Adaptive ADC Sampling for Wide-Range Signal Measurement
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Solution Overview
Problem
In signal measurement systems, accurately determining characteristics of a device under test across a wide range of test signal frequencies is challenging due to inefficiencies in analog-to-digital converter (ADC) operations, particularly at lower frequencies where a large number of digital samples are generated, leading to increased power consumption and processing requirements.
Innovation Solution
A signal measurement system that includes an analog-to-digital converter (ADC) and a controller. The controller adjusts the number of digital conversions performed by the ADC per unit time based on characteristics of the input signal, such as frequency, or digitally determined characteristics derived from previous digital samples, thereby optimizing ADC operations and reducing unnecessary sample generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the ADC conversion frequency is set based on the top end of the spectroscopy frequency range to accurately convert high frequency signals, then measurement precision is improved, but power consumption increases and processing requirements become excessive for low frequency signals
Solution Approach 1:
The ADC conversion frequency is dynamically adjusted based on the actual signal frequency being measured. The controller monitors the input signal frequency and adapts the ADC sampling rate accordingly, switching between different conversion frequencies to match the signal characteristics. This dynamic adaptation ensures accurate conversion while minimizing power consumption by avoiding unnecessarily high sampling rates for low frequency signals.
Solution Approach 2:
The system changes the ADC conversion frequency parameter based on the signal frequency range. For high frequency signals, a higher conversion frequency is used to maintain measurement precision, while for low frequency signals, a lower conversion frequency is applied to reduce power consumption and processing burden. This parameter adjustment resolves the contradiction between maintaining accuracy and reducing energy use.
2Measurement precision
If the ADC conversion frequency is set high to accommodate the highest signal frequency, then the highest frequency measurement is improved, but a very large number of digital samples are generated per period at low frequencies increasing processing burden
Solution Approach 1:
The system dynamically adjusts the ADC conversion frequency based on the detected signal frequency. When high frequency signals are present, the ADC operates at a high conversion rate to capture sufficient samples per period. When low frequency signals are detected, the conversion frequency is reduced accordingly. This dynamic control optimizes the balance between measurement accuracy and processing complexity by generating only the necessary number of samples.
Solution Approach 2:
The conversion frequency parameter is changed according to the signal frequency range being measured. The controller modifies this parameter in real-time to match the signal characteristics, ensuring that the ADC generates an appropriate number of samples per signal period. This prevents the generation of excessively large numbers of samples for low frequency signals while maintaining adequate sampling for high frequency signals.
3Reliability
If the ADC generates a large number of digital samples per period at low frequencies, then complete signal periods are captured, but memory requirements and processing speed requirements increase significantly
Solution Approach 1:
The ADC conversion frequency is dynamically controlled to generate an optimal number of digital samples based on the signal frequency. For low frequency signals, the conversion frequency is reduced to generate fewer samples per signal period, thereby reducing memory and processing requirements while still capturing complete periods. For high frequency signals, the conversion frequency is increased to ensure sufficient samples are captured. This dynamic adjustment maintains signal representation accuracy while minimizing the quantity of digital samples generated.
Data Source
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AI summary
The present disclosure relates to a signal measurement system, a controller and a method for digitally converting an input signal. The signal measurement system comprises an analog-to-digital converter (ADC) configured to receive the input signal and generate a plurality digital samples of the input signal. The signal measurement system also comprises a controller configured to control the number of digital conversions of the input signal performed by the ADC per unit time, based on at least one of a characteristic of the input signal and/or a digitally determined characteristic of the input signal, wherein the digitally determined characteristic of the input signal is based on one or more previous digital samples of the input signal generated by the ADC.