High-Voltage Noise Cancellation Using Floating Isolated Supplies

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Solution Overview

Problem

High voltage signals used in electron microscopes are noisy, leading to reduced accuracy in measurements due to distortion of scan patterns and detection signals, and existing noise reduction solutions are large, expensive, and inefficient.

Innovation Solution

A high voltage noise reduction unit comprising an input for receiving high voltage signals, positive and negative isolated supply units, a low pass filter, and an amplifier to filter and amplify the signal, utilizing low voltage components that are less noisy and cost-effective, breaking the linkage between nominal voltage and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a passive filter is used to suppress high voltage noise, then noise reduction is achieved, but the device becomes very big and expensive

Engineering Contradiction:

Improvenoise levelVSAvoiddevice size

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent replaces the mechanical/passive filter system with an active electronic system consisting of operational amplifiers and feedback circuits. This substitution allows noise suppression to be achieved through electronic control rather than physical filtering components, dramatically reducing the device size while maintaining effectiveness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the operating parameters by using high voltage supply with active control circuits that dynamically adjust to maintain low noise levels. The system uses feedback mechanisms to control the high voltage output, transforming the approach from passive physical filtering to active parameter control.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If a passive filter is used to suppress high voltage noise, then noise reduction is achieved, but the device becomes very expensive

Engineering Contradiction:

Improvenoise levelVSAvoidmanufacturing cost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent replaces expensive passive filter components with relatively inexpensive active electronic components such as operational amplifiers and feedback circuits. This substitution dramatically reduces manufacturing costs while achieving the same or better noise suppression performance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention uses standard, off-the-shelf electronic components that are inexpensive and widely available, replacing costly specialized passive filter components. The use of common operational amplifiers and standard circuit elements makes the solution economically viable.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Power

If high power active components are used, then high voltage output is achieved, but noise increases

Engineering Contradiction:

Improveoutput powerVSAvoidnoise level

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The patent employs feedback control circuits that monitor the high voltage output and actively adjust the control signals to minimize noise. The feedback mechanism allows the system to maintain high power output while continuously suppressing noise through dynamic control adjustments.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The invention changes the control parameters by using precision reference voltages and adjustable gain stages that allow high voltage output while maintaining low noise characteristics. The system dynamically adjusts operating parameters to optimize both power and noise performance.

Inventive Principle:

Principle #35Parameter changes

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 effectively reduces noise in high voltage signals, improving the accuracy of electron microscopy measurements while being compact and economical, using off-the-shelf low voltage components that maintain low voltage differences across them.

Implementation Method 1

a low pass filter that is configured to filter the high voltage input signal to provide a filtered high voltage signal

Methodology Applied

Scientific EffectLow pass filter: Filter (electronic)

Data Source

PatentUS20240313725A1High voltage noise cancellation

Publication Date: 2024.09.19 APPL MATERIALS ISRAEL LTD

AI summary

A high voltage noise reduction unit that includes (i) an input that is configured to receive a high voltage input signal (HVIS); (ii) a positive isolated supply unit that is configured to receive the HVIS and to output a positive supply signal that floats on the HVIS; (iii) a negative isolated supply unit that is configured to receive the HVIS and to output a negative supply signal that floats on the HVIS; (iv) a low pass filter that is configured to filter the HVIS to provide a filtered high voltage signal; and (v) an amplifier that is configured to receive the positive supply signal, to receive the negative supply signal, to receive the filtered high voltage signal and amplify the filtered high voltage signal to provide a high voltage output signal.