Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics 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

method to measure the diode impedance?

Status
Not open for further replies.
S

sensen9966

Junior Member level 3
Joined
May 9, 2006
Messages
29
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,503
i have several types of diodes, now i want to know the real impedance of those diodes by setting up some measurement. is there somebody know about what should i do to do that to get the accurate impedance as possible as i can?

Normal microstrip line structure with dielectric constant of 2.54 or 10.2 can fabricate if it's needed.
VNA also available with TRL calibration.

what is the fast and accurate way to measurement in this situation? thank you very much.
 

Simply short circuited and current supplied diode can be connected to a microstrip line and then small signal impedance under certain biasing condition ( even zero bias) can be measured.
I mean..

Connector->-MS Line->-Blocking Capacitor->-DUT->-Ground.
You should supply a bias current after blocking capacitor capacitor.
 

    S

    sensen9966

    Points: 2
    Helpful Answer Positive Rating
BigBoss said:
Simply short circuited and current supplied diode can be connected to a microstrip line and then small signal impedance under certain biasing condition ( even zero bias) can be measured.
I mean..

Connector->-MS Line->-Blocking Capacitor->-DUT->-Ground.
You should supply a bias current after blocking capacitor capacitor.
Click to expand...

thanks.

and what's the Blocking Capacitor component used for?

i have seen several technical papers supplying the methods, the attachment is a simple method i found, but i still confuse the detail of measurement flow.

Could you show a little more detail of process? i am really new about active component measurement.

thank you very much.
 

and how to de-embeding the MS Line & Blocking Capacitor to get the DUT impedance from VNA?

For the attached paper method.

1, fabricate a microstrip line with the shorted ground end.
2, fabricate the same microstrip line but plus the diode between the end of microstrip line and shorted ground.

but how to calculate the DUT impedance?
 

You should connect a 50 pure resistor instead of diode and then measure the s-parameter.After that replace the resistor with DUT and measure again the s-parameter.
Then, extract the first s-parameter set from the second one..( on a smith chart or de-embeddding on VNA directly..)

Blocking capacitor is used to prevent the VNA from DC voltage.Because zero biasing diode will have different impedance than biased one..
 

    S

    sensen9966

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top