Recommended Citation Junker, M. et al. (2006) Abstract-Measurements of phase noise of a 40-GHz carrier signal are presented. The carrier is generated by the amplification of harmonics due to stimulated Brillouin scattering. An analogy to a generation of millimeter waves by an erbium-doped fiber instead of the Brillouin amplifier is investigated and discussed. In our setup, both show a comparable behavior in respect to their noise characteristics.Index Terms-Brillouin scattering, millimeter-wave generation, phase noise.