Transistor availabilty in Agilent ADS

Sir,
I want to design microwave power amplifier at 2.5GHz. I am searching for the transistors.I read some literature s about the power amplifier design. In literature s, whatever they used transistors for their work. Those transistors I searched in the ADS2009,are not in the available in the ADS Component library. For example, I am discussing those transistor below

(1) For GSM 900MHz , they have used the transistor LDMOS Motorola MRF 184. I have searched in the ADS2009 library, it is not available.

(2) For designing 5.7 to 5.9 GHz power amplifier , they have the transistors Nitronex NPTB0004 HFET. This is also not available in the ADS 2009.

Suppose our desired transistor is not available in the library of ADS,what we have to do. If their non linear device model is not created in ADS model. What we have to do. Can anybody help me resolve this difficulty.

For MRF 184 search at Freescale,you will find ADS models and project files( datasheet,application notes ect).
For Nitronex NPTB0004, look at http://www.propagation.gatech.edu/EC...ect2_Team1.pdf
and http://www.nitronex.com/NPTB00004_Product_Page.html
Request the model from Nitronex directly...

BigBoss Sir,
Thank you for your timely help, it is more helpful to me. What I asked generally is, whatever desired transistor if not available in the ADS2009 component library. What we have to do. Externally google search it and get it and how to transfer them to schematic window of ADS. Only details about the transistors is available , what about their symbols (schematic) and how to work practically in the ADS environment. Clearly read posting #1 question, if the company created nonlinear model is created other environment like MWO, how to work with those nonlinear model in ADS.

In order to create a component with its model.
First , you can create a schematic with parastic elements ( bondings,package parasitics etc) and model from "Nonlinear Model Palette" and fill the model variables.
Once you complete your model, create a symbol or use a exisiting symbol from palette ( more information, see ADS help..)
In ADS library, the components have crypted model parameters and you can not create such models by yourself.

Luckily if you have found your transistor model from the vendor than follow the attached doc and you will learn how to add that in your schematic... moreover model created and distributed by the vendor will work on any RF platform (ADS or MWO)...
but if you didn't find the model on internet than ADS allows you to create a model yourself which is a bit complex task...
Cheers!