Patent Application
20180006363
In some embodiments, the present disclosure relates to an antenna device applicable to a base station and a relay station in a mobile communication (PCS, cellular, CDMA, GSM, LTE, etc.) network. More particularly, the present disclosure in some embodiments relates to a signal distributing/combining apparatus for distributing or combining radio frequency (RF) signals in an antenna device.
Generally, a base station or a relay station (hereinafter collectively referred to as “base station”) of a mobile communication system has been divided into a base station main unit configured to process transmit and receive signals and an antenna device including a plurality of radiating elements for transmitting/receiving radio signals. The base station main unit is usually installed at a low position on the ground, and the antenna device is installed at a high position such as a building roof or a tower, and the base station main unit and the antenna device may be connected to each other through a feeding cable or the like.
The antenna device of the base station includes a plurality of radiating elements for transmitting/receiving high frequency radio signals. At this time, the radiating elements are installed on one surface (for example, the front surface) of a metal reflecting plate having a relatively large area. Further, the antenna device is provided with various circuits or devices for processing signals transmitted and received via the plurality of radiating elements, and, for example, the circuits or devices may be fixedly installed on the back face of the reflecting plate. Such devices may include a phase shifter for adjusting the phase of the signals of the multiple radiating elements, and an apparatus for distributing/combining the transmit and receive signals of the internal devices and the radiating elements. At this time, the respective devices may be connected via a signal transmission line, and a substantial portion of which is formed of coaxial cable.
Meanwhile, in the antenna device of such a structure, it is a serious matter, in addition to having the required transmission/reception properties of the signal for the band, to suppress PIMD (Passive Intermodulation Distortion) generated by discontinuous contact surfaces, unstable connection state or other causes in the respective device structure itself and at the connections between devices.
In this case, the antenna device almost invariably requires a signal distributing/combining apparatus and the structure for making connections through soldering a coaxial cable to that signal distributing/combining apparatus, which in turn requires effective measures to suppress PIMD that can be generated due to unstable connection state occurring at the connections between the signal distributing/combining apparatus and the coaxial cable or due to nonuniform soldering state, etc.
Therefore, in some embodiments, the present disclosure seeks to provide a signal distributing/combining apparatus in a mobile communication base station antenna apparatus, which is capable of suppressing the PIMD generated at the connection with the coaxial cable, stabilizing the quality of soldering at the connection, and stabilizing the grounding quality of the apparatus.
In accordance with some embodiments of the present disclosure, a signal distributing/combining apparatus in an antenna device of a mobile communication base station includes a circuit board and a support plate. The circuit board is configured to have an upper surface formed with a signal distributing/combining conductor pattern for a high frequency signal distributing/combining operation. The support plate is configured to have an upper mounting surface of a size corresponding to the circuit board, to mate with the circuit board so that an underside of the circuit board is in close contact with the upper mounting surface for supporting the circuit board, and to fixedly mate with the antenna device at a reflection plate on a bottom side of the support plate. Here, the support plate is provided with a plurality of cable holders for supporting and fixating coaxial cables for signal transmission, which are connected from outside of the signal distributing/combining apparatus, the signal distributing/combining conductor pattern is formed with a plurality of signal input/output portions. The plurality of cable holders is formed on the signal distributing/combining conductor pattern at portions corresponding to at least some of the plurality of signal input/output portions, the cable holders having a structure formed elongated longitudinally and corresponding to outer conductors of the coaxial cables in order to mount the coaxial cable by inserting the outer conductors.
The cable holders may be formed at predetermined positions in the support plate such that inner conductors of the coaxial cables are placed in contact with the upper surface of the circuit board.
The underside of the circuit board and the upper mounting surface of the support plate for mounting the circuit board may be bonded together with a solder cream which is melted and cured with a reflow soldering method.
The upper surface of the circuit board may be formed with a coupling conductor pattern for generating a coupling signal in a non-contact coupling scheme with the signal distributing/combining conductor pattern.
The upper surface of the circuit board may be formed with a ground conductor pattern in a peripheral region adjacent to the signal distributing/combining conductor pattern and the coupling conductor pattern, and the ground conductor pattern may have a plurality of via holes for making an electrical connection with grounding layer on the underside of the circuit board.
The support plate may have open areas, and include a plurality of cable holders corresponding respectively to the coaxial cables for mounting the coaxial cables connected to the underside of the circuit board after passing through the open areas.
The support plate may include multiple fastening protrusions which protrude downwardly of the support plate and are respectively formed with screw fastening recesses for screw fastening with a reflection plate of the antenna device.
The support plate may include a mounting surface configured to mount the circuit board and to have one or more partition members formed in a predetermined length and a predetermined height. The circuit board may have one or more slots to be coupled with the partition members in such a manner that the partition members are inserted. And the partition members may be formed so as to protrude from the upper surface of the circuit board on which the conductor pattern is formed to a preset height.
As described above, the signal distributing/combining apparatus in the mobile communication base station antenna device according to at least one embodiment of the present disclosure can suppress the PIMD generated at the connection with the cable, stabilize the quality of the soldering at the connection, and stabilize the grounding quality of the apparatus.
Hereinafter, at least one embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, specific details such as specific components are disclosed, which are provided only for a better understanding of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the idea or the scope of the disclosure. In the following description, like reference numerals designate like elements as possible, although the elements are shown in different drawings, wherein some reference numerals are refrained from being shown to avoid excessively complicating the drawings.
Further, a signal distributing/combining apparatus 7 according to at least one embodiment of the present disclosure may be provided, for example, in a central portion on the back surface of the reflection plate 1 of the antenna device. For example, the signal distributing/combining apparatus 7 receives transmitted signals input from the base station's main unit device (not shown) outside the antenna device and distributes the input signals to the antenna's interior devices including the upper and lower phase shifters 6, 5, and it combines the receive signals received via the radiating elements of the antenna device and outputs the combined signals to the base station main unit side.
In addition, the radome 4 of the antenna device may be provided with other additional distributing/combining circuits, or amplifiers, filters, etc. and it may be appropriately installed with various electronic components (not shown) such as a detection circuit for detecting various operational states of the antenna including signal transmission quality and a main control device (e.g., an MCU etc.) for controlling the overall operation. However, for convenience of explanation, illustration of these electronic components is omitted in
Meanwhile, as shown in
On the other hand, the signal distributing/combining apparatus 7 may be mainly provided with a printed circuit board on which a conductor pattern is formed for high frequency signal distributing/combining. When connecting a coaxial cable to a printed circuit board, it is typical to apply a method of soldering the inner conductor of the coaxial cable to the input/output end of the conductor pattern. Likewise, when connecting the coaxial cable to the signal distributing/combining apparatus 7, the interconnection is also made by a soldering method, but in this case, the signal distributing/combining apparatus 7 according to some embodiments, as will be described later, provides a structure capable of suppressing the occurrence of PIMD, particularly at the connecting portion of the coaxial cable.
Referring to
As indicated by a dotted box in
In addition to the signal distributing/combining conductor pattern 742, the circuit board 74 of the signal distributing/combining apparatus 7 may be provided with a coupling conductor pattern 743 for generating a coupling signal in a non-contact coupling scheme with the signal distributing/combining conductor pattern 742. The coupling signal generated by the coupling conductor pattern 743 may be transmitted to the relevant device in order to confirm the quality of the signal transmitted from the corresponding signal distributing/combining conductor pattern 742.
In order to improve the grounding characteristics of the signal distributing/combining conductor pattern 742 and the coupling conductor pattern 743, the circuit board 74 may be further provided, on its upper surface, with a ground conductor pattern 745 in a peripheral region adjacent to the signal distributing/combining conductor pattern 742 and the coupling conductor pattern 743. In the ground conductor pattern 745, particularly at its edge portion, a large number of via holes (reference numeral 7452 in
The support plate 72 of the signal distributing/combining apparatus 7 is coupled to the circuit board 74 in a manner that it is in close contact with the lower surface of the circuit board 74, and some embodiments of the present disclosure feature a soldering method for bonding the underside of the circuit board 74 and the upper mounting surface of the support plate 72 for mounting the circuit board 74. For example, the circuit board 74 may be printed with a solder cream where it is joined to the support plate 72, and the circuit board 74 printed with the solder cream may be mounted on the mounting surface of the support plate 72, and thereafter the solder cream may be melted and cured with a reflow soldering method within a high heat furnace. At this time, depending on the material of the support plate 72, in order to enable the soldering operation on the support plate 72 or to improve the quality of soldering, corresponding portions to the solder cream may undergo a plating treatment in advance with a material such as tin. In this way, joining by the circuit board 74 and the support plate 72 by using the reflow soldering method can remarkably stabilize the ground contact quality of the circuit board 74 and the support plate 72.
Further, the support plate 72 may have some areas removed to form a plurality of open areas (indicated by A in
The support plate 72 is also provided with a plurality of cable holders 722 for supporting and fixating coaxial cables for signal transmission. The multiple cable holders 722 each corresponds to the shape and diameter (including some clearance) of the outer conductor of the coaxial cable, in order to mount the coaxial cable in a manner that the outer conductor of the coaxial cable is embedded or placed, by having, for example, a U-shaped structure formed elongated longitudinally.
In the circuit board 74 mounted on the support plate 72, a plurality of signal input/output sections of the signal distributing/combining conductor pattern 742, that is, its areas to be connected with the coaxial cable may be at least partially configured to be formed at one edge of the circuit board 74. To this end, the multiple cable holders 722 are formed in portions corresponding to the plurality of signal input/output portions of the signal distributing/combining conductor pattern 742. Further, the portions where the cable holders 722 are formed are suitably designed in consideration of the thickness of the circuit board 74 or the like so that inner conductors of the coaxial cables fixed by the cable holders 722 are not spaced apart from the upper surface of the circuit board 74 but exactly aligned with the signal input/output portions of the signal distributing/combining conductor pattern 742.
The cable holders 722 may be formed to protrude laterally from one side of the support plate 72, and the support plate 72 including such multiple cable holders 722 may be integrally formed, for example, through a die-casting process.
Once the coaxial cables are attached to the cable holders 722 having such a configuration, soldering work is carried out at the contact portions between the cable holder 722 and the outer conductors of the coaxial cables and at the contact portions between the inner conductors of the coaxial cable and the conductor pattern of the circuit board 74 so that the support plate 72 and the coaxial cable are fixedly connected electrically and mechanically. This method of connecting the coaxial cable for signal transmission to the support plate 72 by utilizing the cable holders 722 enables accurate and uniform processing together with ease of work, and further enables the product after the processing to firmly maintain the connection state between the support plate 72 and the coaxial cables in the actual use environment. This can substantially suppress PIMD that can be generated in the connection part between the relevant signal distributing/combining apparatus and the coaxial cable.
Meanwhile, some of the signal input/output portions of the signal distributing/combining conductor pattern 742 and/or the coupling conductor pattern 743 on the circuit board 74 mounted on the support plate 72 may be formed to connect with the coaxial cable(s) via the underside of the circuit board 74. In that case, the corresponding coaxial cable is connected to the circuit board 74 on the underside of the support plate 72 through the open areas formed in the support plate 72. In other words, the pattern design may dictate some of the signal input/output portions of the conductor pattern to be formed on the circuit board 74 inwardly rather than peripherally of the circuit board 74. In that case, the relevant portions are formed with holes (reference numeral 748 in
The support plate 72 may be further provided on its underside with a plurality of cable holders 729 for fixedly and/or supportively mount the coaxial cables connected to the underside of the circuit board 74. The multiple cable holders 729 each corresponds to the shape and diameter of the coaxial cable, in order to mount the coaxial cable in a manner that the outer conductor of the coaxial cable is embedded or placed, by having at least, for example, a U-shaped groove formed on the lower surface of the support plate 72.
Further, as shown in
The support plate 72 may be provided with additional structures for other functions such as facilitating the coupling operation with the circuit board 74 and securing the coupled state. For example, a guardrail member 725 may be formed on the support plate 72 so as to surround at least a part of a mounting surface on which the circuit board 74 is mounted. In addition, the support plate 72 may be formed, on the mounting surface for the circuit board 74, with one or more coupling protrusion members 726, and in correspondence therewith, the circuit board 74 may have one or more coupling holes 749 to be coupled with the coupling protrusion members 726 in such a manner that the coupling projection members 726 are inserted. Further, in the support plate 72, one or more partition members 728 may be formed in an appropriate length, and in correspondence therewith, the circuit board 74 may have one or more slots 747 to be coupled with the partition members 728 in such a manner that the partition members 728 are inserted.
The partition member 728 formed on the support plate 72 is configured to function not only to facilitate the coupling operation and maintain a stable coupling state between the support plate 72 and the circuit board 74 but also to prevent signal leakage or interference of signals between the conductor patterns formed on the circuit board 74. For example, the partition member 728 is formed so as to protrude from the upper surface of the circuit board 74 on which the conductor pattern is formed to a preset height. This provides electrically grounded vertical barrier walls of the partition member 728 to its opposite side conductor patterns on the circuit board 74. Multiples of such partition member 728 minimize signal leakage or signal interference between the conductor patterns with their partition member 728 interposed.
For example, the antenna device may have a multi-band service structure wherein the signal/distribution coupling conductor pattern 742 is formed with distinguishable conductor patterns for signal distributing/combining for each band. In such a structure, the partition member 728 may formed to be positioned between the conductor patterns for band-specific signal distributing/combining so as to prevent band-specific signal leakage and signal interference.
At this time, the external conductor 224 of the coaxial cable 22 is inserted firmly in the cable holder 722 so that the coaxial cable 22 is fixed by the cable holder 722 with the inner conductor 226 contacting the signal input/output section of the signal distributing/combining conductor pattern 742. Thereafter, as shown in the dot-dash line circles A of
At this time, a part of the covering 712 of the coaxial cable 71 is inserted or placed in the cable holder 729 so that the coaxial cable 71 is fixed by the cable holder 729 with the outer conductor 714 contacting the ground layer on the underside of the circuit board 74. The inner conductor 716 of the coaxial cable 71 is installed by inserting into a cable connection hole 748 formed in the circuit board 74. On the other hand, to better secure the coaxial cable 71 held in the cable holder 729, the cable holder 729 may be formed to have a guard member 7292 structured for clamping that coaxial cable 71 by its side.
First, a signal distributing/combining conductor pattern will be described. For example, a signal (for example, a transmit signal) provided from a first input/output connector (I/O connector 1) through the coaxial cable is input to a pattern a1 which is a first input terminal ‘in1’, and the input signal at pattern a1 is subsequently distributed from patterns b1 and d1 to a downward or lower phase shifter D/PS #1, a 0 degree phase-shift radiating element 1 (i.e., with no phase shift) and an upward or upper phase shifter U/PS #1. The signal for distribution to the lower phase shifter D/PS #1 is provided to a pattern c1, the signal for distribution to the radiating element 1 is provided to a pattern e1, and the signal for distribution to the upper phase shifter U/PS #1 is provided to a pattern f1.
In ordinary antenna devices, the radiating elements in a single service band are arranged in a row in the vertical direction, and for vertical steering adjustment, the radiating elements in the normally vertical arrangement are relatively phase shifted based on their positions in the arrangement. In the antenna having such a structure, for example, the radiating elements positioned on the upper side with respect to the centrally positioned radiating element (radiating element with no phase shift) are phase shifted through the aforementioned upper phase shifter by a positive [+] angle to have respective phase differences, and the radiating elements positioned thereunder are phase shifted through the aforementioned lower phase shifter by a negative [−] angle to have the respective mutual phase differences.
In concert with this arrangement, the signal distributing/combining conductor pattern as described above may appropriately distribute the signal input by one input/output connector (I/O connector 1) and transfer the signal via the pattern c1 to the lower phase shifter D/PS #1, via the pattern e1 to the radiating element with no phase shift, and via the pattern f1 to the upper phase shifter U/PS #1. Detailed structures such as the shapes and lengths of the patterns a1 to f1 are appropriately designed in consideration of the phase, mutual impedance and others of the signals to be distributed and transferred.
On the other hand, a signal provided from a second input/output connector (I/O connector 2) through the coaxial cable is input to a pattern a2 which is a second input terminal ‘in2’, and the input signal at pattern a2 is subsequently distributed from patterns b2 and d2 for further subsequent distribution via patterns c2, f2 and e2 to a lower phase shifter D/PS #2, a 0 degree phase-shift radiating element 2 (i.e., with no phase shift) and an upper phase shifter U/PS #2, respectively.
It can be understood from the signal distributing/combining conductor pattern as illustrated that, in a dual polarized antenna structure for example, the patterns for processing the signal input at the first input/output connector (I/O connector 1) are the signal processing pattern for generating a polarized wave of +45 degree, and the patterns for processing the signal input at the second input/output connector (I/O connector 2) are the signal processing pattern for generating a polarized wave of −45 degree. In addition, the above signal distributing/combining conductor pattern has been described by exemplifying the function of distributing transmit signals, but it can be understood that this pattern can do the reverse as well for performing to combine and provide the receive signals to the I/O connector side. In other words, the signal distributing/combining conductor pattern in
On the other hand, in
In addition, the structure of another embodiment as described above may be made similar to that of the embodiment shown in
As described above, the configurations and operations of the signal distributing/combining apparatuses of the present disclosure in an antenna device of the mobile communication base station may be achieved according to some embodiments which are particularized for illustration, but it is to be understood that other variations may be made without departing from the scope of the disclosure.
For example, in the above description, the signal distributing/combining apparatuses according to some embodiments of the present disclosure are disposed centrally of the reflection plate and connected via the coaxial cable to the input/output connector, upper and lower phase shifters, and others, although the signal distributing/combining apparatuses connected via the coaxial cable to various other devices. Further, the signal distributing/combining apparatuses may be properly installed in other parts than the central portion of the reflection plate.
In the above description, the signal distributing/combining conductor pattern of the signal distributing/combining apparatus according to some embodiments of the present disclosure has been explained by way of example, that it corresponds to the 8T8R structure as a whole, but in addition to this, the present disclosure may also be applied to 4T4R or any other structures.
Additionally, in the above-described embodiments, there may be various variations and modifications to the detailed structure of the circuit patterns of the circuit board and/or the detailed structures of the support plate, and therefore the scope of the technical idea of the present embodiments is not limited by the illustrations as above. Accordingly, one of ordinary skill would understand that the scope of the claimed invention is not to be limited by the explicitly described above embodiments but by the claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2015-0035802 | Mar 2015 | KR | national |
The present application is a continuation of International Patent Application No. PCT/KR2015/013737, filed Dec. 15, 2015, which claims priority to Korean Patent Application No. 10-2015-0035802, filed on Mar. 16, 2015. The disclosures of the above-referenced applications are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2015/013737 | Dec 2015 | US |
| Child | 15705294 | US |
