Weak Signal Detection System for Electron Microscopes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing weak signal detection systems face challenges in improving signal detection accuracy in semiconductor inspection devices and electron microscopes, particularly due to increased complexity, power consumption, and instability caused by noise generation circuits, especially when noise intensity is weak or absent.
Innovation Solution
A nonlinear signal detection system comprising a statistical data acquisition unit, nonlinear characteristic unit, signal detection ratio evaluation unit, parameter adjustment unit, and signal processing unit, which measures and adjusts parameters to optimize signal processing and noise handling, reducing the need for noise generation circuits and improving signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If averaging operations are increased to improve signal detection accuracy, then signal-to-noise ratio improves, but device complexity and power consumption increase
Solution Approach 1:
The patent applies parameter changes by modifying the statistical parameters (mean and variance) of the noise signal to transform weak or absent noise into optimal noise levels that enhance signal detection. This allows the system to achieve high signal-to-noise ratios without increasing the number of averaging operations or processing channels, thereby improving measurement precision while avoiding increased device complexity.
Solution Approach 2:
The patent converts the harmful effect of weak or absent noise (which limits signal detection) into a beneficial effect by artificially generating noise with optimized statistical parameters. This transformed noise becomes a useful resource that enhances signal detection capability without requiring additional hardware complexity or power consumption.
2Measurement precision
If noise generation circuits are added to improve signal detection, then signal-to-noise ratio improves, but device complexity and power consumption increase
Solution Approach 1:
The patent implements self-service by using the existing detector's inherent noise characteristics and signal processing capabilities to generate and process the noise signal. Instead of adding separate noise generation circuits, the system utilizes its own existing components (detector, amplifier, signal processing unit) to perform noise generation and processing, thereby avoiding additional power consumption and device complexity.
3Measurement precision
If noise intensity is increased to improve signal detection, then signal-to-noise ratio improves, but system stability deteriorates due to noise wrapping around peripheral circuits
Solution Approach 1:
The patent applies parameter changes by precisely controlling the statistical parameters (mean and variance) of the generated noise signal. By optimizing these parameters, the system achieves the desired signal-to-noise ratio while maintaining system stability. The noise is generated with controlled intensity and characteristics that prevent it from wrapping around peripheral circuits and causing instability.
Solution Approach 2:
The patent implements feedback by using the signal detection ratio evaluation unit to assess the quality of signal detection and the parameter adjustment unit to optimize noise signal parameters based on this evaluation. This closed-loop feedback mechanism ensures that noise intensity is optimized for signal detection while maintaining system stability, preventing noise from becoming excessive and causing instability.
Data Source
AI summary
This weak signal detection system has: a statistical data acquisition unit which measures the average value or distribution of an input signal in which is noise superimposed on a desired signal, calculates parameters such as the amplitude or noise dispersion of the desired signal, and outputs the calculated data obtained thereby; a nonlinear characteristic unit which outputs a signal having a nonlinear response with respect to the magnitude of the voltage or the current of the input signal; a signal detection ratio evaluation unit which determines whether the output signal from the nonlinear characteristic unit is the desired signal, calculates the detection ratio in the event that the signal is the desired signal, and outputs detection ratio data; a parameter adjustment unit which, on the basis of detection ratio data obtained by the signal detection ratio evaluation unit and calculated data obtained by the statistical data acquisition unit, adjusts a control parameter pertaining to the responsiveness of the nonlinear characteristic unit; and a signal processing unit which performs signal processing of the output signal of the nonlinear characteristic unit, and conversion to digital data or image data. In so doing, it is possible to provide a weak signal detection system having improved signal detection accuracy, and an electron microscope equipped with the system.