent creates multiple discrete resonant elements that collectively cover the entire operational bandwidth, with each element maintaining high efficiency at its designated frequency range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs variable reactive loading to dynamically adjust resonant parameters. By changing the reactance values, different resonant frequencies can be activated or tuned, allowing the antenna to maintain optimal efficiency across varying bandwidth requirements and frequency bands.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If low band resonators are made larger to improve resonance, then resonance quality is improved, but device integration deteriorates

Engineering Contradiction:
Improveresonance qualityVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

Large low-band resonant structures are nested within the device footprint by positioning them along the device edges or stacking them vertically. This allows the resonators to achieve their required electrical length for high-quality resonance while maintaining compact overall device dimensions through efficient spatial utilization.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions low-band resonators from planar configurations to three-dimensional structures, utilizing vertical spacing and立体 arrangements. This enables the resonators to achieve sufficient electrical length for high-quality resonance without increasing the device's planar footprint, thereby improving both resonance quality and device integration.

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

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 antenna design maintains high efficiency across the frequency range, particularly in low frequency bands, and supports carrier aggregation by allowing real-time tuning of one resonance while keeping the other fixed, enhancing power transfer and impedance matching.

Implementation Method 1

A multi-resonant antenna structure with a metal frame, featuring two closely spaced low band resonances

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 2

one resonance is adjustable using a MEMS-based variable reactance device

Methodology Applied
Scientific EffectVariable reactance: Capacitance

Data Source

PatentEP3529856B1Multi-resonant antenna structure
Publication Date: 2023.08.02 QORVO US INC
  • EP3529856B1 patent drawingFigure 1~2
  • EP3529856B1 patent drawingFigure 3~4
  • EP3529856B1 patent drawingFigure 5A~5C

AI summary

The present disclosure generally relates to any device capable of wireless communication, such as a mobile telephone or wearable device, having one or more antennas. The antenna has a structure with multiple resonances to cover all commercial wireless communications bands from a single antenna with one feed connection to the main radio system. The antenna is usable where there are two highly efficient, closely spaced resonances in the lower part of the frequency band. One of those resonances can be adjusted in real time by using a variable reactance attached to the radiator while the other resonance is fixed.