US-20260128532-A1 - DUAL CIRCULAR-POLARIZED ORBITAL ANGULAR MOMENTUM ANTENNAS WITH ELECTRONICAL BEAM STEERING PROPERTIES AND SYSTEMS AND METHODS OF USING THE SAME

US20260128532A1US 20260128532 A1US20260128532 A1US 20260128532A1US-20260128532-A1

Abstract

Antennas, systems, and methods for electronically steering an Orbital Angular Momentum (OAM) beam carrying multiple OAM modes with dual circular-polarization is presented. An OAM antenna includes a plurality of concentric arrays and at least one electromagnetic signal confining structure between neighboring concentric arrays. Each concentric array has a respective plurality of dual circular-polarized (CP) waveguide antenna elements collectively operable to emit a respective OAM beam component carrying one or more dual CP OAM modes. Dual CP antenna elements of a concentric array are coupled to a feed structure via respective bottom ends thereof. Each feed structure is configured to process signals in accordance with the one or more OAM modes associated with a corresponding dual CP waveguide antenna element and in accordance with beamsteering parameters.

Inventors

Mohammad Akbari CHOUBAR

Assignees

HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20241106

Claims (20)

1 . An antenna for either or both transmitting and receiving an Orbital Angular Momentum (OAM) electromagnetic beam, the antenna comprising: a plurality of concentric arrays, each concentric array of the plurality of concentric arrays comprising: a respective aperture; and a respective plurality of dual circular-polarized waveguide antenna elements, each dual circular-polarized waveguide antenna element of the respective plurality of dual circular-polarized waveguide antenna elements comprising a top end and a bottom end for coupling to a feed structure; and one or more concentric electromagnetic signal confining structures, wherein, each neighboring pair of concentric arrays of the plurality of concentric arrays have at least one electromagnetic signal confining structure of the one or more electromagnetic signal confining structures therebetween.
2 . The antenna of claim 1 , wherein the respective bottom end of each dual circular-polarized waveguide antenna element comprises: a first rectangularly arranged port for either or both transmitting and receiving one or more right-hand circular polarized components of the OAM electromagnetic beam; a second rectangularly arranged port for either or both transmitting and receiving one or more left-hand circular polarized components of the OAM electromagnetic beam; and wherein, a partial wall separates the first and second rectangularly arranged ports.
3 . The antenna of claim 2 , wherein all concentric arrays of the plurality of concentric arrays are coplanar.
4 . The antenna of claim 3 , further comprising: a single central dual circular-polarized waveguide antenna element along a central axis of the antenna.
5 . The antenna of claim 4 , wherein: the plurality of concentric arrays comprises: a first concentric array comprising a first plurality of dual circular-polarized waveguide antenna elements; and a second concentric array surrounding the first concentric array, the second concentric array comprising a second plurality of dual circular-polarized waveguide antenna elements having double the dual circular-polarized waveguide antenna elements as compared to the first plurality of dual circular-polarized waveguide antenna elements; the antenna comprising a central frequency and the OAM electromagnetic beam comprising a wavelength at the central frequency; and each neighboring pair of dual circular-polarized waveguide antenna elements in each plurality of concentric arrays are spaced apart at a distance of about half the wavelength.
6 . The antenna of claim 5 , further comprising: an outer concentric electromagnetic signal confining structure surrounding the second concentric array; and an inner concentric electromagnetic signal confining structure surrounding the single central dual circular-polarized waveguide antenna element; wherein the outer and inner concentric electromagnetic signal confining structures each comprise at least three decoupling rings.
7 . The antenna of claim 6 , further comprising a concentric electromagnetic signal confining structure comprising at least five decoupling rings between the first and second concentric arrays.
8 . The antenna of claim 6 , wherein: the first concentric array is configured to transmit, receive, or both transmit and receive a first component of the OAM electromagnetic beam comprising a non-zero order OAM mode having an absolute value of up to 16; and the second concentric array is configured to transmit, receive, or both transmit and receive a second component of the OAM electromagnetic beam comprising a non-zero order OAM mode having an absolute value of up to 32; and the single central dual circular-polarized waveguide antenna element is configured to transmit, receive, or both transmit and receive a third component of the OAM electromagnetic beam comprising a zero order OAM mode.
9 . The antenna of claim 1 , wherein each concentric electromagnetic signal confining structure of the one or more concentric electromagnetic signal confining structures comprises: five or more decoupling rings, each decoupling ring of the five or more decoupling rings concentric with the plurality of concentric arrays and comprising a depth of about ¼ of a wavelength of the OAM electromagnetic beam at a central frequency of the antenna.
10 . The antenna of claim 1 , wherein a diameter of the respective aperture of an outermost concentric array of the plurality of concentric arrays is about 40 times a wavelength of the OAM electromagnetic beam at a central frequency of the antenna.
11 . The antenna of claim 1 , configured to emit the OAM electromagnetic beam steerable at: an azimuth steering angle ranging from about 0° to about 360°; and an elevation steering angle ranging from about −42° to about 42° measured from a central axis of the plurality of concentric arrays to a central axis of a beam conical of the emitted OAM electromagnetic beam.
12 . The antenna of claim 1 , wherein the respective aperture of each concentric array is sized such that a respective OAM beam component of the OAM electromagnetic beam, transmitted, received, or both transmitted and received by the respective concentric array has a same or similar cone angle.
13 . The antenna of claim 1 , further comprising an outermost concentric electromagnetic signal confining structure surrounding an outermost concentric array of the plurality of concentric arrays.
14 . A system comprising: one or more feed structures, each feed structure of the one or more feed structures comprising: at least one main board; at least one beam former; and at least one front-end module; and an antenna for either or both transmitting and receiving an OAM electromagnetic beam, the antenna comprising: a plurality of concentric arrays, each concentric array of the plurality of concentric arrays comprising: a respective aperture; and a respective plurality of dual circular-polarized waveguide antenna elements, each dual circular-polarized waveguide antenna element of the respective plurality of dual circular-polarized waveguide antenna elements comprising a top end and a bottom end coupled to one of the one or more feed structures; and one or more concentric electromagnetic signal confining structures, wherein, each neighboring pair of concentric arrays of the plurality of concentric arrays have at least one electromagnetic signal confining structure of the one or more electromagnetic signal confining structures therebetween.
15 . The system of claim 14 , wherein each feed structure of the one or more feed structures is configured, in a transmit configuration, to: generate a plurality of respective OAM beam component signals; and provide each OAM beam component signal of the plurality of respective OAM beam component signals to at least one of the plurality of dual circular-polarized waveguide antenna elements of one of the plurality of concentric arrays, thereby causing the corresponding concentric array to emit a respective at least one OAM mode of the OAM electromagnetic beam directed according to provided beamsteering parameters.
16 . The system of claim 14 , wherein each feed structure of the one or more feed structures comprises at least one microstrip to waveguide transition.
17 . The system of claim 14 , wherein: the at least one beam former of each feed structure of the one or more feed structures comprises one or more of a Butler matrix and a Rotman lens; and the at least one front-end module of each feed structure of the one or more feed structures comprises one or more variable phase shifters.
18 . A method for generating and steering an Orbital Angular Momentum (OAM) electromagnetic beam, comprising: generating, by each feed structure of one or more feed structures, a respective plurality of OAM beam component signals by processing a plurality of input signals in accordance with beamsteering parameters and a respective at least one OAM mode of the OAM electromagnetic beam; and providing each respective plurality of OAM beam component signals to an OAM electromagnetic beam antenna comprising: a plurality of concentric arrays, each concentric array of the plurality of concentric arrays comprising: a respective aperture; and a respective plurality of dual circular-polarized waveguide antenna elements, each dual circular-polarized waveguide antenna element of the respective plurality of dual circular-polarized waveguide antenna elements comprising a top end and a bottom end coupled to one of the one or more feed structures; and one or more concentric electromagnetic signal confining structures, wherein, each neighboring pair of concentric arrays of the plurality of concentric array have at least one electromagnetic signal confining structure of the one or more electromagnetic signal confining structures therebetween, wherein each respective plurality of OAM beam component signals is provided, via the one or more feed structures, to a corresponding concentric array of the plurality of concentric arrays; and emitting, by each corresponding concentric array of the plurality of concentric arrays, a respective OAM beam component of the OAM electromagnetic beam comprising the respective at least one OAM mode and directed according to the beamsteering parameters.
19 . The method of claim 18 , wherein: the OAM electromagnetic beam antenna further comprises a single central dual circular-polarized waveguide antenna element along a central axis of the thereof; and wherein emitting, by each corresponding concentric array of the plurality of concentric arrays, the respective OAM beam component of the OAM electromagnetic beam comprising the respective at least one OAM mode and directed according to the beamsteering parameters further comprises: emitting, by the single central dual circular-polarized waveguide antenna element, the respective OAM beam component comprising a zero order OAM mode of the OAM electromagnetic beam; and emitting, by each concentric array of the plurality of concentric arrays, the respective OAM beam component comprising the at least one non-zero order OAM mode of the OAM electromagnetic beam.
20 . The method of claim 18 , further comprising steering the emitted the OAM electromagnetic beam in accordance with the beamsteering parameters comprising: an azimuth steering angle ranging from about 0° to about 360°; and an elevation steering angle ranging from about −42° to about 42° measured from a central axis of the plurality of concentric arrays to a central axis of a beam conical of the emitted OAM electromagnetic beam.

Description

TECHNICAL FIELD The present disclosure pertains to the field of wireless antennas, and in particular to apparatuses, systems, and methods for generating and steering an electromagnetic beam carrying multiple dual circular-polarized Orbital Angular Momentum (OAM) modes using concentric arrays of dual circular-polarized antenna elements. BACKGROUND The future generation of wireless networks (e.g., sixth generation of wireless communication (6G)) will offer unprecedented performance in terms of data rate, latency and energy efficiency, and connection density. One of the key technologies that will enable future generations of wireless communication is the use of extremely large-scale antenna arrays, which can create highly directional beams to focus the electromagnetic (EM) energy towards the intended receivers. These beams can be steered in the far-field region, where the EM waves propagate as plane waves, or in the near-field region, where the EM waves have spherical wave fronts. OAM, or orbital angular momentum, is a property of EM waves that describes the rotation of the wave front around the propagation axis. OAM can be used to create multiple orthogonal modes of EM waves, each carrying a different amount of OAM, and thus increase the spectral efficiency of wireless communication. Due to its ability to provide dependable and effective wireless communication, electronically beam steered antenna systems have become a significant component of mobile applications. These antennas employ cutting-edge technologies to steer the beam in a specified direction, improving signal quality and coverage, by varying the phase and amplitude of each feeding probe. For example, to follow a moving target, such as a user or a base station, the OAM beam steering antenna for mobile applications can dynamically track and modify their orientation. A beam steering antenna is a useful choice for future generation mobile networks (e.g., 6G) since it can provide enhanced spectral efficiency, reduced interference, and optimal signal intensity. Challenges arise in generating a highly directional EM beam carrying multiple OAM modes steerable azimuthally and having an elevation steering range suitable for mobile wireless applications. Mechanically-steered antenna designs for steering an EM beam typically have high associated costs and are limited in steering response time and accuracy by movement of mechanical components of the antenna. Coaxial antenna designs are prone to phase adjustment issues and impedance matching problem between a transmitter and receiver. Azimuthal phase ripple is a common problem in OAM antenna designs impacting the steering performance of the antenna. Stacked uniform circular arrays (UCAs) antenna designs are prone to coupling and EM interference between individual UCAs. In addition, OAM antenna systems known in the art are bulky, have a limited scan range, and/or are prone to poor radiating performance (e.g. deteriorated side lobe level, insufficient directivity, high loss, poor quality of phase calibration, and/or low efficiency) for practical wireless application. Therefore, there is a need for systems and methods for generating and steering an OAM beam that obviates or mitigates one or more limitations of the prior art. This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention. SUMMARY Aspects of the present disclosure provide for an antenna array which can be used to generate and transmit one or more EM beams carrying multiple OAM modes carrying dual circular-polarization properties. The EM beams are generated via beamforming techniques and are also steerable by suitable adjustments (e.g. gain and phase adjustments) made in association with such beamforming. The present disclosure provides for various design features of the antenna array, which are considered beneficial. These design features include but are not necessarily limited to: the use of multiple concentric arrays (for example, uniform circular arrays (UCAs)) of dual circular-polarized (CP) waveguide antenna elements; each concentric transmitting a different subset of one or more OAM modes; dual CP waveguide antenna element numbering and physical dimensioning of the multiple concentric arrays to create an effective overall antenna; EM signal confining structures between neighboring concentric arrays; feed structures coupled to dual CP waveguide antenna elements to provide EM signals thereto; and co-orientation and design of dual CP waveguide antenna elements used in the array. According to implementations of the present disclosure, there is provided an antenna for either or both transmitting and receiving an Orbital Angular Momentum (OAM) electromagnetic beam, the antenna comprising a plurality of concentric arrays. E