Complex wave systems had been studied by means of microwave techniques. Eleven different topics had been approached resulting in joint publications with four other P projects and with four external E projects. The following topics had been addressed: (i) Investigation of “rogue waves”: The algebraic -2/3 decay in the scintillation index characterizing branched flow was observed experimentally. (ii) Reappearance of regular states: In a mushroom billiard the reappearance of partially flooded regular states after opening the system was found. In a cosine billiard resonance assisted tunneling was found. (iii) Non-linear effects in the side band structure of Floquet systems: By driving the electrical properties of a “tin”-resonator we observed a hysteresis effect in the Floquet side band structure. (iv) Goos-Hänchen shift and Fresnel filtering: Generating a plane wave by superimposing measurements from different antenna positions, we observed a shift of the outgoing wave reflected from an teflon-air interface. (v) Skipping orbits: Using a quasi-one-dimensional wave guide with surface roughness we were able to separate two different scattering mechanisms by introducing appropriate correlations in the disorder. (vi) Metamaterials in disordered one-dimensional waveguides: We realized metamaterial by means of coupled split ring resonators. In a free space measurement a frequency range was found with a negative index of refraction. Unfortunately this effect vanished inside a wave guide. (vii) Classical features in the fidelity decay: By changing the shape of a chaotic cavity by means of a piston-like perturbation a non-monotonic behaviour of the fidelity as a function of the perturbation strength was found. (viii) Cross-section correlations: We found that the cross-section correlation with only one index in common compared to the correlation without any index in common were anticorrelated as a function of the coupling strength. (ix) Graphene-like structures with microwaves: We realized a tight binding microwave system using dielectric cylinders with a high index of refraction (n=6). With this setup we were able to investigate graphene like structures with disorder, boron nitride but also a Dirac oscillator. (x) Resonances in systems with a fractal classical repeller: The fractal Weyl law and the the predicted minimal resonance width in a three and five disk system was verified experimentally. (xi) Nearest level spacing statistics in open chaotic systems: The Wigner distributions for the nearest neighbour spacing distribution have to be modified for open systems. Using a 2 × 2 matrix approach an analytic description was derived and verified experimentally.