Patent Description:
The field of the invention is wireless communication.

The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

Antennas in future telecommunication networks are expected to present high gain in a broadband frequency range, as well as a reconfigurable radiation pattern. This is of particular interest for <NUM> systems which require greater thru-put and more precise optimization for peak performance. Currently there are limited methods of being able to electronically control and adjust this beamwidth without changing the antenna.

By common definition, antenna reconfigurability is remote / dynamic control of such antenna parameters as gain, radiation pattern (including beamwidth and beam shape), number of beams, polarization, with reversible modifications of its properties. The reconfiguration capability of reconfigurable antennas is used to maximize the antenna performance in a changing scenario or to satisfy changing operating requirements.

In many cases, previously deployed three-sector antennas will upgrade to nine-sector antennas to increase capacity. For example, there is demand for reconfigurable antennas with ability to change one wide beam (covering <NUM>° sector) to multiple beams, which together provide the same <NUM>°coverage. Also, in some wireless scenarios, beamwidth of an antenna might need to be dynamically adjusted (for example, from standard <NUM>° 3dB BW to <NUM>° 3dB BW) for coverage optimization / improvement.

In the telecommunication industry, typically BSA antennas are used (consisting of multiple radiating elements phased together into a phased array antenna), these antennas provide coverage for cellular use. It is well known that adjusting this coverage (i.e., adjusting the vertical/horizontal beamwidth of the antenna) can be a useful tool in optimizing capacity and coverage of users.

One possible method of adjusting resultant beamwidth is applying an isotropic dielectric lens in front of the radiating element or antenna. An isotropic spherical dielectric lens <NUM> is shown in prior art <FIG>. Lens <NUM> has equal magnitude of dielectric constant (DK) in all axes (X, Y, Z). However, this method does not provide a solution for variable beamwidth, as well as the ability to adjust only the horizontal or vertical beam. Reconfiguring for different beamwidths using isotropic dielectric lenses requires the use of a new antenna, and therefore fails to provide a standard solution which can be used on different types of existing BSA antennas.

Polarization diversity and MIMO performance can be also improved by use of polarization agility (in particular, with circular polarization). The additional antenna gain and degrees of freedom (pattern, polarization) provided by reconfigurable antennas can be used to overcome significant path loss and shadowing, especially at higher frequencies (<NUM>), and for better in-building penetration. Accordingly, there is still a need for an antenna system that solves these problems to provide high performance base station antenna with adjustable number of beams and pattern/polarization reconfigurability.

Thanks to the invention of light-weight, low loss, low cost artificial dielectric material (see, e.g., <CIT>) lensed antennas are used more widely in advanced <NUM> / LTE wireless communications. This provides better coverage and capacity compared to traditional antenna arrays, see e.g., https://matsing. com Lensed antennas also open doors to antenna reconfigurability, because the advancement in wireless communications requires the integration of multiple radios into a single platform to maximize connectivity and capacity. The '<NUM> patent describes many different materials that can be used in lensed antennas, and such materials are referred to herein as "Matsing materials".

US Patent Publication No. <CIT> provides good examples of advanced base station lensed antennas, but such antennas do not have reconfigurability (i.e. pattern, gain, polarization cannot be dynamically adjusted), because the lens uses isotropic dielectric materials (i.e. material has the same dielectric constant in any direction, X, Y, Z).

Japanese Patent Application Publication No. <CIT> relates to a lens antenna in which focal length is adjusted substantially constantly regardless of variation in dielectric constant, in order to improve the antenna gain.

This application describes apparatus and methods in which one or more anisotropic lenses are used to vary one or more of beamwidth, beam direction, polarization, and other parameters for BSA and other types of antennas.

As shown below, the above-mentioned requirements to reconfigurable antennas can be achieved by moving of anisotropic dielectric body (bodies) near the antenna aperture. Although this method of antenna reconfigurability looks universal, it is illustrated below with application to base station antenna technology. Artificial anisotropic dielectric material is much less expensive and lighter compare to natural anisotropic dielectric material.

Anisotropic lenses with varying magnitude of dielectric value (DK) in relation to the direction of the applied electric field are described, as well as lenses with varying magnetic constant (permeability) in relation to the direction of the applied magnetic field. Key practical antenna applications such as variable beamwidth (or beamforming) for all types of <NUM>/LTE/<NUM> BSA antennas are presented. For antenna applications, different shaped (cylindrical, spherical, disc, rectangular) anisotropic dielectric lenses are described that can be used to adjust single or multiple antenna parameters. Parameters include being able to adjust the resultant beamwidth, beam direction, polarization, gain, and sidelobe levels for single and multiple resultant antenna beams. Depending on the shape and DK orientation used, the lens can be mechanically rotated or moved to gradually increase/decrease the resultant beamwidth as well as other parameters of the antenna.

Furthermore, different types of materials and methods of fabrication are given. Some contemplated embodiments use spherical lenses constructed using a light weight polymer based material with embedded conductive fibers oriented in a single direction. Other contemplated embodiments use conductive fibers oriented in different orientations. Multiple examples are given including spherical lenses used to adjust resultant beamwidth of single-polarization antennas, dual-polarization antennas as well as multi-beam antennas. Further examples are given for independent horizontal and vertical beamwidth adjustment, as well as simultaneous horizontal and vertical beamwidth adjustment.

As a solution for remote adjustment of antenna parameters, methods of remote adjustment such as mechanical movement or rotation of lenses and electronic movement and/or rotation of lenses are discussed. Examples of adjustment of other antenna parameters such as beam direction are also provided. Other applications can include radar, satellite, as well as magnetic anisotropic lenses for multiple applications.

Although in many instances it might be preferable to move one or more lenses relative to one or more radiating elements, the physics is such that moving an element relative to a lens can achieve the same goal. Accordingly, this application uses the term "mutually orienting" with respect to lenses and radiating elements to include situations where either or both of a radiating element or a lens is being moved or otherwise oriented. And any description of either one of a radiating element or its associated lens being moved or oriented should be interpreted as if the description had specified "mutually orienting".

In a preferred embodiment, an antenna system includes at least one spherical lens, each having a first dielectric permittivity in a first direction and a second dielectric permittivity in a second direction, where the lens is coupled to at least one radiating element. The anisotropic lens advantageously allows for adjustment of the resultant output beamwidth, output beam direction, output beam polarization, output beam gain, and output beam sidelobe levels. In some embodiments, the anisotropic lens can be substantially cylindrical, disc-shaped, or rectangular. As used herein, and unless the context dictates otherwise, the term "output beam" is intended to include the radiation pattern power contours, received into or transmitted out from the antenna or antenna system described, due to an RF signal resulting from any electromagnetic-based form of communication.

Thus, in first aspect of the present invention, rotation of an anisotropic body (in particular a cylinder with a plurality of parallel short wires) provides a base station antenna with pattern reconfiguration (including transformation from one beam to multi-beam operation) and limited polarization agility.

In a second aspect of present invention, rotation of anisotropic body (in particular, cylinder with plurality of crossed short wires) provides a base station antenna with full polarization agility.

In a third aspect of present invention, independent rotation of two anisotropic bodies (in particular, inner cylinder with plurality of crossed short wires and outer hollow cylinder with plurality of parallel short wires) provides full pattern reconfiguration (including single- and multi-beam operation) and full polarization agility.

<FIG> is a simple embodiment in which a single spherical, anisotropic dielectric lens <NUM> has magnitude of DK (dielectric constant) oriented in the Y axis, as depicted by arrow <NUM>.

<FIG> depicts a beam 304A emanating from a single radiating element <NUM>, polarized in direction of arrow <NUM>, to emit an applied electric field, and passing through an anisotropic lens <NUM> also oriented to have a main DK in a Y direction <NUM>. At this orientation both the magnitude of the dielectric constant and the direction of the applied electric field from the radiating element are parallel in the vertical direction, and the resultant beam is horizontally relatively narrow.

<FIG> depicts a beam 304B emanating from a single radiating element <NUM>, polarized in direction of arrow <NUM>, to emit an applied electric field, and passing through an anisotropic lens <NUM>, oriented to have a main DK in an X direction <NUM>. At this orientation the magnitude of the DK and the direction of the applied electric field from the radiating element are orthogonal, and the resultant beam is horizontally relatively broader.

<FIG> depicts a cross-section of an anisotropic lens <NUM> showing orientation of substantially parallel fibers <NUM> in the Y direction, which can be rotated or moved along a plane that includes the fibers, either mechanically or electronically, to allow variable and remote adjustment of the beamwidth from a single polarization element. An exemplary lens of this type can be a spherical lens made from a light-weight polymer based material embedded with the conductive fibers.

<FIG> depicts a lens <NUM> having fibers <NUM> positioned in orthogonal directions, in this case the DK values of the lens are oriented in both +<NUM> and +<NUM> directions. This provides a solution for adjusting beamwidth without changing resulting polarization of the beam for a dual polarization element. In other examples different orientations of DK can be used to variably adjust the resultant polarization.

It is also contemplated that a given anisotropic lens can have multiple orientations of DK values. For example, <FIG> depicts a lens <NUM> comprising disc <NUM> with fibers <NUM>, and disc <NUM> with fibers <NUM>. As shown, the fibers on the two discs are orthogonal, forming X shaped orientations. Discs <NUM> and <NUM> could be positionally fixed relative to one another, or rotatable relative to one another.

<FIG> depicts a lens <NUM> having conductive fibers (not shown), collectively oriented along diagonal arrows <NUM> and <NUM>, and in some embodiments layered as in <FIG>. This is an example of an anisotropic lens that can be applied to a cross-polarized polarized element, which would permit changing beamwidth without changing polarization.

<FIG> depicts a lens assembly <NUM> that includes torus lens <NUM>, which has DK in the Y direction <NUM>, applied in front of multiple single-polarized radiating elements (805A-C) all polarized in the Y direction. When the lens <NUM> is rotated around the Z axis, the resultant beamwidth (not shown) from all elements is adjusted.

It is contemplated that lens <NUM> could be moved along horizontal and/or vertical planes to vary the resultant polarization. Anisotropic lenses with different shapes can be applied to variably adjust resultant polarization for single and dual-polarized elements and antennas. Similar principals can be applied to multi-beam antennas.

<FIG> depicts a single cylindrical anisotropic lens <NUM>, which has DK in the direction of arrow <NUM>, positioned in front of a single radiating element or antenna <NUM>. Mechanical or electronic rotation of lens <NUM> about the Y axis adjusts the beamwidth or other characteristics of the resulting beam (not shown). Lens <NUM> could, for example, have a single orientation magnitude of DK <NUM>.

<FIG> depicts a spherical anisotropic lens <NUM> positioned in front of multiple radiating elements or antennas 1003A, 1003B, 1003C. Lens <NUM> had conductive fibers <NUM> oriented as shown. Rotation or other movement of lens <NUM> concurrently adjusts the beamwidth or other characteristics of the resulting beam(s) (not shown).

<FIG> is similar to <FIG>, except that in this example, a single curved cylinder anisotropic lens <NUM>, which has DK in the direction of arrow <NUM>, is positioned in front of multiple radiating elements or antennas <NUM>, <NUM>. Mechanical or electronic rotation of lens <NUM> about the Y axis adjusts the beamwidth or other characteristics of the resulting beam(s) (not shown).

As should be apparent from the examples herein, individual anisotropic lenses of different shapes and combinations can be placed in front of single antenna elements, as well as multiple element antennas and radiating elements to satisfy specific requirements. Among other things, one or more anisotropic lenses can be used to simultaneously, or independently, adjust the resulting horizontal and vertical beamwidths, and/or other beam characteristics.

In particular, cylindrical or disc shaped anisotropic lenses can be used to variably adjust resultant horizontal or vertical beamwidth. <FIG> depicts an anisotropic cylindrical lens <NUM>, physically oriented in the Y axis, with DK oriented in the X axis. Lens <NUM> is applied (positioned in front of) radiating element <NUM> with linear polarization along the z direction. Due to the shape of lens <NUM> and its orientation, rotation of the lens <NUM> about the Y axis narrows the vertical beam <NUM> but has no effect on the horizontal beam.

Other shaped lenses with different DK orientations can be used depending on application. For example, <FIG> depicts a disc shaped anisotropic lens <NUM> applied to radiating elements <NUM>, <NUM>. Lens <NUM> is anisotropic with respect to arrow <NUM>, and can be rotated on different axes in order to adjust resultant vertical or horizontal beamwidth.

Anisotropic lenses can also be applied to a variety of antennas including radar, BSA, satellite and others. For example, anisotropic lenses can be applied to standard phased array antennas (BSA antennas typically used in telecommunications). Individual lenses can be applied to each individual radiating element of the phased array antenna, and all of the lenses can then be mechanically or electronically turned or rotated simultaneously or individually as needed in order to adjust resultant parameters of the antenna.

<FIG> depicts a phased array antenna <NUM> that includes multiple radiating elements 1401A, 1405A, 1410A, and 1415A, in front of which are positioned multiple spherical anisotropic lenses <NUM>, <NUM>, <NUM>, <NUM>, each with its DK oriented in the Y direction. Lenses <NUM>, <NUM>, <NUM>, <NUM> can be simultaneously rotated around the Z axis in order to adjust the resultant beamwidth (not shown) of the antenna <NUM>.

<FIG> depicts a phased array antenna <NUM> that includes multiple radiating elements <NUM>, <NUM>, <NUM>, <NUM>, in front of which are positioned multiple cylindrical anisotropic lenses, one with its DK oriented in the X direction 1501X, 1505X, 1510X, 1515X, and another in the Y direction 1501Y, 1505Y, 1510Y, 1515Y. The lenses can be rotated along their long axes in order to adjust the resultant beamwidth, rotation of the 1501Y, 1505Y, 1510Y, 1515Y lenses to adjust horizontal beam width, and rotation of the 1501X, 1505X, 1510X, 1515X lenses to adjust the vertical beamwidth (not shown).

It is also contemplated to use a single or multiple cylindrical anisotropic lenses (not shown) which are sized and dimensioned to receive beams from all elements of a phased array antenna.

<FIG> depicts two coplanar, anisotropic cylindrical lenses <NUM>, <NUM> placed in front of a phased array antenna <NUM> with elements 1603A, 1603B, 1603C, and 1603D, oriented in the Y axis. The lenses <NUM>, <NUM> have their DK oriented in the X or Z axes. As the lenses <NUM>, <NUM> are rotated (either mechanically or electronically) the resultant beam direction is changed. Use of multiple cylinders allows resulting beams to be steered more precisely.

It is also contemplated that a large isotropic lens can be used in conjunction with multiple, smaller anisotropic lenses to adjust resultant RF parameters of an antenna. <FIG> depicts a large spherical isotropic lens <NUM> positioned in front of multiple smaller anisotropic lenses 1705A, 1705B, 1705C, which are positioned in front of radiating elements 1710A, 1710B, 1710C, respectively a multibeam antenna.

<FIG> depicts a configuration similar to that of <FIG>, which includes a large isotropic lens <NUM> used in conjunction with multiple, smaller anisotropic lenses 1755A, 1755B, 1755C and radiating elements 1460A, 1760B, 1760C. Here, a controller (not shown) is configured to independently or simultaneously rotate lenses 1755A, 1755B, 1755C to adjust resultant beam parameters of an antenna.

In <FIG>, a reconfigurable Luneburg lens <NUM> (which can be spherical, cylindrical, or planar) uses at least one liquid dielectric liquid with a high dielectric constant. Differing amounts of the liquid can be inserted into the lens using micro-pipes, and resulting lenses can have different distributions of DK to form beams with different beamwidths / shapes. Another, more traditional way to move the liquids into the lens is using of pumps, or micropumps, such as the Bartels micropumps available from Mikrotechnik (see http://www. bartels-mikrotechnik. de/content/view/<NUM>/<NUM>/lang. Both electronic (electrowetting) or mechanical (with pumps) control methods can be used to transfer the dielectric liquid(s), and both are PIM-free.

Pipes can have uniform distribution inside the lens (to achieve quasi-homogeneous lens with resulting DK <NUM> - <NUM>) or can have increased concentration to the center ε= <NUM> - (r/R)<NUM> for multi-layer Luneburg Lens (R is radius of the lens). The center might or might not be filled with a dielectric liquid. Table <NUM> below show examples of these dielectrics with DK from about <NUM> to about <NUM>. All liquids shown in Table <NUM> are electrostatically movable, i.e. can be moved (into lens or out of lens) by application of static electrical field (so called electrowetting). Also, all of them has low PIM (passive intermodulation) which is beneficial for wireless communications applications, as <NUM> / LTE.

<FIG> depicts a reconfigurable antenna <NUM> having a lens <NUM> comprising multiple concentric plastic pipes 1902A, 1902B, 1902C positioned about central core <NUM>, a reservoir <NUM>, pumps <NUM>, and a radiator <NUM>. All of a dielectric liquid is in the reservoir <NUM>, and the pipes are delineated with dotted lines. The lens <NUM> is homogeneous with low DK (<NUM> - <NUM>) and low focusing ability, so the radiation pattern has a wide beam <NUM>. The core <NUM> can include the dielectric liquid or another dielectric material.

In <FIG> the pipes 1902A and 1902B of lens <NUM> contain a dielectric liquid (shown with solid line) that was pumped in from the reservoir (shown only in <FIG>). The resulting (average) DK inside lens <NUM> is higher, and the beamwidth is narrower. In <FIG>, pumps <NUM> and reservoir <NUM> (or electronic circuits in the case of electrowetting) are not shown for simplicity.

In <FIG> all of the pipes 1902A, 1902B, 1902C are filled with the dielectric liquid. The resulting DK inside the lens <NUM> is higher, and its distribution is approximately the same as required for a multi-layer Luneburg Lens: ε= <NUM> - (r/R)<NUM>, resulting in a narrow beam <NUM> with low sidelobes. 3dB beamwidth in this case is approximately equal 30λ/ R [deg].

In <FIG> all of the pipes 1902A, 1902B, 1902C are filled with the dielectric liquid. Antenna <NUM> has five radiators 1903A, 1903B, 1903C, 1903D, and 1903E, which emit electromagnetic waves that are beam formed through lens <NUM> to produce <NUM> narrow dual-polarized beams 1920A, 1920B, 1920C, 1920D, and 1920E, respectively. This provides high capacity coverage <NUM>. For comparison, one wide beam <NUM>, which would be formed by the central element with none of the pipes activated by being filled with the dielectric liquid, has a relatively lower low capacity coverage for the same geographic area.

Antenna <NUM> of <FIG> could advantageously be used for wireless / cellular communications, in which the antenna can cover the same geographic area with one wide beam (low traffic/low capacity) or with multiple beams (higher traffic/ higher capacity). Accordingly, adaptive beamforming can be achieved which is especially desirable for <NUM> applications. Single or dual polarized radiators could be used in any of the embodiments of <FIG>).

It is also contemplated, that asymmetrical micro-pipes activations and other adaptive beamforming methods could also be used, including null forming in the direction of interference.

In other contemplated embodiments, micro-pipes can be used instead of wires / conductive fibers for antenna solutions similar to configurations shown in <FIG>.

<FIG> is a horizontal cross-section of a spherical, reconfigurable, dual-polarized lens <NUM>. Empty pipes are depicted by dotted lines <NUM>, provide relatively weak polarization along arrows <NUM>, <NUM>, and result in formation of a relatively wide beam. In <FIG>, the pipes are filled with a dielectric liquid, depicted by solid lines <NUM>, and provide relatively weak polarization along arrows <NUM>, <NUM>, which results in formation of a relatively narrow beam.

In <FIG> a reconfigurable base station antenna <NUM> includes an anisotropic cylindrical lens <NUM> with motor <NUM>, making available rotation lens <NUM> about its axis of rotation <NUM>. Antenna <NUM> also contains three vertical columns (linear arrays) <NUM>, <NUM>, <NUM> of radiators <NUM> which have linear slant +/-<NUM>° polarization. Radiators <NUM> are connected through phase shifters <NUM> to input connectors <NUM> (total <NUM> connectors). Phase shifters <NUM> are used beam tilting of each of columns <NUM>, <NUM>, <NUM> and placed on the rear side of reflector <NUM>.

<FIG> is a horizontal cross-sectional view of the reconfigurable base station antenna of <FIG>. Conductive fibers <NUM> with length <NUM> ~ <NUM>. 1λ are depicted inside lens <NUM>, all oriented in <NUM>° direction. For wideband operation, conductive fibers <NUM> can have different length. To support wires <NUM>, light weight foam polymer <NUM> is used with low dielectric constant (close to <NUM>). Matching layer <NUM> (optional) provides reduction of reflection from lens <NUM> when it is rotated to position close to <NUM>°. Radio <NUM> is connected to central column <NUM>, other columns <NUM>, <NUM> are not connected. Arrow <NUM> shows direction of radiation.

With lens position shown in <FIG>, in direction of radiation <NUM>, lens has dielectric constant close to <NUM>, because wires <NUM> are orthogonal to vector E of column <NUM>. Lens does not focus EM waves from column <NUM>. Column <NUM> has wide azimuthal beam <NUM> (<FIG>), covering <NUM>° sector in three sectored cell site (as shown in <FIG>, where <NUM> is hexagonal cell). In <FIG>, cell <NUM> sectorization is shown for a <NUM>-sectored cell.

In <FIG>, 10dB azimuth beam <NUM> has 10dB azimuth width of about <NUM>°. With lens <NUM> rotation from <NUM>° to <NUM>°, 10dB azimuth beamwidth can be gradually adjusted from about <NUM>° to about <NUM>° and antenna gain is increased by 5dB.

In <FIG>, lens <NUM> is rotated to <NUM>° position, and in this position, wires <NUM> are mostly parallel to vectors E of all three columns, and lens <NUM> does focus EM waves from columns <NUM>, <NUM>, <NUM>, resulting in three narrower beams. Three radios <NUM>, <NUM>, <NUM> cover <NUM>° sector <NUM> of hexagonal cell <NUM> with <NUM> times increased capacity compare to <FIG>.

As shown in <FIG>, the three <NUM>-beam base station antenna of <FIG> delivers three beams to a <NUM>° sector. Central beam <NUM> is symmetrical and little bit narrower compare to outer beams <NUM>, <NUM> which are slightly asymmetrical. Together, beams <NUM>,<NUM>, <NUM> deliver coverage of cell sector <NUM> close to optimal, with minimal interlace <NUM> and gaps <NUM>.

Polarization diversity / MIMO performance does suffer with rotation of cylinder <NUM> from <NUM> to <NUM>°, because orthogonal polarization is maintained, from +/-<NUM> orthogonal linear to R-L circular polarization. With R-L circular polarization, MIMO performance can be improved because circular polarization providesbetter in-building penetration, which is especially important for high (<NUM>) frequencies.

With rotation of cylinder <NUM>, antenna vertical pattern stays practically unchanged (the same beam tilt, the same elevation beamwidth). Equally, azimuth beamwidth also does not change with elevation beam tilt, even with heavy tilts (<NUM>°+). This helps to manage the same geographic coverage when antenna is reconfigured from one wide beam to three narrow beams.

<FIG> depict another embodiment in which a different kind of artificial anisotropic dielectric is used. Antenna assembly is the same as in <FIG>, but cylindrical lens <NUM> is different and it has <NUM> functions: <NUM>) focusing the beam in the azimuth plane; <NUM>) works as a polarizer. With rotation of cylinder <NUM>, azimuth beamwidth stays the same, but antenna polarization is changed from +/-<NUM>° (rotation angle is <NUM>°) to circular (LHCP +RHCP, rotation angle is +/-<NUM>°). Conductive fiber particles in cylinder <NUM> have shape of crosses with +/-<NUM>° orientation to horizon, with the length of arms <NUM> ~ <NUM>. 1λ, and these crosses are parallel to each other, as shown in <FIG>. Radiation elements of antenna (+/-<NUM>° polarized) are schematically shown as big crosses <NUM>, and one column of elements is shown for simplicity. In <FIG>, rotation angle <NUM>° is shown. Resulting polarization of antenna is linear slant +/-<NUM>° in this case, because direction of cross arms <NUM> coincide with +/-<NUM>° linear polarization of elements <NUM>. In <FIG>, rotation angle <NUM>° is shown. Resulting polarization of antenna is circular (LHCP +RHCP, or R-L basis) in this case, because vertical component of vector E has <NUM>° phase shift compare to its horizontal component. This phase shift is controlled by concentration of crosses <NUM> in the lens <NUM>. In addition to crosses <NUM>, lens <NUM> can be also filled with isotropic dielectric <NUM> (for example, with artificial dielectric by <CIT>) to provide required azimuth beamwidth. Antenna azimuth beamwidth is not changed with rotation, because projections of vector E on crossed arms stay the same, invariant to rotation of lens <NUM>. Note, that with others angles of rotation, two orthogonal elliptical polarizations are provided, with axial ratio from <NUM> to <NUM>.

Depending on the MIMO environment, different orthogonal polarization basis (linear, elliptical or circular) can be selected to improve MIMO performance. Antenna with <NUM> circular polarizations (LHCP +RHCP) have benefits compare to linear polarization, as reported in Analysis of MIMO Diversity Improvement Using Circular Polarized Antenna <NPL>.

Not only crosses (as shown in <FIG>), but others shapes of conductive particles can be used in anisotropic lenses for polarization agility, including, for example, conductive rings (circular, square, diamond) and discs. In some embodiments, separated slant conductive fibers <NUM>, oriented orthogonally, can be used in lens <NUM>, as shown in <FIG>.

In <FIG>, <FIG>, another anisotropic cylindrical lens <NUM> is shown which can provide both antenna pattern and polarization reconfigurability, and it contains two coaxial cylinders. Inner cylinder <NUM> with crosses <NUM> is responsible for polarization agility, and it is rotated by motor <NUM>. Hollow cylinder <NUM> with vertical fibers <NUM> is responsible for pattern agility, and it is rotated by motor <NUM>. Antenna assembly (not shown) is similar to presented in <FIG>, but the lens in <FIG> and <FIG> is different, and two motors are used instead of the one in <FIG>). In <FIG>, an exploded isometric view is schematically shown. In <FIG>, cross-sectional (horizontal and vertical) views of anisotropic lens <NUM> are shown. In this embodiment, antenna reconfigurability is obtained by moving (rotation) of two anisotropic bodies.

Performance of cylindrical lens <NUM> is similar to described above (<FIG>, <FIG>): with rotation of lens <NUM> by motor <NUM>, azimuth beam width can be changed and number of beams can be changed. With rotation of lens <NUM> by motor <NUM>, orthogonal polarization basis of the antenna can be changed from linear +/-<NUM>° to circular R-L (similar as was described above for <FIG>.

Antenna shown in <FIG>, <FIG> has several degrees of freedom:.

In embodiments of <NUM> - 29A, 29B, there may be more or fewer than three columns of radiating elements.

Instead of conductive (metal) particles, other material(s) can be used to build anisotropic materials, including non-conductive fibers with high dielectric constant, oriented mostly in one (or two orthogonal) directions.

In another embodiment, parallel carbon fibers can be used for antenna gain adjustment without changing antenna pattern. When carbon fibers are oriented orthogonal to vector E, antenna gain is maximal and when they are oriented parallel to vector E, antenna gain is minimal.

Particles can be distributed uniformly in dielectric body (can be low density foam) to form homogeneous lens, or can have more concentration in central area to help wideband matching. Special distribution of density (for example, Luneburg) is also possible.

Performance of the cylindrically shaped anisotropic dielectric bodies described should be interpreted generically to illustrate proposed apparatus and methods. Other shapes of anisotropic dielectric body (as spherical, truncated spherical, hemispherical, spheroidal) can be used for different applications. Arrays of spherical and / or cylindrical anisotropic dielectric bodies can also be used.

Anisotropic dielectric and magnetic lenses discussed herein can be made using fibers, flakes, discs or other materials having magnetic properties, provided the resulting lenses can be oriented to produce required resultant DK orientation. Preferred materials include a polymer or foam base, embedded with conductive fibers/flakes/discs or ferro-electric materials. Such conductive fibers/flakes/discs must be oriented in a specific direction, or in multiple directions to produce the required resultant DK orientation. If fibers are oriented in an X, Y or Z axis, then DK will be oriented in the X, Y, or Z axis, respectively.

Another possibility is to use standard isotropic materials (such as Matsing materials), and then add anisotropic properties to such materials. One example is to layer an isotropic material with anisotropic material in order to create anisotropic properties in one part of the overall material. Typically Matsing materials are chaotically (randomly) distributed, and thus a combination can be used, where <NUM>% of the material is randomly distributed and <NUM>% of the material has a direction (anisotropic).

By mixing materials, one can adjust the overall value of dielectric of the lens. Whereas orientating conductive fibers of a single material would produce a lens with an overall dielectric constant range from <NUM>-<NUM>, a mixed material could have a dielectric constant ranging from <NUM>-<NUM>, or any value between <NUM> and <NUM>.

Lenses can be placed in front of elements or antennas, and rotated or otherwise moved in one or more of their X Y Z axes to adjust polarization and other beam parameters. It is contemplated that adjustable parameters include beamwidth, beam-direction, beam polarization, beam gain, and beam sidelobe level.

A single anisotropic lens can be applied to (placed in front of) one or more radiating elements or antennas, with the radiating elements or antennas operative independently or in an arrayed fashion. Multiple anisotropic lens can also be applied to (placed in front of) one or more individual radiating elements or antennas, with the various lenses operating independently or in an arrayed fashion. Beams from one or more radiating elements or antennas can pass through anisotropic lenses serially or in parallel.

<FIG> is a flowchart depicting a method <NUM> of variably adjusting a characteristic of a first beam emitted by a first radiating element (step <NUM>). The method <NUM> comprises installing an anisotropic lens in front of a first radiating element (step <NUM>), and moving at least one of the lens and the antenna to adjust the characteristic (step <NUM>).

In some embodiments, method <NUM> further includes at least one of using multiple pieces of a first conductive material to achieve an anisotropic effect within the lens (step 3002A), using different orientations of multiple pieces of a conductive material to achieve an anisotropic effect within the lens (step 3002B); and modifying an existing installation where the first radiating element has been previously deployed (Step 3002C).

In some embodiments, method <NUM> further includes at least one of: adjusting the characteristic further adjusts at least one of a beamwidth, a beam-direction, a beam polarization, a beam gain, and a beam sidelobe level (step 3003A); mutually orienting the radiating element with respect to the lens such that the radiating element sequentially occupies different positions about a meridian of the lens (step 3003C); mutually orienting the first radiating element with respect to the lens by mechanically moving the lens relative to the first radiating element (step 3003B); and modifying the characteristic with respect to both the first beam from the first radiating element, and a second beam from a second radiating element (step 3003D).

The discussion herein provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

In some embodiments, the numbers expressing quantities of components, properties such as orientation, location, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term "about. " Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. The use of any and all examples, or exemplary language (e.g. "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

Claim 1:
A communication system, comprising:
a first lens (<NUM>) configured to be anisotropic with respect to dielectric permittivity;
a first radiating element (<NUM>) mutually positionable with respect to the lens (<NUM>) such that the first radiating element (<NUM>) can alternatively direct a first beam (304A) through the lens (<NUM>) along a first orientation (<NUM>) having a first dielectric permittivity, and a second beam (304B) through the lens (<NUM>) along a second orientation (<NUM>) having a different, second dielectric permittivity;
wherein the first orientation (<NUM>) is different than the second orientation (<NUM>);
wherein the first beam (304A) and the second beam (304B) are produced by the first radiating element (<NUM>); and
wherein the first lens (<NUM>) is configured such that the first and second beams (304A; 304B) have at least one of (i) different vertical and horizontal beamwidths and (ii) different polarizations.