  Forward transition radiation is considered in an ultrasonic superlattice
excited in a finite thickness plate under oblique incidence of relativistic
electrons. We investigate the influence of acoustic waves on both the intensity
and polarization of the radiation. In the quasi-classical approximation,
formulas are derived for the vector potential of the electromagnetic field and
for the spectral-angular distribution of the radiation intensity. It is shown
that the acoustic waves generate new resonance peaks in the spectral and
angular distributions. The heights and the location of the peaks can be
controlled by choosing the parameters of the acoustic wave. The numerical
examples are given for a plate of fused quartz.
