In a direct digital synthesizer, what are the unwanted components found on its output?

In a direct digital synthesizer (DDS), the unwanted components found on its output primarily manifest as spurs at discrete frequencies. These spurious signals, or "spurs," can arise due to non-idealities in the digital conversion process, such as quantization errors and clock jitter. The nature of DDS involves generating a waveform by numerically calculating its values, and imperfections in this process lead to these spurs, which can create unwanted distortion in the output signal.

Spurs are typically characterized by being present at specific frequencies, often harmonically related to the fundamental frequency of the output signal. They can interfere with the desired signal, especially in applications requiring high precision and low distortion, such as in communications and signal processing.

Other potential outputs like noise spikes or phase errors may indeed affect the quality of the output signal, but they are not as directly representative of the spurious components that specifically occur in a direct digital synthesizer's output. Low-frequency oscillations can also be a concern in some contexts, but they are not classified as spurious outputs in the same manner as spurs.