Abstract: A rotary microwave antenna system suitable for satellite or cellular microwave radio telecommunications features an integrated, low-profile, rotary microwave joint, slip ring and antenna assembly. The rotary antenna system includes a stator (i.e., stationary portion), for attachment to a mobile platform (e.g., an automobile or other vehicle), having a rotary joint coaxial microwave coupler for electrically coupling a microwave transmission line from a microwave telecommunications radio system to a microwave antenna element of an microwave antenna rotatable about an axis relative to the mobile platform. The rotary antenna system also includes a rotor (i.e., rotary portion) for attachment to the microwave antenna. The rotor includes a slip ring circuit (or brushes) for coupling power and low frequency electrical signals to the microwave antenna through contacting brushes (or slip ring) attached to the stator, rotates relative to the stator, and is concentric with the axis of rotation of the microwave antenna.