How to enhance the operation frequency of an amplifier?

[abcyin]

Hi, all,

For a simple differential amplifier, with resistor load or diode-connected MOSFET load, how to enhance the operation frequency to, for example, 3GHz. I am using a 0.35um BiCMOS process, and I found that it's a little bit difficult to make this possible, so could anybody tell me is there any way to make it?

Any circuit structure or hints are welcome, Thanks in advance.

 

[dgnani]

use BJT as input pair and pump enough current to get a good gm, if the capacitive output load is high... well is it? what's the application?

 

[leo_o2]

3GHz might be impossible for the process in point view of nowaday's theory.

 

[dgnani]

Hi leo,

I doubt intrinsic device bandwidth would be a problem in 0.35 SiGe process, a quick sample of one of their models shows tau_f (forward transit time) setting a limit (for infinite gm) transition frequency ~180GHz, which should leave enough margins when you take into account gm and intrinsic caps

 

[leo_o2]

I supposed Si process. Thanks.