In the first demo, the real and imaginary part of transfer function $H_k(f)$ is shown per iteration (frequency flat). The overall transfer function $H_{\text{sum}}(f)$ is with periodic frequency selectivity $\tau_{\text{period}} = \frac{2 \ell_2}{v_{\text{ph}}}$ (constructive and destructive interference caused by the superpostion of iterations). Here, the rotation bandwidth $B_{\text{Rot}} =\frac{1}{\tau_1}$, where $\tau_1 = \frac{\ell_1 +\ell_3}{v_{\text{ph}}}$ is the propagation delay of the first iteration. In the case of only one iteration, $B_{\text{Rot}}$ is the bandwidth where the phase of $H_1(f)$ changes by $2 \pi$.

Here, the stop frequency of simulation is calculated as $$ f_{\text{stop}} = B_{\text{Rot}} \cdot N_{\text{Rot}} = \frac{v_{\text{ph}}}{\ell_1 +\ell_3} \cdot N_{\text{Rot}} $$ where $N_{\text{Rot}}$ is the number of rotations of $H_1(f)$ in $0 \leq f \leq f_{\text{stop}}$, in this case, we decide $N_{\text{Rot}} = 2$.

In this demo, $N_{\text{Frames}} = 50$ is fixed, therefore, number of frames per rotation (Frame rate) is $R_{\text{Frame}} = \frac{N_{\text{Frames}}}{N_{\text{Rot}}} = 25$.