Simulating DC analysis using ADS.

[amir_syakir]

Hi everyone, I want to simulate a DC analysis of a transistor using ADS to obtain I-V curve. I need to simulate the transistor based on the information from a data sheet. The value I can retrieve from the data sheet are Id, Vds, Ig, Vgs, Rds, Rg, Ciss which is (Cgs + Cgd), Coss which is (Cds + Cgd), Crss which is the Cgd. How can I simulate this transistor? I tried to simulate using Linear Devices FET, but the graph will of course be a linear graph. Can anyone help me? I attach the data sheet with this post.

 

[BradtheRad]

A bjt b-e junction is a PN junction. Non-linear like a diode.
Try simulating that junction by itself to see if its I-V curve imitates a diode. If so then go the next step, apply supply voltage and continue simulating and observing.

If it doesn't imitate a diode then try a diode alone. If a diode doesn't create a non-linear I/V curve then you need a different component model.

 

[amir_syakir]

A bjt b-e junction is a PN junction. Non-linear like a diode.
Try simulating that junction by itself to see if its I-V curve imitates a diode. If so then go the next step, apply supply voltage and continue simulating and observing.

If it doesn't imitate a diode then try a diode alone. If a diode doesn't create a non-linear I/V curve then you need a different component model.

But the transistor is a GaN HEMT. Does that still mean I need to use bjt?

 

[BradtheRad]

High electron mobility transistor. Its characteristics have similarities and differences compared to a bjt. Does ADS contain a model for GaN HEMT? If not then perhaps you can start with a bjt or mosfet model, and alter its parameters.

I believe your goal is to find:

* What threshold of voltage and/or current starts to turn on the device?

* What is range of operation where device performance is non-linear? Where does it transition to linear?

* What levels of current flow result from various combinations of gate drive versus supply voltage?

It's essential to learn the principles of gate structure and turn-on.
Also to study the 'gate drive application note' mentioned in the data sheet.