Liquid Crystal High-Frequency Switch With Dielectric Layer

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Solution Overview

Problem

Conventional high-frequency devices face challenges in achieving low loss, rapid switching time, and cost-effectiveness, especially at frequencies of 5GHz or higher, due to issues like high losses in semiconductor technologies, slow switching in liquid crystal technologies, and complex, expensive semiconductor components.

Innovation Solution

The introduction of a dielectric layer with a high dielectric constant between the signal and ground electrodes in a liquid crystal-based high-frequency device, reducing the thickness of the liquid crystal layer and forming electrodes into segments to apply different control voltages, thereby reducing power loss and switching time while maintaining low power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the thickness of the liquid crystal layer is increased to reduce power loss, then the loss decreases, but the switching time increases due to slow liquid crystal rearrangement

Engineering Contradiction:
Improvepower lossVSAvoidswitching time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The liquid crystal layer is segmented into multiple thinner layers (first liquid crystal layer and second liquid crystal layer) separated by a dielectric layer. This segmentation allows each layer to be thinner, reducing the switching time while the collective structure maintains adequate power loss performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A dielectric layer with high dielectric constant is introduced between the signal electrode and the liquid crystal layer. This intermediary concentrates the electric field in the dielectric layer, accelerating liquid crystal alignment and reducing switching time without requiring a thicker liquid crystal layer for power loss reduction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If the thickness of the liquid crystal layer is decreased to reduce switching time, then the switching time decreases, but the power loss increases

Engineering Contradiction:
Improveswitching timeVSAvoidpower loss
Core Design Contradiction:
Loss of timeVSLoss of energy

Solution Approach 1:

The device uses a composite structure combining liquid crystal layers with a dielectric layer having high dielectric constant. This composite material approach allows the liquid crystal layers to be thinner (reducing switching time) while the dielectric layer compensates for power loss through its high dielectric constant and low loss characteristics.

Inventive Principle:
Principle #40Composite materials

3Device complexity

If standard semiconductor technologies are used for switching devices, then the device structure is simple, but high losses are encountered resulting in low energy efficiency

Engineering Contradiction:
Improvedevice structureVSAvoidpower loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The invention changes the fundamental operating parameters by using liquid crystal materials with high dielectric constant and low loss characteristics instead of standard semiconductor switching devices. This parameter change enables low power loss while maintaining a relatively simple planar device structure without complex semiconductor fabrication.

Inventive Principle:
Principle #35Parameter changes

4Loss of energy

If conventional liquid crystal technologies are used with thick LC layer, then the power loss is reduced, but the switching speed is slow due to peculiarities of liquid crystal reaction

Engineering Contradiction:
Improvepower lossVSAvoidswitching speed
Core Design Contradiction:
Loss of energyVSSpeed

Solution Approach 1:

The invention adds a vertical dimension to the electric field distribution by introducing a dielectric layer with high dielectric constant between the signal electrode and the liquid crystal layer. This creates a concentrated electric field in the vertical direction that accelerates liquid crystal alignment, enabling fast switching without requiring a thick liquid crystal layer.

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

This configuration achieves a low loss of 3.7dB/360 degrees and a switching time of less than 10ms, while being cost-effective, by concentrating electric field energy in the dielectric layer and accelerating liquid crystal alignment, thus improving the performance and efficiency of high-frequency devices.

Implementation Method 1

a first dielectric layer disposed between the first liquid crystal layer and the first ground electrode... The first dielectric layer may have a dielectric constant that is larger than the dielectric constant of the first liquid crystal layer

Methodology Applied
Scientific EffectDielectric constant: Dielectric Permittivity

Implementation Method 2

a first liquid crystal layer disposed between the signal electrode and the first ground electrode... depending on a control voltage applied to some of the electrodes, the liquid crystal alignment in the first liquid crystal layer may be changed

Methodology Applied
Scientific EffectLiquid crystal response to electric field: Electro-Optic Effects

Data Source

PatentEP3577712B1Liquid crystal-based high-frequency device and high-frequency switch
Publication Date: 2023.05.24 SAMSUNG ELECTRONICS CO LTD
  • EP3577712B1 patent drawingFigure 1~4
  • EP3577712B1 patent drawingFigure 5~8
  • EP3577712B1 patent drawingFigure 9~12

AI summary

A high-frequency device and/or a high-frequency switch including the same may include: a signal electrode; a first ground electrode arranged in parallel with the signal electrode; a first liquid crystal layer disposed between the signal electrode and the first ground electrode; and a first dielectric layer disposed between the first liquid crystal layer and the first ground electrode, and/or between the signal electrode and the first liquid crystal layer. The first dielectric layer may have a dielectric constant that is larger than the dielectric constant of the first liquid crystal layer. The high-frequency device and/or the high-frequency device including the same may be variously implemented.