BACKGROUND

The present disclosure, in some embodiments thereof, relates to an antenna array and, more specifically, but not exclusively, to a distributed layout of radiating elements and connection ports of the antenna array.

A cellular communication system may utilize massive multiple-input multiple-output MIMO as the key radio technology to provide multiple “smart” antennas in an antenna array. Massive MIMO, by making use of smart antennas, may perform beamforming to serve its users. In general, with respect to beam forming there may be a requirement that the beam energy of the antenna to be efficiently concentrated on desired areas and the interference to non-desired coverage areas minimized. With multiple antenna arrays, a requirement may be to have beams that sweep across target areas without leaving coverage holes in the target areas.

SUMMARY

It is an object of the present invention to provide an apparatus, a system, and a method for a smart antenna.

The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

A planar antenna topology comprising multiple connection ports and multiple radiators arranged in multiple columns and multiple rows. One or more of the multiple of radiators in one or more columns of the multiple columns, and one or more of another of the multiple of radiators in an adjacent column of the multiple of columns are polarized to transmit electrical fields at common polarization angles. An extremity of radii of radiators centrally located in one or more of the multiple rows are separated from an extremity of radii of radiators centrally located in an adjacent row of the multiple rows by a predefined electrical distance. The predefined electrical distance is of substantially half a wavelength of an operating frequency of the planar antenna topology. An extremity of radii of radiators centrally located in the one or more columns are separated from an extremity of radii of radiators centrally located in the adjacent column by the predefined electrical distance.

Each column of the multiple columns may comprise a one or more of clusters each including a group of radiators from the multiple radiators that share a common connection port. The centrally located columns of the plurality of columns may comprise a higher number of clusters than the externally located columns.

The number of radiators in each cluster may be equal to the number of rows in the multiple of rows. The radiators are dual polarized radiators. The radiators may be regularly distributed both horizontally and vertically by the predefined electrical distance between the group and another group in the one or more columns. Regularly distributed between the group in the one or more columns and an adjacent column of radiators of the multiple radiators to enable the measurement of the passive return loss [S 11 , S22] and the coupling [S 12, S21] . The measurement being between the connection ports and/or between the common connection ports. A regular distribution of the connection ports may enable a connection to the radiators without having to utilize adaption layers to enable the connection. The number of clusters in the one or more column is a power of two.

A method to manufacture a planar antenna topology, the method comprising multiple connection ports connected to multiple radiators. The multiple radiators arranged into multiple columns and multiple rows. One or more of the multiple of radiators is polarized in one or more column of the multiple of columns and one or more another of the multiple radiators in an adjacent column of the multiple columns to transmit electrical fields at common polarization angles. An extremity of radii of radiators centrally located in one or more of the multiple of rows is separated from extremity of radii of radiators centrally located in an adjacent row of the multiple of rows by a predefined electrical distance. The predefined electrical distance is of substantially half a wavelength of an operating frequency of the planar antenna topology. An extremity of radii of radiators centrally located in the one or more column is isolated from an extremity of radii of radiators centrally located in the adjacent column by the predefined electrical distance.

Each column of the multiple columns may comprise a one or more of clusters each including a group of radiators from the multiple radiators that share a common connection port. The centrally located columns of the plurality of columns may comprise a higher number of clusters than the externally located columns. The number of radiators in the group includes the same number of radiators in each group or different numbers of radiators in each group. The number of radiators in the group may be equal to the number of rows in the multiple of rows. The radiators may be dual polarized radiators. The radiators may be regularly distributed by the predefined electrical distance. The passive return loss [Si l, S22] and the coupling [S12, S21] may be measured between the connection ports and/or being between the common connection ports. Another planar antenna topology may be stacked upon the planar antenna topology to double the number of rows of the multiple rows responsive to the polarizing of the radiators and/or clusters, the separating of radiators and/or clusters and to the isolating radiators and/or clusters.

According to a first aspect, a greater data transmission rate for an antenna array is by virtue of overall general improvement of coupling levels for the antenna array when compared to coupling levels of other antenna arrays. Further, the antenna array provides a greater diversity of radiation patterns for the antenna array by virtue of clusters separately fed from other clusters in the middle column. The greater diversity of radiation patterns enable the beam energy of the antenna array to be efficiently concentrated on desired areas. The interference to non-desired coverage areas minimized and to provide beams that sweep across target areas without leaving coverage holes in the target areas.

According to a second aspect, improvement of coupling levels for the antenna array are by virtue of the extremities of radii of multiple radiators included in multiple clusters in the middle column separated longitudinally by at least half a wavelength from each other. Further that the extremities of radii radiators in each cluster are separated longitudinally by at least half a wavelength from each other. The extremities of radii of Radiators in columns on either side of the middle column are also separated laterally from the clusters in the middle column by at least half a wavelength from each other. The extremities of radii of radiators in columns on either side of the middle column are also separated longitudinally by at least half a wavelength from each other. Such a topographical layout for the antenna array avoids falling into the redundancy of using four vertical columns as opposed to three for a given aperture of the antenna array. Four vertical columns means an increased number of radiators that may appear to beneficial, however, the radiators are laterally closer to each other and therefore separated by less than half a wavelength from each other. Consequently, for four columns, coupling levels between beams emitted from the antenna array get worse and radiation patterns become highly correlated, which result in poorer performance of an antenna as shown in the descriptions that follow.

According to a third aspect, the radiators being regularly distributed, minimizes the passive return loss [Sn, S22] at the connection ports and to improve the coupling [S12, S21] and hence isolation between the connection ports. The regular distribution of the ports, enables the use of conventional radio equipment without having to utilize adaption layers. Further, the antenna array aims at obtaining symmetry that allows for regular port distribution and is favorable for balanced performance over the geographical areas of a cellular network.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the disclosure, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the disclosure are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the disclosure. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the disclosure may be practiced.

In the drawings:

FIGs. 1, 1A, IB shows a topside plan views and a bottom side plan views of antenna arrays, in accordance with some embodiments;

FIG. 2 shows three plan views of topologies of three respective antenna arrays, in accordance with some embodiments;

FIG. 3 shows multiple field (F) plots for two antenna arrays, in accordance with some embodiments;

FIG. 4 shows a graph of cumulative distribution function (CDF) versus Shannon Thp (sum of co-scheduled user equipments] UEs) in bits per second per hertz, in accordance with some embodiments;

FIG. 5 shows a distribution of phase centers for antenna array, in accordance with some embodiments; FIG. 6 shows two field plots 60 and 62 for antenna arrays 10, in accordance with some embodiments;

FIG. 7 shows a tabular comparisons between several antenna arrays, in accordance with some embodiments; and

FIG. 8 shows a method of manufacture for an antenna array, in accordance with some embodiments.

DETAILED DESCRIPTION

The present disclosure, in some embodiments thereof, relates to relates to an antenna array and, more specifically and, more specifically, but not exclusively, to a distributed layout of radiating elements and connection ports of the antenna array.

By way of introduction, the 5G cellular communication system may make use of several frequency ranges, including sub-6GHz and mm-wave bands. Upper frequency bands may suffer from poor propagation characteristics, whereas lower frequency bands may be more attractive in terms of propagation and coverage but may require large antennas since a lower frequency means a larger wavelength/ electrical lengths of radiators. Often antennas may be required to operate within constrained dimensions that may make their design difficult. 5G may utilize massive multi input multi output (MIMO) as the key radio technology. Massive MIMO, by making use of “smart” antennas, may perform beam-forming to serve users. Antenna architectures responsive to spatial resolution, optimize the narrowness of the radiation beam along a specific axis with respect to a user distribution. Consequently, antenna architectures responsive to spatial resolution may be beneficial in terms of system performance. Besides antenna radiation aspects, antennas may have to comply with specifications at their input ports; specifically the reflected power (Return Loss) and power coupled from other ports (Isolation).

Communication systems based on (Massive) MIMO make use of antennas with multiple clusters. A cluster may include one or more radiators where each cluster may fed by one transmitter (Tx), receiver (Rx) or a Tx/Rx radio chain. Where radiators are dual polarized, a radiator may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. The allowed size of the radiating structure (aperture) may be constrained, which may cause coupling issues between clusters. Excessively dense packing of radiators may be counterproductive since increased coupling between ports that connect to the radiators and radiation patterns become highly correlated, which may result in poorer performance of an antenna. According to descriptions below, improvement of coupling levels for the antenna array are by virtue of clusters in the middle column separated longitudinally by at least half a wavelength from each other and radiators in each cluster separated longitudinally by at least half a wavelength from each other. Radiators in columns on either side of the middle column are also separated laterally from the clusters in the middle column by at least half a wavelength from each other. Radiators in columns on either side of the middle column are also separated longitudinally by at least half a wavelength from each other. Such a topographical layout for the antenna array avoids falling into the redundancy of using four vertical columns as opposed to three for a given aperture of the antenna array. Four vertical columns means an increased number of radiators that may appear to beneficial, however, the radiators are laterally closer to each other and therefore separated by less than half a wavelength from each other. Consequently, for four columns, coupling levels between beams emitted from the antenna array get worse and radiation patterns become highly correlated, which result in poorer performance of an antenna as shown in the descriptions that follow by way of comparison.

Before explaining at least one embodiment of the disclosure in detail, it is to be understood that the disclosure is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The disclosure is capable of other embodiments or of being practiced or carried out in various ways.

Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.

The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware -based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

Reference is now made to FIG. 1, which shows a topside plan view and a bottom side plan view of antenna array 1, in accordance with some embodiments. In descriptions that follow an allowed size of an antenna array is in terms of its width (rows) and height (columns) in the XY plane. The allowed size is referred to as the aperture of the antenna array. The polarization of antenna radiators are referred to herein, as the orientation of the electric field of the radio wave transmitted by each of the radiators, and is determined by the physical structure of a radiator and its orientation.

In the topside plan view an aperture is three columns wide and two rows high. The first column 1 includes two radiators R1 that are polarized -45° degrees and 45° degrees respectively for the two radiating elements of each radiator Rl. Radiators R1 polarized -45° degrees and 45° degrees with respect to the Y-axis. Polarization of radiators Rl are with reference to an emission of a beam from radiators Rl out of antenna array 1 as solid angles. The emission being in the direction of the Z-axis relative to the XY plane. A radiator Rl may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx (not shown) with respect to the Y -axis. Where radiators Rl are dual polarized (as shown), a radiator Rl may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. With respect to the bottom side plan view, radiators Rl in the first column 1 are fed by a TX/RX radio chain via port P2 and the third column 3 fed by a TX/RX radio chain via port Pl.

In a similar way to first column 1, the third column 3 includes two radiators Rl that are polarized -45° degrees and 45° degrees respectively for the two radiating elements of each radiator Rl. Polarization of radiators Rl is with reference to an emission of a beam from radiators Rl out of antenna array 1 as solid angles. The emission being in the direction of the Z-axis relative to the XY plane. A radiator Rl may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx (not shown). Where radiators Rl are dual polarized, a radiator Rl may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. In column 3, radiators Rl are shown fed as a transceiver TX/RX radio chain. The second column 2 includes cluster CL1 in the first two rows of second column 2. Cluster CL1 includes two radiators R1 in the first and second row. Each radiator R1 in cluster CL1 may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx (not shown). Radiators R1 may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx radio chain (not shown). Where radiators R1 are dual polarized, a radiator R1 may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. With respect to the bottom side plan view, radiators R1 in cluster CL1 are fed via common connection ports PCI 1 and PC 12 so that common connection ports PC 11 and PC 12 correspond to the two polarizations of cluster CL1. Common connection ports PC 11 and PC 12 may connect and be fed separately to each radiator R1 or may be connected and fed together. Cluster CL1 may be polarized to emit a beam adjacent to a beam from the first column 1 or a beam emitted from the third column 3. Radiators R1 in a cluster may be dual polarized radiators. Vertical electrical distance dv between the extremity of radii of two radiators R1 (shown by arrowheads) in cluster CL1 located centrally in column 2 is approximately half a wavelength (X/2) or more over the frequency band of operation of antenna array 1. Similarly, the horizontal electrical distance dv exists between an extremity of radii of radiator R1 in cluster CL1 in the first row and an extremity of radii of radiators R1 in column 1 or column 3 in the first row. According to the aperture of antenna array 1, the number of clusters in the second column is a power of two.

Reference is now made to FIG. 1A, which shows a topside plan view and a bottom side plan view of antenna array 2, in accordance with some embodiments. In rows two to four, a repeat is made of the aperture of antenna array 1 described above with respect to the first two rows. Rows two to four includes radiators R1 in cluster CL2 that are fed via ports PC21 and PC22. Where radiators R1 are dual polarized, a radiator R1 may be fed for two respective polarizations for two transmitters, two receivers or two transceivers so that PC21 and PC22 correspond to the two polarizations of cluster CL2. Ports PC21 and PC22 may connect and be fed separately to each radiator R1 or may be connected and fed together. Radiators R1 in third column 3 are fed by the TX/RX radio chain via ports P2 and P2’. Radiators R1 in first column 1 are fed by the TX/RX radio chain via ports Pl and Pl’. Horizontal electrical distance dv and vertical electrical distance dv between the extremities of radii (shown by arrowheads) between any two radiators R1 is approximately half a wavelength (X/2) or more over the frequency band of operation of antenna array 2. In particular, the vertical electrical distance dv is also between the extremity of radii of bottom radiator R1 in cluster CL1 and the extremity of radii of top radiator R1 in cluster CL2. Both bottom radiator R1 of cluster CL1 and top radiator R1 of cluster CL2 are located centrally in column 2 and are both with their extremity of radii are centrally located in their respective rows 3 and 2. According to the aperture of antenna array 2, the number of clusters in the second column is a power of two and the number of radiators R1 in a cluster is two, however the number radiators R1 in either of the first or third columns is greater that the numbers of radiators R1 in cluster CL1 or cluster CL2.

Reference is now made to FIG. IB, which shows a topside plan view and a bottom side plan view of antenna array 10, in accordance with some embodiments. In the topside plan view with respect to the first four rows, an aperture is three columns wide and four rows high. The first column 1 includes multiple radiators R1 that are polarized -45° degrees and 45° degrees respectively for the two radiating elements of each radiator Rl. Radiators R1 polarized -45° degrees and 45° degrees with respect to the Y-axis. Polarization of radiators Rl are with reference to an emission of a beam from radiators Rl out of antenna array 10 as solid angles. The emission being in the direction of the Z-axis relative to the XY plane. A radiator Rl may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx (not shown) with respect to the Y- axis. Where radiators Rl are dual polarized, a radiator Rl may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. With respect to the bottom side plan view, radiators Rl in the first column 1 are fed by the TX/RX radio chain via ports P2 and P2’.

In a similar way to first column 1, the third column 3 includes multiple radiators Rl that are polarized -45° degrees and 45° degrees respectively for the two radiating elements of each radiator Rl. Polarization of radiators Rl is with reference to an emission of a beam from radiators Rl out of antenna array 10 as solid angles. The emission being in the direction of the Z-axis relative to the XY plane. A radiator Rl may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx (not shown). Where radiators Rl are dual polarized, a radiator Rl may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. In column 3, radiators Rl are shown fed as a transceiver TX/RX radio chain. With respect to the bottom side plan view, radiators Rl in third column 3 are fed by the TX/RX radio chain via ports Pl and Pl’.

The second column 2 includes cluster CL1 in the first two rows of second column 2 and cluster CL2 in the third and fourth rows of second column 2. Cluster CL1 includes two radiators Rl in the first and second row. Each radiator Rl in cluster CL1 or cluster CL2 may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx (not shown). Radiators Rl may be fed by one transmitter (Tx), one receiver (Rx) or one transceiver Tx/Rx radio chain (not shown). Where radiators Rl are dual polarized, a radiator Rl may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. With respect to the bottom side plan view, radiators R1 in cluster CL1 are fed via common connection ports PC 11 and PC 12 so that PC 11 and PC 12 correspond to the two polarizations of cluster CL1. Common connection ports PC 11 and PC 12 may connect and be fed separately to each radiator R1 or may be connected and fed together. Similarly, radiators R1 in cluster CL2 are fed via ports PC21 and PC22 so that PC21 and PC22 may correspond to the two polarizations of cluster CL2. Ports PC21 and PC22 may connect and be fed separately to each radiator R2 or may be connected and fed together. Cluster CL1 may be polarized separately to the polarization of cluster CL2. Either of cluster CL1 or CL2 may be polarized to emit a beam adjacent to a beam from the first column 1 or a beam emitted from the third column 3. Radiators R1 in a cluster may be dual polarized radiators.

In rows five to eight, a repeat is made of the aperture described above with respect to the first four rows. Where radiators R1 are dual polarized, a radiator R1 may be fed for two respective polarizations for two transmitters, two receivers or two transceivers so that PC31 and PC32 correspond to the two polarizations of cluster CL3. Rows five to eight includes radiators R1 in cluster CL3 that are fed via ports PC31 and PC32. Ports PC31 and PC32 may connect and be fed separately to each radiator R1 or may be connected and fed together. Similarly, radiators R1 in cluster CL4 are fed via ports PC41 and PC42 so that PC41 and PC42 may correspond to the two polarizations of cluster CL4. Ports PC41 and PC42 may connect and be fed separately to each radiator R1 or may be connected and fed together. Radiators R1 in third column 3 are fed by the TX/RX radio chain via ports P3 and P3’. Radiators R1 in first column 1 are fed by the TX/RX radio chain via ports P4 and P4’. Horizontal electrical distance dv and vertical electrical distance dv between the extremities of radii (shown by arrowheads) between any two radiators R1 is approximately half a wavelength (X/2) or more over the frequency band of operation of antenna array 10. In particular, the vertical electrical distance dv is also between the extremity of radii of bottom radiator R1 in cluster CL2 and the extremity of radii of top radiator R1 in cluster CL3. Both bottom radiator R1 of cluster CL2 and top radiator R1 of cluster CL3 are located centrally in column 2. Both bottom radiator R1 of cluster CL2 and top radiator R1 of cluster CL3 are with their extremity of radii are centrally located in their respective rows 5 and 4. According to the aperture of antenna array 10, the number of clusters in the second column is a power of two. With respect to antenna arrays described above, in each column of the columns includes one or more clusters CL1-CL4. Each cluster including a group of radiators R1 from the radiators that share a common connection port. The centrally located columns of the multiple columns include a higher number of clusters than the externally located columns on either side of the centrally located columns. In general, a radiator R1 of two radiators R1 included in cluster CL1 for example may emit a beam towards a second beam emitted from the first column 1 or the third column 3 and vice versa. Further, in general, polarization of radiators R1 are with reference to an emission of a beam from radiators R1 out of antenna array 10 as solid angles. The emission being in the direction of the Z-axis relative to the XY plane. Radiators R1 may be polarized -45° degrees and 45° degrees respectively for the two radiating elements of each radiator to have the same polarization or to be cross -polarized. Further, the bottom side plan view of antenna array 10 shows the regular distribution of the ports, which enables the use of conventional radio equipment without adaption layers.

Reference is now made to FIG. 2, which shows three plan views of topologies of respective antenna arrays 22, 23 and 24, in accordance with some embodiments. Common to antenna arrays 22 and 23 are eight rows of radiators Rl. Antenna array 22 has two identical columns and antenna array 23 has three identical columns. Antenna array 24 includes eight rows and four columns of radiators Rl ’ . The extremities of radii of the horizontal radiating elements of radiator Rl ’ are shorter in terms of physical and electrical length from the vertical radiating elements of radiator Rl’. Radiator Rl’ and the columns of antenna array 24 are much narrower and hence the space between radiators Rl’ in the horizontal direction (X-axis) is also narrower when compared to the space between radiators Rl in the horizontal direction (X-axis) for antenna arrays 22 and 23. In other words, the space between radiators Rl’ in the horizontal direction (X-axis) present a greater number density of radiators Rl’ in a row with respect to the horizontal radiating elements of radiator Rl’. A similar shortening of the vertical radiating elements of radiator Rl’ may also be made to give a greater number density of radiators Rl’ in a column. The shortening of both the vertical and horizontal radiating elements of radiator Rl’ may be made by applying a dielectric superstate to a radiator Rl’ .

Antenna array 10 includes clusters CL1-CL4 that are separably polarized to each other. When compared to antenna array 23, antenna array 10 includes separably polarized clusters CL1- CL4. A superstrate may be added to the aperture of antenna array 10. The emission of the beam from radiators Rl out of antenna array 10 being in the direction of the Z-axis relative to the XY plane as a solid angle. Where the superstrate is applied to clusters CL1-CL4, the number density of radiators Rl in each cluster could for example be increased from two radiators Rl to three radiators Rl in the vertical direction (not shown). The increase from two radiators Rl to three radiators Rl in the vertical direction by virtue of shortening of the radii of the vertical radiating elements of radiator Rl to give a greater number density of radiators Rl in each of clusters CL1- CL4. Further, where the superstate is applied to clusters CL1-CL4, the number density of radiators R1 in each cluster could for example be increased from one radiators R1 to two radiators R1 in the horizontal direction (not shown). The increase from one radiator R1 to two radiators R1 in the horizontal direction by virtue of shortening of the radii of the horizontal radiating elements of radiator R1 to give a greater number density of radiators R1 in each of clusters CL1-CL4.

A practical outcome of the increased number density of radiators R1 in clusters located in the central columns enables a greater channel diversity for antenna array 10 compared to other antenna arrays is by means of clusters with different coverage patterns. The resulting superior radiation performance, higher directivity and better beam symmetry to allow symmetrical diagonal beam steering is shown in the drawings and descriptions that follow.

Reference is now made to FIG. 3, which shows multiple field (F) plots for antenna arrays 24 and 10, in accordance with some embodiments. Each plot has a horizontal axis of spherical angle phi (p and vertical axis of spherical angle theta Q of the radiated electric field emitted from various parts of each antenna array. Level of shading shows the level of power (decibels dB) of the radiated electric field at the various points of spherical angles Q and (p of the radiated electric field (F). The field plot for antenna array 24 shows a uniform amplification across the four rows of radiators. By comparison, the field plot for antenna array 10 shows a tapered amplification across the four rows of radiators by virtue of the clusters in column two of antenna array 10. The separably polarized clusters CL1-CL4 and the superstrate that may be added to the aperture of antenna array 10, to provide beamforming capabilities with higher directivity and symmetry to a beam emitted from each of the clusters CL1-CL4. The field plot for antenna array 10 compared to the field plot for antenna array 24, shows a lower level of side lobe interference in lower side lobe 30b compared to lower side lobe 30a.

Scattering parameters (S -parameters) are one type of network representation used for linear, small-signal alternating current (AC) analysis. S -parameters are mostly used for networks operating at radio frequency (RF) and microwave frequencies where signal power and energy considerations are more easily quantified than currents and voltages. S -parameters change with the measurement frequency, so frequency must be specified for any S -parameter measurements stated, in addition to the characteristic impedance Z _o or system impedance Z _s . A two-port network includes four scattering parameters S n, S12, S21 and S22. Scattering parameters S 11 and S22 are the reflection coefficient of the input port and the output port respectively. The level of coupling between ports are represented by scattering parameters S12 and S21. Coupling dB) = 20 log ₁₀ |S ₁₂ 1

The correlation operation consists in a projection of one field onto the other, followed by a normalization by their powers. Envelope correlation coefficient (ECC) indicates how much the between two radiation patterns are independent from each other. The ideal correlation coefficient of a MIMO antenna system for example is zero. Mathematically, envelope correlation coefficient for two fields Fl and F2 may be expressed in general by the following:

Where Q is the spherical coordinate (theta 9, phi cp) and Fi and F2 are the electric field expressed as vectors by the bar above Fi and 2. The how the radiation pattern varies over a sphere for a field F _n is given by the following:

Where 9 and p represent the spherical angles (elevation, azimuth), ae represents a unit vector in the theta 9 direction, and a _q> represents a unit vector in the phi p direction. In terms of scattering parameters S, the envelope correlation coefficient may also be expressed by the following:

Spherical coverage (9, tp) may also be specified by the cumulative distribution function (CDF) of effective isotropic radiated Power (EIRP), which is a combination of transmitted power and antenna array gain. CDF calculations are important when it comes to antenna array design so that an antenna array meets all coverage and gain requirements to achieve the best possible performance. The probability (P) over all directions of the EIRP being between any two values El and E2 of electric field (inclusive) is:

In a typical polar 3D gain or EIRP plot as shown in FIG. 3, the magnitude at each spherical angle (9, tp) is plotted as a radius from the origin. For this type of plot, the EIRP of an antenna system will be contained in the closed region between a sphere of radius Emin (Electric Field) centered on the origin and an equal or larger sphere centered on the origin of radius Emax (Electric Field). A cumulative distribution function (CDF)/(x : gives the probability that x < Xi.

Reference is now made to FIG. 4, which shows a graph of cumulative distribution function (CDF) versus Shannon Thp (sum of co-scheduled user equipments] UEs) in bits per second per hertz, in accordance with some embodiments. Shannon Thp refers to the capacity of the channel, as calculated from Claude Shannon’s channel capacity equation which is the maximum data rate (in bits per second per hertz) one can obtain from a communication system using antenna arrays

22, 23, 24 and 10. The Shannon limit equation below defines how efficiently antenna arrays 22,

23, 24 and 10 use the allotted bandwidth and assumes that a secure transmission is achieved for all antenna arrays 22, 23, 24 and 10, by means of a suitable error protection method provided.

Where S is the signal power in watts and N is the noise power in watts.

Plot 41 is for antenna array 22, plot 42 is for antenna array 23, plot 43 is for antenna array 24 and plot 44 is for antenna array 10. For the same cumulative distribution function (CDF) value of 0.5, antenna array 21 : approximately (~) 8 bits per second per hertz (bits/s/Hz) value, antenna array 22: ~20 bits/s/Hz value, antenna array 23: ~21 bits/s/Hz value and antenna array 10: ~26 bits/s/Hz value. Plot 44 compared to plot 43 gives approximately a 19% difference in data rate. The 19% difference in data rate means a greater data transmission rate for antenna array 10 over the data transmission rate of antenna array 24 for the same CDF value. In other words, the 19% difference means that one can communicate at 1.19 bit per sec per hertz by using antenna array 10 with respect to 1 bit per sec per hertz achieved by antenna array 24.

Reference is now made to FIG. 5, which shows a distribution of phase centers for antenna array 10 , in accordance with some embodiments. The distribution is shown in the XY plane for the aperture of antenna array 10 of three columns wide (500mm) and eight rows high (2000 mm). With reference to an emission of a beam from radiators R1 out of antenna array 10 as solid angles. The emission being in the direction of the Z-axis relative to the XY plane is shown as small circles of phase distribution (PD) Phase distribution C14 corresponds with a phase distribution of the first four rows and first column. Similarly, phase distribution C 18 corresponds with a phase distribution of rows five to eight of the first column. Phase distribution C34 corresponds with a phase distribution with the first four rows and third column. Similarly, C38 corresponds with a phase distribution with rows five to eight of the third column. Phase distribution C22 corresponds with a phase distribution of cluster CL1 in the second columns. Similarly, Phase distribution C24 corresponds with a phase distribution of cluster CL2, phase distribution C26 corresponds with a phase distribution of cluster CL3 and phase distribution C28 corresponds with a phase distribution of cluster CL4.

Phase distribution C26 in the second column is longitudinally displaced from phase distribution C24 in the second column (shown by double arrow line 52) by approximately 200mm which corresponds to the electrical distance between clusters CL2 and CL3 that is approximately half a wavelength (X/2) or more over the frequency band of operation of antenna array 10. Phase distribution C26 in the second column is laterally displaced from phase distribution C18 in the first column (shown by double arrow line 50) by a electrical distance approximately 210mm which is greater than half a wavelength (X/2) over the frequency band of operation of antenna array 10.

The distribution of phase centers for the aperture of antenna array 10 exploits the available horizontal resolution by using three different vertical columns, separated half a wavelength without falling into the redundancy of using four vertical columns as with antenna array 24. When compared to antenna array 23, antenna array 10 includes separably polarized clusters CL1-CL4 and a superstate may be added to the aperture of antenna array 10. Consequentially, antenna array 10 aims at maximal separation among the phase centers of the phase distributions described above, in order to enhance channel richness and to reduce the value of envelope correlation coefficient (ECC). Where envelope correlation coefficient indicates how much two radiation patterns are independent from each other. Description above indicates the benefit of the radiators R1 being regularly distributed over the aperture of antenna array 10 compared to antenna arrays 22, 23 and 24. The radiators R1 being regularly distributed to minimize the passive return loss [Sn, S22] at the connection ports and to improve the coupling [S12, S21] between the connection ports. Radiators R1 being regularly distributed as shown with respect to antenna array 10 is by a horizontal and vertical predefined electrical distance (dv) of half a wavelength. The predefined vertical electrical distance dv is between each cluster in the second column and between extremities of radii of radiators R1 in each cluster. The predefined horizontal electrical distance dv is between each extremity of radii of radiators R1 in each row. Further, antenna array 10 aims at obtaining symmetry, which is favorable for balanced performance over the cell geography or geographical areas of a cellular network and allows for regular port distribution as shown in FIG. 1. Reference is now made to FIG. 6, which shows two field plots 60 and 62 for antenna array 10, in accordance with some embodiments. Plot 60 shows an emission of a beam from radiators R1 out of antenna array 10 for spherical angle phi (p (0° - 360° degrees). The emission being in the direction of the Z-axis relative to the XY plane. The beam from radiators R1 the first and third column and from clusters CL2 and CL3. Plot 62 shows an emission of a beam from radiators R1 out of antenna array 10 for spherical angle phi (p (0° - 360° degrees). The emission being in the direction of the Z-axis relative to the XY plane. The beam from radiators R1 that may be dual polarized are located in rows five to 8 in the first and from rows one to four in the third column and from clusters CL2 and CL3. The higher directivity of clusters in the second column enables beamforming symmetry as shown in both plots 60 and 62 as well and to improve the ‘diagonal beamforming capability as shown in plot 62.

Reference is now made to FIG. 7, which shows a tabular comparisons between antenna arrays 10, 23, 24 and 70, in accordance with some embodiments. Antenna 70 includes radiators R1 that are longitudinally offset in the second column relative to first and third columns. In description which follow for the tabular comparisons, with the exception of antenna array 24 the same radiators R1 are utilized for each of antenna arrays 10, 23, 24 and 70. Radiator RF and the columns of antenna array 24 are much narrower and hence the space between radiators R1 ’ in the horizontal direction X= axis is also narrower when compared to the space between radiators R1 in the horizontal direction X= axis for antenna arrays 22 and 23. The same operating band of frequencies of signals are applied to antenna arrays 10, 23, 24 and 70 and the characteristic impedance Z _o and or system impedance Z _s are the same for all antenna arrays 10, 23, 24 and 70. The same four to one (4:1) height (H) to width (W) aperture ratio is applied to antenna arrays 10, 23, 24 and 70 (H=2000mm, W= 500mm).

Table 1 corresponds to the correlations of fields Fl and F2 of antenna array 24. Field Fl is from radiators RF in rows 5-8 in the first columns of the four columns of antenna array 24. Field F2 is from radiators RF in rows 5-8 in the second column. The first column of Table 1 is for a first scenario when the spherical angles (9, tp) of fields Fl are in the same or common direction as the spherical angles (9, tp) of field F2. The second column Table 1 is for a second scenario when the spherical angles (9, tp) of field Fl are in the opposite direction to the spherical angles (9, tp) of field F2. In the first row of Table 1 is the value of envelope correlation coefficient for the first and second scenarios of the first and second column respectively. In the second row of Table 1 is the value of envelope correlation for the solid angles of the resulting beam from antenna array 24 for the first and second scenarios of the first and second column respectively. In descriptions that follow, the second row includes the values of the ECC when the integrals in the equation for p _e are not calculated over the full surrounding sphere (around the antenna, at far field), but only over the solid angle where the coverage cell is located with respect to the point of view of the antenna), i.e. (p between -60° and +60° , and 0 between 0° (i.e. horizon; approx.) and 90° (i.e. the ground at the bottom of the antenna array).

Table 2 corresponds to the correlations fields F3 and F4 of antenna array 23. Field F3 is from radiators R1 in rows 5-8 in the first column 1. Field F4 is from radiators R1 in rows 5-8 in the second column 2. The first column of Table 2 is for a first scenario when the spherical angles (9, (p) of field F3 are in the same or common direction as the spherical angles (9, (p) of field F4. The second column Table 2 is for a second scenario when the spherical angles (9, tp) of fields F3 are in the opposite direction to the spherical angles (9, (p) of field F4. In the first row of Table 2 is the value of envelope correlation coefficient for the first and second scenarios of the first and second column respectively. In the second row of Table 2 is the value of envelope correlation for the solid angles of the resulting beam from antenna array 23 for the first and second scenarios of the first and second column respectively.

Table 3 corresponds to the correlations fields F5 and F6 of antenna array 70. Field F5 is from radiators R1 in rows 5-8 in the first column 1. Field F6 is from radiators R1 in rows 5-8 in the second column 2. The first column of Table 3 is for a first scenario when the spherical angles (9, (p) of field F5 are in the same or common direction as the spherical angles (9, (p) of field F6. The second column Table 2 is for a second scenario when the spherical angles (9, (p) of fields F5 are in the opposite direction to the spherical angles (9, (p) of field F6. In the first row of Table 2 is the value of envelope correlation coefficient for the first and second scenarios of the first and second column respectively. In the second row of Table 3 is the value of envelope correlation for the solid angles of the resulting beam from antenna array 70 for the first and second scenarios of the first and second column respectively.

Table 4 corresponds to the correlations fields F7 and F8 of antenna array 10. Field F7 is from radiators R1 in rows 5-8 in the first column 1. Field F8 is from radiators R1 in rows 5-6 in the second column 2 which forms cluster CE3. The first column of Table 2 is for a first scenario when the spherical angles (9, tp) of field F7 are in the same or common direction as the spherical angles (9, tp) of field F8. The second column Table 4 is for a second scenario when the spherical angles (9, (p) of fields F7 are in the opposite direction to the spherical angles (9, (p) of field F8. In the first row of Table 4 is the value of envelope correlation coefficient for the first and second scenarios of the first and second column respectively. In the second row of Table 4 is the value of envelope correlation for the solid angles of the resulting beam from antenna array 10 for the first and second scenarios of the first and second column respectively.

Comparing Tables 1-4, the correlations of Table 4 are much more balanced than those of Tables 1-3. In particular the worst case scenario as shown in the second row of the Tables is greatly reduced in Table 4 compared to Tables 1-3.

Reference is now made to FIG. 8, which shows a flowchart of a method 800 with reference to antenna array 10, in accordance with some embodiments. Referring again to FIG. IB, the upper portion of the aperture of antenna array 10 is three columns wide and four rows high. At step 801, radiators R1 in the first column 1 are fed by a TX/RX radio chain via ports P2 and P2’, radiators R1 in third column 3 are fed by the TX/RX radio chain via ports Pl and PF, radiators R1 in cluster CL1 are fed via common connection ports PCI 1 and PC 12 . Where radiators R1 are dual polarized, a radiator R1 may be fed for two respective polarizations for two transmitters, two receivers or two transceivers so that PC 11 and PC 12 correspond to the two polarizations of cluster CL1. Common connection ports PCI 1 and PC 12 may connect and be fed separately to each radiator R1 or may be connected and fed together. Similarly, Radiators R1 in cluster CL2 are fed via ports PC21 and PC22. Ports PC21 and PC22 may connect and be fed separately to each radiator R2 or may be connected and fed together. Similarly, PC21 and PC22 may correspond to the two polarizations of cluster CL2. Cluster CL1 may be polarized separately to the polarization of cluster CL2. Either of cluster CL1 or CL2 may be polarized to emit a beam laterally adjacent to a beam from the first column 1 or a beam emitted from the third column 3. Clusters CL1 and CL2 and their radiators R1 are located and connected longitudinally adjacent to each other in the second or middle column. Radiators R1 in a cluster may be dual polarized radiators.

In rows five to eight, a repeat is made of the aperture described above with respect to the first four rows. Therefore, the first four rows are stacked atop rows five to eight. Rows five to eight includes radiators R1 in cluster CL3 that are fed via ports PC31 and PC32 so that PC31 and PC32 correspond to the two polarizations of cluster CL3. Where radiators R1 are dual polarized, a radiator R1 may be fed for two respective polarizations for two transmitters, two receivers or two transceivers. Ports PC31 and PC32 may connect and be fed separately to each radiator R1 or may be connected and fed together. Similarly, radiators R1 in cluster CL4 are fed via ports PC41 and PC42 so that ports PC41 and PC42 may correspond to the two polarizations of cluster CL4. Ports PC41 and PC42 may connect and be fed separately to each radiator R1 or may be connected and fed together. Radiators R1 in third column 3 are fed by the TX/RX radio chain via ports P3 and P3’. Radiators R1 in first column 1 are fed by the TX/RX radio chain via ports P4 and P4’. According to the aperture of antenna array 10, the number of clusters in the second column may be a power of two and the number of radiators in each cluster may be a power of two.

At step 803, radiators R1 are polarized -45° degrees and 45° degrees with respect to the Y- axis. Polarization of radiators R1 are with reference to an emission of a beam from radiators R1 out of antenna array 10 as solid angles. The emission for each radiator R1 and/ or cluster being in the same direction of the Z-axis relative to the XY plane.

Horizontal electrical distance dv and vertical electrical distance dv between the extremities of radii (shown by arrowheads) between any two radiators R1 is approximately half a wavelength (X/2) or more over the frequency band of operation of antenna array 10.

In particular, at step 805, the vertical electrical distance dv is between the extremity of radii of bottom radiator R1 in cluster CL1 and the extremity of radii of top radiator R1 in cluster CL2. Both bottom radiator R1 of cluster CL1 and top radiator R1 of cluster CL2 are located centrally in column 2 and are both with their extremity of radii, centrally located in their respective rows 3 and 2. The vertical electrical distance dv is also between the extremity of radii of bottom radiator R1 in cluster CL2 and the extremity of radii of top radiator R1 in cluster CL3. In addition, both bottom radiator R1 of cluster CL2 and top radiator R1 of cluster CL3 are located centrally in column 2. Both bottom radiator R1 of cluster CL2 and top radiator R1 of cluster CL3 are with their extremity of radii are centrally located in their respective rows 5 and 4. Further, the vertical electrical distance dv is between the extremity of radii of bottom radiator R1 in cluster CL3 and the extremity of radii of top radiator R1 in cluster CL4. Both bottom radiator R1 of cluster CL3 and top radiator R1 of cluster CL4 are located centrally in column 2 and are both with their extremity of radii, centrally located in their respective rows 6 and 7. According to the aperture of antenna array 10, the number of clusters in the second column may be a power of two.

In particular, at step 807, the horizontal electrical distance dv exists between an extremity of radii of radiator R1 in cluster CL1 in the first row and an extremity of radii of radiators R1 in column 1 or column 3 in the first row. Similarly, for the horizontal electrical distance dv exists between an extremity of radii of radiator R1 in cluster CL1 in the second row and an extremity of radii of radiators R1 in column 1 or column 3 and so on for the next rows and clusters CL2- CL4.Radiators R1 are shown regularly distributed in eight rows and three columns of antenna array 10, according to the predefined electrical distance dv, in order to minimize the passive return loss [Sii, S22] measured and improve the coupling [S12, S21] measured. Measure of the passive return loss and the coupling may be between the common connection ports (for example ports PCI 1- PC42) connected to each cluster, between ports (for example ports Pl- P4’) for the first and third columns and between ports for the first and third columns and the common connection ports. The regular distribution of the ports, enables the use of conventional radio equipment without having to utilize adaption layers.

According to descriptions above, the greater data transmission rate for antenna array 10 is by virtue of overall general improvement of coupling levels for antenna array 10 when compared to coupling levels for antenna arrays 21-23 and 70. Further, the greater diversity of radiation patterns for antenna array 10 may be by virtue of cluster CL1 separately fed from cluster CL2 in the second column or cluster CL3 separately fed from cluster CL4 in the second column. The greater the diversity of radiation patterns for antenna array 10 may be by virtue of the difference in size of clusters CL1- CL4 being smaller in terms of the number of radiators R1 in each cluster, compared to the numbers of radiators R1 in the first or third column. The greater diversity of radiation patterns to enable the beam energy of antenna array 10 to be efficiently concentrated on desired areas and the interference to non-desired coverage areas minimized and to provide beams that sweep across target areas without leaving coverage holes in the target areas.

Descriptions above indicate the benefit of the connection ports and radiating elements being regularly distributed over the aperture of antenna array 10 compared to antenna arrays 22, 23, 24 and 70. The radiators R1 being regularly distributed to minimize the passive return loss [Sii, S22] at the connection ports and to improve the coupling [S12, S21] and hence isolation between the connection ports. Further, antenna array 10 aims at obtaining symmetry by separating horizontally and vertically between radiators by half a wavelength (X/2) in the aperture of the antenna array, which is favorable for balanced performance over the cell geography or geographical areas of a cellular network and allows for regular port distribution as shown in FIG. 1.

Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.

The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

As used herein the term “about” refers to ± 10 %.

The terms "comprises", "comprising", "includes", "including", “having” and their conjugates mean "including but not limited to". This term encompasses the terms "consisting of" and "consisting essentially of".

The term “operating frequency” in the context of an antenna array means the central frequency value between an upper and lower operating frequency range of frequency values of the antenna array. For example if the upper operating and lower frequency values of an antenna array are 6 gigahertz (GHz) and 4 GHz respectively, the operating frequency of the antenna array is 5GHz.

The phrase "consisting essentially of" means that the composition or method may include additional ingredients and/or steps, but only if the additional ingredients and/or steps do not materially alter the basic and novel characteristics of the claimed composition or method.

As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

The word “exemplary” is used herein to mean “serving as an example, instance or illustration”. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.

The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the disclosure may include a plurality of “optional” features unless such features conflict.

Throughout this application, various embodiments of this disclosure may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging/ranges between” a first indicate number and a second indicate number and “ranging/ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub- combination or as suitable in any other described embodiment of the disclosure. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

It is the intent of the applicant(s) that all publications, patents and patent applications referred to in this specification are to be incorporated in their entirety by reference into the specification, as if each individual publication, patent or patent application was specifically and individually noted when referenced that it is to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety.