Chapter 1. Introduction -- Chapter 2.Algorithms for accurate spectral analysis in the presence of arbitrary non-coherency and large distortion -- Chapter 3.Accurate spectral testing with arbitrary non- coherency in sampling and simultaneous drifts in amplitude and frequency -- Chapter 4.High-purity sine wave generation using nonlinear DAC with pre-distortion based on low-cost accurate DAC-ADC co-testing -- Chapter 5.Low cost ultra-pure sine wave generation with self-calibration -- Chapter 6.Accurate spectral testing with non-coherent sampling for multi-tone test -- Chapter 7.Accurate spectral testing with impure test stimulus for multi-tone test -- Chapter 8.Multi-tone sine wave generation achieving the theoretical minimum of peak-to-average power ratio -- Chapter 9.Accurate linearity testing using low purity stimulus robust against flicker noise -- Chapter 10.Summary.