I am following the thesis " Look-ahead Sigma-Delta Modulation and its application to Super Audio CD".
In Chapter 2 (Basics of sigma-delta modulation) page 24 it is mentioned that -- "Typical distortion of an SDM consists of odd harmonic components, i.e. components at (2n + 1) · fin ." I can understand that since the quantizer is non-linear, making sigma delta modulator a non-linear system, odd harmonics prop in the spectrum of the modulator's output.
Can you suggest me the necessary papers/references which can provide me a detailed explanation of the above argument