Time Domain Measurement: TDR or VNA?

Nowadays, semiconductor technology requires that integrated circuits be interconnected at very high-speed data rates. Taking time domain measurements on the digital links can offer challenges for electronic engineers, one of which is to decide which is the better measurement instrument to use in the given signal integrity environment. The time domain reflectometer (TDR) and vector network analyzer (VNA) are the staple instruments to consider, each one having its pros and cons. Here we compare the responses of the two instruments when used for taking time domain measurements of typical signal integrity devices under test (DUTs): a stripline and a through hole on a FR-4 board.