Receiver Sensitivity Control for Photodiode Over-Modulation
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Solution Overview
Problem
Existing compensating sensor systems face issues where receiver sensitivity is not independent of the operating point, leading to potential over-modulation, especially when using photodiodes, which can result in an unusable signal due to sunlight illumination.
Innovation Solution
A method is introduced to adjust the sensitivity of the receiver using control signals within a control loop, ensuring that the receiver output signal is reset except for control errors, and an additional control signal measures changes in physical values like light or magnetic field strengths, using a combination of control loops to maintain sensitivity and compensate for transmitter signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the receiver sensitivity is increased to improve signal detection capability, then the measurement precision is improved, but over-modulation occurs under strong illumination conditions such as sunlight
Solution Approach 1:
The receiver sensitivity is made dynamically adjustable through a control loop that automatically adapts the sensitivity based on the detected signal level. This allows the system to maintain high sensitivity for weak signals while reducing sensitivity to prevent over-modulation under strong illumination, thereby resolving the contradiction between measurement precision and reliability under varying light conditions
Solution Approach 2:
A feedback control loop is implemented that continuously monitors the receiver output signal and adjusts the receiver sensitivity accordingly. The control loop detects when over-modulation is approaching and reduces sensitivity to maintain signal usability, thus resolving the contradiction by using feedback to balance precision and reliability
2Reliability
If the receiver sensitivity is decreased to prevent over-modulation under strong illumination, then the reliability under sunlight is improved, but the measurement precision for weak signals deteriorates
Solution Approach 1:
The system employs dynamic sensitivity adjustment where the receiver sensitivity is not fixed but varies automatically based on the input signal strength. This allows the system to maintain high sensitivity for weak signals and reduce sensitivity for strong signals, resolving the contradiction between reliability under sunlight and measurement precision for weak signals
Solution Approach 2:
The receiver sensitivity parameter is changed dynamically based on the operating conditions. The control loop modifies the sensitivity parameter in real-time to match the illumination conditions, thereby maintaining both reliability under sunlight and measurement precision across different signal strengths
3Device complexity
If a fixed receiver sensitivity is used to simplify the system design, then the device complexity is reduced, but the system cannot adapt to varying operating conditions
Solution Approach 1:
The system implements self-service through an automatic control loop that monitors the receiver output and adjusts the sensitivity without external intervention. This self-adjusting mechanism provides adaptability to varying operating conditions while keeping the user interface simple, effectively resolving the contradiction between device complexity and adaptability
Solution Approach 2:
A feedback control mechanism is introduced that automatically adjusts the receiver sensitivity based on the detected signal conditions. This feedback loop provides the necessary adaptability for varying operating conditions while maintaining relatively simple device architecture, resolving the contradiction between complexity and versatility
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 approach prevents over-modulation and maintains stable receiver sensitivity, ensuring accurate signal generation even under varying conditions, such as sunlight illumination, by dynamically adjusting the receiver's sensitivity and compensating for system noise and control errors.
Implementation Method 1
In the case of employing a photodiode as a sensor, the illumination with sunlight might lead to an over-modulation
Implementation Method 2
at least one receiver D is a hall sensor
Data Source
AI summary
A receiver compensation system and method to operate the receiver compensation system are disclosed. The compensation sensor system includes at least one receiver and at least one control loop. The method to operate the receiver compensation system is characterized in that the receiver is adjusted in its sensitivity by a control signal such that in the case of changes of an input received by the receiver, a control signal of the control loop resets an associated receiver output signal, except for a control error. Further, at least one other signal of the control loop represents or contains a measurement of the change of the input received by the receiver.