Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Who can teach me how to model on chip capacitors?!

Status
Not open for further replies.

YiLi

Junior Member level 2
Joined
Feb 22, 2002
Messages
24
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
129
Dear all....

Can any one teach me, or show me some documents, to learn how to extract on chip capacitor model....and also the Q factor ...
(ex, if I have a measured S parameter form on chip capacitor...how can I use this to extract all the equivilent circuits?!)

Thanx!!


YiLi
 

Tomp

Junior Member level 2
Joined
Apr 30, 2002
Messages
21
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,283
Activity points
105
A very fast way, but very approximate, is to use the TFC model of ADS. You can optimize the model pearameters to obtain the S parameters you measured.
 

YiLi

Junior Member level 2
Joined
Feb 22, 2002
Messages
24
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
129
?!

Sorry, but may I ask you...
what is TFC model?!
and how to use it in ADS...?!
can I find that in the ADS manul?!
should I setup some thing?!

Is it just to set some goals to match the s-parameters from the model to the measured data?!

THANX~
 

Tomp

Junior Member level 2
Joined
Apr 30, 2002
Messages
21
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,283
Activity points
105
You can find the Thin Film Capacitor (TFC) model under the TLines-Microstrip palette. It's a built in model for the thin film capacitor.
 

YiLi

Junior Member level 2
Joined
Feb 22, 2002
Messages
24
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
129
Um...

thanx...

I have tried that....
but...actually...I am trying to model a capacitor for silicon base...
(under CMOS process)...
so I am not sure if this will work or not~~~
(the TFC model seems didn't need me to give it any CMOS parameters...)


Oooops...
 

Tomp

Junior Member level 2
Joined
Apr 30, 2002
Messages
21
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,283
Activity points
105
The TFC model is suited for integrated parallel plate capacitor. If it's not your case you have to go for some custom lumped element model you can find in IEEE - MTTS (for example).
 

Element_115

Advanced Member level 2
Joined
Mar 23, 2002
Messages
509
Helped
72
Reputation
144
Reaction score
42
Trophy points
1,308
Activity points
3,767
I have seen IC designers use @nsoft H~F~S~S to model
IC inductors and Caps, then port them in to C@DENCE
they seemed to get good correlation between the models
and the IC. I believe the Used TMSC in and it was in
CMOS or BiCMOS. You might want to find any IC Fab
house and see if they have any guide lines or libraries.

Hope this might help.
Cheers
 

mmwave

Newbie level 6
Joined
Jul 22, 2001
Messages
11
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
121
I suggest for your application using Momentum to simulate the
actual capacitor geometry you are using. You can import your gdsII file directly into the ADS layout to do this. If you define your silicon substrate losses correctly and also the process layers then you will get a very accurate result. I simulate complete MMICs this way with excellent agreement with measurement up to w-band.
 

toonafishy

Full Member level 6
Joined
Jun 18, 2002
Messages
369
Helped
38
Reputation
76
Reaction score
12
Trophy points
1,298
Location
Earth
Activity points
3,187
You need something much more complex than just the S-parameters. You can get pretty accurate results in A/N/S/O/F/T E/N/S/E/M/B/L/E or A/D/S M/O/M/E/N/T/U/M since this problem is handled in 2.5D EM simulators okay. Or H/F/S/S if you want a real 3D answer but this is not really necessary. It depends on what software you have to use.
 

owell

Junior Member level 3
Joined
Mar 30, 2002
Messages
28
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
130
By way of EM simulator, the curve-fitting method is also needed.
But this will create lots of models.
 

yingyang

Full Member level 2
Joined
Dec 26, 2002
Messages
126
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,298
Activity points
862
chip capacitor modeling

More pratical method....

Measure a fixture with a 50 ohm line and a small gap or the capacitor...
Measure the fixture with the chip capacitor solder on it..
Assuming symmetry of the fixture, de-embed the Y-parameters of the chip capacitor from the overall measured Y-parameters.
 

yingyang

Full Member level 2
Joined
Dec 26, 2002
Messages
126
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,298
Activity points
862
chip capacitor modeling

This method is valid up to 5GHz....
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top