The present disclosure generally relates to wireless communications, and more specifically, to an antenna used in wireless communications and a method for manufacturing the same.
In recent years, rapid increasing demand has emerged for services and systems that depend upon accurate positioning of people and objects. In an indoor scenario, compared to methods of time of arrival (TOA), time difference of arrival (TDOA), and angle of arrival (AOA), using the received signal strength (RSS) may be a more appropriate approach to perform positioning since it can reuse the existing wireless infrastructure and thus tremendously save the hardware costs. Besides, almost all current standard commodity radio technologies, such as Wi-Fi, Zigbee, active radio frequency identification (RFID), and Bluetooth, provide RSS measurements, and the same algorithm can be applied across different platforms consequently.
However, there are complex multipath effects in an unpredictable indoor environment, including shadowing (i.e., blocking a signal), reflection (i.e., waves bouncing off an object), diffraction (i.e., waves spreading in response to obstacles), and refraction (i.e., waves bending as they pass through different mediums). Thus, the RSS measurements will be attenuated in unpredictable ways due to these effects.
One method of increasing the accuracy of an RSS positioning system is using the reconfigurable antenna. The reconfigurable antenna has various abilities, such as reconfiguring the radiation pattern, polarization, or even the operation frequency. Therefore, it can improve the link quality and enable spatial reusability, thereby having a positive impact in tackling the challenges of indoor positioning techniques employing RSS. Additionally, by switching between different antenna elements, a base station can establish a preferred communication with user equipment by each antenna, so as to increase the signal to noise ratio and reduce interferences in dense networks. It has been confirmed that specific reconfigurable antennas could be adopted to increase the channel capacity in Multiple Input Multiple Output MIMO systems, by using spatial and time diversity. However, existing reconfigurable antennas still have various defects and deficiencies and cannot satisfy the actual needs in communications.
In one aspect of the present disclosure, there is provided an antenna. The antenna includes a plurality of radiating plates oriented towards different directions for radiating electromagnetic waves; a plurality of reflecting plates for reflecting the electromagnetic waves, such that the electromagnetic waves radiated by the plurality of radiating plates each have a respective directional radiation pattern; and a switch for selecting a radiating plate from the plurality of radiating plates for performing radiation.
In some embodiments, a planar dipole radiating element may be disposed on one side of the plurality of radiating plates. The planar dipole radiating element may include metal rings symmetrically disposed with respect to a symmetry axis. The metal rings may be rectangular metal rings. A width of a metal patch of the metal rings may be set to broaden an operation bandwidth of the antenna to a predetermined bandwidth. In some embodiments, an L-shaped feeding stub may be disposed on the other side of the plurality of radiating plates. An end of the feeding stub may be connected to one of the metal rings through a via. In some embodiments, the planar dipole radiating element may be fed through a coaxial cable.
In some embodiments, the plurality of radiating plates may form sides of a regular prism. In some embodiments, the regular prism may be a regular triangular prism, and the plurality of radiating plates may be three radiating plates, and wherein the plurality of reflecting plates may be three reflecting plates, and the three reflecting plates may respectively be positioned in three planes defined by lateral edges and a center axis of the regular triangular prism. In other embodiments, the regular prism may be a regular quadrangular prism, and the plurality of radiating plates may be four radiating plates and wherein the plurality of reflecting plates may be eight reflecting plates and four reflecting plates of the eight reflecting plates may respectively be in parallel with four sides of the regular quadrangular prism and form an internal regular quadrangular prism within the regular quadrangular prism, and the other four reflecting plates of the eight reflecting plates may respectively be positioned in four planes defined by lateral edges of the internal regular quadrangular prism and corresponding lateral edges of the regular quadrangular prism.
In some embodiments, the antenna may further include a bottom plate for fixing the plurality of radiating plates and the plurality of reflecting plates. The bottom plate also provides an electrical connection for the plurality of radiating plates. The switch may be disposed on the bottom plate. In some embodiments, the antenna may further include a top plate for fixing the plurality of radiating plates and the plurality of reflecting plates.
In another aspect of the present disclosure, there is provided a method for manufacturing the above antenna.
Through the following detailed description with reference to the accompanying drawings, the above and other objectives, features, and advantages of embodiments of the present disclosure will be easier to understand. Several example embodiments of the present disclosure will be illustrated by way of example but not limitation in the drawings in which:
Throughout the drawings, same or similar reference numbers are used to indicate the same or similar elements.
Principles and spirits of the present disclosure will now be described with reference to various example embodiments illustrated in the drawings. It should be appreciated that description of those embodiments is merely to enable those skilled in the art to better understand and further implement the present disclosure and is not intended for limiting the scope disclosed herein in any manner.
As mentioned above, existing reconfigurable antennas still have various defects and deficiencies. In some existing solutions, a single-anchor indoor positioning system uses a switched-beam antenna, wherein the reconfigurable antenna is a combination of six adjacent radiating elements, which are assembled to form a semi dodecahedron. Each radiating element is implemented in the microstrip antenna technology and is fed by a coaxial probe, with a circular polarization design. A single-pole six-throw radio frequency switch is used to multiplex each radiating element. Under control of a base station, the radio frequency switch connects one of the six radiating elements to the transceiver.
In some other existing solutions, there is provided another reconfigurable antenna. Similarly, this reconfigurable antenna includes a radio frequency feed port (at the center of the antenna) and six antenna branches. Each antenna branch includes one V-shaped planar dipole driven element, one V-shaped director and two straight reflectors. The resultant bent dipole can provide a directional radiation pattern with a horizontal polarization. The hexagonal-shaped ground section also plays a role of a main reflector. Besides, the director and the reflectors concentrate the directional radiation pattern and give an additional radiation gain.
However, the design of these reconfiguration antennas still has some problems. First of all, the existing reconfigurable antennas are a not wideband antennas, which would limit some algorithms and their deployment in multi-scenarios. Secondly, the number of switchable radiating elements is unsuitable. In most cases, the method of RSS positioning only uses two or three beams. More beam selectivity fails to improve the accuracy of the RSS much, but increases the complexity of control circuits. This view point is confirmed in some tests. Thirdly, the front-back ratio of the gain pattern is low. In order to reduce the interference from the back direction, the front-back ratio should be more than 20 dB and as great as possible. The front-back ratio of the existing antennas is just about 10 dB. Fourthly, it should be determined which one of the circular polarization and the linear polarization is better for the RSS depending on the specific indoor environments.
In view of the above analysis and discussion, to solve the various defects and deficiencies of the existing reconfigurable antennas, the embodiments of the present disclosure present a compact wideband pattern reconfigurable antenna. The structure of the antenna according to an embodiment of the present disclosure is first described with reference to
To radiate electromagnetic waves, a planar dipole radiating element 130 may be disposed on one side of the radiating plate 110. Although
The antenna 100 also includes three reflecting plates 120, 121 and 122 for reflecting the electromagnetic waves, such that the electromagnetic waves radiated by the radiating plates 110, 111 and 112 each have a respective directional radiation pattern. For example, in the embodiment of
Similarly, the reflecting plates 120 and 121 jointly reflect the electromagnetic waves radiated by the radiating plate 112, such that the electromagnetic waves of the radiating plate 112 have a substantially forward radiation pattern. The reflecting plates 121 and 122 jointly reflect the electromagnetic waves radiated by the radiating plate 111, such that the electromagnetic waves of the radiating plate 111 have a substantially forward radiation pattern.
It should be understood that the antenna 100 in
Additionally, the antenna 100 also includes a switch and the switch of the antenna 100 is not illustrated in
Moreover, the antenna 100 may further include a bottom plate 140 for fixing the radiating plates 110, 111 and 112 and the reflecting plates 120, 121 and 122. In some embodiments, the bottom plate 140 can also provide an electrical connection for the radiating plates 110, 111 and 112, such as a radio frequency electrical connection, a direct current electrical connection, etc. In these embodiments, the switch of the antenna 100 can also be disposed on the bottom plate 140. Besides, the antenna 100 may include a top plate 150 for further fixing the radiating plates 110, 111 and 112 and the reflecting plates 120, 121 and 122. In some embodiments, the electrical connection can also be provided for the radiating plates 110, 111 and 112 through the top plate 150.
In the following, the radiating plate 110 is taken as an example to describe the structure of the radiating plate of the antenna 100 with reference to
As shown in
The width W of the metal patch of the metal rings 131 and 132 can be arranged to broaden the operation bandwidth of the antenna 100 to a predetermined bandwidth. That is, the width of the metal rings 131 and 132 may be broadened relative to the width of microstrip lines of conventional microstrip dipoles, such that the antenna 100 may have a broader bandwidth, such as a −20 dB bandwidth greater than 200 MHz.
As further shown in
In the following, possible specific implementations of the antenna 100 will be described in detail with reference to
As shown in
In the embodiment depicted by
In the first embodiment of the bottom plate 140 as shown in
It is noted that the above specific values described with reference to
As mentioned above, the antenna according to the embodiments of the present disclosure may have other numbers of radiating plates and/or reflecting plates, which may have various other position relationships. For example,
As shown in
Besides, different from the antenna 100, the antenna 700 includes eight reflecting plates 720, 721, 722, 723, 724, 725, 726 and 727 for reflecting electromagnetic waves, such that the electromagnetic waves radiated by the radiating plates 710, 711, 712 and 713 each have a respective directional radiation pattern. For example, in the embodiment of
Under such an arrangement, the identical printed radiating plates 710, 711, 712 and 713 are arranged sequentially with an angle of 90 degrees to form the regular quadrangular prism 730 for example. The setting of the reflecting plates 720, 721, 722, 723, 724, 725, 726 and 727 is changed with respect to the setting of the reflecting plates in the antenna 100 to optimize the gain pattern and the return loss. Specifically, the reflecting plates 720, 724 and 727 jointly reflect the electromagnetic waves radiated by the radiating plate 710, such that the electromagnetic waves of the radiating plate 710 have a substantially forward radiation pattern.
Similarly, the reflecting plates 721, 724 and 725 jointly reflect the electromagnetic waves radiated by the radiating plate 711, such that the electromagnetic waves of the radiating plate 711 have a substantially forward radiation pattern. The reflecting plates 722, 725 and 726 jointly reflect the electromagnetic waves radiated by the radiating plate 712, such that the electromagnetic waves of the radiating plate 712 have a substantially forward radiation pattern. The reflecting plates 723, 726 and 727 jointly reflect the electromagnetic waves radiated by the radiating plate 713, such that the electromagnetic waves of the radiating plate 713 have a substantially forward radiation pattern.
The embodiments of the present disclosure provide a radiation pattern switchable reconfigurable antenna of broadband horizontal polarization at lower costs. The antenna is a proposed design for 5G indoor positioning applications, which can flexibly optimize its coverage to improve user experience and reduce interference. The antenna of the embodiments of the present disclosure may include the following features: a linear polarization antenna combination; selecting suitable radiating elements by a RF switch for feeding; a simplified feeding and control signal network; a bandwidth at least greater than 200 MHz (−20 dB); high gains and excellent performance in front-back ratio of the gain pattern. Furthermore, the antenna of the embodiments of the present disclosure may be manufactured with a printed circuit board (PCB) process to achieve higher precision and lower costs.
Compared with existing radiation pattern reconfigurable antennas having similar functions, the antenna according to the embodiments of the present disclosure has the following advantages. It has a compact size and utilizes the PCB process for manufacture to achieve higher precision and lower costs. It has a broader bandwidth, which is at least greater than 200 MHz (−20 dB) and far broader than existing antennas having similar functions. It has a simplified control circuit, which may use only one SP3T switch and require only three control signals. It has a better front-back ratio of the gain and improves positioning accuracy by reducing interference signals.
Furthermore, the embodiments of the present disclosure also provide a method for manufacturing the antenna as described above. As shown in
In some embodiments, the method 1000 includes disposing a planar dipole radiating element on one side of the plurality of radiating plates. In some embodiments, providing a planar dipole radiating element includes symmetrically disposing metal rings with respect to a symmetry axis. In some embodiments, rectangular metal rings may be provided. In some embodiments, a width of a metal patch of the metal rings may be set to broaden an operation bandwidth of the antenna to a predetermined bandwidth.
In some embodiments, an L-shaped feeding stub may be disposed on the other side of the plurality of radiating plates according to the manufacturing method 1000. In some embodiments, an end of the feeding stub may be connected to one of the metal rings through a via. In some embodiments, the planar dipole radiating element may be fed through a coaxial cable.
In some embodiments, the plurality of radiating plates may form sides of a regular prism. For example, in some embodiments, a regular triangular prism may be formed. Correspondingly, three radiating plates and three reflecting plates may be provided, wherein the three reflecting plates are respectively arranged in three planes defined by lateral edges and a center axis of the regular triangular prism.
In some embodiments, a regular quadrangular prism may be formed. Correspondingly, four radiating plates and eight reflecting plates may be provided, such that four of the eight reflecting plates are respectively in parallel with the four sides of the regular quadrangular prism and form an internal regular quadrangular prism inside the regular quadrangular prism. The other four reflecting plates are respectively positioned in the four planes defined by lateral edges of the internal regular quadrangular prism and the corresponding lateral edges of the regular quadrangular prism.
In some embodiments, the manufacturing method 1000 may further include providing a bottom plate for fixing the plurality of radiating plates and the plurality of reflecting plates. In some embodiments, the bottom plate also provides an electrical connection for the plurality of radiating plates. In some embodiments, the switch is disposed on the bottom plate.
In some embodiments, the manufacturing method 1000 may further include providing a top plate for fixing the plurality of radiating plates and the plurality of reflecting plates.
It should be understood that all features described above with reference to the exemplary structure of the antenna are applicable to the corresponding manufacturing method and will not be repeated here.
As used herein, the term “includes” and its variants are to be read as open-ended terms that mean “includes, but is not limited to.” The term “based on” is to be read as “based at least in part on.” The term “one embodiment” and “the embodiment” are to be read as “at least one example embodiment.”
The present disclosure has been described with reference to the several concrete embodiments. However, it should be understood that the present disclosure is not limited to the concrete embodiments disclosed herein. The present disclosure aims to encompass various modifications and equivalent arrangements included within the spirits and scope of the attached claims.
Number | Date | Country | Kind |
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201610711750.9 | Aug 2016 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2017/001106 | 8/23/2017 | WO | 00 |