Patent Application
20220123471
The present application claims the benefit of priority to Chinese Patent Application No. 202011100797.4, filed on Oct. 15, 2020, and to Chinese Patent Application No. 202110492981.6, filed on May 7, 2021, with the entire contents of each above-identified application incorporated by reference as if set forth herein.
The present disclosure generally relates to radio communications, and more specifically, the present disclosure relates to patch radiating elements and antenna assemblies.
Cellular communications systems are well known in the art. In a cellular communications system, a geographic area is divided into a series of sections that are referred to as “cells” which are served by respective base stations. The base station may include one or more base station antennas that are configured to provide two-way radio frequency (“RF”) communications with mobile subscribers that are within the cell served by the base station.
In many cases, each base station is divided into “sectors.” In perhaps the most common configuration, a hexagonally shaped cell is divided into three 120° sectors, and each sector is served by one or more base station antennas that have an azimuth Half Power Beam Width (HPBW) of approximately 65°. Typically, the base station antennas are mounted on a tower structure, with the radiation patterns that are generated by the base station antennas directed outwardly. Base station antennas are often realized as linear or planar phased arrays of radiating elements.
Patch radiating elements are attracting more and more attention because of their advantages such as low height, light weight, low cost, and high polarization purity. For example, arrays of such patch radiating elements can be used in beamforming antennas or to support massive multi-input-multi-output (MIMO) communications. As the number of patch radiating element arrays mounted on a reflector increases, intervals between patch radiating elements in different arrays are reduced. This leads to stronger coupling interference between the arrays. As a result, the isolation performance of the patch radiating elements deteriorates and the cross-polar discrimination is low, ultimately affecting the beamforming performance of the antenna.
Therefore, one of the objectives of the present disclosure is to provide a patch radiating element and an antenna assembly.
According to a first aspect of the present disclosure, a patch radiating element is provided, including: a feeder pillar, which is configured as a PCB feeder pillar; and a patch radiator, which is positioned at a specific position in front of the feeder pillar, wherein a grounded first loop circuit is provided on a first main surface of the feeder pillar, the first loop circuit has a first gap, a first feed circuit coupled to a first RF signal input is provided on a second main surface of the feeder pillar, the first feed circuit crosses the first gap to excite the first loop circuit, thereby feeding the patch radiator, wherein the first loop circuit includes a first opening ring configured to have a rectangular inner circumference and a first stub at at least a first corner of the first opening ring, and an opening of the first opening ring forms the first gap.
According to a second aspect of the present disclosure, a patch radiating element is provided, including: a feeder pillar, which is configured as a PCB feeder pillar; and a patch radiator, which is configured as a rectangular metal sheet and is positioned at a specific position in front of the feeder pillar, wherein a grounded first loop circuit is provided on a first main surface of the feeder pillar, the first loop circuit has a first gap, a first feed circuit coupled to a first RF signal input is provided on a second main surface of the feeder pillar, the first feed circuit crosses the first gap to excite the first loop circuit, thereby feeding the patch radiator, wherein the first main surface of the feeder pillar is further provided with a ground connection portion extending rearward from the first loop circuit, and the ground connection portion has a width smaller than the width of an outer periphery of the first loop circuit.
According to a third aspect of the present disclosure, an antenna assembly is provided, including: a reflector; a first array of first radiating elements arranged on the reflector, the first radiating elements being configured to transmit and receive signals in a first frequency band; and a second array of second radiating elements arranged on the reflector, the second radiating elements being configured to transmit and receive signals in a second frequency band, at least one frequency in the second frequency band being lower than all frequencies in the first frequency band, wherein the first radiating element includes: a feeder pillar, which extends forward from the reflector; and a patch radiator, which is positioned at a specific position in front of the feeder pillar, wherein the feeder pillar is configured as a PCB feeder pillar, a grounded first loop circuit is provided on a first main surface of the feeder pillar, the first loop circuit has a first gap, a first feed circuit coupled to a first RF signal input is provided on a second main surface of the feeder pillar, the first feed circuit crosses the first gap to excite the first loop circuit, so that the first loop circuit feeds the patch radiator in an electromagnetic coupling manner.
According to a fourth aspect of the present disclosure, an antenna assembly is provided, including: a first array of arranged first radiating elements, the first radiating elements being configured to transmit and receive signals in a first frequency band; and a second array of arranged second radiating elements, the second radiating elements being configured to transmit and receive signals in a second frequency band, and the second frequency band is lower than the first frequency band, wherein the first radiating element is the aforementioned patch radiating element.
According to a fifth aspect of the present disclosure, an antenna assembly is provided, including a reflector and a plurality of arrays of the aforementioned patch radiating elements mounted on the reflector.
A plurality of aspects of the present disclosure will be better understood after reading the following specific embodiments with reference to the appended drawings. In the appended drawings:
The present disclosure will be described below with reference to the appended drawings, and the appended drawings illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure may be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure of the present disclosure more complete and to fully explain the protection scope of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed in the present disclosure may be combined in various ways so as to provide more additional embodiments.
It should be understood that in all the appended drawings, the same reference numerals and signs denote the same elements. In the appended drawings, the dimensions of certain features can be changed for clarity.
It should be understood that the words in the specification are only used to describe specific embodiments and are not intended to limit the present disclosure. Unless otherwise defined, all terms (including technical terms and scientific terms) used in the specification have the meanings commonly understood by those skilled in the art. For brevity and/or clarity, well-known functions or structures may not be described further in detail.
The singular forms “a,” “an,” “the” and “this” used in the specification all include plural forms unless clearly indicated. The words “include,” “contain” and “have” used in the specification indicate the presence of the claimed features, but do not exclude the presence of one or more other features. The word “and/or” used in the specification includes any or all combinations of one or more of the related listed items. The words “between X and Y” and “between approximate X and Y” used in the specification shall be interpreted as including X and Y. As used herein, the wording “between about X and Y” means “between about X and about Y,” and as used herein, the wording “from about X to Y” means “from about X to about Y.”
In the specification, when an element is referred to as being “on,” “attached” to, “connected” to, “coupled” with, “contacting,” etc., another element, it can be directly on, attached to, connected to, coupled with or contacting another element or an intervening element may also be present. In contrast, if an element is described “directly” “on” another element, “directly attached” to another element, “directly connected” to another element, “directly coupled” to another element or “directly contacting” another element, there will be no intermediate elements. In the specification, a feature that is arranged “adjacent” to another feature, may denote that a feature has a part that overlaps an adjacent feature or a part located above or below the adjacent feature.
In the specification, words expressing spatial relations such as “upper,” “lower,” “left,” “right,” “front,” “rear,” “top,” and “bottom” may describe the relation between one feature and another feature in the appended drawings. It should be understood that, in addition to the orientations shown in the appended drawings, the words expressing spatial relations further include different orientations of a device in use or operation. For example, when a device in the appended drawings rotates reversely, the features originally described as being “below” other features now can be described as being “above” the other features. The device may also be oriented in other directions (rotated by 90 degrees or in other orientations), and in this case, a relative spatial relation will be explained accordingly.
Embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings.
Referring to
As shown in
In order to meet the requirements on frequency bandwidth and return loss (for example, 15 dB or higher) for modern base station antennas, the patch radiating element 10 may be configured as an air dielectric patch radiating element. The length of the feeder pillar 30 that can extend from the feed board 2 (the length of the feeder pillar 30 extending forward from the feed board 2 may also be described as the distance between the patch radiator 20 and the reflector 51, since the feed board 2 is usually disposed on the front surface of the reflector 51) may be less than 0.2λ, for example, 0.05 to 0.15λ, 0.08 to 0.12λ, or about 0.1λ, wherein, λ is a wavelength corresponding to a center frequency of an operating frequency band of the patch radiating element 10. Therefore, the height of the patch radiating element 10 can be selected to be lower than the height of some conventional radiating elements, which have a feeder pillar height close to 0.25λ. Of course, it is not intended to limit feeder pillars having a higher dimension. In addition, the patch radiating element 10 may be designed as a dual-polarized patch radiating element. As shown in
Still referring to
In some embodiments, the second patch portion 22 may extend from the outer end portion of the first patch portion 21 at any angle. For example, the angle between the second patch portion 22 and the first patch portion 21 may be 60° to 120°, or 80° to 100°. In the embodiment of
Additionally or optionally, the patch radiator 20 may be a sheet metal radiator. The sheet metal radiators are advantageous in that: firstly, the sheet metal radiators can easily realize bending of metal plates, and thus each second patch portion 22 can be integrally shaped with the first patch portion 21; secondly, the cost of the sheet metal radiators can be lower; thirdly, the sheet metal radiators may be formed to have any desired thickness, and hence may exhibit improved impedance matching and/or reduced signal transmission losses; fourthly, the sheet metal radiators may be readily provided with low levels of surface roughness, which may result in improved passive intermodulation (“PIM”) distortion performance.
Additionally or optionally, the first patch portion 21 may be configured as regular shapes, for example, a polygonal metal sheet, a rectangular metal sheet, or a square metal sheet. In the embodiments of
It should be understood that the number, shape, and connection relation of the first patch portion 21 and/or the second patch portion 22 are not limited. In other embodiments, the first patch portion 21 may be configured as a metal sheet with an arc. In other embodiments, it is also possible that a part of the side edges of the first patch portion 21 is connected with the corresponding second patch portion 22.
Additionally or optionally, the second patch portion 22 may be configured as a rectangular metal strip or a metal strip with an arc. In the embodiment of
Next, the feeder pillar 30 of the patch radiating element 10 according to some embodiments of the present disclosure will further be described in detail with reference to
As shown in
The second metal pattern 32 is provided on the second main surface opposite to the first main surface of the feeder pillar 30. As shown in
Additionally or optionally, the grounded metal section 36 in the second metal pattern 32 may further include a first inductive circuit loop 37 with a first gap 371 and a second inductive circuit loop 38 with a second gap 381. The first transmission line 401 in the first metal pattern 31 corresponds to the first inductive circuit loop 37, and the second transmission line 402 in the first metal pattern 31 corresponds to the second inductive circuit loop 38. In other words, the first transmission line 401 on the second main surface is within a perimeter of the first inductive circuit loop 37 on the opposite first main surface, and the second transmission line 402 on the second main surface is within a perimeter of the second inductive circuit loop 38 on the opposite first main surface. In addition, the second feed end 42 and the third feed end 43 in the first metal pattern 31 may be respectively configured as an open stub functioning as a capacitor. In this way, a dual LC resonator can be formed on the feeder pillar 30. That is, the first inductive circuit loop 37 and the second feed end 42 function as a first LC resonator, and the second inductive circuit loop 38 and the third feed end 43 function as a second LC resonator. Since the patch radiator 20 can be equivalent to an RLC parallel resonator, the dual LC resonator can provide more flexible and balanced tuning for the patch radiator 20. Since the patch radiator 20 is transformed from a conventional two-dimensional radiator to a three-dimensional radiator, the equivalent capacitance and/or equivalent inductance parameters of the patch radiator 20 itself may change. The dual LC resonator on the feeder pillar 30 can at least partially compensate or balance the LC parameter changes of the patch radiator 20, and thus can maintain good RF performance, for example, return loss, operating bandwidth, or cross-polar discrimination, etc., given that the horizontal size of the patch radiator 20 is reduced.
Additionally or optionally, longitudinal barriers and/or transverse barriers may be provided for the patch radiating elements 10 to further reduce the coupling interference between adjacent patch radiating elements 10, thereby improving the radiation pattern of the antenna.
A patch radiating element 10 according to some embodiments of the present disclosure will be described below with reference to
The patch radiating element 10 includes a feeder pillar 301 and a feeder pillar 302, and a patch radiator 20 positioned at a specific position in front of (above, in the view direction of
The structure of the feeder pillar 301 will be described below with reference to
The first loop circuit includes an opening ring 611 configured to have a rectangular inner circumference (as shown by the broken lines in the figure). An opening of the opening ring 611 forms a gap 612 of the first loop circuit. In the illustrated embodiment, the gap 612 is located at a front portion (an upper portion in the view direction of
Each loop circuit is configured such that its resonance frequency is substantially the same as a resonance frequency of the patch radiator 20, and the resonance frequency of the first loop circuit and the resonance frequency of the second loop circuit are the same in order to feed the patch radiator 20. The resonance frequency of the loop circuit is related to the length of its current path, that is, related to the perimeter of the inner circumference of the opening ring 611 or 615. The stubs 613 and 617 are provided on the inner circumferences of the opening rings 611 and 615, and the impedance of the loop circuits can be changed without changing the perimeter of the inner circumference of the opening ring 611 or 615, that is, without changing the resonance frequencies of the loop circuits. Therefore, the aforementioned method of setting the stubs 613 and 617 can be used to adjust the impedance matching state of the patch radiating element 10. In the illustrated embodiment, the stub is only provided at the lower left corner of the inner circumference of the first loop circuit and the lower right corner of the inner circumference of the second loop circuit. It should be understood that in other embodiments, one or more stubs may be provided at any one or more corners of the rectangular inner circumference of each loop circuit, as long as the position, shape, size and other characteristics of the stubs in the first loop circuit and the second loop circuit are substantially symmetrical about the first axis X1.
Similar to the description above with reference to
In the illustrated embodiment, the first loop circuit further includes a ground connection portion 614 extending rearward (downward in the view direction of
The width W1 of the ground connection portions 614 and 618 being smaller than the width W2 of the outer periphery of the corresponding opening rings 611 and 615 reduces the size of a portion used to connect the feeder pillars 301 and 302 with a feed board (for example, the feed board 2 in
As described above, the length of the feeder pillar of the radiating element 81 implemented as a patch radiating element extending forward from the feed board is usually less than 0.2 λ1, for example, from 0.05 to 0.15 λ1, from 0.08 to 0.12 λ1, or may be about 0.1 λ1 (λ1 is the wavelength corresponding to the center frequency of a high frequency band in which the radiating element 81 works). This makes the current path in the radiating element 81 not equal to 0.5 λ1, that is, basically not exactly equal to 0.25 λ2 (where λ2 is the wavelength corresponding to the center frequency of a low frequency band in which the radiating element 82 works), and thus the radiating element 81 implemented as a patch radiating element will not generate ¼ wavelength resonance to the radiating element 82. Therefore, the multi-band antenna assembly according to some embodiments of the present disclosure can prevent the common mode resonance generated by the radiating element working in the high frequency band from affecting the radiation pattern of the radiating element working in the low frequency band.
Although exemplary embodiments of the present disclosure have been described, those skilled in the art should understand that many variations and modifications are possible in the exemplary embodiments without materially departing from the spirit and scope of the present disclosure. Therefore, all variations and modifications are included in the protection scope of the present disclosure defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202011100797.4 | Oct 2020 | CN | national |
| 202110492981.6 | May 2021 | CN | national |
