Planar surface features for achieving antenna coverage

1 . An antenna system comprising:

a structure having a planar surface and a second surface opposite the planar surface, the structure configured to provide a feed network for propagating electromagnetic energy along an energy path formed under the planar surface of the structure, the structure including:

a recessed cavity extending away from the planar surface toward the second surface, the recessed cavity having walls that surround a cavity floor, the cavity floor disposed between the planar surface and the second surface;

radiating slots extending through the structure from the cavity floor to the second surface and to the energy path provided by the feed network under the planar surface; and

multiple ridge features that each extend away from the planar surface and away from the second surface, the multiple ridge features on either side of the recessed cavity, the multiple ridge features extending parallel to each other, the multiple ridge features including a ridge length that is parallel with at least one of the cavity walls and a ridge height configured to prevent cross-interference near the radiating slots within the cavity floor thereby narrowing coverage for the electromagnetic energy within the feed network,

the multiple ridge features including:

a first two or more ridge features disposed on a first side of the recessed cavity, the first two or more ridge features extending away from the planar surface and away from the second surface, where none of the radiating slots are disposed between the ridge features of the first two or more ridge features; and

a second two or more ridge features disposed on a second side of the recessed cavity, the second two or more ridge features extending away from the planar surface and away from the second surface, the second side opposite the first side, where none of the radiating slots are disposed between the ridge features of the second two or more ridge features.

2 . The antenna system of claim 1 , wherein the antenna system comprise at least one of aperture antennas, microstrip antennas, microstrip patch antennas, dipole antennas, substrate-integrated waveguide (SIW) antennas, slot array antennas, waveguide end-array antennas, or horn antennas.

3 . The antenna system of claim 1 , wherein the antenna system further comprises:

an interface to a device configured to transmit or receive electromagnetic signals via the feed network through the antenna system.

4 . The antenna system of claim 3 , wherein the device comprises a radar device for a vehicle.

5 . The antenna system of claim 1 , wherein the first two or more ridge features comprise at least three ridge features including a first group of the ridge features arranged on the first side of the recessed cavity and the second two or more ridge features comprise a second group of the ridge features arranged on the second side of the recessed cavity.

6 . The antenna system of claim 5 ,

wherein the multiple ridge features are distributed evenly between the first group and the second group.

7 . The antenna system of claim 5 ,

wherein the multiple ridge features are distributed unevenly between the first group and the second group.

8 . The antenna system of claim 1 ,

wherein the feed network comprises a divider stage, and the radiating slots comprise slots formed into a corresponding output of the divider stage.

9 . The antenna system of claim 1 ,

wherein the feed network comprises a divider stage with a pair of outputs separated by an iris in the divider stage.

10 . The antenna system of claim 9 , wherein the radiating slots comprise slots formed into each output from the pair of outputs.

11 . The antenna system of claim 1 ,

wherein the feed network comprises multiple divider stages, and the radiating slots comprise a single slot formed into a combined output of the multiple divider stages.

12 . The antenna system of claim 1 , wherein the structure comprises a first structure and the planar surface comprises a first planar surface opposite the first structure with a second planar surface, the antenna system further comprising:

a second structure with a third planar surface arranged adjacent to a separation plane dividing the feed network between the second planar surface and the third planar surface, and opposite a fourth planar surface on the second structure; and

the second planar surface including an arrangement of surface features spaced and shaped to form a first part of the feed network between at least two surface features in the arrangement, the first planar surface providing the radiating slots into the first part of the feed network;

the third planar surface including a recessed groove shaped to form a second part of the feed network between side walls of the recessed groove to compliment the first part formed by the surface features,

the at least two surface features comprising adjacent protrusions aligned with opposing side walls of the recessed groove to bound an area of the second planar surface located on and between the adjacent protrusions to form the first part of the feed network, a portion of the second planar surface at each of the adjacent protrusions being contoured to a different opposing side wall of the recessed groove to configure the energy path through the feed network and configure the feed network to prevent energy leakage from the separation plane dividing the feed network.

13 . The antenna system of claim 12 ,

wherein the at least two of the surface features are in different shapes and sizes.

14 . The antenna system of claim 13 ,

wherein the at least two of the surface features sized and shaped to prevent energy leakage from tunnels of the feed network that change dimension or direction of the feed network relative the radiating slots.

15 . The antenna system of claim 12 ,

wherein a rectangular input to the feed network is provided at one end of the recessed groove.

16 . The antenna system of claim 12 ,

wherein a gap distance is maintained about the separation plane between the third planar surface and the arrangement of surface features to configure the feed network to propagate the electromagnetic energy and prevent the energy leakage near the separation plane.

17 . The antenna system of claim 16 , wherein:

a spacing of the surface features is set based on a groove width, and a height of the surface features in the arrangement is set based on a groove depth; and

the feed network comprises a channel width and a channel height set based on a desired electromagnetic energy wavelength for the antenna system, the channel width being defined by the groove width or the spacing of the surface features, and the channel height being defined by the gap distance, the height of the surface features, and the groove depth.

18 . The antenna system of claim 1 , wherein the structure comprises a first plate with another planar surface opposite the planar surface and aligned about a separation plane with a first planar surface of a second plate to complete the feed network under the planar surface and between the first plate and the second plate.