Voltage-Tunable RF Transmission Line for Adaptive Impedance Matching

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Solution Overview

Problem

Existing RF signal processing apparatuses face challenges in dynamically adjusting impedance to compensate for aging effects and manufacturing tolerances, leading to suboptimal performance and efficiency.

Innovation Solution

Incorporation of electrochromic (EC) materials in transmission lines that allow permittivity control via voltage, enabling dynamic impedance transformation and tuning, coordinated with active semiconductor devices for optimal impedance matching and performance adaptation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fixed impedance transmission lines are used, then device structure is simple, but performance degrades due to aging effects and manufacturing tolerances

Engineering Contradiction:
Improveperformance stabilityVSAvoidtransmission line structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by transforming the static, fixed impedance transmission line into a dynamic,可调 impedance transmission line using electrochromic materials. The EC material's permittivity can be changed by applying different voltages, allowing the transmission line impedance to be dynamically adjusted to compensate for aging effects and manufacturing tolerances, thereby improving performance stability while managing device complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies the parameter changes principle by utilizing the voltage-dependent permittivity of electrochromic materials to change the electrical parameters of the transmission line. By applying different control voltages, the permittivity of the EC material changes, which directly alters the characteristic impedance of the transmission line, enabling adaptive performance optimization without requiring complex structural modifications.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If electrochromic materials are incorporated for dynamic impedance tuning, then adaptability improves, but device complexity increases

Engineering Contradiction:
Improveimpedance tuning capabilityVSAvoidtransmission line composition
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent utilizes parameter changes by exploiting the voltage-controlled permittivity of electrochromic materials to achieve dynamic impedance tuning. The EC material layer is integrated into the transmission line structure, and by varying the applied voltage, the permittivity changes, which directly modifies the transmission line's characteristic impedance, providing adaptability for different operating conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies composite materials by combining electrochromic materials with conventional transmission line structures. The EC material is integrated as a functional layer within the transmission line, creating a composite structure that combines the electrical properties of conventional materials with the voltage-tunable permittivity of EC materials, thereby achieving impedance tuning capability.

Inventive Principle:
Principle #40Composite materials

3Reliability

If EC material permittivity is controlled by voltage, then impedance matching improves, but energy consumption increases

Engineering Contradiction:
Improveimpedance matchingVSAvoidcontrol voltage energy
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by pre-configuring the electrochromic material layer within the transmission line structure during manufacturing. The EC material is positioned and prepared in advance, so that when voltage is applied during operation, the impedance matching can be quickly achieved without requiring additional adjustment mechanisms or excessive energy input, thus improving impedance matching while managing energy consumption.

Inventive Principle:
Principle #10Preliminary action

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

Enables flexible impedance matching and compensation for aging and manufacturing variations, enhancing energy efficiency and performance across varying load and frequency conditions.

Implementation Method 1

a first transmission line (110_1) for transmitting radio frequency, RF, signals and an RF device (120) coupled to said first transmission line, wherein said first transmission line comprises an electrochromic, EC, material a permittivity of which can be controlled by applying a first control voltage to said first transmission line

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Data Source

PatentEP3859985B1Apparatus comprising a transmission line for radio frequency signals
Publication Date: 2026.02.11 NOKIA SOLUTIONS & NETWORKS OY
  • EP3859985B1 patent drawingFigure 1~4
  • EP3859985B1 patent drawingFigure 5~7B
  • EP3859985B1 patent drawingFigure 8~9B

AI summary

Apparatus comprising a first transmission line for transmitting radio frequency, RF, signals and at least one RF device comprising at least one active semiconductor device for processing RF signals, wherein said at least one RF device is coupled to said first transmission line, and wherein said first transmission line comprises an electro-chromic, EC, material a permittivity of which can be controlled by applying a first control voltage to said first transmission line.