  We study a coherent conductor supporting a single edge channel in which
alternating current pulses are created by local time-dependent gating and sent
on a beam-splitter realized by a quantum point contact. The current response to
the gate voltage in this setup is intrinsically linear. Based on a fully
self-consistent treatment employing a Floquet scattering theory, we analyze the
effect of different voltage shapes and frequencies, as well as the role of the
gate geometry on the injected signal. In particular, we highlight the impact of
frequency-dependent screening on the process of shaping the current signal. The
feasibility of creating true single-particle excitations with this method is
confirmed by investigating the suppression of excess noise, which is otherwise
created by additional electron-hole pair excitations in the current signal.
