Scattering Properties of Chaotic Microwave Billiards

Reflection and transmission measurements in microwave billiards with attached antennas allow the determination of all components of the scattering matrix including their phases. This is an extraordinary situation, since in usual scattering experiments in nuclear or atomic physics only reduced information such as the scattering cross-section can be obtained where the phase information is completely lost. This allows experimental tests of theoretical predictions of scattering theory inaccessible by any other method. As an example the distribution of reflection coefficients and of the line widths in a chaotic microwave billiard are discussed.