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

Impedance Plot Data from S-Parameter File

Status
Not open for further replies.

chiques

Advanced Member level 4
Joined
Nov 21, 2007
Messages
116
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,298
Location
California
Activity points
2,123
Is it possible to get the impedance data from an s-parameter file?

In this example I'm using Part # GQM2195C2A100GB01

I'm using the s-data from SimSurf (http://ds.murata.co.jp/software/simsurfing/en-us/index.html#
Click on Monolithic Ceramic Capacitors

The S-Data is attached.

The plot I'm looking for is:
GQM2195C2A100GB01_impedance.png
 

Attachments


tony_lth

Advanced Member level 5
Joined
Jul 28, 2010
Messages
2,004
Helped
375
Reputation
752
Reaction score
367
Trophy points
1,363
Location
Beijing
Activity points
11,867
In ADS, the normal way is import S2P file and simulate with Z parameter selected, then can plot with ADS data.
But your component is a Tan capacitor, it is nonsense to plot its impedance over frequency, say 1GHz.
 

chiques

Advanced Member level 4
Joined
Nov 21, 2007
Messages
116
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,298
Location
California
Activity points
2,123

Hawaslsh

Advanced Member level 4
Joined
Mar 13, 2015
Messages
102
Helped
5
Reputation
10
Reaction score
5
Trophy points
18
Location
Washington DC, USA
Activity points
1,279
I did notice that plotting S11 is the same plot as |Z|. I'm just not sure why.
The two are related to one another, its the reason why smith charts were created. A neat way to display both complex reflection and impedance. Although the impedance contours aren't as easy to imagine / use as the X-Y plot you want.

S11 = (Zcap - Zo) / ( Zcap + Zo), assuming a 1 port measurement with the cap as the load of course.

Not sure if that helps,
Sami
 

biff44

Advanced Member level 5
Joined
Dec 24, 2004
Messages
4,831
Helped
1,354
Reputation
2,704
Reaction score
1,031
Trophy points
1,393
Location
New England, USA
Activity points
36,482
if this is a capacitor, you have to realize that the impedance is a complex quantity. i.e. it has real ohms and imaginary reactance. it might be more useful to plot the real and imaginary part on different graphs.

what are you simulating, a series capacitor between two 50 ohm lines?

Note there is some sort of resonance around 4.5 GHz, either caused by the capacitance bulk dielectric acting like a waveguide, or the lead/parasitic inductance resonating with the capacitor.
 

chiques

Advanced Member level 4
Joined
Nov 21, 2007
Messages
116
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,298
Location
California
Activity points
2,123
The two are related to one another, its the reason why smith charts were created. A neat way to display both complex reflection and impedance. Although the impedance contours aren't as easy to imagine / use as the X-Y plot you want.

S11 = (Zcap - Zo) / ( Zcap + Zo), assuming a 1 port measurement with the cap as the load of course.

Not sure if that helps,
Sami
I get this. But I need to get the Zcap from our VNA measurements.

- - - Updated - - -

if this is a capacitor, you have to realize that the impedance is a complex quantity. i.e. it has real ohms and imaginary reactance. it might be more useful to plot the real and imaginary part on different graphs.

what are you simulating, a series capacitor between two 50 ohm lines?

Note there is some sort of resonance around 4.5 GHz, either caused by the capacitance bulk dielectric acting like a waveguide, or the lead/parasitic inductance resonating with the capacitor.
No simulation, all VNA measurements in a series-thru configuration.

Yes, the 4.5 GHz is the parallel resonance frequency. From what I understand this is where the capacitor has maximum impedance (as opposed to the SRF which is minimum impedance.).
 

volker@muehlhaus

Advanced Member level 5
Joined
Apr 11, 2014
Messages
2,508
Helped
982
Reputation
1,966
Reaction score
963
Trophy points
113
Activity points
14,865
But I need to get the Zcap from our VNA measurements.
If the cap is in series between the two ports, the first step is to convert the 2-port data into the differential series element (1-port)

Z = stoz(S)
Zdiff = Z(1,1) – Z(1,2) – Z(2,1) + Z(2,2)

This Zdiff is the capacitor's impedance, similar to your plot.
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top