In Dr.Joel's book and the paper titled "Gating Effects in Time Domain Transforms", the the following is given.
"The VNA time domain compensates for this roll-off through a post-gate renormalization. The post-gate renormalization is a function determined by creating a frequency response that is unit magnitude. A pre-gate window is applied to this unit-response that is the same as the pre-transform window applied to the normal frequency response data.................."
I can't undersatand why the pre-gate window is used. I thought that the final normalizing frequency response could be caculated without the pre-gate window.
look forward the reply!