the GaN HEMT large signal model? plz help!

we know that the GaN is the most importent material for hign freq,hign power application.but we know little about the GaN,there are so many mechanisms we haven't get.
when design the circuit about the large signal ,we haven't the model about GaN,so how can we get the model?can we just use the distributed components to stand the model ,we use resistor ,capacitor ,inductor ,and also some control sources,does anyone have some ideas or have the model ?
i have read some papers about how to build the large signal model ,but i still don't know how to do it ,plz help !

hi.
Some comp. are giving large signal model