Multi-polarized antennas and multi-polarized antenna arrays

Abstract

A multi-polarized antenna comprising a plurality of antenna elements and a dielectric loading operably coupled with the plurality of antenna elements. The dielectric loading is arranged to cooperate with the plurality of antenna elements to (i) at least facilitate transmission and / or reception of electromagnetic waves having a first polarization, electromagnetic waves having a second polarization different from the first polarization, and electromagnetic waves having a third polarization different from the first and second polarizations, and (ii) reduce, limit, and / or eliminate mutual coupling between at least some of the plurality of antenna elements during operation. The first, second, and third polarizations are non-orthogonal.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to multi-polarized antennas and multi-polarized antenna arrays. The antennas and antenna arrays can be used for multiple-input multiple-output (MIMO) applications. BACKGROUND

[0002] Wireless communication technologies can be used for different applications such as high-definition (HD) video, virtual reality (VR) / augmented reality (AR), industrial Internet of Things, autonomous driving, telemedicine, etc. Some of these applications can require wireless communication technologies that can provide characteristics such as high speed, low latency, wide coverage, etc.

[0003] Multiple-input multiple-output (MIMO) technology is known and can be used in multi-antenna systems to improve speed. One example of MIMO technology is spatial multiplexing technology, in which multiple independent channels are used for multiple data streams to improve data transmission and / or reception rates. Polarization multiplexing is one of the forms of spatial multiplexing technology, which can be used to increase channel capacity. FIG. 1 The general concept of polarization multiplexing is shown and the evolution from single-polarization to multi-polarization (e.g., (±45 0 ) dual-polarization and tri-polarization (e.g., co-located or co-planar) is shown. Some examples of co-located tri-polarized antennas can be found in the articles by Fang et al. entitled “Theory and Experiment of Three-Port Polarization-Diversity Cylindrical Dielectric Resonator Antenna” (2014) and Piao et al. entitled “Tripolarized MIMO Antenna Using a Compact Single-Layer Microstrip Patch” (2019). Some examples of co-planar tri-polarized antennas can be found in the articles by Wong et al. entitled “Multipolarized Wideband Circular Patch Antenna for Fifth-Generation Multi-Input–Multi-Output Access-Point Application” (2019) and Wong et al. entitled “Three Wideband Monopolar Patch Antennas in a Y-Shape Structure for 5G Multi-Input–Multi-Output Access Points” (2020).

[0004] Compared to a single-polarized antenna, a dual-polarized antenna can double (i.e., multiply by 2) the channel / communication capacity, and a tri-polarized antenna can triple (i.e., multiply by 3) the channel / communication capacity. However, the problem is that existing multi-polarized antennas can have one or more of the following problems: not being able to provide a desired radiation pattern for all polarization states or directions, not being suitable for use in an antenna array (e.g., for long-distance communication), being bulky and / or structurally complex and thus not easily integrated into some devices / systems, etc. SUMMARY

[0005] In a first aspect, the present invention provides a multi-polarized antenna comprising a plurality of antenna elements and a dielectric loading operably coupled with the plurality of antenna elements. The dielectric loading is arranged to cooperate with the plurality of antenna elements to (i) at least facilitate transmission and / or reception of electromagnetic waves having a first polarization, electromagnetic waves having a second polarization different from the first polarization, and electromagnetic waves having a third polarization different from the first and second polarizations, and (ii) reduce, limit, and / or eliminate mutual coupling between at least some of the plurality of antenna elements during operation. The multi-polarized antenna can be used for multiple-input multiple-output applications. The plurality of antenna elements can function as antenna elements if or when the plurality of antenna elements transmit electromagnetic waves. The multi-polarized antenna can be used to transmit and / or receive electromagnetic waves of different polarizations. The plurality of antenna elements can comprise or be electrically conductive elements. The multi-polarized antenna can be, for example, a tri-polarized antenna, a quad-polarized antenna, a penta-polarized antenna, a hexa-polarized antenna, etc. The first, second, and third polarizations are non-orthogonal.

[0006] Preferably, the first, second, and third polarizations are substantially coplanar and spaced apart. In some examples, the first, second, and third polarizations can be spaced apart by approximately 120 degrees. The first, second, and third polarizations can be linear polarizations.

[0007] Optionally, the plurality of antenna elements comprises or consists of a first antenna element, a second antenna element, and a third antenna element; and the dielectric loading is arranged to cooperate with the first antenna element to facilitate transmission and / or reception of electromagnetic waves having the first polarization, to cooperate with the second antenna element to facilitate transmission and / or reception of electromagnetic waves having the second polarization, to cooperate with the third antenna element to facilitate transmission and / or reception of electromagnetic waves having the third polarization, and to reduce, limit, and / or eliminate mutual coupling between at least two or any two of the first, second, and third antenna elements.

[0008] Optionally, the dielectric loading comprises or consists only of a dielectric member that surrounds or encloses each of the plurality of antenna elements. The dielectric member can be a dielectric block.

[0009] Optionally, the dielectric member comprises a plurality of openings, each of which at least partially surrounds or receives a respective one of the plurality of antenna elements. For example, the dielectric member can comprise a first opening that partially or substantially completely surrounds or receives the first antenna element, a second opening that partially or substantially completely surrounds or receives the second antenna element, and a third opening that partially or substantially completely surrounds or receives the third antenna element. The plurality of openings are spaced apart. The plurality of openings can be through-holes or blind holes. The plurality of openings can have substantially the same shape and / or size.

[0010] Optionally, the dielectric member comprises or consists only of a substantially cylindrical dielectric block having a plurality of openings, each of which at least partially surrounds or receives a respective one of the plurality of antenna elements.

[0011] Optionally, the plurality of antenna elements are arranged on an imaginary circle (path) and are spaced apart at an angle. Optionally, the plurality of antenna elements are substantially equally angularly spaced apart. If the plurality of antenna elements consists only of the first antenna element, the second antenna element, and the third antenna element, the antenna elements are spaced apart at approximately 120 degrees.

[0012] Optionally, the imaginary circle and another imaginary circle defined by the base of the substantially cylindrical dielectric block are substantially concentric (in plan view).

[0013] Optionally, the diameter of the substantially cylindrical dielectric block is between about 0.3λ0to about 0.6λ0, between about 0.3λ0to about 0.5λ0, less than 0.6λ0, about 0.6λ0, less than 0.5λ0, about 0.5λ0, less than 0.4λ0, about 0.4λ0, or about 0.3λ0, where λ0is the wavelength of the center operating frequency of the multi-polarized antenna in free space.

[0014] Each respective antenna element of the plurality of antenna elements can comprise or consist solely of a monopole element, a dipole element, a slot, a patch element, etc. Optionally, each respective antenna element of the plurality of antenna elements comprises a monopole element. Optionally, the monopole element is arranged to be operable in one or more monopole modes, the one or more monopole modes comprising at least one of a quarter- wavelength monopole mode and a half-wavelength monopole mode. Each respective antenna element of the plurality of antenna elements can be shaped as a cylinder, a prism, etc. The cylinder can be a straight cylinder. The cylinder can be a cylinder, an ellipsoid cylinder, a parabolic cylinder, a hyperbolic cylinder, etc. The prism can be a straight prism. The prism can be a triangular prism, a rectangular prism, a cube, a polygonal prism, etc. The plurality of antenna elements can or can not have substantially the same shape and / or size.

[0015] The first antenna element can comprise or consist solely of a monopole element, a dipole element, a slot, a patch element, etc. Optionally, the first antenna element comprises a monopole element. Optionally, the monopole element is arranged to be operable in one or more monopole modes, the one or more monopole modes comprising at least one of a quarter- wavelength monopole mode and a half-wavelength monopole mode. The first antenna element can be shaped as a cylinder, a prism, etc. The cylinder can be a straight cylinder. The cylinder can be a cylinder, an ellipsoid cylinder, a parabolic cylinder, a hyperbolic cylinder, etc. The prism can be a straight prism. The prism can be a triangular prism, a rectangular prism, a cube, a polygonal prism, etc.

[0016] The second antenna element can comprise or consist solely of a monopole element, a dipole element, a slot, a patch element, etc. Optionally, the second antenna element comprises a monopole element. Optionally, the monopole element is arranged to be operable in one or more monopole modes, the one or more monopole modes comprising at least one of a quarter- wavelength monopole mode and a half-wavelength monopole mode. The second antenna element can be shaped as a cylinder, a prism, etc. The cylinder can be a straight cylinder. The cylinder can be a cylinder, an ellipsoid cylinder, a parabolic cylinder, a hyperbolic cylinder, etc. The prism can be a straight prism. The prism can be a triangular prism, a rectangular prism, a cube, a polygonal prism, etc.

[0017] The third antenna element can comprise or consist only of a monopole element, a dipole element, a slot, a patch element, etc. Optionally, the third antenna element comprises a monopole element. Optionally, the monopole element is arranged to be operable in one or more monopole modes, the one or more monopole modes comprising at least one of a quarter- wavelength monopole mode and a half-wavelength monopole mode. The third antenna element can have a shape of a cylinder, a prism, etc. The cylinder can be a straight cylinder. The cylinder can be a cylinder, an ellipsoid cylinder, a parabolic cylinder, a hyperbolic cylinder, etc. The prism can be a straight prism. The prism can be a triangular prism, a rectangular prism, a cube, a polygonal prism, etc.

[0018] Optionally, the multi-polarized antenna further comprises a ground plane, the dielectric loading (or dielectric member) being arranged on the ground plane.

[0019] Optionally, each of the plurality of antenna elements extends substantially perpendicular to the ground plane.

[0020] In some examples, a height of the dielectric member relative to the ground plane is higher than each respective height of the plurality of antenna elements relative to the ground plane. In some other examples, a height of the dielectric member relative to the ground plane is lower than each respective height of the plurality of antenna elements relative to the ground plane. In some further examples, a height of the dielectric member relative to the ground plane is substantially equal to each respective height of the plurality of antenna elements relative to the ground plane. Optionally, the plurality of antenna elements have substantially the same height relative to the ground plane.

[0021] Optionally, in a plan view, the dielectric member is arranged in a center of the ground plane.

[0022] Optionally, the ground plane is provided on or by a substantially cylindrical base body. The base body can be partly or completely made of metal. The base body can be in the form of a disc.

[0023] Optionally, the dielectric member has a first shape and a first size in a plan view, and the ground plane has a second shape and a second size in the plan view. The first shape and the second shape can be substantially the same in the plan view. For example, the first shape and the second shape can be a rectangle, a circle, a square, a triangle, a polygon, an irregular shape, etc. in the plan view. The second size can be greater than the first size in the plan view.

[0024] Optionally, each of the plurality of antenna elements is arranged partly or substantially completely on the ground plane.

[0025] Optionally, the multi-polarized antenna further comprises a feed arrangement operably coupled with the plurality of antenna elements. Optionally, the feed arrangement comprises a plurality of feed devices, each operably coupled with a respective one of the plurality of antenna elements. Optionally, the plurality of feed devices are selectively operable. Optionally, the plurality of feed devices are independently operable. Optionally, at least two of the plurality of feed devices are simultaneously operable.

[0026] In a second aspect, the present invention provides a multi-polarized antenna array comprising one or more (preferably a plurality of) multi-polarized antennas of the first aspect. The multi-polarized antenna array can or can not comprise one or more other antennas (different from the multi-polarized antennas of the first aspect). The one or more multi-polarized antennas of the first aspect and optionally the one or more other antennas can be arranged in an array. The multi-polarized antenna array can be used for multiple-input multiple-output applications. The multi-polarized antenna array can be used for transmitting and / or receiving electromagnetic waves of different polarizations.

[0027] Optionally, the multi-polarized antenna array comprises a plurality of multi-polarized antennas of the first aspect. The plurality of multi-polarized antennas can be arranged in an array. The array can for example have a generally polygonal configuration. In one example, the generally polygonal configuration is a hexagonal configuration in which six multi-polarized antennas are arranged around a central multi-polarized antenna. In another example, the generally polygonal configuration has a hexagonal configuration of one central multi-polarized antenna, six multi-polarized antennas arranged around the central multi-polarized antenna, and a further plurality of multi-polarized antennas arranged around the six multi-polarized antennas.

[0028] Preferably, for each respective one of the multi-polarized antennas, the first polarization, the second polarization, and the third polarization are generally coplanar and spaced apart. In some examples, the first polarization, the second polarization, and the third polarization of one or more of the multi-polarized antennas can be spaced apart by approximately 120 degrees.

[0029] Preferably, the first polarization of all of the multi-polarized antennas in the array is a generally same first polarization; the second polarization of all of the multi-polarized antennas in the array is a generally same second polarization; and the third polarization of all of the multi-polarized antennas in the array is a generally same third polarization. In some examples, the first polarization of all of the multi-polarized antennas in the array is a linear polarization; the second polarization of all of the multi-polarized antennas in the array is a linear polarization; and the third polarization of all of the multi-polarized antennas in the array is a linear polarization.

[0030] Optionally, the multi-polarized antenna array further comprises a ground plane, and the dielectric loading (e.g. dielectric members, dielectric blocks, etc.) of the multi-polarized antennas is arranged on the ground plane. The dielectric loading (e.g. dielectric members, dielectric blocks, etc.) of the multi-polarized antennas is preferably spaced apart.

[0031] Optionally, the dielectric loading of the plurality of multi-polarized antennas corresponds to a dielectric decoupling structure, and the array of multi-polarized antennas further comprises a further dielectric decoupling structure operably coupled with the plurality of multi-polarized antennas to reduce, limit, and / or eliminate mutual coupling between at least two or any two of the plurality of multi-polarized antennas during operation.

[0032] Optionally, the further dielectric loading comprises a plurality of dielectric elements arranged in or on the ground plane. In some examples, the further dielectric loading can be considered a defective ground structure.

[0033] Optionally, the plurality of dielectric elements comprises a plurality of first dielectric decoupling slots arranged in or on the ground plane and disposed between adjacent ones of the plurality of multi-polarized antennas. Optionally, each of the plurality of first dielectric decoupling slots comprises a slot arranged in or on the ground plane and one or more dielectric materials received or filled in the slot. Optionally, the plurality of first dielectric decoupling slots are arranged such that at least one first dielectric decoupling slot is disposed between each two adjacent multi-polarized antennas. Optionally, the plurality of first dielectric decoupling slots have substantially the same shape and / or size. Optionally, each of the plurality of first dielectric decoupling slots is substantially elongated. Optionally, each of the plurality of first dielectric decoupling slots has a narrower middle portion and two wider end portions. Optionally, each of the plurality of first dielectric decoupling slots has a substantially bowtie shape.

[0034] Optionally, the plurality of dielectric elements further comprises a plurality of second dielectric decoupling slots arranged in or on the ground plane and disposed adjacent to one or more of the plurality of multi-polarized antennas. The plurality of second dielectric decoupling slots differ in shape and / or size from the plurality of first dielectric decoupling slots. Optionally, each of the plurality of second dielectric decoupling slots comprises a slot arranged in or on the ground plane and one or more dielectric materials received or filled in the slot. Optionally, the plurality of second dielectric decoupling slots are arranged such that at least two second dielectric decoupling slots are disposed adjacent to each of the one or more of the plurality of multi-polarized antennas, respectively. Optionally, the plurality of second dielectric decoupling slots have substantially the same shape and / or size. Optionally, each of the plurality of second dielectric decoupling slots is substantially elongated. Preferably, each of the plurality of second dielectric decoupling slots is longer than each of the first dielectric decoupling slots. Optionally, each of the plurality of second dielectric decoupling slots has a narrower middle portion and two wider end portions. Optionally, each of the plurality of second dielectric decoupling slots has a substantially bowtie shape.

[0035] Optionally, the multi-polarized antenna array further comprises an artificial magnetic conductor structure arranged on a side of the ground plane opposite the dielectric loading of the multi-polarized antenna. The artificial magnetic conductor structure can be spaced apart from the ground plane. The artificial magnetic conductor structure can be substantially parallel to the ground plane.

[0036] Optionally, the artificial magnetic conductor structure comprises a base having a first side proximate the ground plane and a second side opposite the first side and distal from the ground plane, a conductive ground arranged on the second side of the base, and a plurality of conductive patches arranged on the first side of the base. Optionally, each of the plurality of conductive patches comprises a substantially polygonal (e.g., hexagonal) patch. The shape of the patches can substantially match the shape of the array configuration. Optionally, the artificial magnetic conductor structure defines a plurality of cells, each cell comprising a respective one of the plurality of conductive patches (and a respective base portion and conductive ground portion).

[0037] Optionally, the multi-polarized antenna array further comprises a feed arrangement operably coupled with the plurality of antenna elements of the plurality of multi-polarized antennas. The feed arrangement can comprise a plurality of feed devices, each operably coupled with a respective one of the antenna elements of each of the plurality of multi-polarized antennas. For example, the feed arrangement can comprise a first feed device operably coupled with all of the first antenna elements of the plurality of multi-polarized antennas, a second feed device operably coupled with all of the second antenna elements of the plurality of multi-polarized antennas, a third feed device operably coupled with all of the third antenna elements of the plurality of multi-polarized antennas, and so on.

[0038] In a third aspect, the present invention provides a (larger scale) multi-polarized antenna array having a plurality of the multi-polarized antenna arrays of the second aspect. The multi-polarized antenna array can be used for transmitting and / or receiving electromagnetic waves of different polarizations.

[0039] In a fourth aspect, the present invention provides a multiple-input multiple-output (MIMO) system having at least one multi-polarized antenna of the first aspect. The MIMO system can be a MIMO communication system.

[0040] In a fifth aspect, the present invention provides a multiple-input multiple-output (MIMO) system having at least one multi-polarized antenna array of the second aspect. The MIMO system can be a MIMO communication system.

[0041] In a sixth aspect, the present invention provides a multiple-input multiple-output (MIMO) system having at least one multi-polarized antenna array of the third aspect. The MIMO system can be a MIMO communication system.

[0042] By reference to the detailed description and the accompanying drawings, other features and aspects of the present invention will become apparent. Where appropriate and applicable, any one or more features described herein for one aspect or embodiment may be combined with any one or more other features described herein for any one or more other aspects or embodiments.

[0043] As used herein, terms of degree (e.g., "generally," "approximately," "about," "substantially," etc.) related to quantities or conditions are used to take into account manufacturing tolerances, degradation, trends, tendencies, actual imperfections, etc., depending on the context. In some examples, when a term of degree (e.g., "about" or "approximately") is used to modify a numerical value, such an expression may include ±15%, ±10%, ±5%, ±2%, or ±1% of the stated numerical value.

[0044] Throughout this document, unless stated otherwise, the terms "connected," "coupled," "mounted," "coupled," etc. are intended to encompass both direct and indirect connections, couplings, mountings, couplings, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0046] FIG. 1 It is a schematic diagram of the evolution from unipolarization to tripolarization;

[0047] FIG. 2A is a schematic diagram (perspective view) of a multi-polarized antenna according to one embodiment of the present invention;

[0048] FIG. 2B yes FIG. 2A Schematic diagram of a multi-polarized antenna (top view);

[0049] FIG. 2C yes FIG. 2A Schematic diagram of a multi-polarized antenna (side view);

[0050] FIG. 3A is based on FIG. 2A Multi-polarized antenna. Picture of the manufactured multi-polarized antenna (perspective view).

[0051] FIG. 3B yes FIG. 3A Picture of the multi-polarized antenna (side view);

[0052] FIG. 4 It shows FIG. 2A Schematic diagram of the (intra-antenna) decoupling mechanism in a multi-polarized antenna;

[0053] FIG. 5 is shown with FIG. 4 Schematic diagram of the simulation model and results related to the decoupling mechanism;

[0054] FIG. 6 It shows FIG. 2A The multi-polarized antenna with different antenna element heights h r Graph of the resonant frequencies of the three resonant modes.

[0055] FIG. 7 is a diagram showing the surface current on one of the antenna elements when operating (excited) at 3.5 GHz (as the center frequency);

[0056] FIG. 8 The directivity of one of the antenna elements when operating (being excited) at 3.5 GHz (as the center frequency) is shown (for different antenna element positions k r ) curve graph;

[0057] FIG. 9 is a diagram showing the electric field distribution inside the dielectric block when different antenna elements are excited individually at 3.5 GHz.

[0058] FIG. 10 It shows FIG. 2A Plots of measured and simulated scattering parameters of the / 3A multi-polarized antenna at different frequencies;

[0059] FIG. 11A It shows that FIG. 2A When the first antenna element of the / 3A multi-polarized antenna is working (excited) FIG. 2A Plots of the measured and simulated E-plane and H-plane radiation patterns of the / 3A multi-polarized antenna at 3.5 GHz;

[0060] FIG. 11B It shows that FIG. 2A When the second antenna element of the / 3A multi-polarized antenna is working (excited) FIG. 2A Plots of the measured and simulated E-plane and H-plane radiation patterns of the / 3A multi-polarized antenna at 3.5 GHz;

[0061] FIG. 11C It shows that FIG. 2A When the third antenna element of the / 3A multi-polarized antenna is working (excited) FIG. 2A Plots of the measured and simulated E-plane and H-plane radiation patterns of the / 3A multi-polarized antenna at 3.5 GHz;

[0062] FIG. 12 It is shown in FIG. 2A Graphs of measured and simulated achieved gain and efficiency at different frequencies for the / 3A multi-polarized antenna;

[0063] FIG. 13 It shows about FIG. 2APlots of the calculated ergodic channel capacity at different frequencies (SNR = 20 dB) for a 1 / 3A multi-polarized antenna, an ideal single-input single-output (SISO) system, an ideal 2x2 multiple-input multiple-output (MIMO) system, and an ideal 3x3 MIMO system.

[0064] FIG. 14A is a schematic diagram (top view) of a multi-polarized antenna array according to one embodiment of the present invention;

[0065] FIG. 14B yes FIG. 14A Schematic diagram of a multi-polarized antenna array (side view);

[0066] FIG. 14C yes FIG. 14A A schematic diagram (top view) of a portion of a multi-polarized antenna array;

[0067] FIG. 14D yes FIG. 14A Schematic diagram of the artificial magnetic conductor structure backing the multi-polarized antenna array (top view);

[0068] FIG. 15A is based on FIG. 14A Picture of the multi-polarization antenna array manufactured by (perspective view);

[0069] FIG. 15B yes FIG. 15A Image of the multi-polarized antenna array (side view);

[0070] FIG. 16 yes FIG. 14A Schematic diagram of the (inter-antenna) decoupling mechanism in a multi-polarized antenna array (side view);

[0071] FIG. 17 It is shown in FIG. 14A The distance between two antennas in a multi-polarized antenna array FIG. 16 Configuration of the decoupling mechanism and plots of the scattering parameters at different frequencies;

[0072] FIG. 18 It shows FIG. 14A Configuration of hexagonal units of the backing artificial magnetic conductor structure of the multi-polarized antenna array, and graphs of phase and amplitude responses at different frequencies;

[0073] FIG. 19 It is shown in FIG. 14A Schematic diagram of the grouping and distribution of antenna elements in a multi-polarization antenna array.

[0074] FIG. 20 It is shown in FIG. 14A Among the 21 antenna elements in the multi-polarized antenna array (such asFIG. 19 Figure showing the results of the mutual coupling for the array of multi-polarized antennas of / 15A (with and without decoupling slots);

[0075] FIG. 21 is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example; FIG. 14A Figure showing the measured and simulated scattering parameters of the array of multi-polarized antennas of / 15A at different frequencies;

[0076] FIG. 22 is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example; FIG. 15A Figure showing the measured and simulated scattering parameters of the array of multi-polarized antennas of / 15A at different frequencies;

[0077] FIG. 23A is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example; FIG. 14A Figure showing the measured and simulated E-plane and H-plane radiation patterns of the array of multi-polarized antennas of / 15A at 3.5 GHz when the first antenna element of all antennas of the array of multi-polarized antennas of / 15A is working (excited); FIG. 14A Figure showing the measured and simulated E-plane and H-plane radiation patterns of the array of multi-polarized antennas of / 15A at 3.5 GHz when the second antenna element of all antennas of the array of multi-polarized antennas of / 15A is working (excited);

[0078] FIG. 23B is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example; FIG. 14A Figure showing the measured and simulated E-plane and H-plane radiation patterns of the array of multi-polarized antennas of / 15A at 3.5 GHz when the third antenna element of all antennas of the array of multi-polarized antennas of / 15A is working (excited); FIG. 14A Figure showing the measured and simulated E-plane and H-plane radiation patterns of the array of multi-polarized antennas of / 15A at 3.5 GHz when the third antenna element of all antennas of the array of multi-polarized antennas of / 15A is working (excited);

[0079] FIG. 23C is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example; FIG. 14A Figure showing the measured and simulated realized gain and efficiency of the array of multi-polarized antennas of / 15A at different frequencies; FIG. 14A Figure showing the measured and simulated E-plane and H-plane radiation patterns of the array of multi-polarized antennas of / 15A at 3.5 GHz when the third antenna element of all antennas of the array of multi-polarized antennas of / 15A is working (excited);

[0080] FIG. 24 is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example; FIG. 14A Figure showing the measured and simulated E-plane and H-plane radiation patterns of the array of multi-polarized antennas of / 15A at 3.5 GHz when the third antenna element of all antennas of the array of multi-polarized antennas of / 15A is working (excited);

[0081] FIG. 25 is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example; FIG. 14A Figure showing the measured and simulated E-plane and H-plane radiation patterns of the array of multi-polarized antennas of / 15A at 3.5 GHz when the third antenna element of all antennas of the array of multi-polarized antennas of / 15A is working (excited);

[0082] FIG. 26 is a picture showing the setup for measuring the radiation pattern of the array of multi-polarized antennas of / 15A in one example;

[0083] FIG. 27is a functional block diagram of a multi-polarized antenna of some embodiments of the invention. DETAILED DESCRIPTION

[0084] FIG. 26 A high-level block diagram of a multi-polarized antenna 2600 of the invention is shown, in which only the main components are shown. The multi-polarized antenna 2600 generally includes at least a plurality of electrically conductive antenna elements 2602 and a dielectric loading (or arrangement) 2604 for the antenna elements 2602. The dielectric loading 2604 is operatively coupled with the antenna elements 2602 and is arranged to cooperate with the antenna elements 2602 to facilitate transmission and / or reception of electromagnetic waves having at least three different polarizations and to reduce, limit and / or eliminate mutual coupling between at least some of the antenna elements 2602 during operation. The multi-polarized antenna 2600 can be used to transmit and / or receive electromagnetic waves of different polarizations, for example for multiple-input multiple-output applications. The multi-polarized antenna 2600 can be used as a transmit-only antenna, a receive-only antenna or a transmit-and-receive antenna. If the multi-polarized antenna 2600 is configured to transmit and / or receive electromagnetic waves having three different polarizations, it can be a tri-polarized antenna. If the multi-polarized antenna 2600 is configured to transmit and / or receive electromagnetic waves having more than three different polarizations, it can be a higher-polarized antenna. The at least three different polarizations are non-orthogonal and are preferably coplanar. The multi-polarized antenna 2600 can be used to form a multi-polarized antenna array that includes a plurality of multi-polarized antennas 2600 (or at least one multi-polarized antenna 2600 and at least one other antenna). The multi-polarized antenna array can be used to transmit and / or receive electromagnetic waves of different polarizations, for example for multiple-input multiple-output applications. The multi-polarized antenna array can be used as a transmit-only antenna array, a receive-only antenna array or a transmit-and-receive antenna array. Example embodiments of the multi-polarized antenna 2600 and related antenna arrays are provided below.

[0085] FIG. 27 A multi-polarized antenna 2700 of some embodiments of the invention is shown. Similar to the multi-polarized antenna 2600, the multi-polarized antenna 2700 also includes a plurality of electrically conductive antenna elements and a dielectric loading operatively coupled with the antenna elements. In the multi-polarized antenna 2700, the antenna elements and the dielectric loading define, among other things, a plurality of antenna units in the multi-polarized antenna 2700, such that the multi-polarized antenna 2700 has a plurality of integrated antenna units. Each antenna unit can correspond to a respective communication channel and can be operable to transmit and / or receive electromagnetic waves having a respective polarization state / direction. Any two or more or all of the communication channels (or antenna units) in the multi-polarized antenna 2700 can be selectively or simultaneously operated, and preferably substantially independently operated. FIG. 27The multi-polarized antenna 2700 is shown as including only three antenna elements. However, the multi-polarized antenna 2700 may include more than three antenna elements, wherein each antenna element corresponds to a respective communication channel.

[0086] FIGS. 2A-2C FIG2 shows a multi-polarized antenna 200 according to an embodiment of the present invention. The multi-polarized antenna 200 is only FIG. 26 An example implementation of a multi-polarized antenna 2600 is provided.

[0087] refer to FIGS. 2A-2C Multi-polarized antenna 200 includes three conductive antenna elements 202A, 202B, and 202C and a dielectric loading. The dielectric loading is in the form of a dielectric block 204, which is operably coupled to antenna elements 202A, 202B, 202C. In this embodiment, multi-polarized antenna 200 is a tri-polarized antenna. Dielectric block 204 is arranged to cooperate with antenna elements 202A, 202B, and 202C to facilitate transmission and / or reception of electromagnetic waves having three different, substantially coplanar polarizations and to reduce, limit, and / or eliminate mutual coupling between at least some of antenna elements 202A, 202B, and 202C during operation. Multi-polarized antenna 200 also includes a ground plane 206, on which dielectric block 204 is disposed.

[0088] Antenna elements 202A, 202B, and 202C are all monopole elements that can operate in one or more monopole modes. In this embodiment, antenna elements 202A, 202B, and 202C are generally cylindrical (right cylindrical) and are arranged on or above ground plane 206 and extend generally perpendicular to ground plane 206. In this embodiment, antenna elements 202A, 202B, and 202C have generally the same shape and size (including height). In this embodiment, antenna elements 202A, 202B, and 202C have a height h. r and radius r r The probes are supplied by three SMA connectors (which also serve as feedthroughs). FIG. 2B As shown, antenna elements 202A, 202B, and 202C are arranged at a radius of p. r On the imaginary circle (path) of r are generally equally spaced apart.

[0089] The dielectric block 204 mounted on the ground plane 206 is made of one or more dielectric materials and has a dielectric constant ε r The dielectric block 204 is a dielectric block having a height h d and radius r dThe dielectric block 204 is a generally cylindrical block. The dielectric block 204 has a higher height (relative to the ground plane 206) than the antenna elements 202A, 202B, and 202C. The dielectric block 204 is arranged substantially in the center of the ground plane 206. In plan view, the ground plane 206 is larger than the dielectric block 204. The dielectric block 204 includes three openings, each of which receives or surrounds a corresponding one of the antenna elements 202A, 202B, and 202C. The openings have substantially the same shape and size. The openings are also arranged on an imaginary circle (path) and at an angle θ. r In plan view, the imaginary circle (path) and another imaginary circle (path) defined by the base of the dielectric block 204 are generally concentric ( FIG. 2B In this example, the diameter of the dielectric block 204 is 0.3λ0 and the antenna elements 202A, 202B, 202C are spaced 0.14λ0 apart (λ0 is the wavelength of the center operating frequency of the multi-polarization antenna in free space).

[0090] The ground plane 206 of this embodiment is composed of a g A generally circular aluminum disk of φ 100 mm and thickness t is provided.

[0091] The multi-polarized antenna 200 also includes a feed arrangement operatively coupled to the antenna elements. In this example, the multi-polarized antenna 200 has three feed arrangements 208A, 208B, and 208C, which are provided by three SMA connectors that provide antenna elements 202A, 202B, and 202C. Each feed arrangement is coupled to a respective one of the antenna elements 202A, 202B, and 202C to selectively operate one or more of the antenna elements, or to simultaneously operate two or more of the antenna elements, for receiving and / or transmitting electromagnetic waves.

[0092] The parameter values ​​of the multi-polarized antenna 200 in this embodiment are: r =10,h r =12.5mm, r r =0.635mm,θ r =120°, p r =7.1mm,h d =14mm, r d =12.9mm, r g =40mm, t=2mm.

[0093] FIG. 3A and FIG. 3B Shown according to FIGS. 2A-2C The multi-polarized antenna 300 is manufactured based on the multi-polarized antenna 200 (using the same parameter values). FIG. 3A and FIG. 3BIn the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible.

[0094] In the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible. FIGS. 2A-2C In the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible. FIGS. 2A-2C In the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible. FIG. 4 A decoupling mechanism is shown, i.e., the operation of the dielectric block 404 (e.g., corresponding to the dielectric block 204). In FIG. 4 In the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible. FIG. 4 In the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible.

[0095] FIG. 5 Simulation models and results are shown to verify the concept of the decoupling mechanism of FIG. 4 In the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible. FIG. 5 In the above design of the multi-polarized antenna 300, the antenna elements of the multi-polarized antenna 300 are hidden from view by the dielectric block 304 on the ground plane 306, while the feed devices 308A, 308B, 308C are visible. FIG. 2A The electric field distribution shown illustrates two field nulls (observation points) when the Hertz dipole is excited at the source point. Thus, it can be expected that the source point and the observation points are highly isolated. FIG. 5 The following briefly discusses the resonant modes for implementing the coplanar tri-polarized design in the multi-polarized antenna 200 of

[0096] FIG. 2A To confirm that the resonant modes are not dielectric resonator (DR) modes, the study is done for a Hertz dipole source in a cylindrical DR.

[0097] To confirm that the resonant modes are not dielectric resonator (DR) modes, the study is done for a Hertz dipole source in a cylindrical DR.​FIG. 2A Different antenna element heights h in the multi-polarized antenna 200 r , the fundamental monopole mode (λ g / 4)、DR HEM 11δ mode and the first higher-order monopole mode (λ g / 2) resonant frequency (λ g is the wavelength of the center operating frequency in the dielectric material of the dielectric block). FIG. 6 The three resonant mode frequencies are shown as a function of the antenna element height h. r In the relationship. FIG. 6 In the model used, the parameter values ​​are FIG. 2A The parameter values ​​used in the multi-polarized antenna 200 are the same (h r except that it is changed). FIG. 6 In the figure, different marks represent different resonance modes, where the larger the mark, the better the matching.

[0098] like FIG. 6 As shown, for all antenna element heights h r , DR HEM 11δ The resonant frequency of the mode is not far from the theoretical resonant frequency (2.97 GHz). However, the fundamental monopole mode (λ g / 4) and the first higher-order monopole mode (λ g / 2) the resonant frequency obviously increases with h r In addition, the first high-order monopole mode (λ g / 2) is almost always the resonant frequency of the fundamental monopole mode (λ g / 4) is twice the resonant frequency. FIG. 6 As can be seen from the results, the working mode of the multi-polarized antenna 200 (marked by the black dotted circle, h p = 12.5 mm) is mainly composed of half-wavelength monopole (the first high-order monopole mode (λ g / 2)) caused.

[0099] The resonant modes can also be verified by the current distribution on the antenna elements. FIG. 7 Figure 2 shows the surface current of one of the antenna elements operating (excited) at 3.5 GHz (as the center frequency). FIG. 7 As shown, a semi-sinusoidal current distribution (dashed line) can be found on the antenna element. This indicates that the antenna element operates in the first high-order monopole mode (λ g / 2))work.

[0100] The radiation patterns of the dielectrically loaded antenna elements 202A-202C in the multi-polarized antenna 200 are also studied. FIG. 8The effect of displacement of one of the antenna elements 202A-202C (relative to the center of the dielectric block 204) on the main lobe and radiation null is shown. FIG. 8 In the model, the parameter values ​​are FIG. 2A The parameter values ​​used in the multi-polarized antenna 200 are the same (k r Except, which is p r / r d limited and changed). FIG. 8 As shown, when the antenna element is located at the center of the dielectric block 204 (k r = 0), a typical monopole-like radiation pattern can be observed, and as the antenna element moves away from the center of the dielectric block 204, the antenna response becomes asymmetric, with the main lobe gradually moving toward the boresight direction and the radiation null moving laterally (as shown by the dotted line). In this example, when k r When it is 0.55, the inclination angle of the main lobe is 18°.

[0101] FIG. 9 Shows when FIG. 2A The electric field distribution within the dielectric block 204 when the antenna elements 202A-202C of the multi-polarized antenna 200 are individually excited at 3.5 GHz. FIG. 9 As shown, when the antenna elements are switched from one to another, the electric field direction rotates by an angle of approximately 120°. Dielectric block 204 helps reshape the field distribution near antenna elements 202A-202C, and thus the far-field pattern of multi-polarized antenna 200 is changed to be directional.

[0102] Further testing was performed using prototypes of the multi-polarized antenna 200 and the corresponding multi-polarized antenna 300. Specifically, the antenna's scattering parameters were measured using an Agilent N5230A PNA-L network analyzer, while the antenna's radiation pattern, achieved gain, and efficiency were measured using a Satimo StarLab system.

[0103] FIG. 10 Shown FIG. 2A Measured and simulated scattering parameters of the / 3A multi-polarized antenna at different frequencies. The parameter values ​​used are the same as those used for FIG. 2A The parameter values ​​of the multi-polarized antenna 200 are the same. FIG. 10 As shown, the measured results are generally consistent with the simulation results. Good consistency can also be found between different measured antenna elements. The measured 10dB impedance bandwidth can cover the entire 3.5GHz frequency band (3.4GHz to 3.6GHz) used for 5G communications. The mutual coupling measured between any two antenna elements is expected to be weak, less than -19.50dB across the entire operating band.

[0104] FIGS. 11A-11C Shows whenFIG. 2A When the antenna element of the / 3A multi-polarized antenna is working (being excited), FIG. 2A Measured and simulated E-plane and H-plane radiation patterns of the / 3A multi-polarized antenna at 3.5 GHz. The parameter values ​​used are the same as those used for FIG. 2A The parameter values ​​of the multi-polarized antenna 200 are the same. FIGS. 11A-11C As shown in Figure 2, the measured results are generally consistent with the simulation results. FIGS. 11A-11C In the E-plane, the radiation pattern is (for antenna element #1, For antenna element #2, For antenna element #3, ) and H-plane (for antenna element #1, For antenna element #2, For antenna element #3, ) is shown. FIGS. 11A-11C A largely unidirectional boresight radiation pattern is observed. Due to the asymmetric arrangement of the antenna elements, the measured E-plane mainlobe deviates by approximately 20° from the boresight direction (θ = 0°), which is generally consistent with the simulation results. On the other hand, as expected, the H-plane pattern is largely symmetrical. The cross-polarization level measured in the boresight direction is below -20 dB for all antenna elements.

[0105] FIG. 12 Shown FIG. 2A The simulated and measured achieved gain and efficiency of the / 3A multi-polarized antenna at different frequencies. The parameter values ​​used are the same as those used for FIG. 2A The parameter values ​​of the multi-polarized antenna 200 are the same. FIG. 12 As shown, the measured achieved gain is generally consistent with the simulation results. In addition, the measured results for each antenna element are also generally consistent with each other. The measured gain in the passband is between 5.0dBi and 5.6dBi, and the measured efficiency exceeds 87.5%.

[0106] Using the measured 3D radiation patterns, the envelope correlation coefficient (ECC) between every two antenna elements was calculated. It was found that all ECC values ​​were less than 0.05 across the entire operating frequency band. This indicates that the antenna provides three largely uncorrelated radiation patterns, making it suitable for MIMO applications.

[0107] FIG. 13 Shown in an isotropic scattering environment FIG. 2A The ergodic channel capacity is calculated for a multi-polarized antenna with a wavelength of / 3A. In the calculation, the transmitter signal-to-noise ratio (SNR) is assumed to be 20dB and a Rayleigh fading environment (multipath condition) is assumed. The Rayleigh fading channel matrix is ​​calculated using generated. FIG. 2AThe / 3A's multi-polarized antenna is used for the receiving side of a 3x3 MIMO system, while an ideal three-polarized antenna (lossless and ECC=0) is assumed for the transmitting side. For ease of comparison, the theoretical capacities of ideal 3x3 and 2x2 MIMO systems, as well as an ideal SISO system, are also shown in FIG. 13 FIG. 2A The results show that FIG. 2A the / 3A's design can provide more than 16.4 bits / sec / Hz of channel capacity in the 3.5 GHz band, with a maximum of 16.6 bits / sec / Hz. This means that the / 3A's antenna has a theoretical capacity that is at least 98% and 282% of an ideal 3x3 MIMO and SISO antenna system, respectively.

[0108] To further illustrate the present application, an example multi-polarized antenna array is designed, which is made up of a plurality of FIG. 2A multi-polarized antennas.

[0109] FIGS. 14A-14D A multi-polarized antenna array 1400 of one embodiment of the present application is shown. The multi-polarized antenna array 1400 is an example embodiment of a multi-polarized antenna 2600 (in an array) of FIG. 26 the present application. The multi-polarized antenna array 1400 of the present embodiment is a coplanar three-polarized hexagonal antenna array, which is suitable for long-range communication.

[0110] As shown in FIGS. 14A-14D , the multi-polarized antenna array 1400 of the present embodiment includes seven multi-polarized antennas 200A-200G arranged in a hexagonal configuration array, with one antenna 200A at the center and the other six antennas 200B-200G arranged around the center antenna 200A. The antennas 200A-200G of the present embodiment have substantially the same configuration and construction as the multi-polarized antenna 200 of FIG. 2A the present application (details are not repeated here for simplicity). Briefly, each of the multi-polarized antennas 200A-200G in the multi-polarized antenna array 1400 also includes three antenna elements and a dielectric loading in the form of a generally cylindrical dielectric block operatively coupled with the three antenna elements. For each respective one of the multi-polarized antennas 200A-200G in the present embodiment, the three polarizations are generally coplanar. The ground plane of the antennas 200A-200G is provided by a single large ground plane 1406, such that the dielectric loading (e.g., dielectric block) of each of the multi-polarized antennas 200A-200G is arranged on and spaced apart on the ground plane 1406. In the present example, the feed mechanisms and antenna elements of the multi-polarized antennas 200A-200G are also provided by SMA connectors.

[0111] As shown in FIGS. 14A-14CAs shown, multi-polarized antenna array 1400 also includes additional dielectric loading operatively coupled to multi-polarized antennas 200A-200G to reduce, limit, and / or eliminate mutual coupling between any two or more of them during operation. This additional dielectric loading can be implemented as a defective ground structure. In this embodiment, the additional dielectric loading includes a plurality of dielectric elements 1410A and 1410B arranged in ground plane 1406. These dielectric elements 1410A and 1410B are provided by slots filled with dielectric material arranged in ground plane 1406. In this embodiment, the slots filled with dielectric material have a generally bow-tie shape. This generally bow-tie shape includes an elongated body having a narrower middle portion and two wider ends at either end of the narrower middle portion. There are two types of such dielectric elements: one longer and the other shorter. The shorter type of dielectric element 1410A (shown as a white "bow tie" shape) is disposed between adjacent antennas in the multi-polarized antennas 200A-200G. The longer type of dielectric element 1410B (shown as a black "bow tie" shape) is disposed radially outward of three (every other) outer multi-polarized antennas 200A-200G, and is generally not located between two multi-polarized antennas 200A-200G. In this embodiment, the dielectric elements 1410A and 1410B of different lengths are used to account for edge effects. As shown in the enlarged view of the dielectric elements, each of the dielectric elements 1410A and 1410B has a central width W s1 and end width W s2 , and are offset by p from the center of the dielectric block of the corresponding multi-polarized antennas 200A-200G. s The lengths of the two dielectric elements 1410A and 1410B are L s1 and L s2 .

[0112] like FIG. 14A 、 FIG. 14B and FIG. 14D As shown, the multi-polarized antenna array 1400 further includes an artificial magnetic conductor structure 1412, which serves as a backing structure and is arranged on the side of the ground plane 1406 opposite to the dielectric loading (dielectric block) of the multi-polarized antennas 200A-200G. In this embodiment, the artificial magnetic conductor structure 1412 is spaced apart from the ground plane 1406 and is substantially parallel to the ground plane 1406. The artificial magnetic conductor structure 1412 in this embodiment includes a substrate 1412B, a conductive ground 1412C disposed on the lower side of the substrate 1412B, and a conductive patch layer 1412A disposed on the upper side of the substrate 1412B (the side closer to the ground plane 1406). FIG. 14DAs shown in , the conductive patches in this embodiment are generally hexagonal patches. A plurality of generally hexagonal patches (and their corresponding underlying base portions and conductive ground portions) provide a plurality of generally hexagonal units.

[0113] The multi-polarized antenna array 1400 in this embodiment further includes a feed arrangement 1408 operatively coupled to the antenna elements of the multi-polarized antennas 200A-200G. In one embodiment, the feed arrangement 1408 includes a feed device operatively coupled to all first antenna elements of the multi-polarized antennas 200A-200G, another feed device operatively coupled to all second antenna elements of the multi-polarized antennas 200A-200G, and another feed device operatively coupled to all third antenna elements of the multi-polarized antennas 200A-200G.

[0114] In this embodiment, the isolation between the antenna elements of each multi-polarized antenna 200A-200G is optimized to be approximately 20 dB (similar to the above description of the isolation between the antenna elements of the multi-polarized antenna 200A-200G). FIG. 2A The multi-polarized antenna 200 is the same).

[0115] The parameter values ​​of the multi-polarized antenna array 1400 in this embodiment are: array =46.11mm, r array =90mm, t=2mm, ε s =5,W s1 =2mm, W s2 =7mm, p s =17.5mm,L s1 =23.5mm (length of slot #1), L s2 =26.5mm (length of slot #2), h r =12.5mm, r r =0.635mm,θ r =120°, p r =7.1mm,h d =20mm, r d =12.5mm, r amc =125mm, t amc =4mm,h amc =10mm.

[0116] FIG. 15A and FIG. 15B Show the basis FIGS. 14A-14D The multi-polarization antenna array 1400 is manufactured using the multi-polarization antenna array 1500 (using the same parameter values). FIG. 15A and FIG. 15BIn this case, the antenna elements of the multi-polarized antenna 200A-200G are hidden from view by the corresponding dielectric blocks on the ground plane 1506, while the feed setup 1508 (formed by SMA connectors) and the artificial magnetic conductor structure 1512 are visible.

[0117] As mentioned above, in this embodiment, the isolation between three antenna elements of the same antenna 200A-200G is optimized to about 20 dB. To reduce the mutual coupling between antennas, the antenna array 1400 of this embodiment uses decoupling slots (dielectric elements 1410A, 1410B) which operate as a defective ground structure. The decoupling slots (dielectric elements 1410A, 1410B) can effectively improve the isolation between adjacent antennas 200A-200G in the antenna array 1400.

[0118] FIG. 16 The (inter-antenna) decoupling mechanism provided by the dielectric elements 1410A, 1410B in the multi-polarized antenna array 1400 of FIG. 14A is shown. As shown in step 2 in FIG. 16 , the decoupling slots can radiate towards the back of the antenna, which can result in a relatively large backlobe of the antenna array 1400. Therefore, an artificial magnetic conductor structure 1412 is added to the array 1400 to optimize the front-to-back ratio (FBR).

[0119] Simulations were performed to verify the effectiveness of the dielectric-filled slots of the decoupling mechanism. FIG. 17 The (inter-antenna) decoupling mechanism provided by the dielectric elements 1410A, 1410B in the multi-polarized antenna array 1400 of FIG. 14A is shown. As shown in step 2 in FIG. 16 , the decoupling slots can radiate towards the back of the antenna, which can result in a relatively large backlobe of the antenna array 1400. Therefore, an artificial magnetic conductor structure 1412 is added to the array 1400 to optimize the front-to-back ratio (FBR). FIG. 17 The structure parameters and parameter values used in the model of FIGS. 14A-14D are the same as those used in FIG. 17 . By introducing the dielectric-filled slots in the middle, an additional wave path is established between the two antennas. When the new path provides out-of-phase waves to the original path, the inter-module coupling level can be reduced, limited or eliminated. FIG. 17 The scattering parameters before and after the introduction of the dielectric-filled slots are shown, where the antenna element #1 of one antenna is excited. As shown in , due to the presence of the decoupling slots, the curves of |S 41 |, |S 51 | and |S 61 | show a drop around 3.2 GHz. The coupling between adjacent antennas can be reduced from -13.5 dB to -16.3 dB. At the same time, the isolation within the antenna (between antenna elements of the same antenna) still exceeds 20 dB.

[0120] In this example, considering the array shape and rotational symmetry of the antennas 200A-200G in the antenna array 1400, hexagonal units are selected to construct the backing artificial magnetic conductor structure. FIG. 18 Shown FIG. 14A The configuration of the hexagonal unit of the backing artificial magnetic conductor structure of the multi-polarized antenna array 1400 and the phase and amplitude response at different frequencies. In this embodiment, the unit includes three layers: a metal ground layer, an FR4 base layer and a metal hexagonal patch layer. FIG. 18 In, l mac As shown in the figure, l cell =13.3mm, t amc =4mm, l amc =9.9mm, other parameter values ​​are the same as FIGS. 14A-14D The same. FIG. 18 Also shown are the different side lengths l for the hexagonal patch. mac In order to obtain a more stable gain in the entire operating frequency band, the phase range of the backing artificial magnetic conductor structure is set to between -45° and 45°. FIG. 18 As shown, the frequency of 0° reflection phase increases with l mac The increase of mac =9.9mm, the in-phase range can cover the 3.5GHz operating frequency band and the reflection coefficient exceeds -1.3dB.

[0121] FIG. 19 yes FIG. 14A Schematic diagram of the grouping and distribution of antenna elements of antennas 200A-200G in the multi-polarized antenna array 1400. FIG. 20 As shown, all antenna elements are numbered and divided into three groups (group #a, group #b and group #c), which correspond to three quasi-orthogonal polarizations respectively.

[0122] FIG. 19 The 21 antenna elements of the antennas 200A-200G in the multi-polarized antenna array 1400 are shown (eg, FIG. 20 As shown in Figure 2, the mutual coupling results with and without decoupling slots. FIG. 21 As shown in Figure 1, before loading the decoupling slot filled with dielectric, some mutual couplings are worse than -15 dB. However, after loading the decoupling slot filled with dielectric, the mutual coupling between any two ports is better than -15 dB.

[0123] Multi-polarized antenna array 1400 can achieve three polarization directions along the boresight axis. For each polarization, moderate antenna gain is achieved by simultaneously energizing seven antennas 200A-200G, which are fed by a seven-way in-phase power splitter. In other words, the array has three independent feed ports, designated Port #a, Port #b, and Port #c.

[0124] FIG. 14A Shown FIG. 21 Measured and simulated scattering parameters of the / 15A multi-polarized antenna array at different frequencies. FIGS. 14A-14D The parameter values ​​used in FIG. 21 The parameter values ​​in are the same. FIG. 22 As shown in the figure, the measured scattering parameters of the three ports are generally consistent with the simulation results. All three ports have good matching across the entire operating frequency band (3.4 GHz to 3.6 GHz), and each two ports also have good isolation, with the measured isolation exceeding 17.5 dB.

[0125] FIG. 15A An example is shown for measuring FIGS. 14A-14D The radiation pattern of the multi-polarized antenna array 1500 is set. The parameter values ​​used are the same as FIG. 23A The same as in . FIG. 14A Shows when FIG. 14A When the first antenna elements of all antennas in the / 15A multi-polarized antenna array are working (excited), FIG. 23B Measured and simulated E-plane and H-plane radiation patterns of the / 15A multi-polarized antenna array at 3.5 GHz. FIG. 23C and FIG. 14A Shown respectively when FIGS. 23A-23C The corresponding results when the second antenna elements and the third antenna elements of all antennas of the / 15A multi-polarization antenna array are working (being excited).

[0126] like FIGS. 23A-23C As shown in Figure 2, the measured radiation pattern is roughly consistent with the simulated radiation pattern. FIGS. 23A-23C In the E plane, the radiation pattern is (for port #a, For port #b, For port #c, ) and H-plane (for port #a, For port #b, For port #c, ) is shown. FIGS. 11A-11C As shown in FIG, a quasi-unidirectional radiation pattern with narrow beamwidth in both the E-plane and the H-plane is obtained. It should be noted that the measured tilt angle is from 20° (see FIG. 24) is significantly reduced to 6° in the E-plane. The measured boresight gain (θ = 0°) is only 0.5 dB lower than the peak gain (θ = 6°). Good linear polarization and a generally symmetrical radiation pattern are achieved in the H-plane.

[0127] FIG. 14A Shown FIGS. 14A-14D Measured and simulated boresight gain (θ = 0°) and efficiency of the / 15A multi-polarized antenna array at different frequencies. The parameter values ​​used are the same as FIG. 24 The same as in. FIG. 24 As shown in Figure 2, the measured achieved gain is generally consistent with the simulated achieved gain. Across the entire 3.5 GHz band, the measured achieved gain varies between 12.05 dBi and 12.95 dBi. FIG. 25 Also shown is the measured total antenna efficiency for each port, which exceeds 50.5% and has a maximum value of approximately 70% at 3.46 GHz.

[0128] The ECC (envelope correlation coefficient) between every two ports in array 1400 was calculated based on the measured three-dimensional radiation patterns and found to be less than 0.05 across the entire operating frequency band. Such low ECC levels indicate that antenna array 1400 of this embodiment can provide three substantially uncorrelated, high-gain radiation patterns. The ergodic channel capacity of antenna array 1400 of this embodiment in a 3×3 MIMO system was also calculated based on the measured radiation patterns (assuming an SNR of 20 dB). FIG. 25 The results are shown along with the theoretical capacities of an ideal SISO system (5.8 bits / s / Hz), a 2x2 MIMO system (11.5 bits / s / Hz), and a 3x3 MIMO system (16.7 bits / s / Hz). FIG. 13 As shown, the channel capacity of the antenna array 1400 is greater than 14.15 bits / second / Hz in the 3.5 GHz band and has a peak of 15.5 bits / second / Hz at 3.45 GHz. It should be noted that this channel capacity is lower than the channel capacity of a single antenna ( ​ This difference is due to the fact that the overall efficiency of antenna array 1400 is lower than that of antenna 200 (96%), which is mainly reduced by mutual coupling.

[0129] For an ideal N×N MIMO system (N: the number of antennas on the transmit and receive sides), the channel capacity is almost proportional to N. This leads to the straightforward strategy of deploying more antennas to increase channel capacity. However, more antennas typically require more space, which may be undesirable or unavailable. Therefore, in the above embodiments, it is also necessary to evaluate the area capacity (capacity per unit area) for the MIMO antenna design.

[0130] To this end, the disclosure proposes a metric called channel capacity density (CCD) that characterizes the spatial multiplexing potential in an antenna system by taking into account the antenna footprint. Without CCD, it would be unfair to compare a multi-polarized antenna array with a single-polarized antenna array. In one embodiment, the CCD is defined as

[0131]

[0132] where the antenna area is expressed in wavelength square, and λ0is the wavelength of the center operating frequency in free space.

[0133] For point-to-point wireless systems, the tri-polarized antenna 200 can provide three quasi-orthogonal wireless channels, making it suitable for or advantageous in applications with high bandwidth demand. It is worth mentioning that the tri-polarized antenna 200 has substantially the same footprint as a single-polarized antenna, which means that the design of the tri-polarized antenna 200 is efficient in terms of channel capacity. This advantage can be seen from the newly defined metric CCD, which takes into account the antenna footprint.

[0134] As shown in Table I below, the tri-polarized antenna 200 has the smallest footprint and the channel capacity exceeds 16.4 bits / s / Hz (98% of the ideal 3x3 MIMO system). The tri-polarized antenna 200 has a larger value of CCD because the compact antenna provides three independent channels. This can intuitively indicate that, compared with some other tri-polarized antennas, the tri-polarized antenna 200 can provide more channel capacity in the same footprint. In addition, the tri-polarized antenna 200 can not only be used as a tri-polarized antenna to triple the data rate, but also be used in array design. Based on the compact configuration and the boresight radiation pattern of the tri-polarized antenna 200, a high-gain antenna array 1400 with three coplanar polarizations is also designed.

[0135] Table I: Some features of the tri-polarized antenna of one embodiment of the present disclosure

[0136]

[0137] * The footprint is shown as the diameter of a circle, where in the determination of the footprint, λ0is the wavelength of the center frequency in free space (excluding the size of the ground plane with the feed circuit).

[0138] Some embodiments of the invention provide a tri-polarized multiplexing scheme that can provide nearly triple channel capacity for point-to-point wireless systems compared to a single-polarized counterpart with the same footprint. The tri-polarized scheme can be used for multiplexing purposes. However, it is generally difficult to arrange three co-planar polarizations in a compact antenna footprint due to strong mutual coupling, which is inevitable for neighboring non-orthogonal radiators. In some embodiments of the invention, a dielectrically loaded antenna with good isolation can be obtained by employing a dielectric loading that provides a dielectric air boundary (e.g., for three or more antenna elements). Antenna arrays can be further designed based on the dielectrically loaded antennas. The antennas and antenna arrays in these embodiments are useful candidates when MIMO systems require higher data rates.

[0139] Some embodiments of the invention provide compact dielectrically loaded antennas with three co-planar polarizations for MIMO applications. In one embodiment, its footprint is only 0.30λ0x 0.30λ0. In some embodiments, a generally cylindrical dielectric block is employed to reduce the mutual coupling among three monopole antenna elements so that the three monopole antenna elements are tightly isolated (0.14λ0). The dielectric block can provide additional reflection paths for the waves to effectively cancel the direct waves, thus helping to achieve higher isolation. The dielectric block can also change the radiation pattern of the monopole antenna elements from omnidirectional to unidirectional. When these embodiments of the antennas are equipped for a 3x3 MIMO system, triple data rates can be expected due to polarization multiplexing.

[0140] Some embodiments of the invention provide antennas with compact footprints, thus can be used to build high-gain tri-polarized antenna arrays suitable or advantageous for long-range point-to-point communications. In such MIMO antenna arrays, the mutual coupling among the modules is another problem to be solved. Some embodiments of the invention solve this problem by using additional dielectric loading, e.g., with slots filled with dielectric, which includes appropriate shapes, sizes, and placements to reduce the mutual coupling among the modules in the antenna array. In some embodiments, the decoupling slots are etched on the ground plane of the antennas used for the array, thus the backside radiation is inevitably strong. Some embodiments of the invention solve this undesired backlobe by using an artificial magnetic conductor (AMC) arrangement underneath the ground plane of the antennas. As a result, in these embodiments, three directional radiation patterns with three polarization directions can be obtained from the antenna array. By exploiting polarization multiplexing, the antenna arrays in these embodiments can provide almost triple channel capacity compared to a single-polarized antenna array.

[0141] Those skilled in the art will appreciate that various variations and / or modifications may be made to the invention as shown in the specific embodiments to provide further embodiments of the invention. Therefore, the described embodiments of the invention should be considered in all respects as illustrative and not restrictive. Example optional features of some aspects of the invention are set forth in the Summary of the Invention section. Some embodiments of the invention may include one or more of these optional features (some of which are not specifically shown in the drawings). Some embodiments of the invention may lack one or more of these optional features (some of which are not specifically shown in the drawings). One or more features of one embodiment may be combined with one or more features of another embodiment to provide further embodiments of the invention. In some embodiments, the configuration of antennas and antenna arrays may differ from that shown. For example, the dielectric loading / components / blocks, antenna elements, dielectric components of the decoupling mechanism, etc. of the antennas and antenna arrays may have shapes, sizes, forms, etc. that differ from those shown. The antenna elements in the antennas may be dipole elements, slots, patch elements, etc., i.e., they are not necessarily monopole elements. The spacing of the antenna elements of the antennas may be adjusted as needed. In some embodiments, the dielectric loading / components / blocks / elements of the antennas and antenna arrays may have a dielectric constant or effective dielectric constant that differs from the values ​​shown. In some embodiments, antennas or antenna arrays can be arranged to operate at different frequency or frequencies (e.g., ranges / bands), i.e., not limited to the frequency or frequencies shown (e.g., the 3.5 GHz band). For example, antenna arrays can have different array arrangements or configurations, such as triangular, polygonal, etc. The radiation patterns produced by antennas and antenna arrays can be different from those specifically shown. Antenna arrays can be used as part of a larger antenna array (e.g., a subarray). Antennas and antenna arrays can be applied to MIMO systems, such as MIMO communication systems (electronic devices, base stations, etc.).

Claims

1. A multi-polarization antenna, comprising: multiple antenna elements; as well as a dielectric block having a plurality of openings, each of the openings surrounding or receiving a respective one of the plurality of antenna elements; wherein the dielectric block is arranged to cooperate with the plurality of antenna elements to (i) facilitating the transmission and / or reception of at least an electromagnetic wave having a first polarization, an electromagnetic wave having a second polarization different from the first polarization, and an electromagnetic wave having a third polarization different from the first polarization and the second polarization, and (ii) reducing, limiting and / or eliminating mutual coupling between at least some of the plurality of antenna elements during operation; The first polarization, the second polarization and the third polarization are non-orthogonal.

2. The multi-polarized antenna according to claim 1, wherein: The first polarization, the second polarization, and the third polarization are coplanar.

3. The multi-polarized antenna according to claim 2, wherein: The first polarization, the second polarization, and the third polarization are spaced apart by 120 degrees.

4. The multi-polarized antenna according to claim 1, wherein: The plurality of antenna elements include at least a first antenna element, a second antenna element, and a third antenna element; as well as The dielectric blocks are arranged as follows: cooperating with the first antenna element to facilitate transmission and / or reception of electromagnetic waves having the first polarization; cooperating with the second antenna element to facilitate transmission and / or reception of electromagnetic waves having the second polarization; cooperating with the third antenna element to facilitate transmission and / or reception of electromagnetic waves having the third polarization; and Mutual coupling between at least two or any two of the first antenna element, the second antenna element and the third antenna element is reduced, limited and / or eliminated. 5 . The multi-polarized antenna according to claim 1 , further comprising a ground plane, and the dielectric block is arranged on the ground plane and each of the plurality of antenna elements extends perpendicular to the ground plane. The multi-polarized antenna according to claim 4 , wherein: The plurality of antenna elements are arranged on an imaginary circle and are angularly spaced apart on the imaginary circle.

7. The multi-polarized antenna according to claim 6, wherein: The plurality of antenna elements are equiangularly spaced apart.

8. The multi-polarized antenna according to claim 6, wherein: The dielectric block is cylindrical; and The imaginary circle and another imaginary circle defined by the base of the cylindrical dielectric block are concentric.

9. The multi-polarized antenna according to claim 8, wherein: The cylindrical dielectric block has a to 0.6 The diameter range is is the wavelength of the center operating frequency of the multi-polarization antenna in free space.

10. The multi-polarized antenna according to claim 4, wherein: The first antenna element comprises a monopole element arranged to operate in one or more monopole modes; The second antenna element comprises a monopole element configured to operate in one or more monopole modes; and / or The third antenna element comprises a monopole element arranged to operate in one or more monopole modes.

11. The multi-polarized antenna according to claim 10, wherein: the one or more monopole patterns of the first antenna element comprising at least one of a quarter-wavelength monopole pattern and a half-wavelength monopole pattern; The one or more monopole patterns of the second antenna element include at least one of a quarter-wavelength monopole pattern and a half-wavelength monopole pattern; as well as The one or more monopole patterns of the third antenna element include at least one of a quarter-wavelength monopole pattern and a half-wavelength monopole pattern.

12. The multi-polarized antenna according to claim 4, further comprising a feeding arrangement operatively coupled to the plurality of antenna elements, the feeding arrangement comprising a plurality of feeding devices, each of the feeding devices being operatively coupled to a corresponding one of the plurality of antenna elements.

13. The multi-polarized antenna according to claim 12, wherein: The plurality of feeding devices can operate selectively and / or independently; and / or At least two of the plurality of feeding devices may operate simultaneously.

14. A multiple-input multiple-output system comprising at least one multi-polarized antenna according to claim 1.

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