Frequency response of an amplifier
Variation of the amplifier and the phase angle of the gain (amplification) with the change of signal frequencies is called the frequency response of an amplifier.
Frequency response of a single stage amplifier
Entire frequency range is divided two three parts:
- Middle frequency range
- Low frequency range
- High frequency range
(b) In low frequency range capacitance C1 only affects the output.
Highly pass RC ckt
(c) At high frequency range it behaves as low pass RC ckt.
Response of resistive ckt:
Vo = - gm vi rd | | Rd
| Avm| = µ when Rd>> rd