Derling G Killion

47377968, Apr 12, 1988

Jul 30, 1986

6/890586

Mark E. Bonebright - San Diego CA
Derling G. Killion - San Diego CA

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

H01Q 1914

343782

The radiation pattern of a beam at elevation angles near the horizon is improved for phased array antennas by control of the radiation field intensity near the horizon to reduce multipath disturbances, and to improve the axial ratio of a circularly polarized phased array antenna. This is accomplished by placing a parasitic phase shifting element directly below the antenna beam axis. The waveguide section is designed to produce a phase shift in the portion of antenna radiation energy passing through it to cancel some of the radiation energy in the direction of the horizon. The spacing of the waveguide section in front of the antenna is determined empirically for optimum results, i. e. , for reduction of beam power below about 20. degree. without affecting beam power at high elevation angles.

41986393, Apr 15, 1980

Dec 26, 1978

5/972721

Derling G. Killion - San Diego CA

Cubic Corporation - San Diego CA

H01Q 2100
H01Q 128

343727

The disclosed antenna system includes a non-conductive parabolic dish, a first antenna array rigidly positioned in front of the dish, and a second antenna array extending through the dish and having radiating elements on either side thereof. In one embodiment, a plurality of conductive strips are disposed on the dish in a polarization selective pattern; the first antenna array generates linearly polarized electric fields that are reflected by the strips; and the second antenna array generates linearly polarized electric fields that pass through the strips. In another embodiment of the invention a plurality of conductive areas are disposed on the dish in a checkerboard frequency selective pattern; the first antenna array generates electric fields in a frequency band that are reflected by the pattern; and the second antenna array generates electric fields in a frequency band that are passed by the pattern.