ELLIPTICITY REDUCTION IN CIRCULARLY POLARIZED ARRAY ANTENNAS

Information

  • Patent Application
  • 20150002335
  • Publication Number
    20150002335
  • Date Filed
    June 26, 2014
    10 years ago
  • Date Published
    January 01, 2015
    9 years ago
Abstract
Ellipticity reduction in circularly polarized array antennas is provided herein. An antenna array may include a processor that is configured to control a plurality of elements, each of the plurality of elements producing an elliptically polarized wave having an eccentricity value, the elliptically polarized wave traveling along a direction of propagation, wherein at least a portion of the plurality of elements are incrementally clocked around their direction of propagation, so that a combined output of the plurality of elements is substantially circularly polarized.
Description
FIELD OF THE INVENTION

The present technology generally relates to circularly polarized antennas, and more specifically, but not by way of limitation, to an exemplary antenna having an array of circularly polarized elements that are clocked that the output of the antenna has a minimal ellipticity (e.g., eccentricity), resulting in a more purified circular polarization of the antenna.


BACKGROUND

Circular polarization occurs when elements of an antenna produce an electromagnetic wave (e.g., generated field) that varies rotationally in a direction of propagation. More specifically, circular polarization is comprised of two orthongal and equal magnitude linear polarized waves which are 90 degrees out of phase relative to one another. In most cases, the circular behavior of the electromagnetic wave appears more elliptical that circular, producing what is known as elliptical polarization. In fact, circular polarization and linear polarization are often considered special cases of elliptical polarization. In general, elliptical polarization is defined by an eccentricity, which is a ratio of the major and minor axis amplitudes of the horizontal and vertical waves. That is, circular polarization of an electromagnetic wave can be broken down into both horizontal and vertical components. The eccentricity is introduced when the horizontal and vertical components of the fields are not purely orthogonal to one another, equal, or when the phase shift is other than 90 degrees.


It will be understood that an elliptically polarized wave having an eccentricity of approximately one (1) is what is referred to as a pure circularly polarized wave. In contrast, as the eccentricity of the elliptically polarized wave increases, the wave begins to look more like linear polarization.


SUMMARY

According to some embodiments, the present technology is directed to an antenna array, comprising: (a) a plurality of elements, each of the plurality of elements producing an elliptically polarized wave having an eccentricity value (other than one), the elliptically polarized wave traveling along a direction of propagation, wherein at least a portion of the plurality of elements are incrementally clocked around their direction of propagation, so that a combined output of the plurality of elements is substantially circularly polarized.


According to some embodiments, the present technology is directed to method, comprising: (a) controlling each of a plurality of elements, wherein each of the plurality of elements produce an elliptically polarized wave having an eccentricity value other than one, the elliptically polarized wave traveling along a direction of propagation, wherein at least a portion of the plurality of elements are incrementally clocked around their direction of propagation, so that a combined output of the plurality of elements is substantially circularly polarized.


According to some embodiments, the present technology is directed to a wireless device, comprising an antenna array, the antenna array comprising a plurality of elements, each of the plurality of elements producing an elliptically polarized wave having a polarization vector that is perpendicular to a major access of the elliptically polarized wave, at least a portion of the plurality of elements being incrementally clocked relative to one another such that an ellipticity of a combined output of the antenna array is reduced.


According to some embodiments, the present technology is directed to an antenna array, comprising: (a) a processor; and (b) a memory for storing executable instructions, the processor executing the instructions stored in memory to: (i) control a plurality of elements, each of the plurality of elements producing an elliptically polarized wave having an eccentricity value, the elliptically polarized wave traveling along a direction of propagation, wherein at least a portion of the plurality of elements are incrementally clocked around their direction of propagation, so that a combined output of the plurality of elements is substantially circularly polarized, wherein each of the plurality of elements: (1) is associated with a feed; and (2) comprises a compensating line length in the feed that compensates for a phase shift present in the combined output, caused by clocking of the plurality of elements.





BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the present technology are illustrated by the accompanying figures. It will be understood that the figures are not necessarily to scale and that details not necessary for an understanding of the technology or that render other details difficult to perceive may be omitted. It will be understood that the technology is not necessarily limited to the particular embodiments illustrated herein.



FIG. 1A is a schematic diagram of an exemplary a linear antenna having an array of elliptically polarized elements, constructed in accordance with the present technology;



FIG. 1B is a schematic diagram of exemplary system that comprises a plurality of elliptically polarized antennas;



FIG. 1C is a perspective view of a three dimensional device that includes a plurality of antenna arrays of the present technology;



FIG. 1D is a schematic view of a 4×4 antenna array where at least a portion of a plurality of elements are clocked relative to one another.



FIG. 2 is a block diagram of an exemplary wireless device, such as a wireless radio that incorporates a circularly polarized antenna array, such as the array of FIG. 1A.



FIG. 3 is a block diagram of another exemplary wireless device, such as a wireless radio that incorporates a circularly polarized antenna array, such as the array of FIG. 1A.



FIG. 4 is a method for reducing ellipticity in circularly polarized antenna arrays.



FIG. 5 illustrates an exemplary computing system that may be used to implement embodiments according to the present technology.





DESCRIPTION OF EXEMPLARY EMBODIMENTS

While this technology is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail several specific embodiments with the understanding that the present disclosure is to be considered as an exemplification of the principles of the technology and is not intended to limit the technology to the embodiments illustrated.


It will be understood that like or analogous elements and/or components, referred to herein, may be identified throughout the drawings with like reference characters. It will be further understood that several of the figures are merely schematic representations of the present technology. As such, some of the components may have been distorted from their actual scale for pictorial clarity.


The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the technology. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.


It will be understood that like or analogous elements and/or components, referred to herein, may be identified throughout the drawings with like reference characters. It will be further understood that several of the figures are merely schematic representations of the present technology. As such, some of the components may have been distorted from their actual scale for pictorial clarity.


Array antennas using elliptically polarized elements often exhibit polarization ellipticity significantly greater than desired. Indeed, most antenna elements produce waves that are slightly, if not more, elliptical than purely circular. As mentioned above, circular and linear polarization are often considered as special cases of elliptical polarization. Ellipticity in radiation produced by polarized antennas may cause deleterious effects such as polarization mismatch, loss, or compromised isolation. For example, when two antennas (each with an array of polarized antennas) are transmitting to one another and the radiated fields produced by array elements of either one of the antennas are more elliptical (trending to linear polarization) rather than purely circular, the radiated fields may interfere with one another.


Often times, manufacturers struggling to remedy ellipticity of antennas may attempt to produce circularly polarized elements that individually produce very low and often impractical levels of ellipticity, when the ultimate desire is to achieve circular polarization for an output of the antenna as a whole. That is, trying to cure the eccentricity behavior of the antenna by purifying the radiated fields with individual circularly polarized elements is costly and often impractical.


An antenna array is typically fabricated from identical polarized elements distributed on a substrate or within a dielectric material. For an antenna array intended to produce circular polarization, each element exhibits some degree of elliptical polarization, compromising the resulting array polarization.


Rather than attempting to minimize ellipticity and maximize the circular polarization of an antenna by changing the behavior of individual array elements, the present technology provides an array of elliptically polarized elements where each elliptically polarized element is physically rotated (clocked) relative to the other polarized elements in the array. Each of the polarized elements produces an elliptically polarized wave that travels along a direction of propagation. This direction of propagation is substantially oriented to a central axis of the polarized element Additionally, the direction of propagation is perpendicular to the primary polarization axis of the elliptical wave (electric field direction) produced by the element.


At least a portion of the plurality of elements are incrementally clocked around their direction of propagation roll axes so that a combined output of the plurality of elements is substantially circularly polarized. In some embodiments, all adjacent elements of an antenna array are clocked relative to one another. In other embodiments, some polarized elements of an antenna array are clocked identically to one another such that only a portion of the polarized elements are clocked.


Thus, a plurality of elements that each produces a wave that is elliptical in nature may be arranged in such a way that the aggregate behavior of these circularly polarized elements performs as circular polarization. That is, the combined output of the clocked plurality of elements is substantially circularly polarized.


Typically, the distribution of these elliptically polarized elements in an exemplary antenna is uniform or consistent through 360 degrees. The physical rotation (roll axis) of elements is referred to as “clocking” of elements. In some instances the clocking or angular offset between elements is calculated by determining a total number of elements and dividing 360 degrees by the total number of circularly polarized elements.


An angular offset for example, may include a first element that is set to zero degrees, while an adjacent element is clocked to 90 degrees. The angular offset would be 90 degrees.



FIG. 1A illustrates an exemplary array 100 that includes four elements 105-120 that are arranged onto a substrate 125. The elements 105-120 would be clocked at 90 degrees relative to one another. To clock the four elements, a reference element 105 is chosen and assigned a degree of zero. The next element 110 in the array is clocked to 90 degrees, leaving the remaining elements 115 and 120 clocked at 180 and 270 degrees, respectively. An output of the antenna 100, which includes an aggregated polarization of all the elements averages to a nearly circular polarization. While the example provided above contemplates the use of four elements, it will be understood that any number of elements may be utilized. Thus, the clocking of an N number of elements is calculated as 360/N. In another exemplary embodiment, the antenna may include an array of 12 elements clocked with 120-degree steps. Also, while the elements of the array of FIG. 1A are illustrated being disposed in a linear array configuration, the elements may be arranged in other configurations such as planar, three dimensional object, circular, rectangular, elliptical, offset, alternating, and/or other configurations that would be known to one of ordinary skill in the art. Additionally, while the plurality of elements of the array are illustrated as extending from the same two dimensional surface of the substrate 125, the plurality of elements may also be disposed on a three dimensional surface, such as the array of FIG. 1C. FIG. 1C illustrates an example three dimensional device 150 such as a building or other structure, or even a wireless radio housing. The device 150 includes a plurality of antenna arrays 155A-C. The antenna arrays 155A-C may each comprise a plurality of clock elements, similarly to the exemplary array 100 of FIG. 1A. It will be understood that other types of arrays and combinations of array may likewise be utilized in accordance with the present technology.


Returning back to FIG. 1A, as will be discussed in greater detail below, each of the elements may be associated with a feed, such as feed 140 of element 115. The feed 140 may comprise a compensating line length that is used to mitigate, reduce, and/or eliminate a phase shift that created due to the clocking of the elements.


The rotation or clocking of circularly polarized elements introduces a phase shift into the summation network (the combined output of the antenna). The present technology may mitigate or compensate for this phase shift with, for example, an additional compensating line length in the feed) associated with individual elements. This correction maintains the array distribution as if the clocking had not been performed, while reducing array ellipticity to an acceptable level due to the actual clocking. The compensating line length induces a phase correction, which mitigates or reduces the phase shift due to the element clocking.


It will be understood that in addition to selectively adjusting line lengths for each element, the use of discreet components, such as capacitors or inductors, may also be utilized to induce a compensating phase shift. Indeed, many methods or devices for introducing a phase shift compensation, such as a compensating time delay may be utilized. In some instances, the antenna may include logic that is executed by a processor that induces a phase shift compensation by inducing a time delay. These various methods and devices are also referred to collectively and individually as different means for compensating for a phase shift in the combined output, caused by clocking of the plurality of elements.


Also, circularly polarized antennas of the present technology may be advantageously leveraged in instances where signal isolation is desirable. For instance, circularly polarized antennas of the present technology may be used in radios where chain-to-chain isolation is required. By ensuring that you have purity in circular polarization, and you have alternating right and left circularly polarized chains, the purity of these chains at 90 degrees directly translates into isolation of those chains.


While the above description contemplates addressing polarization of elements at a peak of the beam as illustrated in FIG. 1A, the present technology may likewise be applied to address polarization elsewhere, for example, at 90 degrees.



FIG. 1B illustrates an exemplary system 100 that comprises a plurality of circularly polarized antennas 1-4, where each antenna broadcasts in a fixed direction over a coverage area in such a way that signals broadcast by each of the plurality of circularly polarized antennas are isolated to minimize signal overlap. Each of the antennas, such as antenna 1, may include an array 135 of clocked elements.


In order to eliminate the need for explicit client channel state information (CSI) feedback and maintain compatibility with legacy Single User MIMO (SU-MIMO) 802.11 clients, circularly polarized antennas/streams are isolated in unique fixed directions with limited or no radiation overlap. It is noteworthy that in some embodiments, the plurality of circularly polarized antennas are allowed to overlap, such that the signals broadcast by adjacent antennas slightly overlap. Such overlapping of transmissions by antennas are common in devices such as multiple-input-multiple-output (MIMO) wireless devices, and specifically Multi-User MIMO (MU-MIMO) devices. FIG. 1D is another example array 170 that comprises rows and columns of elements. As an example, a first row includes elements 170A-D, where element 170A is the reference element that is set to zero degrees, with each adjacent element (moving left to right) is clocked approximately 90 degrees. In this embodiment, only horizontally adjacent and diagonally adjacent elements are clocked relative to one another. That is, the elements in row 175A are all referenced to zero degrees. Each of the remaining columns 175B-D are likewise comprised of identically clocked elements. Thus, in this embodiment, only a portion of adjacent elements are clocked relative to one another, while some adjacent elements, such as those that are vertically aligned with one another are not clocked relative to one another.



FIG. 2 is a block diagram of an exemplary wireless device, such as a wireless radio 200 that incorporates a circularly polarized antenna array 205, such as the array of FIG. 1A. The circularly polarized element array 205 is controlled by a processor 210. The wireless device 200 also comprises a memory 215 for storing executable instructions that are executable by the processor 210 to control the array 205, such as causing the elements of the array to transmit and/or receive signals. As mentioned above, the clocking of the elements in the array 205 may induce a phase shift in the combined output of the array 205. In some embodiments, phase shift logic 220 is stored in the memory 215 and is execute by the processor 205 to mitigate, reduce, and/or eliminate the phase shift to an acceptable level.



FIG. 3 is a block diagram of another exemplary wireless device, such as a wireless radio 300 that incorporates a circularly polarized antenna array 305, such as the array of FIG. 1A. This device is constructed similarly to the device of FIG. 2, with the exception that the wireless device 300 includes a capacitor and/or inductor 330 that are configured to mitigate, reduce, and/or eliminate the phase shift in the combined output of the array 305. More specifically, the processor 315 may control the capacitor and/or inductor 330 in such a way that an output of the capacitor and/or inductor 330 causes a mitigation, reduction, and/or elimination of the phase shift. It will be understood that the processor 315 may use a combination of capacitor and/or inductor 330 functions as well as execution of phase shift logic 325 to compensate for the phase shift in the combined output of the array 305.



FIG. 4 is a flowchart of an exemplary method executed by, for example, the wireless radio/device of FIG. 2. The method may comprise controlling 405 each of a plurality of elements. As mentioned above, each of the plurality of elements produce an elliptically polarized wave having an eccentricity value. The plurality of elements are incrementally clocked relative to one another such that a primary polarization axis of each element is pointed in a unique direction. In detail, a combined output of the plurality of elements is substantially circularly polarized due to the clocking of the elements.


Next, the method comprises detecting 410 a phase shift in the combined output of the array. Again, the physical clocking of the elements of the array may induce a phase shift that causes interference in the signals transmitted and/or receive by the wireless device. Mitigation, reduction, or elimination of this phase shift will reduce this noise/interference.


If a phase shift is detected, the method comprises compensating 415 for a phase shift present in the combined output, caused by clocking of the plurality of elements.



FIG. 5 illustrates an exemplary computing device 500 that may be used to implement an embodiment of the present systems and methods. The system 500 of FIG. 5 may be implemented in the contexts of the likes of computing devices, networks, servers, or combinations thereof. The computing device 500 of FIG. 5 includes a processor 510 and memory 520. Memory 520 stores, in part, instructions and data for execution by processor 510. Memory 520 may store the executable code when in operation. The system 500 of FIG. 5 further includes a mass storage device 530, portable storage device 540, output devices 550, input devices 560, a graphics display 570, and peripheral devices 580. The components shown in FIG. 5 are depicted as being connected via a single bus 590. The components may be connected through one or more data transport means. Processor 510 and memory 520 may be connected via a local microprocessor bus, and the mass storage device 530, peripheral device(s) 580, portable storage device 540, and graphics display 570 may be connected via one or more input/output (I/O) buses.


Mass storage device 530, which may be implemented with a magnetic disk drive or an optical disk drive, is a non-volatile storage device for storing data and instructions for use by processor 510. Mass storage device 530 can store the system software for implementing embodiments of the present technology for purposes of loading that software into memory 520.


Portable storage device 540 operates in conjunction with a portable non-volatile storage medium, such as a floppy disk, compact disk or digital video disc, to input and output data and code to and from the computing system 500 of FIG. 5. The system software for implementing embodiments of the present technology may be stored on such a portable medium and input to the computing system 500 via the portable storage device 540.


Input devices 560 provide a portion of a user interface. Input devices 560 may include an alphanumeric keypad, such as a keyboard, for inputting alphanumeric and other information, or a pointing device, such as a mouse, a trackball, stylus, or cursor direction keys. Additionally, the system 500 as shown in FIG. 5 includes output devices 550. Suitable output devices include speakers, printers, network interfaces, and monitors.


Graphics display 570 may include a liquid crystal display (LCD) or other suitable display device. Graphics display 570 receives textual and graphical information, and processes the information for output to the display device.


Peripherals 580 may include any type of computer support device to add additional functionality to the computing system. Peripheral device(s) 580 may include a modem or a router.


The components contained in the computing system 500 of FIG. 5 are those typically found in computing systems that may be suitable for use with embodiments of the present technology and are intended to represent a broad category of such computer components that are well known in the art. Thus, the computing system 500 can be a personal computer, hand held computing system, telephone, mobile computing system, workstation, server, minicomputer, mainframe computer, or any other computing system. The computer can also include different bus configurations, networked platforms, multi-processor platforms, etc. Various operating systems can be used including UNIX, Linux, Windows, Macintosh OS, Palm OS, and other suitable operating systems.


Some of the above-described functions may be composed of instructions that are stored on storage media (e.g., computer-readable medium). The instructions may be retrieved and executed by the processor. Some examples of storage media are memory devices, tapes, disks, and the like. The instructions are operational when executed by the processor to direct the processor to operate in accord with the technology. Those skilled in the art are familiar with instructions, processor(s), and storage media.


It is noteworthy that any hardware platform suitable for performing the processing described herein is suitable for use with the technology. The terms “computer-readable storage medium” and “computer-readable storage media” as used herein refer to any medium or media that participate in providing instructions to a CPU for execution. Such media can take many forms, including, but not limited to, non-volatile media, volatile media and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as a fixed disk. Volatile media include dynamic memory, such as system RAM. Transmission media include coaxial cables, copper wire and fiber optics, among others, including the wires that comprise one embodiment of a bus. Transmission media can also take the form of acoustic or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, a hard disk, magnetic tape, any other magnetic medium, a CD-ROM disk, digital video disk (DVD), any other optical medium, any other physical medium with patterns of marks or holes, a RAM, a PROM, an EPROM, an EEPROM, a FLASHEPROM, and any other memory chip or data exchange adapter, a carrier wave, or any other medium from which a computer can read.


Various forms of computer-readable media may be involved in carrying one or more sequences of one or more instructions to a CPU for execution. A bus carries the data to system RAM, from which a CPU retrieves and executes the instructions. The instructions received by system RAM can optionally be stored on a fixed disk either before or after execution by a CPU.


Computer program code for carrying out operations for aspects of the present technology may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).


The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present technology has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form 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 invention. Exemplary embodiments were chosen and described in order to best explain the principles of the present technology and its practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.


Aspects of the present technology are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. 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 program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.


These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.


The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.


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 technology. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, 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 combinations of special purpose hardware and computer instructions.


While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. The descriptions are not intended to limit the scope of the technology to the particular forms set forth herein. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments. It should be understood that the above description is illustrative and not restrictive. To the contrary, the present descriptions are intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the technology as defined by the appended claims and otherwise appreciated by one of ordinary skill in the art. The scope of the technology should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.

Claims
  • 1. An antenna array, comprising: a plurality of elements, each of the plurality of elements producing an elliptically polarized wave having an eccentricity value, the elliptically polarized wave traveling along a direction of propagation, wherein at least a portion of the plurality of elements are incrementally clocked around their direction of propagation, so that a combined output of the plurality of elements is substantially circularly polarized.
  • 2. The antenna array according to claim 1, wherein the means for compensating for a phase shift in the combined output comprises the processor executing phase shift logic stored in memory to modify the combined output of the plurality of elements to remove or reduce the phase shift.
  • 3. The antenna array according to claim 1, wherein the means for compensating for a phase shift in the combined output comprises the processor controlling a capacitor or an inductor to modify the combined output of the plurality of elements to remove or reduce the phase shift, the capacitor or inductor being electrically coupled to the plurality of elements.
  • 4. The antenna array according to claim 1, wherein the processor further executes the instructions to detect the phase shift in the combined output.
  • 5. The antenna array according to claim 4, further comprising a means for compensating for a phase shift in the combined output, caused by clocking of the plurality of elements.
  • 6. A wireless device, comprising an antenna array, the antenna array comprising a plurality of elements, each of the plurality of elements producing an elliptically polarized wave having a polarization vector that is perpendicular to a major access of the elliptically polarized wave, at least a portion of the plurality of elements being incrementally clocked relative to one another such that an ellipticity of a combined output of the antenna array is reduced.
  • 7. The wireless device according to claim 6, wherein the wireless device is a single user multiple-input-multiple-output device.
  • 8. The wireless device according to claim 6, wherein the wireless device is a multiple user multiple-input-multiple-output device.
  • 9. A method executed within a wireless device that comprises a processor and a memory, the processor executing the instructions stored in memory to perform the method, comprising: controlling each of a plurality of elements, wherein each of the plurality of elements producing an elliptically polarized wave having an eccentricity value, the elliptically polarized wave traveling along a direction of propagation, wherein at least a portion of the plurality of elements are incrementally clocked around their direction of propagation, so that a combined output of the plurality of elements is substantially circularly polarized.
  • 10. The method according to claim 9, further comprising: detecting a phase shift in the combined output; and compensating for a phase shift by executing phase shift logic stored in memory to modify the combined output of the plurality of elements to remove or reduce the phase shift.
  • 11. The method according to claim 10, wherein compensating for a phase shift comprises controlling, by the processor, a capacitor or an inductor to modify the combined output of the plurality of elements to remove or reduce the phase shift, the capacitor or inductor being electrically coupled to the plurality of elements.
  • 12. The method according to claim 9, further comprising compensating for a phase shift present in the combined output, caused by clocking of the plurality of elements using a compensating line length in a feed of each of the plurality of elements.
  • 13. An antenna, comprising: a processor; anda memory for storing executable instructions, the processor executing the instructions stored in memory to:control a plurality of elements, each of the plurality of elements producing an elliptically polarized wave having an eccentricity value, the elliptically polarized wave traveling along a direction of propagation, wherein at least a portion of the plurality of elements are incrementally clocked around their direction of propagation, so that a combined output of the plurality of elements is substantially circularly polarized, wherein each of the plurality of elements:is associated with a feed; andcomprises a compensating line length in the feed that compensates for a phase shift present in the combined output, caused by clocking of the plurality of elements.
  • 14. The antenna according to claim 13, wherein the processor induces a compensation by executing phase shift logic stored in memory to modify the combined output of the plurality of elements to remove or reduce the phase shift.
  • 15. The antenna according to claim 14, wherein the processor induces a compensation by controlling a capacitor or an inductor to modify the combined output of the plurality of elements to remove or reduce the phase shift, the capacitor or inductor being electrically coupled to the plurality of elements.
CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of U.S. Provisional Application Ser. No. 61/841,187, filed on Jun. 28, 2013, titled “ELLIPTICITY REDUCTION IN CIRCULARLY POLARIZED ARRAY ANTENNAS”, which is hereby incorporated herein by reference, including all references cited therein.

Provisional Applications (1)
Number Date Country
61841187 Jun 2013 US