  We present a novel Discontinuous Galerkin Finite Element Method for wave
propagation problems. The method employs space-time Trefftz-type basis
functions that satisfy the underlying partial differential equations and the
respective interface boundary conditions exactly in an element-wise fashion.
The basis functions can be of arbitrary high order, and we demonstrate spectral
convergence in the $\Lebesgue_2$-norm. In this context, spectral convergence is
obtained with respect to the approximation error in the entire space-time
domain of interest, i.e. in space and time simultaneously. Formulating the
approximation in terms of a space-time Trefftz basis makes high order time
integration an inherent property of the method and clearly sets it apart from
methods, that employ a high order approximation in space only.
