Gradient-index lens for aperture-constrained arrays and system, apparatus, and method thereof
AssigneeLockheed Martin Corporation
InventorsJoshua W. Withrow, John P. Barrett
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Abstract
A gradient-index (GRIN) lens comprises an input surface defined by a body configured to receive electromagnetic (EM) waves from an aperture-constrained array; and an output surface defined by the body configured to output phase-aligned EM waves based on the received EM waves from the aperture-constrained array. The GRIN lens can be dimension-constrained in at least one dimension and can have a non-linear permittivity taper in at least a first dimension. The GRIN lens can provide gain for the received EM waves from the aperture-constrained array.
Claims20
An aperture-constrained radar system comprising:
- an electronically scanned aperture-constrained phased array configured to output directive electromagnetic (EM) waves according to a first gain;
- and
- a gradient-index (GRIN) lens provided in front of and aligned with the electronically scanned aperture-constrained phased array to receive the directive EM waves output from the electronically scanned aperture-constrained phased array and output phase-aligned EM waves according to a second gain greater than the first gain,
- wherein the GRIN lens is spaced from the electronically scanned aperture-constrained phased array by a predetermined electrical distance,
- wherein air as a transmission medium is provided between the electronically scanned aperture-constrained phased array and an input side of the GRIN lens and at an output side of the GRIN lens,
- wherein the electronically scanned aperture-constrained phased array is aperture-constrained in one, some, or all of an elevation dimension, an azimuthal dimension, and a direction of radiation dimension,
- wherein the GRIN lens is no greater in dimension than either the azimuthal dimension or the elevation dimension and is greater in dimension than an overall area of the electronically scanned aperture-constrained phased array by no more than 10%, and
- wherein the GRIN lens has a multi-extrema permittivity taper in the aperture-constrained one or more of the elevation dimension, the azimuthal dimension, and the direction of radiation dimension.
An aperture-constrained phased array assembly comprising:
- an aperture-constrained phased array configured to output electromagnetic (EM) waves;
- and
- a gradient-index (GRIN) lens provided in front of and aligned with the aperture-constrained phased array to output phase-aligned EM waves based on the EM waves output from the aperture-constrained phased array,
- wherein the GRIN lens is spaced from the aperture-constrained phased array by a predetermined electrical distance,
- wherein the aperture-constrained phased array is aperture-constrained,
- wherein the GRIN lens is no more than 10% greater in overall height and width than the aperture-constrained phased array, and
- wherein the GRIN lens has a permittivity taper in a first dimension.
A gradient-index (GRIN) lens for a radar sensor comprising:
- an input surface defined by a body configured to receive and transmit electromagnetic (EM) waves received from an aperture-constrained phased array;
- and
- an output surface defined by the body configured to output phase-aligned EM waves based on the EM waves transmitted from the input side,
- wherein the GRIN lens is dimension-constrained in at least one dimension,
- wherein the GRIN lens has a first multi-extrema permittivity taper in a first dimension,
- wherein the GRIN lens is planar or conformal, and
- wherein the GRIN lens is comprised of a plurality of unit cells configured to provide the first multi-extrema permittivity taper based on relative configuration of a first material and a second material different from the first material.
Dependencies are inferred from the claim text.