Segmented Capacitive Rotary Coupler for Broadband Signal Transmission

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Solution Overview

Problem

Existing rotary couplings in military vehicles face challenges in transmitting broadband electrical signals due to wavelength-dependent effects, limiting the transmission to a narrow bandwidth, especially when the stator and rotor electrodes have dimensions comparable to the signal wavelength.

Innovation Solution

The stator and rotor electrodes are segmented into smaller components, with insulation between segments to prevent current flow and reduce line-theoretical effects, allowing for broadband signal transmission. The electrodes are designed with a circular shape and arranged around a cylindrical free space to accommodate optical components, and the segments are kept shorter than a quarter of the signal wavelength to minimize wavelength-dependent effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the stator electrode and/or the rotor electrode is designed as a continuous circumferential conductor, then the transmission of electrical signals is enabled, but transmission line effects occur that degrade transmission characteristics and limit the bandwidth to a narrow wavelength range

Engineering Contradiction:
Improvesignal transmission qualityVSAvoidbandwidth range
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The continuous circumferential stator electrode and/or rotor electrode is divided into multiple discrete electrode segments arranged along the circumferential direction. This segmentation prevents the formation of continuous transmission lines that cause wavelength-dependent effects, thereby enabling broadband signal transmission across a wide frequency range while maintaining reliable electrical signal transfer between the stationary and rotating components.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the stator electrode and/or the rotor electrode is segmented into smaller components, then wavelength-dependent transmission effects are reduced and broadband transmission is enabled, but the device complexity increases

Engineering Contradiction:
Improvebandwidth rangeVSAvoidelectrode structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The electrode is divided into multiple segments that can be independently positioned and electrically isolated from each other. This segmentation approach reduces wavelength-dependent transmission effects by breaking up continuous current paths, thereby enabling broadband operation. The modular segmented structure allows for flexible configuration and easier manufacturing compared to attempting to create a perfectly continuous electrode with controlled impedance characteristics.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different segments of the electrode can be optimized for specific local requirements, such as varying segment lengths or positions to accommodate the rotational movement and maintain optimal capacitive coupling at different rotation angles. This local optimization allows the overall system to achieve broadband performance without requiring complex global electrode designs.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the stator electrode and/or the rotor electrode is arranged around a large diameter free space to accommodate optical components, then the free space for optical components is increased, but the circumference becomes comparable to the signal wavelength, causing transmission line effects

Engineering Contradiction:
Improvefree space volumeVSAvoidsignal transmission quality
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

By segmenting the electrode into discrete sections arranged around the large diameter free space, the continuous circumferential path is broken into smaller segments. This prevents the formation of transmission line effects even when the overall circumference is large, allowing the free space to accommodate optical components like periscopes while maintaining reliable electrical signal transmission through the rotary coupling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The segmented electrode structure acts as an intermediary between the large diameter free space requirement and the signal transmission quality requirement. The segments are positioned to maintain adequate capacitive coupling for signal transmission while being electrically isolated to prevent continuous current paths around the large circumference, thus mediating between the conflicting spatial and electrical requirements.

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 configuration enables efficient broadband transmission of electrical signals, including VHF signals, while allowing for the presence of optical components like periscopes, by reducing wavelength-dependent effects and maintaining a large free space diameter, thus enhancing communication capabilities in military vehicles.

Implementation Method 1

a rotary coupling (9), in particular a capacitive rotary coupling, for non-contact transmission of an electrical signal, comprising a stator electrode (21) and a rotor electrode (11), which are capacitively coupled to one another

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP2715863B1Rotary coupler for non-contact transmission of an electrical signal and vehicle
Publication Date: 2019.07.31 KRAUSS MAFFEI WEGMANN GMBH & CO KG
  • EP2715863B1 patent drawingFigure 1
  • EP2715863B1 patent drawingFigure 2~3
  • EP2715863B1 patent drawingFigure 4~5

AI summary

The invention relates to a swivel coupling for the non-contact transmission of an electrical signal, in particular a VHF signal, having a stator electrode (21) and a rotor electrode (11), which is capacitively coupled to the stator electrode (21) and is rotatable with respect to the stator electrode (21), wherein the stator electrode (21) and/or the rotor electrode (11) are/is segmented. The invention also relates to a vehicle (1) having a signal generator, in particular for VHF signals, and an antenna that is connected to the signal generator, wherein the signal generator and the antenna are connected by means of such a swivel coupling.