What's the maximum I can get from a transistor(BJT) of a given fT?

[surajit]

If a transistor of given fT is used as an emitter follower the what maximum bandwidth can I get from it(probably it will not be full fT) ? Is there any thumb rule for it. Suppose transistor is biased at that current for which ft value is given in data sheet.

please try to help me.

 

[tony_wu_ad]

transistor(BJT) fT

you can simulation with spice and get the ft. use the .ac command