Electronics - Basic Op-Amp Circuits - Discussion

The center frequency of a filter or channel is a measure of a central frequency between the upper and lower cutoff frequencies.

Critical frequency is also called as cut off frequency.

The critical frequency of a filter is defined as the point at which the response drops -3db from the passband.

In band pass the filter will allow frequencies abouve fl and upto frequencies below fh so the center frequency will be thus from abouve formulae it is average of these two frequency.

What is the meaning of geometric average?

The center frequency Fc = (fh + fL)/2 at that time RF system or filter is in resonance mode it gives max output by the filter system in terms of power, voltage and current. Centre frequency is critical in nature with output because power current in maximum finally afterwards at that freq. System RF or filter may go to damage or heating take place component may damage.