Re: Opamp Stability
Hello,
there are different things to say. If you are talking of an amplifier with external feedback circuitry, the question is hypothetical to my opinion. You won't be able to operate it stable with external feedback when it has a GBW of 3 GHz. This may be able with on-chip feedback, possibly also with very small thinfilm hybrid circuits, but is unlikely with housed ICs. But you may try.
Apart from this, filter charateristics will be affected surely by limited GBW. Typically it's impossible to realize low Q filter characteristics as Bessel or Gauss, respectively additional poles are introduced. At best parameters are optimized empirically. Above 0,5 or 1 GHz, also electrical circuit delays must be considered, lumped element models becoming inaccurate.
Regards,
Frank