Can anyone give me a link or material talking about the design of Network Analyzer front end? How can it achieve wide band, high dynamic range and high sensitivity? Thanks.
no, i am sorry, but i looked at it years ago....i don't recall the patent number.
however, i don't understand why you would have trouble finding it.
just enter search-term of "vector network analyzer" or something similar; and also limit responses to those only from Assignee of "hewlett packard".
you might also want to study VNA patents from Wiltron....they have done some good work in modernizing the breed....making nice handheld-size VNA's. A very very detailed patent from Wiltron is...
"Apparatus and method for measuring the phase and magnitude of microwave signals , United States Patent 5524281"