微波EDA网,见证研发工程师的成长!
首页 > 研发问答 > 微波和射频技术 > 天线设计和射频技术 > method to measure the diode impedance?

method to measure the diode impedance?

时间:04-09 整理:3721RD 点击:
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.

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..

Copyright © 2017-2020 微波EDA网 版权所有

网站地图

Top