de-embadding referance plan issue in EM and sonnet
I have simulated a simple structure in EMSight with and without de-embadding
I have chosen reference plan 5 mm apart from edge ports I have a doubts that
these EM simulator does it take account of that part of structure with is left 5 mm from the edge port .
I think it shoud take account that if not then we simulate a different structure what we want to simulate for ex if i simulate 20mm lenght and chooose referense plane
5 mm so if it dosnt take that account then actually we are simulating 15 mm structure right ...
de - embadding is done to remove port discontinuty and remove the effect of side walls ........i dont know if any other reason ....
and more I getting some little deferance at all the freq i simulated that for 1 to 20 GHzs in step of 0.1 except following freq points
forward gain
with de-embadding 16.2 GHzs .... -1.25 db
without de -embadding at same 16.2 GHzs -64.8 db
input insetion loss
with de-embadding 16 GHzs .... -3.01 db
without de -embadding at same 16 GHzs -10.18 db
so why these drastic difference ...
and what is the important of referance plan here....
Thanks and regards
gbaerf
possible reasons:
1. box resonance=>try to open the top and see if you get better agreement with/without de-embedding.
2. the de-embedding standard is close to "a resonant circuit" for some particular frequencies=>try with a different de-embedding length; or upload your project here....
Hi gaebrf:
In these codes, the de-embedding does 4 things:
1. Removes port discontinuity
2. Removes the box wall coupling
3. If you use a reference plane that has some distance from the box wall, it will subtract phase from the results equal the line lengths to the reference plane
4. Again, if you use a reference plane of finite distance from the edge, and you have more than one parallel transmission line, it will remove the cross-coupling between these lines up to the reference plane.
Point #4 can be rather significant in some cases; this doesn't happen in full 3D EM codes, and often doesn't happen in some of the planar EM codes. I think that EMSight and Sonnet do this, though.
--Max