Variable Attenuator Step Error Correction for Semiconductor Non-Linearity

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Solution Overview

Problem

Existing signal generation apparatuses face challenges in obtaining accurate correction values for variable attenuators due to the influence of non-linearity in semiconductor components on the path from the signal generation unit to the measurement unit, especially when the gain is significantly changed.

Innovation Solution

A signal generation apparatus that includes a signal generation unit, a DA converter, a variable attenuator, and a control unit, which performs step error initial value and repetition calculation processes to accurately determine the correction value of the variable attenuator by dividing the maximum attenuation amount into predetermined steps, thereby minimizing the impact of semiconductor non-linearity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the gain of the signal generation unit is greatly changed to obtain correction values, then the correction range is improved, but the measurement precision deteriorates due to non-linearity of semiconductor components

Engineering Contradiction:

Improvecorrection rangeVSAvoidcorrection value accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent divides the attenuation amount correction into multiple discrete steps (0 dB, 3 dB, 6 dB, 9 dB, 12 dB) rather than attempting continuous correction. This segmentation allows measurement at each discrete point with high precision while covering a wide overall correction range, resolving the contradiction between measurement precision and adaptability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary measurement and correction at each discrete attenuation step before final operation. By pre-measuring the actual attenuation at each step and storing correction values, the system ensures high precision correction without needing to make great changes to the signal generation unit gain during normal operation.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If the gain of the signal generation unit is greatly changed during measurement, then the measurement coverage is improved, but the reliability deteriorates due to non-linearity effects

Engineering Contradiction:

Improvemeasurement coverageVSAvoidmeasurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The measurement process is segmented into discrete attenuation steps (0 dB, 3 dB, 6 dB, 9 dB, 12 dB), allowing comprehensive measurement coverage to be achieved through multiple discrete points rather than continuous gain changes. This maintains reliability at each measurement point while achieving broad coverage across the full attenuation range.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system measures the actual attenuation at each step using a measurement unit and feeds back this information to determine correction values. This feedback mechanism ensures that measurement coverage is achieved reliably by using the actual measured values rather than theoretical calculations, compensating for any non-linearity effects.

Inventive Principle:

Principle #23Feedback

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 configuration allows for the precise calculation of correction values for the variable attenuator, enhancing accuracy and reducing the influence of semiconductor non-linearity, thereby improving the overall performance of the signal generation apparatus.

Implementation Method 1

a DA converter that converts the digital signal generated by the signal generation unit into an analog signal of a predetermined radio frequency

Methodology Applied

Scientific EffectDigital to Analog Conversion:

Implementation Method 2

a variable attenuator that attenuates the analog signal converted by the DA converter

Methodology Applied

Scientific EffectSignal Attenuation:

Implementation Method 3

a measurement unit that detects a level of the signal attenuated by the variable attenuator and passed through one or more semiconductor components

Methodology Applied

Scientific EffectSignal Level Detection:

Data Source

PatentUS12074651B2Signal generation apparatus, level correction value calculation system, and level correction value calculation method

Publication Date: 2024.08.27 ANRITSU CORP

AI summary

A signal generation unit 2, a DA converter 3, variable attenuators 40, 42, 44, and 46 that attenuate an analog signal converted by the DA converter 3, a measurement unit 6 that detects a level of the signal attenuated by the variable attenuators 40, 42, 44, and 46 and passed through one or more semiconductor components, and a control unit 7 that obtains a value of a step error, which is a correction value of an attenuation amount of the variable attenuators 40, 42, 44, and 46 in each of a plurality of steps obtained by dividing a maximum value of the attenuation amount of the variable attenuators 40, 42, 44, and 46 by a variation amount, which is a predetermined attenuation amount are included.