전자통신연구실 Linear Systems Superposition Linearity Time-invariant 2
전자통신연구실 Transfer function Impulse response h(t) Transfer function (System function) 3
전자통신연구실 복소 전달함수 Complex transfer function 4
전자통신연구실 Filter Phase[H(f)] |H(f)| A slope = f f 9
전자통신연구실 Low-pass Filter |H(f)| Phase[H(f)] A f f 10
전자통신연구실 Band-pass Filter |H(f)| Phase[H(f)] A f f 11
전자통신연구실 LPF vs. BPF let 12
전자통신연구실 Causality (인과율) A causal system is one which the output for t = to depends on the input for only. A system is causal if for any two input and that are equal for , the corresponding output and are also equal for. In the LTI systems, this is equivalent to the condition that h(t) = 0, t < 0. 14
전자통신연구실 Causality (인과율) In the LTI systems, this is equivalent to the condition that h(t) = 0, t < 0. If h(t) = 0 for t < 0, 15
전자통신연구실 RC Low-pass Filter R + + C _ _ 16
전자통신연구실 RC Low-pass Filter 3 d. B cutoff frequency ideal LPF 17
전자통신연구실 Butterworth Filter 18
전자통신연구실 RLC bandpass Filter 19
전자통신연구실 전력과 에너지 energy spectral density autocorrelation function 23