New Low Gain S-Band Satellite Antenna with Suppressed Back Radiation

Theoretical and experimental results are presented for a waveguide antenna with a cardoid-shaped pattern. The antenna, which operates in the S band, is proposed for telemetry and telecommand on future scientific satellites. The radiation takes place through eight axial slots placed near the end of a circular waveguide which carries a rotating TEll mode. A conical reflector may be attached to the waveguide structure to shape the pattern, which is calculated by solving the electrical field integral equation utilizing the rotational symmetry of the body. The paper also. deals with the excitation of the TEll waveguide mode and the matching of the slots to this mode.