Hi everyone.
This comes from 2008 and 2011 editions (probably, others too); a shunt-shunt feedback topology is recommended to deal with low frequency oscillations in bipolar RF power amplifier stages, due to high current gain at low frequencies.
The text states: "negative feedback [...] increases progressively as the frequency is lowered".
I'd say the opposite. Reactance of C1 gets higher as freq decreases, so I'd say that negative feedback decreases too.
An open circuit at C1 breaks the feedback loop (max gain).
A short circuit at C1 gets maximum feedback (lower gain).
Can anyone point me where I'm wrong?
Thanks.
This comes from 2008 and 2011 editions (probably, others too); a shunt-shunt feedback topology is recommended to deal with low frequency oscillations in bipolar RF power amplifier stages, due to high current gain at low frequencies.
The text states: "negative feedback [...] increases progressively as the frequency is lowered".
I'd say the opposite. Reactance of C1 gets higher as freq decreases, so I'd say that negative feedback decreases too.
An open circuit at C1 breaks the feedback loop (max gain).
A short circuit at C1 gets maximum feedback (lower gain).
Can anyone point me where I'm wrong?
Thanks.
Attachments
-
95.2 KB Views: 30