Modified radar antenna array

1 . A patch antenna comprising:

a radiating microstrip patch element; and

a ground layer corresponding to the patch element,

wherein the ground layer comprises one or more cut-outs near a bottom edge of the ground layer, the one or more cutouts configured to generate distortion in a radiation pattern of the patch antenna, such that the radiation pattern of the patch antenna comprises a beam perpendicular to an antenna aperture, and a sub-beam parallel to the antenna aperture.

2 . The patch antenna of claim 1 , wherein the bottom edge of the ground layer corresponds to a bottom edge of the patch element.

3 . The patch antenna of claim 2 , further comprising:

a dielectric substrate disposed between the antenna and the ground layer, and wherein the ground layer has a same length as the dielectric substrate.

4 . The patch antenna of claim 2 , wherein the ground layer is configured such that the radiation pattern of the patch antenna is reflected by objects located under the antenna.

5 . The patch antenna of claim 1 , wherein a shape of the patch element is a rectangle, a circle, an ellipse, polygon, and/or a combination thereof.

6 . The patch antenna of claim 1 , wherein the antenna is configured to operate at a frequency between 0.4 GHz and 135 GHz.

7 . A method for generating a beam directed under a patch antenna using the patch antenna of claim 1 .

8 . The patch antenna of claim 1 , wherein the one or more cut-outs have a shape selected from the group consisting of rectangular, triangular, circular, elliptical, or polygonal shapes, the one or more cut-outs being positioned adjacent to a bottom edge of the patch element and extending into the ground layer from the bottom edge, the one or more cut-outs configured to generate the distortion in the radiation pattern by directing a portion of the radiated energy in an end-fire direction parallel to the antenna aperture.

9 . An antenna array comprising:

two or more radiating microstrip patch elements with

a ground layer, wherein the ground layer is configured such that an area of the ground layer near a last radiating patch element is configured to shape an antenna pattern with an additional beam directed to a location under the antenna array;

the ground layer comprises one or more cut-outs near a bottom edge of the ground layer, to distort radiation from the last radiating patch element, such that a radiation pattern of the antenna array comprises a beam perpendicular to an antenna aperture, and a sub-beam parallel to the antenna aperture.

10 . The antenna array of claim 9 , further comprising:

a dielectric substrate disposed between the antenna and the ground layer, and wherein the ground layer is shorter in length than the dielectric substrate.

11 . A radar sensor comprising the antenna array of claim 9 , wherein the radar sensor is configured for detecting presence under the radar.

12 . The radar sensor of claim 11 , wherein the radar sensor is configured to detect crawling under the radar.