Non-Reciprocal Circuit Layout for Compact Quantum Signal Isolation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The challenge is to design a non-reciprocal circuit element with excellent isolation characteristics for high-frequency signals, particularly in the context of quantum computers where space is limited, such as in freezing chambers, requiring a small and efficient isolator or circulator.

Innovation Solution

A non-reciprocal circuit element comprising a conductor, magnetic body, absorber, and resonator, where the absorber and magnetic body are positioned differently in the thickness direction, and the resonator overlaps the absorber, with a DC magnetic field applied to control signal propagation, enhancing isolation by trapping high-frequency signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the volume of the freezing chamber is limited, then the quantum processor can be compact, but the non-reciprocal circuit element must be miniaturized to fit

Engineering Contradiction:

Improvevolume of freezing chamberVSAvoidsize of non-reciprocal circuit element

Core Design Contradiction:

Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent places the resonator inside the cavity formed by the conductor, and positions the absorber and magnetic body in overlapping regions with the resonator. This nested arrangement allows multiple functional components to occupy the same spatial envelope, achieving miniaturization of the non-reciprocal circuit element to fit within the limited freezing chamber volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes the thickness direction (z-direction) to arrange components at different positions. The absorber and magnetic body are positioned at different locations when viewed in the thickness direction, allowing three-dimensional packing of components to reduce the overall footprint and achieve compact dimensions suitable for the quantum processor.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If the isolation characteristic is improved, then signal direction control is enhanced, but the device size may increase

Engineering Contradiction:

Improveisolation characteristicVSAvoidvolume of non-reciprocal circuit element

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent combines conductor, magnetic body, absorber, and resonator into a composite non-reciprocal circuit element. The magnetic body provides non-reciprocal phase shift, the absorber provides signal attenuation in the reverse direction, and the resonator enhances the isolation effect through resonant coupling. This composite structure achieves excellent isolation characteristics while maintaining a compact form factor.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The resonator acts as an intermediary element that couples the conductor and enhances the isolation effect. By positioning the resonator to overlap with the absorber in the thickness direction, it mediates the interaction between the signal and the absorber, trapping high-frequency signals and improving isolation without requiring additional space.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Volume of moving object

If the non-reciprocal circuit element is miniaturized, then it can fit in the freezing chamber, but the isolation characteristic may deteriorate

Engineering Contradiction:

Improvevolume of non-reciprocal circuit elementVSAvoidisolation characteristic

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent concentrates the isolation function in specific local regions by positioning the absorber and magnetic body at particular locations when viewed in the thickness direction. The resonator is strategically placed to overlap with the absorber, creating localized regions of high isolation effect. This local quality approach maintains excellent isolation characteristics while minimizing the overall volume of the device.

Inventive Principle:

Principle #3Local quality

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

The design achieves improved isolation characteristics, allowing for miniaturization and effective signal direction control, suitable for quantum computers operating in confined spaces.

Implementation Method 1

a DC magnetic field applied to control signal propagation

Methodology Applied

Scientific EffectDC magnetic field: Magnetic Field

Implementation Method 2

enhancing isolation by trapping high-frequency signals

Methodology Applied

Scientific EffectResonance: Resonance

Implementation Method 3

The second region overlaps the absorber when viewed in the thickness direction

Methodology Applied

Scientific EffectAbsorption: Absorption (EM radiation)

Data Source

PatentUS20250322281A1Non-reciprocal circuit element and quantum computer

Publication Date: 2025.10.16 TDK CORP

AI summary

According to the present invention, a non-reciprocal circuit element includes a conductor, a magnetic body, an absorber, and a resonator. The absorber and the magnetic body are located at different positions when viewed in a thickness direction. The conductor has a first terminal and a second terminal. The conductor has a first region extending between the first terminal and the second terminal and a second region different from the first region. The first region overlaps the magnetic body when viewed in the thickness direction. The second region overlaps the absorber when viewed in the thickness direction. The resonator overlaps the absorber when viewed in the thickness direction.