Performance analysis of sampling switch structures for wideband sigma-delta noise shapers for RF applications

The sampling switch of a wideband sigma-delta noise shaper for RF applications is a very critical component as any nonlinearities within reduces the spurious free dynamic range, SFDR, of the whole modulator. Errors due to nonlinearities are carried on to all other processing stages. The analysis investigates a variety of sampling switches. It is found that apart from insignificant dependence of input voltage level the bootstrap sampling switch also has a significant higher SFDR over the entire bandwidth.