Figure 1

Effects of different values of K . (a) FIR filter with K = 50; (b) FIR filter with K = 100; (c) FIR filter with K = 200; (d) IIR filter with K = ∞; (a)-(c) are calculated by Eq. (6), respectively. (d) is calculated by Eq. (3.b), which is equivalent to Eq. (5.b). These notch filters are designed at f _s  = 500 Hz with f₀ = 60 Hz, and Δf = 2.0 Hz.