  The observational analysis is performed to study the excitation mechanism and
the propagation properties of a quasi-periodic fast-propagating (QFP)
magnetosonic wave. The QFP wave was associated with the eruption of a nearby
mini-filament and a small B4 GOES flare, which may indicate that the generation
of a QFP wave do not need too much flare energy. The propagation of the QFP
wave was along a bundle of funnel-shaped open loops with a speed of about
1100+/-78, and an acceleration of -2.2+/-1.1. Periodicity analysis indicates
that the periods of the QFP wave are 43+/-6, 79+/-18 second. For the first
time, we find that the periods of the QFP wave and the accompanying flare are
inconsistent, which is different from the findings as reported in previous
studies. We propose that the present QFP wave was possibly caused by the
mechanism of dispersive evolution of an initially broadband disturbance
resulted from the nearby mini-filament eruption.
