  We report the formation of bound states in the continuum driven by AC fields.
This system consists of a quantum ring connected to two leads. An AC side-gate
voltage controls the interference pattern of the electrons passing through the
system. We model the system by two sites in parallel connected to two
semi-infinite lattices. The energy of these sites change harmonically with
time. We obtain the transmission probability and the local density of states at
the ring sites as a function of the parameters that define the system. The
transmission probability displays a Fano profile when the energy of the
incoming electron matches the driving frequency. Correspondingly, the local
density of states presents a narrow peak that approaches a Dirac delta function
in the weak coupling limit. We attribute these features to the presence of
bound states in the continuum.
