Connector Assembly Differential Signal Pair Polarity Offset

Solution Overview

Problem

As electronic systems become smaller, faster, and more complex, backplanes face challenges in reducing electrical noise, particularly crosstalk, due to increased signal density and frequency, which degrades signal transmission characteristics.

Innovation Solution

The system employs a connector configuration where differential signal pairs on a backplane have alternating reverse connections, with each pair connecting from a positive launch to a negative launch and vice versa, effectively canceling out crosstalk noise between connectors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If signal conductors are placed closer together to increase density, then the quantity of signals per unit area increases, but electrical noise and crosstalk between conductors increases

Engineering Contradiction:

Improvesignal densityVSAvoidcrosstalk noise

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies pin reversal by swapping the polarity assignments of adjacent differential signal pairs between connector halves. Specifically, odd-numbered pairs connect positive-to-positive and negative-to-negative, while even-numbered pairs connect positive-to-negative and negative-to-positive. This inversion of the conventional uniform connection pattern creates alternating polarity sequences that cause noise signals to cancel each other out, thereby reducing crosstalk while maintaining high signal density

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the harmful crosstalk noise generated by closely spaced conductors into a beneficial cancellation effect. By deliberately creating alternating polarity sequences through pin reversal, the noise signals induced in adjacent pairs have opposite polarities and thus cancel each other out. This transforms the harmful electromagnetic coupling into a useful noise reduction mechanism, allowing high-density routing without sacrificing signal quality

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If signal speed and frequency are increased to improve system performance, then productivity increases, but electrical noise and energy loss increase

Engineering Contradiction:

Improvesignal transmission speedVSAvoidelectrical noise

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies pin reversal by swapping the polarity assignments of adjacent differential signal pairs between connector halves. Specifically, odd-numbered pairs connect positive-to-positive and negative-to-negative, while even-numbered pairs connect positive-to-negative and negative-to-positive. This inversion of the conventional uniform connection pattern creates alternating polarity sequences that cause noise signals to cancel each other out, thereby reducing crosstalk while maintaining high signal density

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the harmful crosstalk noise generated by closely spaced conductors into a beneficial cancellation effect. By deliberately creating alternating polarity sequences through pin reversal, the noise signals induced in adjacent pairs have opposite polarities and thus cancel each other out. This transforms the harmful electromagnetic coupling into a useful noise reduction mechanism, allowing high-density routing without sacrificing signal quality

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Volume of moving object

If connectors are made smaller to reduce backplane size, then the volume of the system decreases, but manufacturing precision requirements increase

Engineering Contradiction:

Improvebackplane sizeVSAvoidconnector precision

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent segments the connector into distinct odd and even numbered signal pairs with different connection patterns. This segmentation allows the implementation of pin reversal on a pair-by-pair basis, making the complex noise cancellation scheme manageable and manufacturable. Each differential pair can be independently configured, which simplifies the manufacturing process compared to redesigning the entire connector geometry

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS8216001B2Connector assembly having adjacent differential signal pairs offset or of different polarity

Publication Date: 2012.07.10 AMPHENOL CORP

AI summary

A connector for connecting a first printed circuit board with a second printed circuit board that comprises a first column of differential signal pair launches offset from a second column of differential signal pair launches on the first printed circuit board so that each differential signal pair in the first column is closest to a launch of a first polarity in a corresponding differential signal pair in the second column on the first circuit board, a first column of differential signal pair launches offset from a second column of differential signal pair launches on the second printed circuit board so that each differential signal pair in the first column is closest to a launch of a second polarity, opposite the first polarity, in a corresponding signal pair in the second column on the second circuit board, and a connector electrically connecting the first column of differential signal pair launches on the first printed circuit board to the first column of differential signal pair launches on the second printed circuit board and electrically connecting the second column of differential signal pair launches on the first printed circuit board to the second column of differential signal pair launches on the second printed circuit board.