A Mode Transducing Antenna

At power levels above those readily handled by standard waveguide, and for long waveguide runs, the TE/sub 01/ mode in circular guide is a preferred transmission line approach. At the antenna, this mode is generally unsuited to radiation since it forms a conical, instead of a pencil beam. Phase and polarization shifting techniques at a reflecting surface cause the illumination to be transduced to form a pencil beam. The techniques have been demonstrated in a 33-GHz model.