Differential Optical Receiver Circuit for Crosstalk Cancellation

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Solution Overview

Problem

Optical communication devices face challenges in reducing electromagnetic crosstalk in complex radiation environments, which affects the performance of optical receivers in processing optical signals.

Innovation Solution

The optical receiver design includes a photodetector and a trans-impedance amplifier with differential branch circuits and a differential amplifier, which divides and cancels interference signals to reduce electromagnetic crosstalk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the optical receiver operates in complex electromagnetic radiation environments, then the optical communication device can function in diverse conditions, but electromagnetic crosstalk occurs during signal processing

Engineering Contradiction:

Improveoperation in complex electromagnetic radiation environmentsVSAvoidelectromagnetic crosstalk

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The trans-impedance amplifier is divided into two separate differential branch circuits: a first differential branch circuit that receives an input signal from a power supply end of the photodetector, and a second differential branch circuit that receives an output signal from the photodetector. Each branch processes signals independently and outputs to separate input ends of the differential amplifier, enabling separate transmission paths for interference signals that can be canceled through differential amplification.

Inventive Principle:

Principle #1Segmentation

2Productivity

If electromagnetic crosstalk signals are present in the optical receiver, then signal processing can continue, but signal transmission accuracy deteriorates

Engineering Contradiction:

Improvesignal processing capabilityVSAvoidsignal transmission accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent converts harmful electromagnetic crosstalk signals into useful differential-mode interference signals that can be canceled. By dividing the crosstalk into two parts and transmitting them through separate differential branch circuits, the interference signals become differential-mode signals that the differential amplifier can reject, thereby converting the harmful effect into a benefit for improving signal transmission accuracy.

Inventive Principle:

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

3Device complexity

If a single trans-impedance amplifier configuration is used, then device complexity is low, but electromagnetic crosstalk cannot be effectively reduced

Engineering Contradiction:

Improvetrans-impedance amplifier structureVSAvoidelectromagnetic crosstalk

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The trans-impedance amplifier is segmented into two independent differential branch circuits with separate signal paths. The first branch circuit includes a first capacitor and first trans-impedance amplifying unit, while the second branch circuit includes a second trans-impedance amplifying unit. Each branch has its own input and output connections to the differential amplifier, creating physically separate transmission paths that enable effective crosstalk cancellation through differential amplification.

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 design improves the reception performance of the optical receiver by increasing the signal-to-noise ratio and ensuring accurate signal transmission.

Implementation Method 1

an optical receiver includes a photodetector and a trans-impedance amplifier

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

the differential amplifier is configured to perform differential amplification processing on the reference signal and the amplified electrical signal

Methodology Applied

Scientific EffectDifferential Amplification:

Data Source

PatentUS20250038862A1Optical receiver

Publication Date: 2025.01.30 HUAWEI TECH CO LTD

AI summary

This application relates to an optical receiver. The optical receiver includes a photodetector and a trans-impedance amplifier that includes a first differential branch circuit, a second differential branch circuit, and a differential amplifier. The first differential branch circuit includes a first capacitor and a first trans-impedance amplifying unit, where an input end of the first capacitor receives an input signal from a power supply end of the photodetector, and an output end of the first capacitor is coupled to an input end of the first trans-impedance amplifying unit. The first differential branch circuit is configured to: amplify the input signal and output a reference signal. The second differential branch circuit is configured to amplify an electrical signal from the photodetector. Signal physical parameter values of the reference signal and an interference signal included in an amplified electrical signal are the same or similar.