Date of Award
Doctor of Philosophy
Electrical and Computer Engineering
Spectral testing has been widely used to characterize the dynamic performances of the electrical signals and devices, such as Analog-to-Digital Converters (ADCs) for many decades. One of the difficulties faced is to accurately and cost-effectively test the continually higher performance devices. Standard test methods can be difficult to implement accurately and cost effectively, due to stringent requirements. To relax these necessary conditions and to reduce test costs, while achieving accurate spectral test results, several new algorithms are developed to perform accurate spectral and linearity test without requiring precise, expensive instruments.
In this dissertation, three classes of methods for overcoming the above difficulties are presented. The first class of methods targeted the accurate, single-tone spectral testing. The first method targets the non-coherent sampling issue on spectral testing, especially when the non-coherently sampled signal has large distortions. The second method resolves simultaneous amplitude and frequency drift with non-coherent sampling. The third method achieves accurate linearity results for DAC-ADC co-testing, and generates high-purity sine wave using the nonlinear DAC in the system via pre-distortion. The fourth method targets ultra-pure sine wave generation with two nonlinear DACs, two simple filters, and a nonlinear ADC. These proposed methods are validated by both simulation and measurement results, and have demonstrated their high accuracy and robustness against various test conditions.
The second class of methods deals with the accurate multi-tone spectral testing. The first method in this class resolves the non-coherent sampling issue in multi-tone spectral testing. The second method in this class introduces another proposed method to deal with multi-tone impure sources in spectral testing. The third method generates the multi-tone sine wave with minimum peak-to-average power ratio, which can be implemented in many applications, such as spectral testing and signal analysis. Similarly, simulation and measurement results validate the functionality and robustness of these proposed methods.
Finally, the third class introduces two proposed methods to accurately test linearity characteristics of high-performance ADCs using low purity sinusoidal or ramp stimulus in the presence of flicker noise. Extensive simulation results have verified their effectiveness to reduce flicker noise influence and achieve accurate linearity results.
Zhuang, Yuming, "Accurate and robust spectral testing with relaxed instrumentation requirements" (2017). Graduate Theses and Dissertations. 16249.