Visible Light Receiver Circuit with Nonlinear Resistive Bias Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional visible light communication systems face communication errors due to ambient light noise, particularly sunlight, which increases the DC component of the photocurrent, reducing the reverse bias voltage applied to photodiodes and leading to system failures.
Innovation Solution
A visible light receiver circuit with a photoelectric conversion unit that includes a light receiving element, a first resistive element, and a nonlinear resistive circuit connected in parallel, where the nonlinear resistive circuit's resistance decreases with increasing DC component of the photocurrent, maintaining a stable bias voltage for the light receiving element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional photoelectric conversion unit with a simple resistor is used, then the circuit configuration is simple and cost is reduced, but the reverse bias voltage becomes unstable under high ambient light conditions causing communication errors
Solution Approach 1:
The patent changes the electrical parameter (resistance) of the resistive element based on the DC component of photocurrent. The resistive element's resistance decreases as the DC component increases, which compensates for the voltage drop and maintains stable reverse bias voltage across varying ambient light conditions.
Solution Approach 2:
The resistive element automatically adjusts its own resistance based on the DC component of the photocurrent without requiring external control circuits. This self-adjusting mechanism maintains stable reverse bias voltage while keeping the circuit simple and avoiding additional active components.
2Object-affected harmful factors
If ambient light shielding measures are implemented, then the influence of ambient light noise is reduced, but the device structure becomes complex and costly
Solution Approach 1:
The patent extracts and addresses only the DC component of the ambient light noise through the nonlinear resistive element, while allowing the AC component (signal) to pass through unaffected. This selective handling of the harmful DC component avoids the need for complex shielding structures.
Solution Approach 2:
By changing the resistance parameter of the resistive element based on the DC component level, the patent dynamically compensates for ambient light noise without requiring physical shielding structures, thereby maintaining device simplicity.
3Reliability
If active bias control circuits are used, then the reverse bias voltage stability is improved, but the circuit complexity increases and noise is introduced
Solution Approach 1:
The resistive element serves itself by automatically adjusting its resistance based on the DC component of the photocurrent. This eliminates the need for external active control circuits, operational amplifiers, or feedback mechanisms that would add complexity and noise.
Solution Approach 2:
The patent uses a simple passive resistive element instead of complex active control circuits. This disposable-like simple component achieves bias stability without requiring expensive or complex active components, maintaining circuit simplicity and low noise.
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
The solution ensures a stable reverse bias voltage for the photodiode even under high ambient light conditions, reducing noise and maintaining communication integrity while simplifying the circuit configuration and reducing costs.
Implementation Method 1
a photoelectric conversion unit 110 including a photodiode 111 serving as a light receiving unit
Implementation Method 2
a nonlinear resistive circuit unit connected to the first resistive element in parallel, the nonlinear resistive circuit unit having a resistance decreasing with an increase in an applied voltage thereof
Data Source
AI summary
A visible light receiver circuit, which reduces the influence of ambient light, has a simple configuration, and generates low noise, is provided. The visible light receiver circuit includes a photoelectric conversion unit. The photoelectric conversion unit includes a photodiode having a cathode connected to a power source, a resistor connected in series to an anode of the photodiode, and a nonlinear resistive circuit connected in parallel to the resistor. The nonlinear resistive circuit includes, for example, a series circuit including a Zener diode and a resistor.