A Note on Microwave Guided Propagation in the Case of Anomalous Dispersion

A group velocity greater than that of light, in propagation through dispersive media, was theoretically predicted by Brillouin. We present a simple experiment of propagation in a waveguide, where an externally introduced absorption band originates anomalous dispersion and acts as a dispersive medium. As expected, the group velocity was greater than the light speed.