Optical Receiver Threshold Adjustment for Dispersion-Distorted Signals
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Solution Overview
Problem
Existing optical receivers face challenges in maintaining sensitivity due to waveform distortion caused by dispersion in optical transmission lines and changes in optical signal intensity, often requiring large AGC circuits that increase power consumption and size.
Innovation Solution
An optical receiver design incorporating a light-receiving block, discriminating block, detecting block, controlling block, and adjusting block, which generates signals to adjust the offset voltage of a differential amplifier, allowing the crosspoint in complementary signal waveforms to adapt to dispersion, distance, and intensity, thereby maintaining sensitivity without an AGC circuit and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an AGC circuit is installed to suppress reduction in optical sensitivity, then optical sensitivity is maintained, but the receiver becomes large and consumes large amounts of power
Solution Approach 1:
The patent extracts and eliminates the AGC circuit from the receiver structure, replacing it with a simplified threshold adjustment mechanism that achieves the same sensitivity maintenance function without the complexity and power consumption of traditional AGC circuits
Solution Approach 2:
The patent changes the threshold parameter dynamically based on detected waveform characteristics (such as crosspoint position) to maintain optimal reception sensitivity without requiring complex AGC circuitry, thereby reducing device size and power consumption while preserving reliability
2Reliability
If an AGC circuit is installed to suppress reduction in optical sensitivity, then optical sensitivity is maintained, but power consumption increases
Solution Approach 1:
The patent removes the power-intensive AGC circuit and replaces it with a low-power threshold adjustment mechanism that achieves sensitivity maintenance through simpler electronic components and algorithms
Solution Approach 2:
The patent implements dynamic threshold parameter adjustment based on waveform analysis, which consumes significantly less power than traditional AGC circuits while achieving the same goal of maintaining optical sensitivity across varying signal conditions
3Reliability
If intensity detection is used to suppress reduction in optical sensitivity, then some sensitivity maintenance is achieved, but it is insufficient for dispersion-induced waveform distortion
Solution Approach 1:
The patent implements dynamic threshold adjustment that adapts to different waveform distortion types (including dispersion-induced distortion) by detecting crosspoint position and other waveform characteristics, making the system versatile against multiple distortion mechanisms rather than relying on fixed intensity detection
Solution Approach 2:
The patent replaces the insufficient intensity detection mechanism with a more sophisticated waveform analysis system that examines crosspoint position and other temporal characteristics, enabling effective compensation for dispersion-induced waveform distortion that simple intensity detection cannot address
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 effectively suppresses sensitivity reduction from waveform distortions and intensity changes, enabling a more compact and power-efficient optical receiver by dynamically adjusting the bias voltage of the avalanche photodiode based on dispersion, distance, and intensity signals.
Implementation Method 1
a semiconductor light-receiving element which receives an optical signal and outputs a photo current in accordance therewith
Data Source
AI summary
An optical receiver of the present embodiment has a light-receiving block, a discriminating block, a detecting block, a controlling block, and an adjusting block. The light-receiving block generates complementary signals in accordance with a photo current output from a semiconductor light-receiving element which receives an optical signal. The discriminating block has a differential amplifier having input terminals connected to output terminals of the light-receiving block via respective coupling capacitors. The detecting block generates an intensity signal corresponding to the photo current. The controlling block generates a first signal in accordance with a dispersion signal corresponding to dispersion of an optical transmission line, a distance signal corresponding to the distance of the optical transmission line, and an intensity signal. The adjusting block generates a second signal used for adjusting an offset voltage between the inputs of the differential amplifier in accordance with the first signal, and an output terminal of the adjusting block is connected to one of the input terminals of the differential amplifier for providing the second signal.