The present disclosure generally relates to antennas that may be low profile, ultra-wideband, and/or omnidirectional.
This section provides background information related to the present disclosure which is not necessarily prior art.
For in-building cellular network applications, certain applications require a single-input single-output (SISO) antenna that is ultra-low profile and that is aesthetic looking for the building ceiling. Conventional SISO antennas tend to have a high profile. To reduce the profile, wide or bow tie antennas may be used. But then the antenna may be too large in size and have very deep null at low band.
Conventional SISO antennas have been traditionally designed as a dipole parallel to the ceiling, but this may have a very deep null and not be omnidirectional in the azimuth plane. Also, conventional symmetrical dipole designs may be limited in terms of size and radiation pattern options. Thus, it is challenging to design an SISO antenna with ultra-wideband performance (e.g., from 350 MHz to 6000 MHz, etc.) while at the same time reducing the deep null effect due to the conventional symmetrical dipole design especially for the cellular band and reasonable radiation properties up to the 6 GHz band.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding (though not necessarily identical) parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
As explained in the background above, it is challenging to design an SISO antenna for ultra-wideband performance (e.g., from 350 MHz to 6000 MHz, etc.) while at the same time reducing the deep null effect of the conventional symmetrical dipole design especially for the cellular band and reasonable radiation properties up to the 6 GHz band. Ultra-wideband (UWB) structures have been considered that are based on the basic discone type antenna structure.
A conventional discone antenna (e.g., a 3D structure discone antenna transferred to 2D structure, etc.) has to be modified in order to meet the 350 MHz band and achieve an ultra-wideband operation from 350 MHz to 6000 MHz. With this antenna modification, the discone antenna 1 required a large radome 5 having a diameter of 370 millimeters (mm) to fit around and cover the printed circuit board (PCB) 9 of the 2D discone antenna 1 as shown in
Disclosed herein are exemplary embodiments of antennas (e.g., antenna 100 (
In exemplary embodiments, an antenna generally includes radiators or radiating elements within an interior cooperatively defined between a radome (e.g., a plastic flat circular radome, flat dielectric radome, etc.) and a baseplate or support member (e.g., plastic baseplate, etc.). The baseplate may include a threaded stud feature (broadly, a mounting feature or fixture) for installing the antenna to a ceiling (broadly, a mounting surface). The radome may be configured to be coupled to the baseplate without using metal mechanical fasteners (e.g.,
The radiators may comprise PCB radiators, stamped radiators, flexible PCB (fpcb) radiators, electrically-conductive tape or foil, combination thereof, etc. For example, the radiator and a ground plane (broadly, a ground element) may comprise a flexible trace construction including flexible electrically-conductive traces or materials along opposite first and second (or top and bottom) sides of a flexible PCB (broadly, a substrate). The flexible electrically-conductive materials may comprise metal foil or tape (e.g., aluminum foil or tape, other non-ferromagnetic foils or tapes, etc.) and/or stamped metal (e.g. stamped aluminum, other stamped non-ferromagnetic materials, etc.). An exemplary embodiment may include aluminum tape for adhering the PCB to a dielectric sheet (e.g., plastic sheet, etc.).
In an exemplary embodiment, an antenna may have a single PCB construction including a low PIM (passive intermodulation) rated PCB. See, for example,
In another exemplary embodiment, an antenna may have a hybrid or multi-piece construction including a low PIM rated PCB and non-ferromagnetic foil (e.g., aluminum foil, other metal foils, etc.) on a dielectric sheet (e.g., plastic film, etc.) or stamped non-ferromagnetic material (e.g., stamped aluminum, other stamped metals, etc.). The low PIM rated PCB may be relatively small and/or smaller in size than the PCB used for the single PCB construction. See, for example,
In exemplary embodiments, the antenna may include asymmetrical arms. In which case, the antenna should not be considered a typical dipole antenna having symmetrical arms. The antenna may be considered an asymmetrical arm shorted dipole or a planar shorted discone antenna. The longer/larger asymmetrical arm may be referred to as a ground plane while the other asymmetrical arm may be referred to as the radiator.
Several antenna features may be configured (e.g., modified, etc.) to allow or provide an ultra-wideband antenna that fits within a relatively small radome (e.g., having a diameter of 270 mm or less, etc.) and that has an operating frequency range (e.g., extended down to, etc.) down to 350 MHz with relatively small steps (e.g., miniaturized or reduced steps, etc.). In exemplary embodiments, one or more of the following features may be modified for and/or provided to an antenna:
In exemplary embodiments, contributions to the antenna's ultra-wide bandwidth may include one or more:
In exemplary embodiments, there are several factors that lower the risk of high PIM level:
In exemplary embodiments, several factors play important roles to have reduced null and more omnidirectional radiation patterns at azimuth plane for horizontal planar asymmetrical dipole antennas as disclosed herein:
Accordingly, disclosed herein are exemplary embodiments of antennas that may have or provide one or more of the following features or advantages over conventional dipole antennas. For example, an antenna disclosed herein may have less null at azimuth plane as compared to a conventional dipole. An antenna disclosed herein may have a wide bandwidth, may enable a stable low PIM product, and/or may have a lower profile as compared to other conventional antennas. An antenna disclosed herein may have a reduced size as compared to a conventional dipole of a UHF band antenna.
With reference now to the figures,
In this exemplary embodiment, the antenna 100 may have a single PCB construction. For example the antenna 100 may include a single low PIM rated PCB 104 having a first or top side 108 (
As shown in
The radiating element 116 (
The shorting line 128 (e.g., shorting trace, etc.) extends generally between the radiating element 116 and the patch 120. The stub 132 (e.g., a generally rectangular stub, etc.) is provided along the shorting line 128, e.g., at a location closer to the radiating element 116 than it is to the patch 120. The addition of the stub 132 may help the antenna 100 maintain good bandwidth at the UHF band. See, for example, the line graphs in
The additional arm or radiating element 124 increases an electrical length of the antenna 100. The antenna 100 also includes the additional proximity patch 148 along the second side 112 of the PCB 100. The additional proximity patch 148 also increases an electrical length of the antenna 100. The addition of the arm 124 and patch 148 may allow the antenna 100 to have a VSWR of less than 2 while operating at lower frequencies, such as shown in
The microstrip line 144 extends generally between the antenna feed point 136 and the cable feed point 140. The microstrip line 144 is configured such that the microstrip line's width tapers or decreases along the microstrip line 144 in a direction from the cable feed point 140 to the antenna feed point 136. Accordingly, a width of the microstrip line 144 is larger at the cable feed point 140 and smaller at the antenna feed point 136.
The patch 120 may be relatively wide and/or otherwise configured to proximity couple to the ground plane 152 along the PCB's second side 112. In alternative embodiments, the patch 120 may be replaced by a plate thru hole (PTH), which may a higher risk of a higher PIM level if the PTH quality is not consistent. Without changing the wide patch 120, a PTH may also be introduced at a certain location if a DC short is needed, which PTH may then have less impact on PIM performance.
Electrically-conductive material (e.g., copper traces, etc.) may be provided or disposed along the first side 108 to thereby define or provide the electrically-conductive surfaces or components 116, 120, 124, 128, 132, 136, 140, 144, 148, and 152 along the first and second sides 108, 112 of the PCB 100. Additionally, or alternatively, metal foil or tape (e.g., aluminum foil or tape, other non-ferromagnetic foils or tapes, etc.) and/or stamped metal (e.g. stamped aluminum, other stamped non-ferromagnetic materials, etc.) may be used in other exemplary embodiments.
As shown in
The radome 160 and baseplate 164 cooperatively define an interior in which the PCB 104 is positioned as shown in
The radome 160 and baseplate 164 are configured to protect the PCB 104 and electrically-conductive elements (e.g., radiating element 116, patch 120, additional radiating arm 124, shorting line 128, stub 132, antenna feed point 136, cable feed point 140, microstrip line 144, patch 148, ground plane 152, etc.) from damage, e.g., due to environmental conditions, etc. The radome 160 and baseplate 164 may be formed from a wide range of materials, such as, for example, thermoplastic materials (e.g., polycarbonate blends, Acrylonitrile-Butadiene-Styrene (ABS), Polycarbonate-Acrylonitrile-Butadiene-Styrene Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, other dielectric materials, etc. within the scope of the present disclosure.
The baseplate 164 includes a threaded stud feature 168 (broadly, a mounting feature or fixture) for installing the antenna 100 to a ceiling (broadly, a mounting surface) with a plastic nut. The threaded stud feature 168 is generally hollow such that the feed cable 142 (e.g., coaxial cables, other transmission lines, etc.) may be fed through the hollow interior of the threaded stud feature 168 to the cable feed location 140 of the antenna 100. The feed cable 142 may be a low PIM rated coaxial cable to feed the antenna 100 for better PIM performance and low PIM rating. Alternatively, the feed cable 142 may be standard coaxial cables to feed the antenna 100 for a standard version of the antenna. As shown in
In this exemplary embodiment, the antenna 200 may have a hybrid or multi-piece construction including a low PIM rated PCB 204 and non-ferromagnetic foil 206 (e.g., aluminum foil, other metal foils, etc.) on a dielectric sheet 210 (e.g., plastic film, etc.). The low PIM rated PCB 204 may be relatively small and/or smaller in size than the PCB 104 of antenna 100.
As shown in
As shown in
The PCB's second side 212 includes electrically-conductive material thereon (e.g., copper, etc.) that corresponds to portions of the proximity patch 148 and the ground plane 152 of the antenna 100. The PCB's second side 212 includes a proximity patch 248 and a ground plane 252.
As shown in
The radome 260 and baseplate 264 cooperatively define an interior in which the PCB 204 may be positioned. The baseplate 264 may be configured for holding the antenna components. For example, the baseplate 264 includes a recess or pocket 272 configured for receiving the PCB 204 therein such that the PCB 204 is positioned correctly relative to the baseplate 264. This also allows the trace of the aluminum foil 206 to be loaded by both the dielectric baseplate 264 and the dielectric radome 26, which may help to slightly increase the antenna's electrical size. The baseplate 264 may include protrusions extending upwardly for positioning within corresponding openings in the PCB 204 and the aluminum foil 206 and plastic film 210, to thereby align and retain the PCB 204 and aluminum foil 206 in place.
The radome 260 and baseplate 264 are configured to protect the PCB 204, aluminum foil 206, and plastic film 210 from damage, e.g., due to environmental conditions, etc. The radome 260 and baseplate 264 may be formed from a wide range of materials, such as, for example, thermoplastic materials (e.g., polycarbonate blends, Acrylonitrile-Butadiene-Styrene (ABS), Polycarbonate-Acrylonitrile-Butadiene-Styrene Copolymer (PC/ABS) blend, etc.), glass-reinforced plastic materials, synthetic resin materials, other dielectric materials, etc. within the scope of the present disclosure.
The baseplate 264 includes a threaded stud feature 268 (broadly, a mounting feature or fixture) for installing the antenna 200 to a ceiling (broadly, a mounting surface) with a dielectric (e.g., plastic, etc.) nut. The threaded stud feature 268 is generally hollow such that the feed cable 242 (e.g., coaxial cables, other transmission lines, etc.) may be fed through the hollow interior of the threaded stud feature 268 to the cable feed location 240 of the antenna 200. The feed cable 242 may be a low PIM rated coaxial cable to feed the antenna 200 for better PIM performance and low PIM rating. Alternatively, the feed cable 242 may be standard coaxial cables to feed the antenna 200 for a standard version of the antenna. The cable feed point 242 may be located at or towards a center of the PCB 204, radome 260, and baseplate 264. This allows the cable feed point 242 to be located within or overlap the hollow interior of the threaded stud feature 268, which may be located at about the center of the baseplate 264.
Also shown in
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. In addition, advantages and improvements that may be achieved with one or more exemplary embodiments of the present disclosure are provided for purpose of illustration only and do not limit the scope of the present disclosure, as exemplary embodiments disclosed herein may provide all or none of the above mentioned advantages and improvements and still fall within the scope of the present disclosure.
Specific dimensions, specific materials, specific shapes, and/or specific antenna operational performance data disclosed herein are example in nature and do not limit the scope of the present disclosure. The disclosure herein of particular values and particular ranges of values for given parameters are not exclusive of other values and ranges of values that may be useful in one or more of the examples disclosed herein. Moreover, it is envisioned that any two particular values for a specific parameter stated herein may define the endpoints of a range of values that may be suitable for the given parameter (i.e., the disclosure of a first value and a second value for a given parameter can be interpreted as disclosing that any value between the first and second values could also be employed for the given parameter). For example, if Parameter X is exemplified herein to have value A and also exemplified to have value Z, it is envisioned that parameter X may have a range of values from about A to about Z. Similarly, it is envisioned that disclosure of two or more ranges of values for a parameter (whether such ranges are nested, overlapping or distinct) subsume all possible combination of ranges for the value that might be claimed using endpoints of the disclosed ranges. For example, if parameter X is exemplified herein to have values in the range of 1-10, or 2-9, or 3-8, it is also envisioned that Parameter X may have other ranges of values including 1-9, 1-8, 1-3, 1-2, 2-10, 2-8, 2-3, 3-10, and 3-9.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. For example, when permissive phrases, such as “may comprise”, “may include”, and the like, are used herein, at least one embodiment comprises or includes the feature(s). As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore 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. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
The term “about” when applied to values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters. For example, the terms “generally,” “about,” and “substantially,” may be used herein to mean within manufacturing tolerances (e.g., angle+/−30′, 0-place decimal+/−0.5, 1-place decimal+/−0.25, 2-place decimal+/−0.13, etc.). Whether or not modified by the term “about,” the claims include equivalents to the quantities.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements, intended or stated uses, or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/731,428 filed Sep. 14, 2018. The entire disclosure of the above application is incorporated herein by reference.
Number | Date | Country | |
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62731428 | Sep 2018 | US |