  The controlled and accurate emission of coherent electronic wave packets is
of prime importance for future applications of nano-scale electronics. Here we
present a theoretical and experimental analysis of the finite-frequency noise
spectrum of a periodically driven single electron emitter. The electron source
consists of a mesoscopic capacitor that emits single electrons and holes into a
chiral edge state of a quantum Hall sample. We compare experimental results
with two complementary theoretical descriptions: On one hand, the Floquet
scattering theory which leads to accurate numerical results for the noise
spectrum under all relevant operating conditions. On the other hand, a
semi-classical model which enables us to develop an analytic description of the
main sources of noise when the emitter is operated under optimal conditions. We
find excellent agreement between experiment and theory. Importantly, the noise
spectrum provides us with an accurate description and characterization of the
mesoscopic capacitor when operated as a periodic single electron emitter.
