有噪信号下ADC量化特性的分析与应用

传统的ADC特性参数的测试,通常是将一纯度很高的模拟正弦信号作为激励信号,然后在无噪的条件下,通过对数字输出结果进行分析从而得出ADC的特性参数.然而,在很多实际应用领域中,通常输入的信号叠加有噪声.本文研究了有噪信号下ADC量化特性,提出了有噪信号下ADC量化特性的分析模型,并从理论上做出了相应解释.研究分析表明,有噪信号下ADC量化有其自身规律,利用本文提出的测试方法,输入信号的任何微小变化都可反映在测试结果中,这一方面可以使得在原高分辨率ADC的基础上获得更高的分辨率成为可能,另一方面可为微弱信号采集系统正确选用性能优良的ADC提供足够的技术支持,有助于改进微弱信号检测或低信噪比情况下的系统设计.最后给出了ADC有噪信号下的量化累加输出信噪比曲线,可为实际工程应用提供参考.

ADC Quantization Nonlinearity Under a Signal in Colored Noise and Its Application

The characteristics of ADC quantization nonlinearity under a signal in colored noise are analyzed.Analytic method and theoretical explanati on are given.Our research shows that ADC quantization,under the condition of low SNR,has its own regulation .Using the test method presented by this paper,test result of accumulation can correspond to any tidy change of input signal.So we can get higher resolution based on primary high resolution ADC.We also can im prove the system design of weak signal detection.At last,we point out that it's necessary to test the characteri stics of ADC quantization nonlinearity under the condition of low SNR for engineering application.