A plot of the slope of the phase/frequency characteristic over the range of frequencies of interest, i.e., a graph of dφ/dω, where φ is the phase shift in radians at a particular frequency and ω is the angular frequency in radians per second.; 在所关心的频率范围之内的相频特性曲线的斜率曲线,即dφdω曲线。这里φ是在一个特 殊频率上的相移,以弧度表示,ω是角频率,以弧度/秒表示。