Double Leaf Spring Finger Grounding for High-Speed Connectors

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Solution Overview

Problem

High-speed computer ports, such as those compatible with USB 3.0 or USB 3.1, generate radio frequency interference in the 2.4 GHz spectrum, degrading the sensitivity and functionality of nearby wireless devices like Wi-Fi and Bluetooth due to electromagnetic interference.

Innovation Solution

A communication port connector with a shell and double leaf spring fingers that electrically ground the plug to the device's chassis, minimizing energy leakage and interference by creating a conductive path between the plug and the device's ground plane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-speed ports (USB 3.0/3.1) are used to provide fast data transfer, then productivity is improved, but radio frequency interference is generated that degrades wireless device sensitivity

Engineering Contradiction:
Improvedata transfer speedVSAvoidradio frequency interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A ground spring finger acts as an intermediary element between the connector shell and the circuit board ground. This spring finger provides a dedicated low-impedance path for RF currents to flow to ground, mediating the interference issue by offering a controlled impedance path that prevents RF energy from radiating and affecting wireless devices while maintaining high-speed data transfer capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The ground spring finger's length is specifically designed to be less than one-tenth of the wavelength of the highest frequency signal. This parameter change ensures that the spring finger behaves as an electrically short element, presenting a low impedance path to ground for RF frequencies while maintaining mechanical flexibility and electrical connectivity for high-speed signals

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a ground spring finger is added to provide RF shielding, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveelectromagnetic shielding effectivenessVSAvoidconnector structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ground spring finger is integrated directly into the connector assembly, merging the RF grounding function with the existing connector structure. The spring finger is electrically connected to the connector shell and the circuit board ground, combining multiple functions (mechanical support, electrical connection, and RF shielding) into a single integrated component rather than adding separate discrete elements

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ground spring finger is designed as a flexible elastic component that can deform to accommodate assembly tolerances and maintain reliable electrical contact. This flexible design allows the grounding element to adapt to variations in assembly while maintaining low-impedance RF grounding, eliminating the need for complex adjustment mechanisms or rigid precision-machined ground structures

Inventive Principle:
Principle #30Flexible shells and thin films

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

Prevents radio frequency interference, allowing wireless devices to operate effectively even when close to high-speed connectors, enhancing usability and reducing user frustration by eliminating lag and connectivity issues.

Implementation Method 1

the spring finger is configured to contact the shell and the circuit board and is conductive between the shell and the circuit board

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

the spring finger includes an elastic body and a free end, the free end of the spring finger extending away from the circuit board when the spring finger is in the released state

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3602698B1Grounding for high-speed connectors
Publication Date: 2021.08.04 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3602698B1 patent drawingFigure 1
  • EP3602698B1 patent drawingFigure 2
  • EP3602698B1 patent drawingFigure 3

AI summary

To address the issue of radio frequency interference with high-speed connectors, a communication port connector for use in a computing device is provided. The communication port connector may include a shell that defines a void that is configured to receive an electrical plug. Port-side electrical contacts in the shell may be configured to make electrical connections with plug-side electrical contacts. One or more double leaf spring fingers may be formed in a side of the shell, with each double leaf spring finger including a first spring finger coupled to a second spring finger. The first spring finger may be configured to contact the electrical plug, and the second spring finger may be configured to contact a chassis of the computing device, thereby creating a ground path to ground the electrical plug to the primary ground plane of the device when it is inserted into the communication port connector.