Switchable lens antenna with integrated frequency selective structure

Patent metadata

Field	Value
Publication number	US-10938124-B2
Application number	US-201816191630-A
Country	US
Kind code	B2
Filing date	Nov 15, 2018
Priority date	Nov 15, 2018
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

The disclosed structures and methods are directed to antenna systems configured to transmit and receive a wireless signal in and from different directions. A switchable lens antenna has excitation ports radiating radio-frequency (RF) wave into a parallel-plate waveguide structure, and a frequency selective structure (FSS). The antenna presented herein is configured to operate in two modes depending on a steering angle of the RF wave propagating in the parallel-plate waveguide structure. When the steering angle is about or less than a threshold steering angle, FSS is OFF due to its stubs being electrically disconnected from the parallel-plate waveguide structure. When the steering angle is higher than the threshold, FSS is ON with stubs being electrically connected to the parallel-plate waveguide structure. When ON, FSS provides phase variance to the RF wave propagating in the parallel-plate waveguide structure and increases steering angle of the RF wave.

First claim

The invention claimed is:

1. A switchable lens antenna for transmission of a radio-frequency (RF) wave, the antenna comprising:
a parallel-plate waveguide structure;
an array of excitation ports operable to radiate the RF wave into the parallel-plate waveguide structure, the array of excitation ports radiating the RF wave in an initial steering angle; and
a frequency selective structure having frequency selective elements, each frequency selective element comprising:
a stub configured to introduce a phase variance to modify the steering angle of the RF wave when the stub is electrically connected to the parallel-plate waveguide structure; and
a switchable element operatively connected to the stub and the parallel-plate waveguide structure, the switchable element configured to selectively electrically disconnect the stub from the parallel-plate waveguide structure when the antenna is in a first operational mode and to electrically connect the stub to the parallel-plate waveguide structure when the antenna is in a second operational mode.

2. The switchable lens antenna of claim 1 , wherein:
the antenna is in the first operational mode in response to the initial steering angle of the RF wave radiated by the array of excitation ports being about or less than a threshold steering angle, and
the antenna is in the second operational mode in response to the initial steering angle of the RF wave radiated by the array of excitation ports being higher than the threshold steering angle.

3. The switchable lens antenna of claim 1 , further comprising a controller configured to:
determine operational mode of the antenna, the operational mode being one of the first operational mode and the second operational mode; and
operate the switchable element to selectively electrically disconnect the stub from the parallel-plate waveguide structure when the antenna is in a first operational mode and to electrically connect the stub to the parallel-plate waveguide structure when the antenna is in the second operational mode.

4. The switchable lens antenna of claim 2 , wherein the threshold steering angle is approximately a half of a half-power beam width of the RF wave radiated by the array of excitation ports at a boresight when the antenna is in the first operational mode.

5. The switchable lens antenna of claim 1 , wherein the frequency selective elements comprise a first frequency selective element having a first stub and a second frequency selective element having a second stub, and the second frequency selective element is located further away from a boresight of the antenna and the second stub is longer than the first stub.

6. The switchable lens antenna of claim 1 , wherein the frequency selective element is electrically connected to the parallel-plate waveguide structure through a via electrically connected to a ground surface of the parallel-plate waveguide structure.

7. The switchable lens antenna of claim 1 , wherein the switchable element is a diode.

8. The switchable lens antenna of claim 1 , further comprising vertically polarized radiators located at an output of the parallel-plate waveguide structure and configured to vertically polarize the RF wave.

9. The switchable lens antenna of claim 1 , wherein the parallel-plate waveguide structure is a printed circuit board.

10. The switchable lens antenna of claim 1 , wherein the frequency selective elements are positioned in at least one frequency selective structure row, each frequency selective element in the frequency selective structure row being located radially at about equal distance from a geometrical center of the array of excitation ports and a distance between neighbouring frequency selective elements in each frequency selective structure row is approximately the same.

11. A frequency selective structure for a lens-based antenna, the lens-based antenna having a parallel-plate waveguide structure and an array of excitation ports operable to radiate a radio-frequency (RF) wave into the parallel-plate waveguide structure, the array of excitation ports radiating the RF wave in an initial steering angle, the frequency selective structure comprising:
a frequency selective element having:
a stub configured to introduce a phase variance to modify the steering angle of the RF wave when electrically connected to the parallel-plate waveguide structure; and
a switchable element operatively connected to the stub and to the parallel-plate waveguide structure, the switchable element configured to selectively electrically disconnect the stub from the parallel-plate waveguide structure when the antenna is in a first operational mode and to electrically connect the stub to the parallel-plate waveguide structure when the antenna is in a second operational mode.

12. The frequency-selective structure of claim 11 , wherein the switchable element is a diode.

13. A method for wireless communication, the method comprising:
determining an initial steering angle of a radio-frequency (RF) wave radiated into a parallel-plate waveguide structure;
in response to the initial steering angle being about or lower than a threshold steering angle, electrically disconnecting frequency selective elements from the parallel-plate waveguide structure; and
in response to the initial steering angle being higher than the threshold steering angle, electrically connecting the frequency selective elements to the parallel-plate waveguide structure to introduce a phase variance to modify the steering angle of the RF wave propagating in the parallel-plate waveguide structure.

14. The method of claim 13 , wherein the frequency selective elements are located in at least one frequency selective structure row, each frequency selective structure row being approximately equally distant from a geometrical center of an array of excitation ports radiating the RF wave into the parallel-plate waveguide structure.

15. The method of claim 13 , wherein the threshold steering angle is approximately a half of a half-power beam width of the RF wave.

16. The method of claim 13 , wherein a distance between neighbouring frequency selective elements in each frequency selective structure row is approximately the same.

17. The method of claim 13 , further comprising vertically polarizing the RF wave at an output of the parallel-plate waveguide structure with vertically polarized radiators.

18. The method of claim 13 , wherein electrically connecting the frequency selective elements to and from the parallel-plate waveguide structure is done by electrically connecting and disconnecting a stub to and from a ground surface of the parallel-plate waveguide structure by a switchable element.

Assignees

• Boutayeb Halim
• Zhai Wenyao
• Repeta Morris
• Huawei Tech Co Ltd

Inventors

• Boutayeb Halim
• Zhai Wenyao
• Repeta Morris

Classifications

• G02B27/09

  Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for {(adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005)} · CPC title

• H01Q21/0031

  Parallel-plate fed arrays; Lens-fed arrays (multibeam arrays H01Q25/008) · CPC title

• H01Q21/0012

  Radial guide fed arrays · CPC title

• H01Q15/002

  said selective devices being reconfigurable or tunable, e.g. using switches or diodes · CPC title

• H01Q3/247

  by switching different parts of a primary active element · CPC title