The present disclosure generally relates to antenna, and more particularly relates to antenna arrays.
Antenna arrays having multiple antennas therein are often used to transmit and receive data to and from multiple sources. Cellular tower antennas, for example, are often in communication with numerous cellular phones or other electronic devices. Electronic devices may be capable of utilizing multiple communication protocols such as 3G, 4G, 5G, or the like, to communicate with an antenna array. Often, a single antenna array is designed to be capable of handling the different communication protocols which may use different frequency bands.
In accordance with one embodiment, an antenna array is provided. The antenna array may include, but is not limited to, a first plurality of reflectors, each of the first plurality of reflectors having a face, a first edge and a second edge, wherein the first edge of each of the first plurality of reflectors is coupled to the second edge of another of the first plurality of reflectors, a first plurality of antenna elements arranged on the face of at least one of the first plurality of reflectors, the first plurality of antenna elements configured to radiate within a first frequency band, a second plurality of antenna elements arranged at a corner of at least two of the first plurality of reflectors, the corner comprising an area where the first edge of one of the first plurality of reflectors is coupled to the second edge of another one of the first plurality of reflectors, the second plurality of antenna elements configured to radiate within a second frequency band different than the first frequency band, a second plurality of reflectors, the second plurality of reflectors mounted to an end of the first plurality of reflectors, and a third plurality of antenna elements arranged on a face of at least one of the second plurality of reflectors, the third plurality of antenna elements configured to radiate within a third frequency band different than the first frequency band and the second frequency band.
In accordance with another embodiment, an antenna array is provided. The antenna array may include, but is not limited to a first plurality of reflectors arranged in a first shape, the shape comprising at least two faces and at least two edges, a first plurality of dipole antennas arranged on the at least two faces of the first plurality of reflectors, the first plurality of dipole antennas configured to radiate within a first frequency band, a second plurality of dipole antennas arranged at the at least two edges of the first plurality of reflectors, the second plurality of dipole antennas configured to radiate within a second frequency band different than the first frequency band, a second plurality of reflectors arranged in a second shape, the second shape comprising at least two faces and at least two edges, and a third plurality of dipole antennas arranged on a face of at least one of the second plurality of reflectors, the third plurality of dipole antennas configured to radiate within a third frequency band different than the first frequency band and the second frequency band.
The detailed description will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Thus, any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or detail of the following detailed description.
There are sometimes size restrictions relative to the size (e.g., height and width) of an antenna array depending upon where the antenna array is to be installed. When numerous communication protocols, and thus numerous frequency bands, have to be handled by a single antenna, it can be difficult to fit all of the required antenna elements within the single antenna array. An antenna array including an arrangement of antenna elements which are interleaved in an azimuth plane is discussed herein. As discussed in further detail below, the arrangement allows more antenna elements to be placed within a given area, which allows for omni-directional performance across multiple frequency bands within a smaller antenna array.
The antenna array 100 further includes multiple reflectors 110 which form the internal structure of the antenna array 100. The reflectors 110 may be formed from any conductive material. The reflectors 110 may be galvanically connected to one another, galvanically isolated from one another, or a combination thereof. In the embodiment illustrated in
The number of reflectors 110 may depend upon the number of frequency bands the antenna array 100 is intended to cover and the desired bandwidth of the antenna array 100. In general, the more antenna elements 105 that can be arranged inside of an antenna array 100, the more bandwidth the antenna array may cover. Furthermore, in order to achieve an omni-directional radiation pattern, antenna elements 105 generally should be arranged on multiple sides of the antenna array 100.
As discussed above, size restrictions may be placed upon an antenna array 100 which may limit the height and width of the antenna array 100. The size restrictions would generally limit the size of the reflectors 110, and thus the number of antenna elements 105 that could be placed inside the antenna array 100. Size restrictions can also be limiting with respect to the number of frequency bands the antenna array 100 can cover. These limitations can prevent an antenna array from having a functional omni-directional pattern across all of the frequency bands used therein.
In order to overcome limitations in size, to increase the number of antenna elements 105 within the antenna array 100, and/or to increase the number of frequency bands available to the antenna array 100, the antenna array 100 includes antenna elements 105 which are mounted on the face of the reflectors 110 and antenna elements 105 which are mounted on at the corners of the reflectors 110. In the example illustrated in
As seen in
The antenna elements 165 which are arranged at the corners 135-150 of the reflectors 110 may have to be compensated for their position. Adjustments to the length of the radiating elements (e.g., dipole arms, etc.), the dimensions of a parasitic element if used, the width and/or length of a balun, and the like, may be made to compensate for the position of the antenna elements 165.
The antenna elements 165 which are arranged on the corners 135-150 of the reflectors 110 may be mounted on a feed board 170. The feed board 170 receives a radio frequency signal and splits the signal that will be sent to each antenna element 165. The feed board 170 includes transmission lines which are distributed such that each antenna element 165 receives equal power and that the phase of the radio frequency signal is appropriate for the antenna element 165. For example, when the antenna element 165 is a dual polarized dipole antenna, as illustrated in
The reflectors 205, 215 and 225 include dipole antennas 235 and 240. In the embodiment illustrated in
The reflectors 210, 220 and 230 may each include eight dual-polarized dipole antennas 265. The dipole antennas 265 may operate over, for example, a frequency range of 3550-3700 MHz. The eight dual-polarized dipole antennas 265 may be mounted on two feed boards 270 which feed the dual-polarized dipole antennas 265.
The antenna array 200 further includes dual-polarized dipole antennas 275 which are mounted at the edges of the reflectors 205-230. In other words, the dual-polarized dipole antennas 275 are mounted at the boundary between two of the reflectors 205-230. In the embodiment illustrated in
While the antenna array 200 is described as covering four frequency bands (i.e., 698-960 MHz, 1695-2400 MHz, 3550-3700 MHz and 5150-5925 MHz), the number of frequency bands and their exact frequency ranges can vary depending upon the needs of the antenna array 200 by increasing, or decreasing, the number of antenna elements and by adjusting the operating frequency thereof.
In one embodiment, for example, the antenna array 200 may utilize twelve input/output (I/O) ports to cover the four bands. For example, two I/O ports may cover the 698-960 MHz band, four I/O ports may cover the 1695-2400 MHz band, four I/O ports may cover the 3550-3700 MHz band, and two I/O ports may cover the 5150-5925 MHz band. Each I/O port offers an omni-directional pattern which is obtained by combining three sectors (i.e., antenna elements on different reflectors or edges). Each sector of each band has four antenna elements in elevation plane except the 698-960 MHz band which has two elements. Each of the sets of dual-polarized dipoles are in group of four which are fed with a four-way splitter with proper phase and amplitude difference. To make omnidirectional pattern the three panels are combined with a three-way splitter with equal power and phase. As can be seen dipoles for 698-960 MHz, 1695-2400 MHz, and 3550-3700 MHz bands are in close proximity. The antenna array 200 illustrated in
The antenna array is made with dual-polarized dipoles 310 operating in the 2 GHz range (1695-2690 MHz), dual-polarized dipoles 320 operating in the 3.5 GHz range (3550-3700 MHz), and dual-polarized dipoles 330 operating in the 5 GHz range (5150-5925 MHz). As seen in
In the embodiment illustrated in
One benefit of the embodiment illustrated in
Each of the reflectors 410 may have a width based upon the size of the antenna elements mounted thereon, namely, the antenna elements 420. In other words, the size of the reflectors 410 is based upon the frequency range of the antenna elements 420 thereon. In one embodiment, for example, the antenna array 400 may need better than twenty decibels coupling between adjacent elements. In this exemplary embodiment, in order to have better than twenty decibels coupling between adjacent elements, the width of the reflectors may around 0.6-0.8λ, or in this example, around eighty millimeters.
The antenna array 400 further includes reflectors 450. As seen in
As discussed above, because the antenna elements 430 are mounted at the corners of the reflectors 410, the overall size of the antenna array 400 is reduced as the antenna elements 430 would otherwise need to be mounted on separate reflectors adjacent to the antenna elements 420 (i.e., the antenna array would be wider as there would be more reflectors), or placed on the reflectors above or below the antenna elements 420 (i.e., the antenna array would be taller as the reflectors 410 would need to be longer to fit the antenna elements 430 on the faces thereof). Accordingly, by arranging the antenna elements 430 at the corner of the reflectors, there is space within a predefined requirement (e.g., a limit of two feet tall), to fit the antenna elements 470 on the separate reflectors 450. By having reflectors of two sizes, the omni-directional pattern for the antenna elements 470 is improved.
Returning to
While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.
This application claims the benefit of U.S. provisional patent application Ser. No. 62/595,274, filed Dec. 6, 2017 and provisional patent application Ser. No. 62/647,989, filed Mar. 26, 2018, the entire contents of which are incorporated by reference herein.
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20120280878 | Timofeev | Nov 2012 | A1 |
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Number | Date | Country | |
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20190173162 A1 | Jun 2019 | US |
Number | Date | Country | |
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62595274 | Dec 2017 | US | |
62647989 | Mar 2018 | US |