Variable Attenuator Step Error Correction Under Semiconductor Nonlinearity
Find Innovative SolutionsGenerate Solutions
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 initial and second step error calculation processes to calculate the correction value of the variable attenuator by setting specific gain and attenuation amounts, thereby minimizing the impact of semiconductor non-linearity.
Engineering Contradictions & Design Principles
Engineering 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
Solution Approach 1:
The patent divides the attenuation amount correction into multiple steps (first step error calculation process and second step error calculation process) rather than making one large correction. By segmenting the correction process into smaller incremental steps, the system maintains measurement precision while achieving a wide overall correction range. Each step uses small gain changes that avoid semiconductor non-linearity, and the corrections are accumulated to achieve the total required correction.
2Reliability
If the gain of the signal generation unit is greatly changed, then the correction coverage is improved, but the measurement precision deteriorates due to non-linearity effects
Solution Approach 1:
The correction process is segmented into multiple small-step calculations rather than one large correction. The first step error calculation process and second step error calculation process each handle small gain variations, avoiding semiconductor non-linearity. The accumulated effect of these segmented corrections achieves wide correction coverage while maintaining high precision in each individual step.
Solution Approach 2:
The patent performs preliminary measurements at specific gain settings (zero gain and negative variation amount) before calculating the correction value. This preliminary action establishes reference points that allow accurate correction calculation without requiring large gain changes during the actual correction process, thus avoiding non-linearity effects while achieving comprehensive correction coverage.
Data Source
AI summary
A signal generation unit 2, a DA converter 3, variable attenuators 40, 42, 44, and 46 that attenuate the 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.