Transmitting antenna employing parasitic end fire directors

Claim 2

An antenna assembly for transmitting signals of a given wavelength, comprising an elongated electrically conductive supporting structure having a major transverse dimension such as to affect the pattern of the antenna assembly, a driven antenna element carried by said supporting structure and defining a radiation axis extending therefrom, and at least one end-fire parasitic director having an axis extending generally from said structure and comprising a conductive member having a first planar portion on one side of said axis being transverse thereto and a second planar portion on the opposite side of said axis defining an angle of at least about 30* from the normal thereto, said director being so positioned relative to said driven antenna and supporting structure as to alter the shape of the antenna pattern produced by the combined effects of said driven antenna and supporting structure, while not intersecting the radiation axis of said driven element, to provide a selected pattern for said antenna assembly.

Claim 3

The antenna assembly of claim 1 wherein said first and second planar portions of said conductive member have a combined linear dimension in a plane parallel to the plane of the nondirectional field produced by said driven element oF between approximately one-fourth and one-half wavelength.

Claim 4

The antenna assembly of claim 2 wherein said combined linear dimension is approximately one-third wavelength.

Claim 5

The antenna assembly of claim 2 wherein said conductive member has a linear dimension normal to the plane of the nondirectional field produced by said driven element of at least approximately one-third wavelength.

Claim 6

The antenna assembly of claim 1 wherein said first planar portion of said conductive member is located between said director axis and said supporting structure, and said second planar portion is located on the outside of said assembly.

Claim 7

The antenna assembly of claim 5 wherein said second planar portion defines an acute angle with said director axis and said acute angle faces the same general side of the assembly as said radiation axis.

Claim 8

The antenna assembly of claim 1 wherein said end-fire director comprises another conductive member having a portion thereof transverse to said director axis and spaced therealong from said first mentioned conductive member a distance approximately from one-eighth to one-half wavelength.

Claim 9

The antenna assembly of claim 7 wherein said distance is approximately one-fourth wavelength.

Claim 10

The antenna assembly of claim 1 further comprising another end-fire director like said first mentioned end-fire director, wherein each of said directors is mounted to said elongated supporting structure on opposite sides of said driven element with their respective axes defining a plane approximately normal to the longitudinal axis of said structure and intersecting said longitudinal axis within one-half wavelength of the center of said driven element.

Claim 11

An antenna assembly for transmitting signals of a given wavelength, comprising a vertical elongated electrically conductive supporting structure having a transverse dimension of at least approximately one-fourth wavelength, at least one bay including a driven antenna element carried by said structure for producing radiation of horizontal polarization and defining a radiation axis extending from said element, means for feeding electrical energy signals to said driven antenna element, and a pair of end-fire parasitic directors having their respective axes extending generally horizontally from said driven element, each of said directors comprising a conductive member having a linear dimension in a plane parallel to the plane of the electric field vector of the transmitted signal of approximately one-fourth to one-half wavelength, said conductive member comprising a first planar portion between the director axis and said structure being transverse to said director axis and a second planar portion on the opposite side of the director axis defining an angle of at least about 30* from the normal thereto, said conductive member having a vertical dimension of at least approximately one-third wavelength, said director being so positioned relative to said driven antenna and supporting structure as to alter the shape of the antenna pattern produced by the combined effects of said driven antenna and supporting structure, while not intersecting said radiation axis, to provide a selected pattern for said antenna assembly.

Claim 12

An antenna assembly for transmitting signals of a given wavelength, comprising a vertical elongated electrically conductive supporting structure having a transverse dimension of at least approximately one-fourth wavelength, at least one bay including a driven antenna element carried by said structure for producing radiation of horizontal polarization and defining a radiation axis extending from said element, means for feeding electrical energy signals to said driven antenna element, and a pair of end-fire parasitic directors having their respective axes extending generally horizontally from said driven element, each of said directors comprising a conductive member having a linear dimension in a plane parallel to the plane of the electric field vector of the transmitted signal of approximately one-fourth to one-half wavelength, said conductive member comprising a first planar portion between the director axis and said structure being transverse to said director axis and a second planar portion on the opposite side of the director axis defining an angle of at least about 30* from the normal thereto, said conductive member having a vertical dimension of at least approximately one-third wavelength, said director being so positioned relative to said driven antenna and supporting structure as to alter the shape of the antenna pattern produced by the combined effects of said driven antenna and supporting structure, while not intersecting said radiation axis, to provide a selected pattern for said antenna assembly.

Claim 13

The antenna assembly of claim 10 wherein said first and second planar portions of said conductive member each comprise a pair of separated conductive parts in planes parallel to the electric field vector and respectively defining the plane of each of said planar portions.

Claim 14

The antenna assembly of claim 10 wherein said conductive member is formed by a bent plate with the first planar portion of the plate being transverse to the director axis and the second planar portion of the plate being bent toward said driven element.

Claim 15

The antenna assembly of claim 10 wherein said end-fire directors each comprise another conductive member having a portion thereof transverse to said director axis and spaced therealong from said first mentioned conductive member a distance approxiMately from one-eighth to one-half wavelength.

Claim 16

The antenna assembly of claim 10 wherein said directors are mounted to said vertical supporting structure with their respective axes defining an approximately horizontal plane intersecting said structure within one-half wavelength of the center of said driven element.