中文说明：
直接数字频率合成器中相位累加杂散，幅度量化杂散及DAC非线性杂散的功率谱密度曲线频谱图。
English Description：
The power spectral density curves and spectrums of phase accumulation spurious, amplitude quantized spurious and DAC nonlinear spurious in direct digital frequency synthesizer are presented.