Frequency deviation
= Frequency deviation
{title2=$\Delta f=\max_t|f_i(t)-f_c|$}
The peak frequency deviation is the largest <absolute value> of the <instantaneous frequency> offset from the chosen <carrier wave> <frequency> $f_c$. For $f_i=f_c+K_fM\cos(2\pi f_mt)$, it is $\Delta f=|K_f|M$. It is a <frequency>, measured in <hertz>, rather than a <wave phase> or an exact <signal bandwidth>.