Folded waveguide for antenna

Patent metadata

Field	Value
Publication number	US-11444364-B2
Application number	US-202017131534-A
Country	US
Kind code	B2
Filing date	Dec 22, 2020
Priority date	Dec 22, 2020
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

This document describes a folded waveguide for antenna. The folded waveguide may be an air waveguide and includes a hollow core that forms a rectangular opening in a longitudinal direction at one end, a closed wall at an opposite end, and a sinusoidal shape that folds back and forth about a longitudinal axis that runs in the longitudinal direction through the hollow core. The hollow core forms a plurality of radiation slots, each including a hole through one of multiple surfaces that defines the hollow core. The radiation slots are arranged on the one surface to produce a particular antenna pattern. The radiation slots and sinusoidal shape enable the folded waveguide to prevent grating lobes from appearing in the particular antenna pattern on either side of a horizontal-polarity, main beam, or to prevent X-band lobes from appearing in the particular antenna pattern on either side of a vertical-polarity, main beam.

First claim

What is claimed is:

1. An apparatus, the apparatus comprising:
a folded waveguide comprising a hollow core, the hollow core forming:
a rectangular opening in a longitudinal direction at one end;
a closed wall at an opposite end;
a sinusoidal shape that folds back and forth about a longitudinal axis that runs in the longitudinal direction through the hollow core; and
a plurality of radiation slots, each of the radiation slots comprising a hole through one of multiple surfaces of the folded waveguide that defines the hollow core, the plurality of radiation slots being arranged on the one of the multiple surfaces to produce a particular antenna pattern for a device and an antenna element that is directly coupled to the opposite end of the hollow core.

2. The apparatus of claim 1 , wherein each of the plurality of radiation slots is configured to dissipate, from the hollow core, a portion of electromagnetic radiation that enters the rectangular opening before that portion of the electromagnetic radiation can reach the antenna element that is electrically coupled to the opposite end of the hollow core.

3. The apparatus of claim 1 , wherein each of the plurality of radiation slots is sized and positioned on the one of the multiple surfaces to produce the particular antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core.

4. The apparatus of claim 3 , wherein the plurality of radiation slots is evenly distributed between the rectangular opening and the closed wall, and along the longitudinal axis that runs in the longitudinal direction through the hollow core.

5. The apparatus of claim 4 , wherein each adjacent pair of radiation slots from the plurality of radiation slots comprises two radiation slots that are separated along the longitudinal axis by a common distance to produce the particular antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core.

6. The apparatus of claim 5 , wherein the common distance is less than one wavelength of electromagnetic radiation that reaches the opposite end of the hollow core.

7. The apparatus of claim 4 , wherein each adjacent pair of radiation slots from the plurality of radiation slots comprises two radiation slots that are separated along the longitudinal axis by a common distance to prevent grating lobes or X-band lobes within the particular antenna pattern.

8. The apparatus of claim 1 , wherein each radiation slot from the plurality of radiation slots comprises a lateral slot that is perpendicular to the longitudinal axis to produce a horizontal-polarized antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core.

9. The apparatus of claim 1 , wherein each radiation slot from the plurality of radiation slots comprises a longitudinal slot that is parallel to the longitudinal axis to produce a vertical-polarized antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core.

10. The apparatus of claim 1 , wherein a first half of the plurality of radiation slots comprises a longitudinal slot that is parallel to the longitudinal axis, and a second half of the plurality of radiation slots comprises a lateral slot that is perpendicular to the longitudinal axis to produce a circularly polarized antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core.

11. The apparatus of claim 1 , wherein the folded waveguide comprises metal.

12. The apparatus of claim 1 , wherein the folded waveguide comprises plastic.

13. A system, the system comprising:
an antenna element;
a device configured to transmit or receive electromagnetic signals via the antenna; and
a folded waveguide comprising:
a hollow core forming:
a rectangular opening in a longitudinal direction at one end;
a closed wall at an opposite end that is directly coupled to the antenna element;
a sinusoidal shape that folds back and forth about a longitudinal axis that runs in the longitudinal direction through the hollow core; and

a plurality of radiation slots, each of the radiation slots comprising a hole through one of multiple surfaces of the folded waveguide that defines the hollow core, the plurality of radiation slots being arranged on the one of the multiple surfaces to produce a particular antenna pattern at the antenna element.

14. The system of claim 13 , wherein the device comprises a radar device.

15. The system of claim 13 , further comprising a vehicle comprising the antenna element, the device, and the folded waveguide.

16. The system of claim 13 , wherein each of the plurality of radiation slots is configured to dissipate, from the hollow core, a portion of electromagnetic-radiation that enters the rectangular opening before that portion of the electromagnetic-radiation can reach the antenna element that is electrically coupled to the opposite end of the hollow core.

17. The system of claim 13 , wherein each of the plurality of radiation slots is sized and positioned on the one of the multiple surfaces to produce the particular antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core.

18. The system of claim 13 ,
wherein each radiation slot from the plurality of radiation slots comprises a lateral slot that is perpendicular to the longitudinal axis to produce a horizontal-polarized antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core;
wherein each radiation slot from the plurality of radiation slots comprises a longitudinal slot that is parallel to the longitudinal axis to produce a vertical-polarized antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core; or
wherein a first portion of the plurality of radiation slots comprises a longitudinal slot that is parallel to the longitudinal axis, and a second portion of the plurality of radiation slots comprises a lateral slot that is perpendicular to the longitudinal axis to produce a circularly polarized antenna pattern at the antenna element that is electrically coupled to the opposite end of the hollow core.

19. The system of claim 13 , wherein each of the plurality of radiation slots comprises a hole through a particular surface of the multiple surfaces, the particular surface being one of two surfaces that folds back and forth about the longitudinal axis that runs in the longitudinal direction through the hollow core.

20. The system of claim 13 , wherein each of the plurality of radiation slots comprises a hole through a particular surface of the multiple surfaces, the particular surface being one of two surfaces that is perpendicular to two other surfaces that fold back and forth about the longitudinal axis that runs in the longitudinal direction through the hollow core.

Assignees

• Aptiv Tech Ltd

Inventors

• Shi Shawn

Classifications

• H01Q21/0043 Primary

  Slotted waveguides (combination with horns H01Q13/0233) · CPC title

• H01Q13/22

  Longitudinal slot in boundary wall of waveguide or transmission line {(H01Q13/203 takes precedence)} · CPC title

• H01P3/14

  flexible · CPC title

• H01Q1/3233

  particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems · CPC title

• H01Q13/06 Primary

  Waveguide mouths (horns H01Q13/02) · CPC title