Proximity Sensor with Separate Waveguide Paths
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Solution Overview
Problem
Existing proximity sensors face limitations in achieving a wide detection range and are often dependent on the permeability of the metallic target, with fixed bandwidths and limited range due to resonance frequency methods, making it difficult to accurately measure distances beyond a certain threshold.
Innovation Solution
A proximity sensor utilizing a microwave oscillator that emits a transmission wave, with a waveguide design allowing for separate transmission and reception paths, enabling the determination of both reflection and transmission factors to calculate distance independently of target permeability, thereby extending the detection range and improving linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If resonance frequency method is used for distance measurement, then measurement precision is improved, but detection range is limited
Solution Approach 1:
The patent divides the waveguide into separate transmission and reception paths, allowing independent optimization of each path for precision while extending overall detection range through the combined system architecture
Solution Approach 2:
The patent changes the operating parameters by using microwave frequencies with separate transmission and reception paths, enabling the system to achieve both high measurement precision through resonance detection and extended detection range by operating outside the constraints of single-path resonance methods
2Device complexity
If fixed bandwidth operation is used, then device complexity is reduced, but adaptability is limited
Solution Approach 1:
The patent implements dynamic bandwidth adjustment capability where the system can adapt its operational bandwidth based on detection requirements, allowing it to switch between narrow bandwidth for precision measurements and wider bandwidth for extended range detection without increasing fundamental device complexity
3Measurement precision
If resonance frequency method is used, then measurement precision is improved, but target permeability dependency increases
Solution Approach 1:
The patent extracts the reception path from the transmission path, allowing the system to measure both reflection and transmission factors independently. This enables calculation of distance that compensates for target permeability effects by using the transmission path as a reference
Solution Approach 2:
The separate reception path acts as an intermediary that provides reference measurements, allowing the system to mediate between the transmitted and reflected signals to eliminate target permeability dependency while maintaining measurement precision
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 provides a significantly wider detection range, up to a factor of 10, with improved linearity and the ability to detect very small distances, while being independent of target permeability and allowing for narrow or zero bandwidth operation, compliant with EMV requirements.
Implementation Method 1
a microwave oscillator which provides an output signal which is provided as a transmission wave 16 and is irradiated in the direction of a target 12 as a free space transmission wave 16c
Implementation Method 2
the target 12, which is electrically conductive or at least has an electrically conductive surface, reflects as free space reflection wave 30a
Implementation Method 3
The transmission wave 16 is led into a waveguide 22 as a waveguide transmission wave 16b
Data Source
AI summary
A proximity sensor for measuring the distance from a target contains a microwave oscillator providing a transmission wave output signal emitted toward the target as a free space transmission wave which is reflected by an electrically conductive target surface as a free space reflection wave received by the proximity sensor as a reflection wave. The distance is determined from the transmission wave and the reflection wave. The transmission wave is guided in a waveguide transmission path as a waveguide transmission wave. The transmission wave is coupled into the waveguide with a wave mode leading to the detachment of the waveguide transmission wave at the waveguide front end aperture into the free space transmission wave and to the propagation of the free space transmission wave to the target. At least one reception path is electromagnetically decoupled from the transmission path and guides the reflection wave as a waveguide reflection wave.