frequency response of a cs amplifier with indutcive degeneration

Hello all,
I was just performing the frequency response analysis for an inductively degenerated CS amplifier. I have a few queries related to this

1. Why is it so that there are no derivations available of Miller effect for inductively degenerated CS amplifier? is it because the analysis is same as for a CS amplifier with source grounded? but how?


2. When I analyzed the CS inductively degenerated amplifier in presence of Cgd, I get the following expression for input impedance

Zin = [1/(sL + 1/sCgs + gmL/Cgs] in parallel to [1/(1+A)Cgd]


Can somebody explain how this expression indicates the reduction in bandwidth of the amplifier ?

Thanks