Three identical RC-Coupled transistor amplifiers are cascaded. If each of the amplifiers has a frequency response as shown in figure, the overall frequency response is as given as

The current gain of a bipolar transistor drops at high frequencies because of

The $${f_T}$$ of a BJT is related to its $${g_{m,}}\,\,{C_\pi }$$ and $${C_\mu }$$ as follows

An npn transistor has a beta cut-off frequency $${f_\beta }$$ of 1MHz and Common Emitter short circuit low frequency current gain $${\beta _o}$$ of 200. The unity gain frequency $${f_T}$$ and the alpha cut-off frequency $${f_\alpha }$$ respectively are