Segmented Acoustic Wave Filter Layout for Lower Resonator Heating

Solution Overview

Problem

When an acoustic wave resonator is divided into three or more segmented resonators connected in series, the interaction between these resonators can lead to increased temperature, degrading the electric power handling capability of acoustic wave filters.

Innovation Solution

The acoustic wave filter includes at least three segmented resonator devices connected in series, with each device having an InterDigital Transducer (IDT) electrode, and the centers of adjacent IDT electrodes are not aligned in the direction orthogonal to the acoustic wave propagation direction, reducing interaction and heat buildup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If an acoustic wave resonator is divided into three or more segmented resonators connected in series, then power consumption per unit area is reduced, but temperature increases due to interaction between adjacent segmented resonators, degrading electric power handling capability

Engineering Contradiction:

Improvepower consumption per unit areaVSAvoidtemperature of acoustic wave filter

Core Design Contradiction:

Use of energy by moving objectVSTemperature

Solution Approach 1:

The patent applies asymmetry by intentionally misaligning the centers of IDT electrodes of adjacent segmented resonator devices in the direction orthogonal to the acoustic wave propagation direction. This asymmetric arrangement breaks the symmetry of the acoustic wave paths between adjacent resonators, thereby reducing their interaction and the resulting temperature increase, while maintaining the power consumption benefits of segmentation.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent addresses the temperature issue by manipulating the spatial arrangement in the direction orthogonal to the acoustic wave propagation direction. By adjusting the lateral position (in the orthogonal dimension) of IDT electrode centers, the patent reduces unwanted interaction between adjacent resonators without affecting the series connection topology or the power consumption characteristics.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Power

If an acoustic wave resonator is divided into three or more segmented resonators connected in series, then electric power handling capability is improved, but temperature increases due to interaction between adjacent segmented resonators, degrading electric power handling capability

Engineering Contradiction:

Improveelectric power handling capabilityVSAvoidtemperature of acoustic wave filter

Core Design Contradiction:

PowerVSTemperature

Solution Approach 1:

The patent applies asymmetry by intentionally misaligning the centers of IDT electrodes of adjacent segmented resonator devices in the direction orthogonal to the acoustic wave propagation direction. This asymmetric arrangement breaks the symmetry of the acoustic wave paths between adjacent resonators, thereby reducing their interaction and the resulting temperature increase, while maintaining the power consumption benefits of segmentation.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent addresses the temperature issue by manipulating the spatial arrangement in the direction orthogonal to the acoustic wave propagation direction. By adjusting the lateral position (in the orthogonal dimension) of IDT electrode centers, the patent reduces unwanted interaction between adjacent resonators without affecting the series connection topology or the power consumption characteristics.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Device complexity

If segmented resonator devices are arranged with aligned IDT electrode centers, then device complexity is reduced, but interaction between adjacent resonators increases, causing temperature rise

Engineering Contradiction:

Improvealignment configurationVSAvoidtemperature of acoustic wave filter

Core Design Contradiction:

Device complexityVSTemperature

Solution Approach 1:

The patent applies asymmetry by intentionally misaligning the centers of IDT electrodes of adjacent segmented resonator devices in the direction orthogonal to the acoustic wave propagation direction. This asymmetric arrangement breaks the symmetry of the acoustic wave paths between adjacent resonators, thereby reducing their interaction and the resulting temperature increase, while maintaining the power consumption benefits of segmentation.

Inventive Principle:

Principle #4Asymmetry

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 effectively improves the electric power handling capability by preventing local temperature increases and maintaining the filter's size without increasing its volume.

Implementation Method 1

acoustic wave filter includes at least three segmented resonator devices connected in series to one another and aligned in a direction that crosses an acoustic wave propagation direction, wherein each of the at least three segmented resonator devices includes an InterDigital Transducer (IDT) electrode

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

acoustic wave filter includes at least three segmented resonator devices connected in series to one another and aligned in a direction that crosses an acoustic wave propagation direction

Methodology Applied

Scientific EffectAcoustic wave propagation: Surface Acoustic Wave

Data Source

PatentUS12107566B2Acoustic wave filter

Publication Date: 2024.10.01 MURATA MFG CO LTD

AI summary

An acoustic wave filter includes at least three segmented resonator devices connected in series to one another and aligned in a direction that crosses an acoustic wave propagation direction and each including an InterDigital Transducer (IDT) electrode, and centers of respective IDT electrodes of an adjacent pair of the at least three segmented resonator devices in the acoustic wave propagation direction are not aligned when seen from a direction orthogonal to the acoustic wave propagation direction.