Optical Receiver Circuit for Out-of-Band Signal Extraction

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Solution Overview

Problem

Existing optical receivers struggle to effectively detect and extract out-of-band (OOB) signals, which are crucial for monitoring and managing communication channels, due to the challenges of separating OOB data from high-speed in-band signals.

Innovation Solution

The implementation of an optical receiver circuit that includes a photodiode, current mirror circuits for extracting voltage differential signals, a limiting amplifier for amplifying these signals, and a demodulation circuit to extract the OOB data from the amplified signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional optical receiver circuits are used, then the structure is simple, but the ability to detect and extract out-of-band signals is insufficient

Engineering Contradiction:
ImproveOOB signal detection capabilityVSAvoidreceiver circuit structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The optical receiver circuit is segmented into distinct functional modules: photodiode for optical-to-electrical conversion, current mirror circuits for signal extraction, limiting amplifier for signal conditioning, and demodulation circuit for data recovery. Each module performs a specific function in the OOB signal detection chain, enabling precise detection while maintaining modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Current mirror circuits serve as intermediary components between the photodiode and limiting amplifier. These circuits convert the photocurrent from the photodiode into voltage differential signals that can be properly amplified and processed by subsequent stages, bridging the gap between optical detection and electrical signal processing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If OOB signals are not effectively detected, then the receiver structure remains simple, but monitoring and management of communication channels is impaired

Engineering Contradiction:
Improvechannel monitoring capabilityVSAvoidsignal extraction circuit
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The circuit extracts OOB signals by separating them from the main optical carrier through current mirror circuits that respond selectively to OOB frequency components. The limiting amplifier further extracts and conditions the OOB signal by clipping the amplified waveform to remove high-frequency in-band components, leaving only the OOB information for demodulation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The demodulation circuit processes the extracted OOB signal to recover monitoring data about channel status, power levels, and signal quality. This information provides feedback that can be used to adjust transmitter power, optimize receiver sensitivity, and maintain reliable communication links under varying conditions.

Inventive Principle:
Principle #23Feedback

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 solution enables efficient detection and extraction of OOB signals, allowing for improved monitoring and management of communication channels, which can lead to reduced power consumption and enhanced signal quality.

Implementation Method 1

a photodiode configured to generate an electrical signal based on a received optical out-of-band signal

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP4236348B1Out-of-band signal detection
Publication Date: 2025.04.23 II VI DELAWARE INC
  • EP4236348B1 patent drawingFigure 1~2
  • EP4236348B1 patent drawingFigure 3
  • EP4236348B1 patent drawingFigure 4

AI summary

An out-of-band (OOB) signal detector is disclosed. The OOB signal detector may include a first node configured to receive an alternating current (AC) portion and a direct current (DC) portion of an electrical signal. The AC portion may include modulated OOB data carried by the electrical signal. The OOB signal detector may also include a current to voltage processing circuit configured to extract the AC portion of the electrical signal. The OOB signal detector may additionally include a limiting amplifier circuit configured to receive the extracted AC portion and to generate an amplified signal based on the extracted AC portion. The OOB signal detector may further include an analog-to-digital converter circuit configured to sample the amplified signal and to generate a digital sample that represents the modulated OOB data.