  The tunneling through an opaque barrier with a strong oscillating component
is investigated. It is shown, that in the strong perturbations regime (in
contrast to the weak one), higher perturbations rate does not necessarily
improve the activation. In fact, in this regime two rival factors play a role,
and as a consequence, this tunneling system behaves like a sensitive
frequency-shifter device: for most incident particles' energies activation
occurs and the particles are energetically elevated, while for specific
energies activation is depressed and the transmission is very low. This effect
is unique to the strong perturbation regime, and it is totally absent in the
weak perturbation case. Moreover, it cannot be deduced even in the adiabatic
regime. It is conjectured that this mechanism can be used as a
frequency-dependent transistor, in which the device's transmission is governed
by the external field frequency.
