Patent Application
20250030157
The present application claims priority to Chinese Patent Application No. 202310876728.X, filed Jul. 17, 2023, the entire content of which is incorporated herein by reference as if set forth fully herein.
The present disclosure relates to the field of communication, in particular, to a radio frequency device and a base station antenna.
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 order to accommodate the ever-increasing volumes of cellular communications, cellular operators have added cellular services in a variety of new frequency bands. In some cases, it is possible to use linear arrays of so-called “wide-band” or “ultra wide-band” radiating elements to provide service in multiple frequency bands. Therefore, for example, a radiating element operating within a frequency range of 1.7 to 2.7 GHz can be used to support cellular services in multiple different frequency bands. Base station antennas may also typically include multiple radiating element arrays, and these arrays are designed to operate in different frequency bands. For example, in a common multi-band antenna design, an antenna may have one or more linear arrays of “low-band” radiating elements configured to provide services in some or all of the 617-960 MHz bands, and one or more linear arrays of “mid-band” radiating elements configured to provide services in, for example, some or all of the 1427-2690 MHz bands.
In addition to the radiating element, the base station antenna includes a variety of radio frequency devices, such as phase shifters, filters, and power dividers. A phase shifter is a device that is capable of adjusting the phase of a radio signal. Phase shift may be introduced to a radio frequency signal by transmitting the radio frequency signal in a medium. The phase shifter is a device that uses this principle to change the phase of the radio frequency signal. Most modern multi-band antennas include a phase shifter to adjust the radiation pattern produced by each radiating element array, or the downtilt angle of an “antenna beam.” Such downtilt angle adjustment may be used to adjust the coverage area of each radiating element array.
However, with the integration of more and more frequency bands and more and more functional modules (for example, phase shifters, filters, coaxial cables and radiating element arrays, etc.) in the base station antenna, the installation space and/or operation space (such as welding space) in the base station antenna is further restricted. This causes the design size of some radio frequency devices, for example, phase shifters or filters, to be subject to strict restrictions. A limited design size may result in smaller gaps between transmission lines within the radio frequency device, creating undesirable coupling interference between transmission lines that may negatively affect radio frequency performance of the radio frequency device.
One aspect of the present disclosure relates to a radio frequency device, wherein the radio frequency device comprises: a substrate; a conductive circuit disposed on the substrate, the conductive circuit configured to transmit a signal and comprising a plurality of segments of transmission lines; and a decoupling element disposed on the substrate positioned between adjacent first and second segments of transmission lines, the decoupling element comprising a first arm adjacent to the first segment of transmission line, a second arm adjacent to the second segment of transmission line, and a connecting portion connecting the first and second arms, the decoupling element configured to at least partially reduce coupling between the first and second segments of transmission lines.
According to an embodiment of the present disclosure, by providing a decoupling element between two adjacent segments of transmission lines in a shorter distance in a conductive circuit of a circuit board of a radio frequency device, coupling between the two segments of transmission lines can be at least partially reduced, thereby improving radio frequency performance of the radio frequency device including the circuit board, e.g., reducing return loss and reducing insertion loss.
In some examples, the first arm of the decoupling element is generally parallel to the second arm.
In some examples, the first arm of the decoupling element is generally parallel to the first segment of transmission line and the second arm of the decoupling element is generally parallel to the second segment of transmission line.
In some examples, the first arm and the second arm of the decoupling element are substantially equal in length.
In some examples, the decoupling element is generally U-shaped.
In some examples, an operating frequency band of the radio frequency device comprises a first frequency band and the decoupling element has a length that is between one fifth and one third of a wavelength at a central frequency of the first frequency band.
In some examples, the length of the decoupling element is about a quarter of the wavelength at the central frequency of the first frequency band.
In some examples, the decoupling element is a first decoupling element, wherein the operating frequency band of the radio frequency device comprises a second frequency band different from the first frequency band, and wherein the radio frequency device comprises a second decoupling element whose length is between one fifth and one third of a wavelength at a central frequency of the second frequency band.
In some examples, the length of the second decoupling element is about a quarter of the wavelength at the central frequency of the second frequency band.
In some examples, a plurality of decoupling elements are arranged between the adjacent first and second segments of transmission lines, the plurality of decoupling elements arranged sequentially along a direction of space between the first and second segments of transmission lines, at least a first portion of the plurality of decoupling elements including the first decoupling element, and at least a second portion of the plurality of decoupling elements including the second decoupling element.
In some examples, the decoupling element is generally H-shaped or A-shaped.
In some examples, the decoupling element is a first decoupling element having a first shape, and wherein the radio frequency device comprises a second decoupling element having a second shape that is different from the first shape.
In some examples, the radio frequency device comprises a plurality of decoupling elements arranged sequentially along a direction of space between the first and second segments of transmission lines, the plurality of decoupling elements including the first and second decoupling elements.
In some examples, the decoupling element is a first decoupling element having a first shape and a first orientation, and wherein the radio frequency device comprises a second decoupling element having the first shape and a second orientation different from the first orientation.
In some examples, the radio frequency device comprises a plurality of decoupling elements arranged sequentially along a direction of space between the first and second segments of transmission lines, the plurality of decoupling elements including the first and second decoupling elements.
In some examples, a distance between the two adjacent segments of transmission lines is less than 10 mm. In other examples, a distance between the two adjacent segments of transmission lines is less than 4 mm. In some examples, at least one of the two adjacent segments of transmission lines is serpentinely coiled.
In some examples, the substrate comprises a first surface and a second surface opposite to the first surface, the conductive circuit comprises a first conductive circuit disposed on the first surface and a second conductive circuit disposed on the second surface, and the first conductive circuit is electrically connected to the second conductive circuit via a conductive structure.
In some examples, the first conductive circuit is symmetrical with the second conductive circuit relative to the substrate.
In some examples, the radio frequency device is configured as a phase shifter, a filter, a power divider, a duplexer, a feeder panel, or a combiner.
In some examples, the radio frequency device is configured as a cavity phase shifter.
In some examples, the cavity phase shifter is configured as a vertical feed cavity phase shifter.
Another aspect of the present disclosure relates to a radio frequency device, wherein the radio frequency device comprises: a substrate; a conductive circuit disposed on the substrate, the conductive circuit configured to transmit a signal and including multiple segments of transmission lines; and a decoupling element disposed between adjacent first and second segments of transmission lines of the conductive circuit, the decoupling element having a substantially U-shaped shape.
In some examples, the first arm of the decoupling element is generally parallel to the second arm.
In some examples, the first arm and the second arm of the decoupling element are substantially equal in length.
In some examples, an operating frequency band of the radio frequency device comprises a first frequency band and the decoupling element has a length that is about a quarter of a wavelength at a central frequency of the first frequency band.
In some examples, the decoupling element is a first decoupling element, wherein the operating frequency band of the radio frequency device comprises a second frequency band different from the first frequency band, and wherein the radio frequency device further comprises a second decoupling element whose length is about a quarter of a wavelength at a central frequency of the second frequency band.
In some examples, the decoupling element is a first decoupling element having a first orientation, and wherein the radio frequency device comprises a second decoupling element that has a second orientation that is different from the first orientation.
In some examples, a distance between the two adjacent segments of transmission lines is less than 4 mm.
In some examples, at least one of the transmission lines is serpentinely coiled.
In some examples, the substrate comprises a first surface and a second surface opposite to the first surface, the conductive circuit comprises a first conductive circuit disposed on the first surface and a second conductive circuit disposed on the second surface, and the first conductive circuit is electrically connected to the second conductive circuit via a conductive structure, wherein the first conductive circuit is symmetrical with the second conductive circuit relative to the substrate.
In some examples, the radio frequency device is configured as a cavity phase shifter.
Still another aspect of the present disclosure relates to a base station antenna, including: the radio frequency device as described above; and a radiating element array, where the radio frequency device is electrically connected to at least some radiating elements in the radiating element array.
The above-mentioned technical features, the technical features to be mentioned below and the technical features shown separately in the drawings may be arbitrarily combined with each other as long as the combined technical features are not contradictory. All feasible feature combinations are technical contents clearly recorded herein. Any one of a plurality of sub-features contained in the same sentence may be applied independently without necessarily being applied together with other sub-features.
Note, in the examples described below, the same reference signs are sometimes jointly used between different attached drawings to denote the same parts or parts with the same functions, and repeated descriptions thereof are omitted. In this Specification, similar labels and letters are used to indicate similar items. Therefore, once an item is defined in one attached drawing, it does not need to be further discussed in subsequent attached drawings.
For ease of understanding, the position, dimension, and range of each structure shown in the attached drawings and the like may not indicate the actual position, dimension, and range. Therefore, the disclosed invention is not limited to the positions, dimensions, and ranges disclosed in the attached drawings and the like.
The present disclosure will be described below with reference to the attached drawings, wherein the attached drawings illustrate certain examples 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 examples described below; in fact, the examples 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 of ordinary skill in the art. It should also be understood that the examples disclosed in the present disclosure may be combined in various ways so as to provide more additional examples.
It should be understood that the terms used herein are only used to describe specific examples, and are not intended to limit the scope of the present disclosure. All terms used herein (including technical terms and scientific terms) have meanings normally understood by those skilled in the art unless otherwise defined. For brevity and/or clarity, well-known functions or structures may not be further described in detail.
As used herein, when an element is said to be “on” another element, “attached” to another element, “connected” to another element, “coupled” to another element, or “in contact with” another element, etc., the element may be directly on another element, attached to another element, connected to another element, coupled to another element, or in contact with another element, or an intermediate element may be present. In contrast, if an element is described as “directly on” another element, “directly attached” to another element, “directly connected” to another element, “directly coupled” to another element or “directly in contact with” another element, there will be no intermediate elements. As used herein, when one feature is arranged “adjacent” to another feature, it may mean that one feature has a part overlapping with the adjacent feature or a part located above or below the adjacent feature.
As used herein, spatial relationship terms such as “upper”, “lower”, “left”, “right”, “front”, “back”, “high”, and “low” can explain the relationship between one feature and another in the drawings. It should be understood that, in addition to the orientations shown in the attached drawings, the terms expressing spatial relations also comprise different orientations of a device in use or operation. For example, when a device in the attached 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 by other means (rotated by 90 degrees or at other positions), and at this time, a relative spatial relation will be explained accordingly.
As used herein, the term “A or B” comprises “A and B” and “A or B”, not exclusively “A” or “B”, unless otherwise specified.
As used herein, the term “schematic” or “exemplary” means “serving as an example, instance or explanation”, not as a “model” to be accurately copied. Any realization method described exemplarily herein may not be necessarily interpreted as being preferable or advantageous over other realization methods. Furthermore, the present disclosure is not limited by any expressed or implied theory given in the above technical field, background art, summary of the invention or examples.
As used herein, the word “basically” means including any minor changes caused by design or manufacturing defects, device or component tolerances, environmental influences, and/or other factors.
In addition, for reference purposes only, “first”, “second” and similar terms may also be used herein, and thus are not intended to be limitative. For example, unless the context clearly indicates, the words “first”, “second” and other such numerical words involving structures or elements do not imply a sequence or order.
It should also be understood that when the term “comprise/include” is used herein, it indicates the presence of the specified feature, entirety, step, operation, unit and/or component, but does not exclude the presence or addition of one or a plurality of other features, steps, operations, units and/or components and/or combinations thereof.
The present disclosure provides a radio frequency device, including a substrate, a conductive circuit disposed on the substrate, and at least one decoupling element disposed on the substrate. The conductive circuit is configured to transmit a signal and can include multiple segments of transmission lines. Each decoupling element is positioned between two adjacent segments of transmission lines and includes a first arm, a second arm, and a connecting portion connecting the first arm and the second arm. Each decoupling element may be configured to at least partially reduce coupling between the two segments of transmission lines, thereby improving radio frequency performance of the radio frequency device, e.g., reducing return loss and reducing insertion loss.
It should be understood that the radio frequency device mentioned in the present disclosure may be a variety of functional devices applied in base station antennas, and is not limited to the type of devices described in specific examples. In some examples, the radio frequency device may be a phase shifter or a power divider. In other examples, the radio frequency device may be a filter, a duplexer, a feeder panel, or a combiner. The radio frequency device according to the present disclosure may be electrically connected to at least some radiating elements in a radiating element array in the base station antenna.
Next, the radio frequency device according to some embodiments of the present disclosure is described in detail with a cavity phase shifter as an example.
As various radiating element arrays in the base station antenna 1 and various radio frequency devices become increasingly integrated, conductive circuits on the circuit board in the radio frequency device are becoming more dense, resulting in a very narrow spacing between many adjacent transmission lines of the conductive circuit. In the illustrated example, multiple cavity phase shifters 4 are mounted at a distance from each other to the rear side of the reflector 2. The circuit boards 6 in the various cavity phase shifters 4 may be disposed substantially perpendicular to the reflector 2, thereby forming vertical feed cavity phase shifters 4. Subject to the design space in the base station antenna 1, such a cavity phase shifter 4 is generally constructed to have an elongated profile, i.e., the transverse dimension of the cavity phase shifter 4 perpendicular to the reflector 2 is much smaller than its longitudinal dimension parallel to the reflector 2 and extending along the longitudinal direction of the base station antenna 1. The interior dimensions of such cavity phase shifter 4 are particularly compact, resulting in particularly limited placement space for the conductive circuits on the circuit board 6 therein. For example, the distance between two adjacent segments of transmission lines at some locations of the circuit board 6 in the cavity phase shifter 4 is less than 10 mm, 6 mm, or even less than 4 mm. The arrangement of such a compact conductive circuit can result in undesirable electromagnetic coupling between adjacent transmission lines. Electromagnetic coupling may also be referred to as mutual inductance coupling. When two segments of transmission lines are closer, there may be mutual inductance between the two segments of transmission lines, so that a current change in each segment of transmission line may affect the other transmission line by mutual inductance, resulting in an energy transfer between the two segments of transmission lines. Such electromagnetic coupling can cause undesirable conditions such as increased return loss and insertion loss, and deformation of gain distribution.
As further shown in
As shown in
Advantageously, the two arms 11 of the decoupling element 9 may be disposed substantially parallel to each other. Advantageously, the two arms 11 of the decoupling element 9 may be disposed substantially parallel to the respective transmission lines 10 adjacent to the two arms 11. Advantageously, where the transmission line 10 adjacent to the decoupling element 9 is not straight (e.g., the serpentine or meandered transmission line seen in
The decoupling element 9 may be formed as approximately upper U-shaped. It will be understood that the “U” shape referred to herein should be broadly understood as having two arms with same or different lengths, with the two arms connected at end portions thereof. Thus, as seen in
It will be understood that the shape of the decoupling element 9 is not limited to be U-shaped, but may also be H-shaped, A-shaped, or the like, as shown in
It will be understood that the decoupling element 9 described above is not limited to the circuit board 6 applied to the cavity phase shifter 4, or may be a circuit board applied to other types of phase shifters, or may be a circuit board applied to other radio frequency devices (e.g., filters, power dividers, duplexers, feeder panels, or combiners) of the base station antenna 1.
According to an embodiment of the present disclosure, by providing a decoupling element between two adjacent segments of transmission lines in a shorter distance in a conductive circuit of a circuit board of a radio frequency device, coupling between the two segments of transmission lines can be at least partially reduced, thereby improving radio frequency performance of the radio frequency device including the circuit board, e.g., reducing return loss and reducing insertion loss.
Although some specific examples of the present disclosure have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration rather than for limiting the scope of the present disclosure. The examples disclosed herein can be combined arbitrarily without departing from the spirit and scope of the present disclosure. Those skilled in the art should also understand that various modifications can be made to the examples without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the attached claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202310876728.X | Jul 2023 | CN | national |
