Circuit Board Layout Using Power-Line Capacitance for HF Noise Control

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Solution Overview

Problem

Conventional circuit boards face challenges in reducing noise interference with high frequency signals transmitted through signal conductors, particularly due to noise coupling through power supply conductors.

Innovation Solution

The circuit board design includes a signal conductor, a power supply conductor that extends along at least a portion of the signal conductor, and a first reference conductor insulated from both the signal and power supply conductors. This configuration utilizes capacitance between the power supply and signal conductors to define a high frequency signal transmission line, reducing noise interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the power supply conductor is connected to the first reference conductor to reduce insertion loss, then the insertion loss of the power supply line is reduced, but noise from the power supply conductor affects the high frequency signal transmitted through the signal conductor

Engineering Contradiction:

Improveinsertion lossVSAvoidnoise interference

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The power supply conductor is divided into two segments: a first power supply conductor connected to the signal conductor for reducing insertion loss, and a second power supply conductor connected to the reference conductor for noise reduction. This segmentation allows each segment to perform its specific function independently without interfering with each other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The harmful noise coupling function is extracted from the power supply system by separating the noise-sensitive reference conductor connection from the signal-conductor connection. The second power supply conductor specifically handles the reference conductor connection, isolating it from the signal path to prevent noise extraction into the signal line.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If the power supply conductor extends along the signal conductor to reduce insertion loss, then the power supply effectiveness is improved, but the device complexity increases due to additional conductor arrangements

Engineering Contradiction:

Improvepower supply effectivenessVSAvoidconductor arrangement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The first power supply conductor serves multiple functions: it provides power supply to the signal conductor, acts as a reference for the signal conductor, and reduces insertion loss. This multi-functionality reduces the need for separate components and simplifies the overall conductor arrangement.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The power supply function and reference function are merged in the first power supply conductor, which is connected to both the signal conductor and the reference conductor. This merging reduces the number of separate conductors needed and simplifies the overall structure while maintaining effectiveness.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the first reference conductor is connected to the power supply potential, then the reference function is provided, but noise from the power supply conductor couples into the reference conductor and affects the high frequency signal

Engineering Contradiction:

Improvereference functionVSAvoidnoise coupling

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The second power supply conductor acts as an intermediary between the reference conductor and the power supply potential. It provides the necessary reference function while isolating the reference conductor from direct noise coupling with the signal conductor, thus mediating between power supply and reference needs without harmful interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively reduces or prevents noise from affecting high frequency signals, while also minimizing the size and insertion loss of the circuit board by optimizing the layout and function of the power supply and reference conductors.

Implementation Method 1

This configuration utilizes capacitance between the power supply and signal conductors to define a high frequency signal transmission line, reducing noise interference.

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS12342452B2Circuit board and electronic device

Publication Date: 2025.06.24 MURATA MFG CO LTD

AI summary

A circuit board includes a board body, a signal conductor, a power supply conductor, and a first reference conductor. The signal conductor is in the board body and a high frequency signal is transmitted through the signal conductor. The power supply conductor is in the board body and is connected to a power supply potential. The power supply conductor extends along at least a portion of the signal conductor. The first reference conductor is in the board body and is insulated from the signal conductor and the power supply conductor.