Acoustic Wave Circulator Switching for Low-Loss Full Duplex Isolation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional circulators in wireless communication devices require lossy and non-linear circuit elements to modify the resonant frequency, leading to inefficiencies and interference between transmit and receive paths.

Innovation Solution

A circulator design utilizing a plurality of branches with first and second acoustic wave resonators in series, each coupled with parallel switching devices, allowing for toggling to eliminate the need for lossy and non-linear elements and ensuring only one resonator is active at a time, thereby isolating transmit and receive paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional circulators use lossy and non-linear circuit elements to modify resonant frequency, then the resonant frequency can be adjusted, but insertion loss increases and efficiency decreases

Engineering Contradiction:

Improveresonant frequency adjustmentVSAvoidinsertion loss

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The single resonator is segmented into multiple resonators (first resonator and second resonator) with different fixed resonant frequencies. Switching elements are introduced to selectively connect different resonators to different ports, replacing the need for lossy frequency-modifying circuit elements. This segmentation allows frequency adaptation without insertion loss by choosing the appropriate resonator for the operating frequency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The circulator employs dynamic switching between different resonators using switching elements (such as switches or variable capacitors). The switching elements dynamically reconfigure the circuit connections to activate the appropriate resonator based on the operating frequency, enabling adaptability without requiring lossy non-linear elements traditionally used for frequency modification.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If conventional circulators use lossy circuit elements to modify resonant frequency, then frequency adaptation is achieved, but transmit and receive paths experience interference

Engineering Contradiction:

Improveresonant frequency modificationVSAvoidinterference between transmit and receive paths

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

By segmenting the resonator system into multiple independent resonators with distinct fixed frequencies, each resonator can be optimized for specific frequency bands. The switching elements isolate the active resonator from inactive ones, preventing interference between transmit and receive paths while maintaining frequency adaptability through selective activation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Switching elements act as intermediaries between the multiple resonators and the circulator ports. These switching elements selectively connect the appropriate resonator to the transmit or receive path, isolating the active path from the inactive path and eliminating interference while enabling frequency adaptation through controlled connection changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If a single resonator is used in conventional circulators, then the structure is simple, but lossy elements are required to modify resonant frequency

Engineering Contradiction:

Improveresonator structureVSAvoidinsertion loss from lossy elements

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

Instead of using a single resonator with lossy modifying elements, the invention segments the resonator function across multiple resonators with fixed but different resonant frequencies. This eliminates the need for lossy frequency-modifying circuit elements while achieving frequency adaptability through selective switching between the segmented resonators.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple resonators with different fixed frequencies collectively provide universal frequency coverage. By designing the set of resonators to cover the required frequency range, the system achieves multi-functionality (operating at multiple frequencies) without requiring lossy elements, as each resonator is optimized for its specific frequency with minimal losses.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 design minimizes interference and improves efficiency by eliminating the need for lossy and non-linear elements, enhancing signal routing and reducing insertion loss.

Implementation Method 1

Each of the branches comprises a first acoustic wave resonator and a second acoustic wave resonator coupled in series with the first acoustic wave resonator

Methodology Applied

Scientific EffectAcoustic wave resonance: Resonance

Data Source

PatentUS12597910B2Circulator for full duplex communications

Publication Date: 2026.04.07 QUALCOMM INC

AI summary

An example circulator generally includes a plurality of branches. Each of the branches includes a first acoustic wave resonator and a second acoustic wave resonator coupled in series with the first acoustic wave resonator. Each of the branches further includes a first switching device and a second switching device. The first switching device is coupled in parallel with the first acoustic wave resonator. The second switching device is coupled in parallel with the second acoustic wave resonator.