vanjer wrote on Dec 14th, 2008, 7:46pm:but does anyone know how to do S21 normalization calibration using VNA? it is not a full 2 port calibration, isn't it?
There will be 2 ports used, and the response should be S21, but how to do S21normalization and what is S21 normalization?
Who can understand your question with your above explanation in a start of this topic ?
You have to explain your question correctly and in detail.
This is true for your last post(
http://www.designers-guide.org/Forum/YaBB.pl?num=1227954859).
My answers are:
(1) Calibrate VNA without cable in full two port SOLT.
(2) Connect cable1-PA-Loop_SMA1 to port 1.
Connect cable2-Loop_SMA2 to port 2.
(3) Measure S21 without DUT antenna.
This S21 value is reference for measuring antenna(resonator).
Then insert DUT antenna(Resonator) between SMA1 and SMA2. Here you have to keep same position of SMA1 and SMA2 as (3).
In antenna measurement you can only measure relative gain not absolute gain.
Here I assume SMA is electrically very small compared to DUT antenna(resonator) and weak coupling between SMA and DUT.
If these are not satisfied, measurement results could be largely affected by interaction between Loop_SMA and DUT such as double resonance phenomena. BPF can be realized by resonator coupling structure.
See my last answer to your last question.