就常规的LC滤波系统,有几个概念有点晕:
- 转折频率(corner frequency):又叫截止频率(cutoff frequency): 截止频率（是指一个系统的输出信号能量开始大幅下降的边界频率。a cutoff frequency, corner frequency, or break frequency is a boundary in a system's frequency response at which energy flowing through the system begins to be reduced (attenuated or reflected) rather than passing through. (wikipedia: http://en.wikipedia.org/wiki/Cutoff_frequency) 这个应该是直接在系统中求得出来的.
- 穿越频率(cross-over frequency):系统增益为0db时所对的频率. 增益交叉/接频率.---这个可以理解.
- 谐振频率: 这个可以理解,当LC电路中,复阻抗为0的时候的频率.
- 截止频率（Wc）：用来描述系统频率特性的一个指标，也称剪切频率。其定义为幅频穿越0dB处的频率，截止频率对应的相频曲线上的相位反映了系统的相对稳定性。相位裕度定义为截止频率(Wc)对应的相位+180°，相位裕度大于0