NEW DOUBLE BEAM SCANNING ANTENNA.

Abstract

A new double beam scanning antenna is proposed which is found to radiate two beams, one of which is fixed while the other is scanning. The antenna consists of a waveguide whose aperture was tapered symmetrically from both sides. A cylindrical ferrite post was placed at the center of the notch which was biased axially with a d. c. magnetic field. In general, the scanning angle increases with d. c. biasing magnetic field (magnet current) for all notch angles investigated with ferrite and ferrite loaded with dielectric rings. The dielectric loading is found to improve the radiation characteristics in general. The deviation in the beam is found to depend on the direction of the biasing magnetic field. However, there is a critical thickness of the dielectric ring which provides the maximum radiated power and there is a critical value of the field beyond which no change is observed in the beam position.