Flexible Planar Transmission Line With Dual-Filter Mode Suppression

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Solution Overview

Problem

Existing flexible planar transmission lines for cryogenic circuits suffer from limited signal attenuation beyond a certain frequency, leading to significant leakage of higher order EM modes, which restricts overall filtering effectiveness and requires numerous transmission lines for qubit communication, increasing thermal noise and power consumption.

Innovation Solution

A flexible planar transmission line design featuring a concatenation of two filters: a low-pass filter to attenuate frequency components and a high-pass filter to attenuate higher order EM modes, combined with EM absorptive materials and a meander-shaped signal line, to achieve improved attenuation across a wider frequency range and reduce thermal noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a single low-pass filter is used to attenuate frequency components, then attenuation is achieved up to a dedicated cut-off frequency, but higher order EM modes propagate well above the cut-off frequency and convert back to ground mode, causing signal leakage

Engineering Contradiction:

Improvesignal attenuationVSAvoidfiltering effectiveness

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The filtering function is segmented into two distinct filters: a first low-pass filter for attenuating frequency components up to the cut-off frequency, and a second high-pass filter for attenuating higher order EM modes. This segmentation allows each filter to specialize in a specific frequency range, preventing the leakage problem where higher order modes would otherwise convert back to ground mode and bypass the filtering effect.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second high-pass filter acts as an intermediary element that specifically targets and attenuates higher order EM modes before they can convert back to ground mode and cause signal leakage. This intermediary filter complements the first low-pass filter by handling the frequency components that the first filter cannot effectively attenuate.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the number of transmission lines is increased to accommodate more qubits, then individual communication capability is improved, but thermal noise and power consumption increase

Engineering Contradiction:

Improvequbit communication capabilityVSAvoidthermal noise and power consumption

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The dual-filter configuration provides universal filtering capability that benefits all signal lines passing through it. Instead of requiring separate filtering solutions for each transmission line, the concatenated filters create a robust filtering system that can be shared across multiple qubit communication channels, reducing the overall thermal noise and power consumption while maintaining individual communication capability.

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

The solution provides enhanced signal attenuation up to 80 dB at 6 GHz, reducing thermal noise and power consumption while maintaining flexibility and scalability, enabling efficient communication with cryogenic qubit devices.

Implementation Method 1

the first filter comprises a first chamber provided in the dielectric layer between the signal line and the first conducting layer, wherein the first chamber comprises EM absorptive material

Methodology Applied

Scientific EffectElectromagnetic absorption: Absorption (EM radiation)

Implementation Method 2

a second filter arranged to attenuate higher order modes of the signal, wherein the second filter comprises a second chamber provided in the dielectric layer

Methodology Applied

Scientific EffectElectromagnetic mode attenuation: Filter (electronic)

Data Source

PatentUS20240421459A1Flexible planar transmission line with a filter

Publication Date: 2024.12.19 DELFT CIRCUITS BV

AI summary

The invention relates to a flexible planar transmission line for communication between a first electronic device and a second electronic device. The flexible planar transmission line comprises a first conducting layer, a dielectric layer, a second conducting layer, a signal line provided in the dielectric layer and a concatenation of a first filter and a second filter, wherein the first filter being arranged to attenuate frequency components of a signal and a second filter being arranged to attenuate higher order modes of the propagated signal.