# Resonant Frequency and Transfer Functions

Apogee
Suppose I have some sort of a filter, whose transfer function is given by H(w), where w is the angular frequency of the input signal in radians per second. I want to know the maximum value of the transfer function. If I solve for the resonant frequency w0, which from my understanding is the frequency at which the impedance seen at the input is purely real, is the maximum value of the transfer function given by H_max = H(w0)?

Also, would the normalized transfer function be defined as H(w)/H_max = H(w)/H(w0)?