Engineering Alternative design for a CE-CC cascade amplifier

[PhysicsTruth]

Homework Statement

Given a CE amplifier with gain of about -50, design a buffer emitter follower, mentioning all the parameters that can be controlled by the designer, and connecting the load resistance such that the voltage gain isn't affected.

Relevant Equations

$Z_{in} = \beta (r_{e}+R_{C})$
$A_{v} = -(R_{C}||Z_{in})/r_{e}$

Here is a common CE-CC cascade amplifier-

Here, the output of the emitter amplifier is directly connected to Q2, without any coupling capacitor or any voltage divider bias. This may harm the base-emitter junction of Q2 in case of unwanted output voltage from Q1 collector. But in that case, the calculations would change completely, where $Z_{in}$ would be perhaps $RB1||RB2||[\beta(r_{e} + R_{C})]$, where r_e would be the internal emitter resistance for Q2 and RB1,RB2 are the base biasing resistors. How to account for the output impedance, the impedance matching and the bias resistor values in this case, such that the AC gain remains at -50?

 

[Tom.G]

Since transistor types and gains are not given, you can assume transistors with very high (almost infinite) h_FE. This allows you to ignore loading effects between succesive stages.

From there you might try simplifying the circuit and calculate one stage at a time. For instance, assume that Q2 does not exist and find the DC operating point of Q1, etc.

Since signal frequency and capacitor values are not specified, they can be 'assumed to be appropriate' for the circuit.