Flush mounted steerable array antenna

Claim 2

A rotatable directional antenna which remains substantially flush with the adjacent surfaces over the range of beam positions, comprising: means for supplying RF energy which is to be propagated; a planar array of radiating elements consisting of a plurality of closely spaced parallel columns of radiating elements for collectively propagating a narrow beam of electromagnetic energy; a rotary mount for supporting the radiating element; means for dividing the supplied RF energy among the columns of radiating elements so that energy having substantially the same phase is coupled to all of the radiating elements that comprise a column of elements; means for providing azimuth and elevation information signals which in combination define the desired beam position; means for deriving from the elevation information signal a plurality of phase information signals suitable for controlling the position of the radiated beam within an azimuth plane which includes the broadside axis of the array; a plurality of phase shifters each responsive to one of the outputs of said dividing means and to one of said phase information signals for individually controlling the phase of the energy coupled to the radiating elements that comprise a column of elements with respect to the phase of the energy coupled to others of said elements so as to cause the narrow beam of electromagnetic energy to be positioned within said azimuth plane in accordance with said elevation information; means responsive to the azimuth information signal for mechanically rotating the rotary mount about the broadside axis of the array for positioning said azimuth plane at the desired azimuth position; whereby the antenna remains substantially flush with the adjacent surface as the narrow beam of electromagnetic energy scans a region in space.

Claim 3

A rotatable directional antenna which remains substantially flush with the adjacent surfaces over the range of beam positions, comprising: means for supplying RF energy which is to be propagated; a planar array of linearly polarized radiating elements, responsive to said supplied RF energy, arranged in a plurality of closely spaced parallel columns of radiating elements, each of said elements being arranged to propagate only the dominant mode, with the elements within each column being stacked in the direction of the magnetic field vector for collectively propagating a narrow beam of electromagnetic energy in the plane of the electric field vector; a rotary mount for supporting the radiating elements; means for dividing the supplied RF energy among the columns of radiating elements so that energy having substantially the same phase is coupled to all of the radiating elements that comprise a column of elements; means for providing azimuth and elevation information signals which in combination defines the desired beam position; Means for deriving from the elevation information signal a plurality of phase information signals suitable for controlling the position of the radiated beam within the plane of the electric field vector; a plurality of phase shifters each responsive to one of the outputs of said dividing means and to one of said phase information signals for individually controlling the phase of the energy coupled to the radiating elements that comprise a column of elements with respect to the phase of the energy coupled to others of said elements so as to cause the narrow beam of electromagnetic energy to be positioned within the plane of the electric field vector in accordance with said elevation information; means responsive to the azimuth information signal for mechanically rotating the rotary mount about the broadside axis of the array for positioning the plane of the electric field vector in accordance with said azimuth information; whereby the antenna remains substantially flush with the adjacent surface as the narrow beam of electromagnetic energy scans a region in space.

Claim 4

A rotatable directional antenna which remains substantially flush with the adjacent surfaces over the range of beam positions, comprising: means for supplying RF energy which is to be propagated; a planar array of linearly polarized radiating elements, responsive to said supplied RF energy, arranged in a plurality of closely spaced parallel columns of radiating elements, each of said elements being arranged to propagate only the dominant mode, with the elements within each column being stacked in the direction of the magnetic field vector for collectively propagating a narrow beam of electromagnetic energy in the plane of the electric field vector; a rotary mount for supporting the radiating elements; means for dividing the supplied RF energy among the columns of radiating elements so that energy having substantially the same phase is coupled to all of the radiating elements that comprise a column of elements; means for providing azimuth and elevation information signals which in combination defines the desired beam position; Means for deriving from the elevation information signal a plurality of phase information signals suitable for controlling the position of the radiated beam within the plane of the electric field vector; a plurality of phase shifters each responsive to one of the outputs of said dividing means and to one of said phase information signals for individually controlling the phase of the energy coupled to the radiating elements that comprise a column of elements with respect to the phase of the energy coupled to others of said elements so as to cause the narrow beam of electromagnetic energy to be positioned within the plane of the electric field vector in accordance with said elevation information; means responsive to the azimuth information signal for mechanically rotating the rotary mount about the broadside axis of the array for positioning the plane of the electric field vector in accordance with said azimuth information; whereby the antenna remains substantially flush with the adjacent surface as the narrow beam of electromagnetic energy scans a region in space.

Claim 5

A phased array antenna as specified in claim 2 which additionally includes a thin sheet of dielectric material parallel to and separated from the array of radiating elements and a plurality of thin flat strips of conductive material mounted on said dielectric sheet, said conductive strips collectively having dielectric characteristics over the desired range of wavelengths for providing impedance matching between the array of radiating elements and free space.

Claim 6

A phased array antenna as specified in claim 1 in which the array of radiating elements consists of slots or holes in a conductive ground plane arranged on a substantially flat circular rotatable member.

Claim 7

A phased array antenna as specified in claim 1 which additionally includes a thin sheet of dielectric material parallel to and separated from the array of radiating elements and a plurality of thin flat strips of conductive material mounted on said dielectric sheet, said conductive strips collectively having dielectric characteristics over the desired range of wavelengths for providing impedance matching between the array of radiating elements and free space.

Claim 8

An antenna as specified in claim 2 in which the center-to-center spacing between the elements in the direction of the electric field vector is less than 0.5 times the free space wavelength at the high end of the operating bandwidth.