Hi guy,
I'm studying the MASH sigma delta modulator and run into two issues, please refer to the attached figure:
1) In such a 2-1-1 sdm, how can I derive the signal transfer function Y(z)? The figure gives the result, but I can not get it from this sdm.
2)  In the cancellation logic part, how can I derive the results shown in the form on top right corner? In other words, why should g2' equal with 2g1'g2? Why H1(z)=Z^-1?

Would you please give me any hints or key derived progress? Thank you very much.
trashbox