Overtone BAW Resonator Stacks for High-Frequency RF Filters

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing acoustic wave filters face challenges in achieving high resonant frequencies while maintaining effective power handling, particularly for radio frequency signals.

Innovation Solution

The development of acoustic wave filters that incorporate overtone mode bulk acoustic wave resonators with stacked piezoelectric layers, which are configured to excite overtone modes as main modes, along with fundamental mode resonators for improved power handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If acoustic wave resonators are designed to achieve high resonant frequencies, then the resonant frequency is improved, but the power handling capability deteriorates

Engineering Contradiction:

Improveresonant frequencyVSAvoidpower handling capability

Core Design Contradiction:

SpeedVSPower

Solution Approach 1:

The resonator is divided into multiple piezoelectric layers stacked in series, each layer contributing to the overall resonant frequency while distributing the power handling stress across multiple layers. This segmentation allows the resonator to achieve high resonant frequencies (5-20 GHz) while maintaining power handling capability through the distributed structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The resonator employs composite piezoelectric layer structures with different material properties optimized for specific functions. The stacked piezoelectric layers form a composite structure that simultaneously achieves high resonant frequency and enhanced power handling capability by combining materials with complementary characteristics.

Inventive Principle:

Principle #40Composite materials

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 solution enables the acoustic wave filters to achieve high resonant frequencies, ranging from 5 GHz to 20 GHz, while maintaining enhanced power handling capabilities, suitable for applications in fifth generation New Radio (5G NR) systems.

Implementation Method 1

a first plurality of stacked piezoelectric layers positioned between a pair of first electrodes. The first bulk acoustic wave resonator is configured to excite an overtone mode

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

In BAW resonators, acoustic waves propagate in a bulk of a piezoelectric layer

Methodology Applied

Scientific EffectAcoustic wave propagation: Acoustics

Implementation Method 3

The first bulk acoustic wave resonator is configured to excite an overtone mode as a main mode of the first bulk acoustic wave resonator

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS12267065B2Acoustic wave filter with overtone mode resonators

Publication Date: 2025.04.01 SKYWORKS GLOBAL PTE LTD

AI summary

Aspects of this disclosure relate to acoustic wave filters with bulk acoustic wave resonators configured to excite an overtone mode as a main mode. A bulk acoustic wave resonator of the filter can include a plurality of stacked piezoelectric layers positioned between a pair of electrodes.