Optical Receiver Shielding for Noise Resistance

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Solution Overview

Problem

Conventional optical receivers are susceptible to electromagnetic noise due to direct exposure of signal lines and terminals, leading to deterioration of reception sensitivity and amplification noise resistance, especially when integrated with optical transmitters in the same enclosure.

Innovation Solution

The optical receiver design incorporates a conductor pattern or ground pattern surrounding the signal lines to shield electromagnetic waves, with power sources integrated into the TIA chip, reducing external electromagnetic interference by grounding or using capacitors for stabilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If signal lines and terminals are directly exposed for easy connection, then ease of operation is improved, but electromagnetic noise susceptibility increases

Engineering Contradiction:
Improveconnection easeVSAvoidelectromagnetic noise susceptibility
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A conductor pattern or ground pattern is introduced as an intermediary shielding structure between external electromagnetic sources and the signal lines/terminals. This conductor pattern acts as a mediator that intercepts electromagnetic waves before they reach the sensitive signal lines, thereby reducing noise susceptibility while maintaining direct exposure connections for ease of operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If photodiodes and transimpedance amplifiers are integrated on the same chip, then device complexity is reduced, but electromagnetic interference increases

Engineering Contradiction:
Improveintegration levelVSAvoidelectromagnetic interference
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The integrated chip is segmented into distinct functional regions: a photodiode array region and a transimpedance amplifier region. The conductor pattern creates electromagnetic shielding partitions between these regions, allowing high-level integration while reducing internal electromagnetic interference through spatial segmentation and localized shielding

Inventive Principle:
Principle #1Segmentation

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 significantly reduces electromagnetic interference, enhancing the optical receiver's noise resistance and sensitivity, even in environments with high electrical noise from adjacent transmitters.

Implementation Method 1

The optical receiver design incorporates a conductor pattern or ground pattern surrounding the signal lines to shield electromagnetic waves

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

an optical receiver 2 and an optical transmitter 3. An input optical signal inputted to the optical receiver 2 is converted into electric signals by four channels of dual photodiodes (PDs) 5

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3474467B1Optical receiver
Publication Date: 2020.12.09 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP3474467B1 patent drawingFigure 1
  • EP3474467B1 patent drawingFigure 2
  • EP3474467B1 patent drawingFigure 3

AI summary

An optical receiver is configured so as to be as less susceptible to noise as possible even in the case where high noise occurs inside an optical transceiver. The optical receiver includes a connection part that connects two photodiodes (PDs) constituting a dual photodiode and a transimpedance amplifier (TIA), wherein signal lines from the dual photodiode are surrounded by a conductor pattern that is not connected to each of the signal lines for each channel, and the conductor pattern is connected to a ground pattern on the transimpedance amplifier or a power source pattern for the PDs.