US 4,283,729 A · Multiple beam antenna feed

Abstract

An open array antenna having a plurality of columns of radiating elements and a feed network, said feed network having a sum channel, a difference channel, and a sidelobe suppression channel formed in common in an input power divider and first, second, third and fourth power dividers, said power dividers connected in a corporate arrangement for providing equal length paths of minimum length to the columns of radiating elements, said power dividers comprising a plurality of hybrids having preselected coupling ratios and interconnections to form the input power divider with input ports for sum, difference, and SLS RF power, and to output sum, difference, difference minus sum, and SLS amplitudes to the first and second power dividers, and sum, difference and SLS amplitudes to the third and fourth power dividers, the hybrids of the first and second power dividers forming tapered sum and SLS amplitudes and forming tapered difference power by selectively combining the difference minus sum amplitudes to the difference amplitudes as a control for the difference amplitudes to provide power for a difference pattern which is independent of the amplitudes for the sum and SLS pattern excitations for a preselected number of the columns of radiating elements and the hybrids of the third and fourth power dividers forming substantially independent tapered sum, difference, and SLS amplitude excitations for the remaining columns of radiating elements, said sum, difference and SLS amplitude excitations of the columns of radiating elements combining to form sum, difference, and SLS beam patterns.

Claims14

Dependent claims

An array antenna comprising:

(a) an RF energy feed network having a plurality of input mechanisms for receiving RF power for a plurality of independent beams, a plurality of hybrid junctions selectively connected to the plurality of input mechanisms and a plurality of output mechanisms connected selectively to the plurality of hybrids, said plurality of hybrids selectively interconnected and having coupling ratios for maintaining independent modes of propagation and selectively dividing the power to provide RF energy at selected amplitudes to the output mechanisms,
(b) a plurality of radiating elements divided into first and second halves connected to the plurality of hybrid output mechanisms for array excitation, and
(c) said plurality of hybrids is divided into first, second and third portions, said first and second portions of hybrids operatively connected to the first and second halves of said radiating elements to form two independent, isolated, orthogonal antenna beams, one beam being an optimized low sidelobe sum beam (.SIGMA.) and the other beam being the algebraic difference between an independently, optimized difference beam and sum beam (.DELTA.-.SIGMA.), and said third portion of said hybrids operatively connected to the first and second portions of said hybrids to form an input power divider to the first and second portions of hybrids.

An array antenna comprising a plurality of columns of radiating elements and a feed network operatively connected to the columns of radiating elements, said radiating elements arranged in first and second sections with a center column therebetween and a backfill column therebehind, said feed network having a sum channel, a difference channel and a sidelobe suppression channel formed in common in an input power divider and first, second, third and fourth power dividers, said power dividers connected in a corporate arrangement for providing equal length paths of minimum length to the columns of radiating elements of the first and second sections, said power dividers comprising a plurality of hybrids having preselected coupling ratios and interconnections:

to form the input power divider with input ports for sum, difference, and SLS RF power, and output ports for sum, difference, difference minus sum, and SLS amplitudes for the first and second power dividers, and sum, difference, and SLS amplitudes to the third and fourth power dividers, to form the first and second power dividers with input ports connected to selected output ports of the input power divider for forming tapered sum and SLS amplitudes, and tapered difference power by selectively combining the difference minus sum amplitudes to the difference amplitudes as a control for the difference amplitudes to provide power for a difference pattern excitation which is independent of the amplitude for the sum and SLS pattern excitations and output ports for a preselected number of columns of radiating elements of each of the first and second sections, and to form the third and fourth power dividers with input ports connected to selected output ports of the input power divider for forming substantially independent tapered sum, difference, and SLS amplitude excitations, and output ports for the remaining columns of radiating elements of the first and second sections, said columns of radiating elements responsive to said sum, difference, and SLS amplitude excitations of the columns of radiating elements to form sum, difference and SLS beam patterns.

Dependencies are inferred from the claim text.

Multiple beam antenna feed

Life of this patent

Multiple beam antenna feed

Life of this patent

Abstract

Claims14