  The dispersion of spin waves in vertical meander-shaped CoFeB thin films
consisting of segments located at 90{\deg} angles with respect to each other is
investigated by Brillouin light scattering spectroscopy. We reveal the periodic
character of several dispersive branches as well as alternating frequency
ranges where spin waves are allowed or forbidden to propagate. Noteworthy is
the presence of the frequency band gaps between each couple of successive modes
only for wave numbers k=n$\pi$/a, where n is an even integer number and a is
the size of the meander unit cell, whereas the spectra show propagating modes
in the orthogonal film segments for the other wavenumbers. The micromagnetic
simulations and analytical calculations allow us to understand and explain the
results in terms of the mode spatial localization and symmetry. The obtained
results demonstrate the wave propagation in three dimensions opening the path
for multi-level magnonic architectures for signal processing.
