Avalanche Photodiode Sensor for Incidence Angle Measurement
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Solution Overview
Problem
Existing radiation source position determination devices are complex, require large surfaces, and lack fully integrated solutions for precise and automatic measurement of incidence angles, particularly in applications like the automobile industry and building services engineering.
Innovation Solution
A semiconductor-based sensor with avalanche photodiodes and an application-specific integrated circuit for analogue signal processing, integrated on a single chip, which amplifies small radiation changes for high spatial resolution and minimizes surface area, allowing for compact and efficient determination of incidence angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate photo elements or sensor arrays are used for spatially resolved detection, then measurement precision of incidence angle is improved, but device complexity and surface area increase
Solution Approach 1:
The patent merges multiple photo-sensitive elements into a single integrated position-sensitive detector (PSD) chip that can detect radiation position directly, eliminating the need for separate optical components like lenses and multiple discrete sensors. This integration maintains high measurement precision while significantly reducing device complexity.
Solution Approach 2:
The patent introduces a microlens array as an intermediary component that focuses incident radiation onto the PSD chip, enabling precise angular measurement without requiring complex optical systems. The microlens array mediates between the radiation source and detector, simplifying the overall device structure.
2Device complexity
If digital readout of photo elements is used, then device complexity is reduced, but measurement precision deteriorates due to limited resolution
Solution Approach 1:
The patent replaces digital readout systems with an analogue evaluation circuit that directly processes the continuous position signal from the PSD chip. This substitution maintains high measurement precision by preserving the continuous nature of the position information while simplifying the evaluation process through direct analogue computation of incidence angles.
3Reliability
If larger photo sensitive surfaces are used, then detection capability for small currents is improved, but device size increases
Solution Approach 1:
The patent changes the operating parameters of the photo-sensitive elements by using a PSD chip with high internal gain capability and optimizing the evaluation circuit for maximum signal amplification. This allows the use of a compact sensor surface while maintaining high detection capability through enhanced signal processing rather than increased surface area.
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 enables precise and automatic determination of radiation source position with reduced surface area and simplified evaluation, achieving high spatial resolution and robustness against interference, suitable for compact integration in various applications.
Implementation Method 1
A single photon is sufficient to release an electron in avalanche photodiodes. This in turn triggers an avalanche effect through the acceleration by a field with a high field strength in the barrier layer. The impact ionization leads to a further generation of voltages. Therefore, an amplification of the effect by up to a hundred times takes place.
Implementation Method 2
A single photon is sufficient to release an electron in avalanche photodiodes
Data Source
AI summary
A sensor and a corresponding method for the determination of the incidence angle of a radiation source are provided. The sensor has a diode assembly of avalanche photodiodes in a semiconductor layer and an application specific integrated circuit, a distance layer, an aperture structure located on the distance layer, and contacts for electrically connecting the sensor. The layers and structures are positioned directly on top of each other and match in their shape, size or thickness.