Patent Application
20220384935
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 clamed invention, or that any publication specifically or implicitly referenced is prior art.
As wireless networks data throughput, quality of service, capacity, and overall reliability continue to be challenged with the exponential growth of data and fifth generation (5G) services, network designers and operators are using more numerous radio transceivers with wider bandwidths and increasing number of ports to provide 4×4 MIMO (multiple input, multiple output), 256 QAM (quadrature amplitude modulation), and CA (Carrier Aggregation). Capacity is further improved by splitting cells from the traditional three sectors to six and nine sectors using multiple beams from a common antenna aperture. This creates a need for base station antennas that provide ultra-wide, multiple bands of high-performance sector coverage with as many ports as possible while maintaining the traditional base station antenna (BSA) apertures that have been seen on towers for decades. Example of the multi-port BSA could be found in https://www.commscope.com/catalog/antennas/product_details.aspx?id=69751, with 12 LB and HB ports, but it cannot provide splitting cells (for capacity improvement) and does not cover new 5G frequency bands (600 MHz and 3.3-4.2 GHz).
Lens based multiple beam antennas are growing in popularity due to their superior performance, notably in crucial port to port isolation, compared to the common Butler Matrix approach. The teaching of lightweight low loss artificial dielectric materials (see U.S. Pat. No. 8,518,537) opens new opportunities for wideband multiband multibeam antennas. Also, U.S. Pat. No. 8,199,063 teaches 4 LB dipoles, having bended arms, with a nested HB element between them. However, the disadvantage of the 063' reference is that of a narrow band for LB (<15%) and one beam only for HB operations.
All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
The inventive subject matter provides apparatus, systems and methods in which a high port count base station antenna uses an array of spherical lenses with multiple ports per frequency band, containing multiple frequency bands, and capable of multiple beam operation.
In a preferred embodiment, an antenna system comprises a plurality of spherical, dielectric lenses, stacked vertically, where each lens is surrounded by four or more lower frequency radiating elements, or one circular element. In one embodiment of the invention, each lens is surrounded by four lower frequency dipole radiators, each radiator consists of dipole arms shaped in a circular arc with a radius of curvature similar to the radius of the lens. This multiple band array element structure can be used as the building block for one or more array columns to form high gain narrow vertical beam antenna ports.
A spherical lens is a lens with a surface having a shape of (or substantially having a shape of) a sphere. As defined herein, a lens with a surface that substantially conform to the shape of a sphere means at least 50% (preferably at least 80%, and even more preferably at least 90%) of the surface area conforms to the shape of a sphere. Examples of spherical lenses include a spherical-shell lens, the Luneburg lens, etc. The spherical lens can include only one layer of dielectric material, or multiple layers of dielectric material. A conventional Luneburg lens is a spherically symmetric lens that has multiple layers inside the sphere with varying indices of refraction.
The lower frequency elements are combined into one or more vertical arrays using a variable phase shift, remote electrical tilt capable, feed network. The higher frequency bands use radiators that illuminate a primary dielectric lens to create a plane wave phase front, combined in a vertical array using a variable phase shift, remote electrical tilt capable, feed network. One or more higher frequency vertical arrays can be used with a single column of lenses to produce multiple beams in the azimuth plane.
In a preferred embodiment, the higher frequency elements move on a circular arc near the surface of the primary lens. This movement can coincide or be independent with movement of higher frequency elements in other columns, or the structure consisting of the four lower frequency elements. It should be clear to those skilled in the art that a number of embodiments are possible using multiple columns of higher frequency arrays to form multiple beams.
Wideband multiband dual-polarized lensed multibeam base station phased array antennas and low-band radiators for such antennas are disclosed. Dual-polarized low band element has shape close to circular. One version of low band element comprises a conductive ring with 4 symmetrically located feed gaps.
Another version of low band element comprises four coupled symmetrical dipoles located in a circular LB element. Inside a circular LB element, a spherical dielectric lens is placed, with artificial dielectric as preferable option for lens structure. The low band radiator with lens is adapted for frequency band 600-960 MHz and provides a horizontal beamwidth of approximately 60 degrees. In some embodiments, low band elements are located in 2 columns to support 4×4 MIMO operation. The multi-band base station antenna comprises high-band radiators adapted for 1.69-2.69 GHz, with pairs of HB radiators placed inside some of low band elements, forming two output beams with horizontal beamwidth of approximately 35 degrees. In related embodiments, the multi-band base station antenna comprises high-band FB radiators adapted for 3.3-4.2 GHz, with pairs of HB radiators placed inside some of circular LB elements, forming two output beams with horizontal beamwidth of approximately 24 degrees.
In some embodiments, circular low band elements are combined in the same array with cross-shaped low band elements, with their horizontal and vertical arms interspersed amongst the high-band radiators. In another embodiment, radiation pattern optimization is achieved by combination of lenses with different diameter and/or truncation.
A LB element is key part of wideband multi-band dual-polarized lensed multibeam base station phased array antennas. Dual-polarized circular element are configured to fit with spherical lenses and be used in multiband multibeam antennas.
Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
In some embodiments, for better beam shaping, a circular element can have spherical lens 103, as schematically shown in
In
In
In some embodiments, HB (FB) elements can be placed above common reflector 340 (
In another 2-band embodiments, lens 320 can be used to form different (e.g. more than 2) number of beams (for example 3, 4 or 5 FB beams) which can benefit with 5G massive MIMO beamforming).
In exemplary embodiments, radiating sub-elements of LB circular element 405 are coupled via capacitive coupling or inductive coupling. In a related embodiment, a planar capacitor or an overlapping capacitor can be used to provide capacitive coupling. In a preferred embodiment, the arms of radiating sub-elements can include stop-band filters or chokes, similar as those described above.
Although a lens in general improves performance of LB element
The circular LB element with lens allows an extremely compact configurations, which is in particular suitable as a basic element for multiband/multibeam antennas with a plurality of columns (and/or rows).
In
In an exemplary embodiment, for an F-band (FB) antenna configuration, an array of 3 lensed 3-beam antennas is used for each column. As depicted by
In certain embodiment, HB and FB elements are using secondary lenses. Secondary lenses are playing important role for optimization of radiation patterns of HB and FB antenna arrays. In a preferred embodiment, secondary lens 510 is placed above radiating element 530 and has a non-spherical shape, which provides benefits for pattern optimization, as shown in
For further antenna total width reduction, combination of LB circular elements with other type of LB elements can be advantageous. As schematically shown in
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.
As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
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. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. 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.
It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
