Ideal Band-Pass (L 8-13)
This demo shows an ideal band-pass filter $$ H(\mathrm{j}\omega) = \mathrm{rect}\!\left(\frac{\omega}{\Delta\omega}\right) \ast \big[\delta(\omega-\omega_0) + \delta(\omega+\omega_0)\big] $$ in the frequency domain with its impulse response $$ h(t) = \frac{\Delta\omega}{\pi} \mathrm{si}\!\left(\frac{\Delta\omega}{2}t\right) \cdot \cos(\omega_0 t). $$ You can adjust the bandwidth \(\Delta\omega\) and the center frequency \(\omega_0\).