Patent Application
20170317428
The present disclosure relates to multiband WiFi directional antennas.
This section provides background information related to the present disclosure which is not necessarily prior art.
A common way to provide a dual polarized, dual band antenna assembly is to use separate radiating elements for the low band and the high band. For example, first and second dipoles elements may be respectively used for the low and high bands.
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 parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
Disclosed herein are exemplary embodiments of multiband WiFi directional antennas configured to have symmetrical directional beam or similar beamwidths on perpendicular planes. The multiband WiFi directional antenna is configured to be operable within at least a first WiFi frequency range and a second WiFi frequency range different than the first WiFi frequency range. For example, the multiband WiFi directional antenna may be configured for dual band operation from about 2.4 Gigahertz (GHz) to about 2.5 GHz and from about 5.15 GHz to about 5.9 GHz. Alternatively, the multiband WiFi directional antenna may be configured to be operable in more or less than two frequency ranges or bands (e.g., broadband (wideband) covering several bands, etc.) and/or in one or more other frequency ranges or bands (e.g., one or more non-WiFi frequency ranges, etc.).
In an exemplary embodiment, an antenna includes four radiating elements or radiators on top of a dielectric (e.g., plastic, etc.) base plate (broadly, a base or support member). Two of the radiating elements are vertically polarized, while the other two radiating elements are horizontally polarized. Each radiating element is connected with a cable (broadly, a feed) such that there are four cables each connected to a corresponding one of the four radiating elements.
A radome or housing is positioned over the radiating elements and coupled (e.g., mechanically fastened with screws, etc.) to the base plate. The radiating elements are disposed within an interior collectively defined by and generally between the radome and the base plate such that the radiating elements are protected from and not exposed to the environment (e.g., dirt, dust, water, etc.). For example, the antenna may be configured to satisfy the IP67 ingress protection standard where 6 indicates total protection against solid objects/dust and 7 indicates protection against liquids up to and including the effects of immersion in 15 centimeters to 1 meter of liquid.
Each radiating element includes first and second (or upper and lower) electrically-conductive (e.g., metal or metallic, etc.) parts coupled (e.g., mechanically fastened by rivets, etc.) together. The second or lower part of the radiating element is coupled (e.g., mechanically fastened by pems, etc.) to an electrically-conductive (e.g., aluminum, etc.) ground plane or reflector.
A feeding board (broadly, a feed element) is within an interior area or space defined between portions of the radiating element. The feeding board is used to excite the radiating element. The feeding board is inserted into a slot defined by the ground plane/reflector such that first and second (or upper and lower) portions of the feeding board are along opposite upper and lower (or top and bottom) surfaces of the ground plane or reflector. The radiating element may then be positioned relative to (e.g., lowered downward onto, etc.) the feeding board and ground plane/reflector such that the upper portion of the feeding board is inserted through a slot in the lower or second part of the radiating element. The radiating element may then be coupled to the ground plane/reflector. Alternatively, the radiating element may be coupled to the ground plane/reflector before the feeding board is inserted into the slot of the ground plane or reflector. Then, the lower portion of the feeding board may be inserted into the aligned slots of the radiating element and the ground plane/reflector after the radiating element is positioned on and coupled to the ground plane/reflector. In either case, the positioning of the feeding board within the slots of the radiating element and the ground plane/reflector may help retain (e.g., via a friction fit or interference fit, etc.) the feeding board in place relative to the radiating element and the ground plane/reflector.
A cable (e.g., coaxial cable, other transmission line, etc.) is electrically connected (e.g., using a feed-through, etc.) to a back side of the lower portion of the feeding board. The front side of the lower portion of the feeding board includes a resistive network along the feeding board (e.g., resistors soldered to the feeding board and/or placed directly on via surface mount technology (SMT), etc.) RF energy enters through the cable and travels in a microstrip line (broadly, transmission line) along the front side of the feeding board. The RF energy excites an electric field in the top of the radiating element.
The sidewalls and bottom portion of the ground plane/reflector may be operable for reflecting and/or directing signals from the radiating element in a same general direction such that the radiating element radiates a symmetrical directional beam in a direction generally perpendicular and away from the ground plane/reflector at a first WiFi frequency range (e.g., from about 2.4 GHz to about 2.5 GHz) and a second WiFi frequency range (e.g., from about 5.15 GHz to about 5.9 GHz, etc.). The combination of the four radiating elements or radiators forms a MIMO access point with space and polarization diversity.
With reference now to the figures,
Each antenna element module 104 is connected with a cable 108 (broadly, a feed) such that there are four cables 108 each connected to a corresponding one of the four antenna element modules 104. The antenna element modules 104 are positioned on top of a dielectric base plate 112 (broadly, a base or support member). The base plate 112 may be made from various dielectric or electrically non-conductive materials, such as plastic, etc.
In this particular example, the vertically polarized antenna element modules 104A, 104B are located towards a top of the antenna 100 or closest to the cables 108, while the horizontally polarized antenna element modules 104C, 104D are located towards a top of the antenna 100. Alternatively, the antenna element modules 104 may be arranged differently. For example, another exemplary embodiment may have the horizontally polarized antenna element modules 104C, 104D located towards a bottom of the antenna 100 or closest to the cables 108, while the vertically polarized antenna element modules 104A, 104B are located towards a top of the antenna 100. Other exemplary embodiments may have one horizontally polarized antenna element module 104C or 104D and one vertically polarized antenna element module 104A or 104B located towards a bottom of the antenna 100 or closest to the cables 108, while the other horizontally polarized antenna element module and other vertically polarized antenna element module are located towards a top of the antenna 100.
As shown in
A seal or sealing member 124 (e.g., an O-ring having a U-shaped profile, elastomeric sealing member, a rubber sealing member, a thermoplastic elastomer sealing member, etc.) may be disposed between the radome 116 and the base plate 112 to help seal the interior collectively defined by and generally between the radome 116 and the base plate 112, such that the antenna element modules 104 are protected from and not exposed to the environment (e.g., dirt, dust, water, etc.). For example, the antenna 100 may be configured to satisfy the IP67 ingress protection standard where 6 indicates total protection against solid objects/dust and 7 indicates protection against liquids up to and including the effects of immersion in 15 centimeters to 1 meter of liquid.
As shown in
As shown in
The second or lower part 136 of the radiating element 128 includes first and second end portions 156 (e.g., trapezoid shaped end portions, etc.) that are respectively coupled (e.g., mechanically fastened by rivets 140, etc.) to the corresponding first and second portions 148 of the first or upper part 132 of the radiating element 128. The second or lower part 136 of the radiating element 128 also includes a middle portion 160 (e.g., rectangular shaped portion, etc.) and first and second connecting portions 164 (e.g., trapezoid shaped portions, etc.) connecting and extending between the middle portion 160 and the corresponding first and second end portions 156. Alternatively, the second part 136 of the radiating element 128 may be configured differently, such as with different shapes, etc.
With continued reference to
The radiating element 128 may be coupled to the ground plane or reflector 168, such as by mechanical fasteners, welding, adhesives, etc. In this exemplary embodiment, pems 180 are inserted through aligned holes in the middle portion 160 of the second part 136 of the radiating element 128 and the bottom portion 172 of the ground plane or reflector 168, to thereby couple the radiating element 128 to the ground plane or reflector 168.
Each antenna element module 104 further includes a feeding board 184 (broadly, a feed element). The feeding board 184 includes a microstrip line 188 (broadly, transmission line) along a first side of the feeding board 184. The feeding board 184 is positioned within an interior area or hollow center portion defined between portions of the radiating element 128 as shown in
The feeding board 184 may first be inserted into a slot defined by the bottom portion 172 of the ground plane or reflector 168 such that first and second (or upper and lower) portions of the feeding board 184 are on opposite upper and lower (or top and bottom) surfaces of the bottom portion 172 of the ground plane or reflector 168 as shown by a comparison of
As shown in
During operation, RF energy enters through the cable 108 and travels in the microstrip line 188 to excite an electric field in the top of radiating element 128. In this exemplary embodiment, each radiating element 128 radiates a symmetrical directional beam in a direction generally perpendicular and away from the bottom portion 172 of the ground plane or reflector 168 at a first WiFi frequency range from about 2.4 GHz to about 2.5 GHz and a second WiFi frequency range from about 5.15 GHz to about 5.9 GHz, etc. The combination of the four antenna element modules 104 and their radiating elements or radiators 128 may be used to form a MIMO access point with space and polarization diversity.
As shown by a comparison of
As shown in
Exemplary embodiments disclosed herein may provide one or more (but not necessarily any or all) of the following features or advantages over some existing antennas. For example, a multiband WiFi directional antenna disclosed herein may have a relatively low cost construction (e.g., may not require a network board, etc.), may be relatively easy to manufacture, and/or may have a compact size as compared to some other conventional WiFi directional antennas. As another example, a multiband WiFi directional antenna disclosed herein may be used as one of several antennas in a panel antenna or as part of a multiple input multiple output (MIMO) antenna system. A multiband WiFi directional antenna disclosed herein may be configured for dual band operation with about a 9 dBi (decibels relative to isotropic) gain and/or with a symmetrical beam for each band (e.g., about 65 degrees by 65 degrees, etc.) and/or provide the ability to reduce gain to below 6 dBi for compliance. A multiband WiFi directional antenna disclosed herein may be configured to have symmetrical and consistent beam over wideband frequencies while keeping material cost very low and/or provide the ability to adjust gain for both bands to meet compliance. A multiband WiFi directional antenna disclosed herein may be configured to have radiation patterns that are relatively narrow at the principle E-plane and H-plane. By comparison, a conventional dual band dipole directive antenna has a radiation pattern that is wide at one of the principal planes, i.e., the H-plane.
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 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, and/or specific shapes 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 3l-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. 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.
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.
