Question

The bandwidth of an RC-coupled amplifier is limited by
1. Coupling capacitors at the low frequency end and bypass capacitors at the high frequency end
2. Coupling capacitors at the high frequency end and bypass capacitors at the low frequency end
3. Bypass and coupling capacitors at the low frequency end and device shunt capacitors at the high frequency end
4. Device shunt capacitors at the low frequency end and bypass as well as coupling capacitors at the high frequency end

Answer 1

Correct Answer - Option 3 : Bypass and coupling capacitors at the low frequency end and device shunt capacitors at the high frequency end

• In capacitively coupled amplifiers, the coupling and bypass capacitors affect the low-frequency cut-off. These capacitors form a high-pass filter with circuit resistances.
• Coupling and bypass capacitors are also called external capacitors.
• For high-frequency response, it is determined by the device’s internal capacitance and the Miller effect.
• Device internal capacitance is shunted and also called as Junction capacitors.