Hello all, I have been trying to simulate a circuitry involving a transistor for the microphone line. I believe it was used for amplication of the external audio signal (not too sure, maybe can share the circuit). I am using the ADS to simulate my circuit. The problem I faced was the transistor model was not in my ADS library and the information I got now is the spec. The transistor is a BJT silicon NPN epitaxial planer type with Hfe = 210 - 340 gain. The p/n is 2SD2216 from panasonic. I was using Q2N2222 transistor as a replacement by changing the Hfe value and I'm not sure whether I am doing the right thing. My questions are whether I can used other transistor model and change the Hfe to represent it? How do I create my own transistor model in ADS software? thanks in advance!