Abstract: A scanning array antenna employs a solid rotating core having an anisotropic refractive index within an apertured waveguide that emits radiation in response to an input beam propagating through the waveguide. Rotating the core changes its refractive index relative to the input beam, causing the radiated beams to undergo an angular scanning. The solid rotating waveguide core can be formed from a dispersion of aligned elongate conductive members in an isotropic dielectric, from a liquid crystal medium, or from a dispersion of aligned elongate conductive members in a liquid crystal medium. The antenna is operable in reciprocal transmission and reception modes.