WO2013176370A1

WO2013176370A1 - Antenna phase conversion device and antenna phase conversion system

Info

Publication number: WO2013176370A1
Application number: PCT/KR2012/011866
Authority: WO
Inventors: Tae Kyung Yook; Hyung Soo Shin; Ho Yong Kim; Tae Hoon Lee; Yong Chan Cho; Joong Kwan Kim
Original assignee: Ls Cable Ltd.
Priority date: 2012-05-22
Filing date: 2012-12-31
Publication date: 2013-11-28
Also published as: KR20130130281A

Abstract

An antenna phase conversion system and an antenna phase conversion device are provided. The antenna phase conversion system includes an antenna for emitting a beam, the antenna including a phase shifter, a phase conversion device connected to the phase shifter to change the phase of the beam, and a controller for generating a control signal for remotely controlling the phase conversion device and transmitting the generated control signal to the phase conversion device. The control signal is one of an RS485 signal or an On-Off Keying (OOK) signal and the phase conversion device controls the phase shifter based on an input control signal from among the RS485 signal or the OOK signal.

Description

ANTENNA PHASE CONVERSION DEVICE AND ANTENNA PHASE CONVERSION SYSTEM

The present invention relates to an antenna phase conversion device and an antenna phase conversion system using the same.

Communication providers should secure appropriate coverage using base station antennas in order to provide mobile communication. When a base station antenna is installed outdoors, coverage and communication load are predicted through a certain prediction method and the base station antenna is installed taking into consideration the predicted coverage and communication load. In this case, the antenna is down-tilted in order to minimize interference caused by a neighboring base station.

Specifically, the variety of base station environments has increased as the complexity of various mobile communication service frequency bands used by communication systems or communication providers has increased in a situation in which the spread of 4G LTE systems is in progress as a successor to 2G and 3G systems. Thus, antenna down-tilting is needed in order to minimize signal interference in such various environments with an increasing number of base stations.

Antenna down-tilting methods may be classified into mechanical tilting and electrical tilting. Mechanical tilting is a method of physically tilting an antenna using an angle bracket. Electrical tilting is a method of changing the phase of an antenna without changing the characteristic impedance of the antenna using a phase shifter provided on the antenna.

Although mechanical tilting has an advantage in that the antenna has a simple configuration, it has a problem in that base station operation costs are high and working on the antenna is very dangerous since the worker should climb the antenna in order to work on the antenna to change the beam of the antenna. On the other hand, although electrical tilting has an advantage in that beam pattern uniformity and variability are improved since beam tilting is electrically performed through phase change. Especially, compared to mechanical tilting, the probability of generation of a communication gray zone due to pattern distortion in a cell coverage is low and it is also possible to achieve accurate network design due to uniform gain reduction in the cell coverage.

A Remote Electrical Tilting (RET) method which enables a number of antennas to be controlled and monitored from a remote location has widely been used recently.

An RET system basically includes an electrical tilting antenna having a phase shifter, a Remote Control Unit (RCU) (or an electrical motor) which can change the phase of a beam through mechanical cooperation with the phase shifter, a controller that generates a control signal for remotely controlling operation of the RCU, and a user terminal that allows the user to manipulate the controller.

Communication protocols and interface standards of the RET system have been specified by the Antenna Interface Standards Group (AISG). When new devices or parts associated with the RET system are developed or new functions are added, they should be implemented so as to suit the standards specified by the AISG.

In addition, there is a need to develop devices and technologies to reduce costs associated with installation and operation of the RET system and also to achieve compatibility in various environments.

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an antenna phase conversion device and an antenna phase conversion system which include both an AISG cable interface and an RF cable interface such that the antenna phase conversion device and the antenna phase conversion system can be implemented in various configurations.

It is another object of the present invention to provide an antenna phase conversion system that satisfies AISG standards regardless of the type of a connection cable between an antenna phase conversion device and a controller.

It is another object of the present invention to provide an antenna phase conversion device that can control a phase shifter of an antenna regardless of the type of an input control signal.

The present invention is not limited to the above objects and other objects not described above will be clearly understood from the following description.

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of an antenna phase conversion system comprising an antenna for emitting a beam, the antenna including a phase shifter, a phase conversion device connected to the phase shifter to change a phase of the beam, and a controller for generating a control signal for remotely controlling the phase conversion device and transmitting the generated control signal to the phase conversion device, wherein the control signal is one of an RS485 signal or an On-Off Keying (OOK) signal, and the phase conversion device controls the phase shifter based on an input control signal from among the RS485 signal or the OOK signal.

The phase conversion device may include an Antenna Interface Standards Group (AISG) interface connected to an AISG cable to receive the RS485 signal, an RF cable interface connected to an RF cable to receive the OOK signal, a drive unit for controlling the phase shifter connected to the drive unit through a knob to change the phase of the beam, and a control unit for controlling the drive unit based on one of the RS485 signal or the OOK signal.

The phase conversion device may further include a switching unit for selectively connecting the AISG interface or the RF cable interface to the control unit.

The phase conversion device may further include a conversion unit that is located between the RF cable interface and the switching unit and that converts the OOK signal input through the RF cable interface to an RS485 signal.

The phase conversion device may be connected to the controller using an AISG cable and receives the RS485 signal from the controller.

The phase conversion device may be connected to the controller using an RF cable and receives the OOK signal from the controller.

The phase conversion device may be connected to the controller via a pair of bias tees connected through an RF cable.

And in accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of an antenna phase conversion device comprising a drive unit connected to a phase shifter of an antenna to adjust a phase of an antenna beam, a control unit for controlling operation of the drive unit based on a control signal received from an external controller, and a cable interface connected to the controller to receive the control signal from the controller, wherein the cable interface includes an Antenna Interface Standards Group (AISG) interface connected to an AISG cable and an RF cable interface connected to an RF cable.

The antenna phase conversion device may further comprising a switching unit for selecting and connecting one of the AISG interface and the RF cable interface to the control unit and transferring the received control signal to the control unit.

The control signal may be one of an RS485 signal or an On-Off keying (OOK) signal.

The control signal may be the RS485 signal when the AISG cable is connected to the AISG interface.

The control signal may be the OOK signal when the RF cable is connected to the RF cable interface.

The RF cable interface may be connected to the controller via a pair of bias tees connected through an RF cable.

The antenna phase conversion device may further comprising a conversion unit that is located between the RF cable interface and the switching unit and that converts the OOK signal input through the RF cable interface to an RS485 signal.

According to one embodiment of the present invention, it is possible to provide an antenna phase conversion device which includes both an AISG cable interface and an RF cable interface such that it is possible to implement an antenna phase conversion system with various configurations.

Also, according to one embodiment of the present invention, it is possible to implement an antenna phase conversion system so as to satisfy AISG standards regardless of the type of a connection cable between an antenna phase conversion device and a controller.

Also, according to one embodiment of the present invention, it is possible to control a phase shifter of an antenna regardless of the type of an input control signal.

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates an exemplary antenna phase conversion system configured according to an AISG standard scheme;

FIG. 2 illustrates another exemplary antenna phase conversion system configured according to an AISG standard scheme;

FIG. 3 illustrates a configuration of an antenna phase conversion system according to an embodiment of the present invention;

FIG. 4 illustrates a detailed configuration of an antenna phase conversion device according to an embodiment of the present invention;

FIG. 5 illustrates operations of the components of an antenna phase conversion device according to an embodiment of the present invention when the antenna phase conversion device is connected to a controller using an AISG cable; and

FIG. 6 illustrates operations of the components of an antenna phase conversion device according to an embodiment of the present invention when the antenna phase conversion device is connected to a controller using an RF cable.

The present invention may be modified in various ways and provide various embodiments. The present invention will be described below through a detailed description of specific embodiments illustrated in the accompanying drawings. The detailed description is not intended to limit the present invention and it should be understood that the present invention includes all changes, equivalents, or substitutions within the spirit and scope of the present invention.

In the following description of the present disclosure, a detailed description of known related technologies will be omitted when it may obscure the subject matter of the present disclosure. Numbers or ordinal numbers (for example, first and second) that are used in the description of this specification are merely reference symbols for discriminating between components.

When it is stated that one component is “connected” or “coupled” to another component, it is to be understood that the two components may not only be directly “connected” or “coupled” but may also be indirectly “connected” or “coupled” via another component unless specifically stated otherwise.

A detailed description of embodiments for practicing the present invention will now be given with reference to the accompanying drawings.

FIG. 1 illustrates an exemplary antenna phase conversion system configured according to an AISG standard scheme.

As shown in FIG. 1, the antenna phase conversion system may include an antenna 100, an antenna phase conversion device 200, a controller 300, and a management terminal 400.

The antenna 100 may be connected to a base station 500 to emit an RF signal to the outside or to receive an RF signal from the outside. Specifically, the antenna 100 may be connected to the base station 500 through an RF Feeder cable (hereinafter referred to as an RF cable) and may receive an RF signal from the base station 500 and emit the received RF signal to the outside or may transmit an RF signal received from the outside to the base station 500. Here, a pair of RF cables C100 for reception and transmission may be connected between the antenna 100 and the base station 500.

The antenna 100 may include a phase shifter and may adjust the phase of an antenna beam by controlling the phase shifter. Control of the phase shifter is performed through the antenna phase conversion device 200 coupled to the antenna 100.

The antenna phase conversion device 200 may control a drive motor (hereinafter referred to as a drive unit) such as an actuator according to a control signal generated and transmitted by the controller 300 to rotate or move vertically a knob connected to the phase shifter to control the phase of an antenna beam (for example, to change the beam phase from phase P1 to phase P2 or from phase P2 to phase P1).

An AISG cable C200 may be used to connect the antenna phase conversion device 200 and the controller 300 to each other. The AISG cable C200 is also referred to as an RS485 communication cable and is of a multi-pole connector type having 8 pins. Two of the 8 pins, RS485A and RS485B, may be used to transmit a control signal and DC power may be supplied to the antenna phase control device through one pin that is used for +12V DC power signals.

The antenna phase conversion system may further include a management terminal 400 for manipulating the controller 300. The management terminal 400 may be connected to the controller 300 through an RS232 cable or a UTP cable.3

In the configuration of the antenna phase conversion system shown in FIG. 1, the controller 300 and the antenna phase conversion device 200 are connected in a point to point manner and are connected directly to each other using the AISG cable C200. Therefore, the length of the AISG cable is increased, signal loss is great, and cable thickness is increased.

FIG. 2 illustrates another exemplary antenna phase conversion system configured according to an AISG standard scheme.

As shown in FIG. 2, the antenna phase conversion system may include an antenna 100, an antenna phase conversion device 200, a controller 300, and a management terminal 400, similar to the antenna phase conversion system of FIG. 1. Unlike the antenna phase conversion system of FIG. 1, the antenna phase conversion device 200 and the controller 300 may be connected through a pair of Smart Bias Tees (SBTs) 600.

The controller 300 may be controlled using the management terminal 400 to generate a control signal and the generated control signal may be transmitted to the antenna phase conversion device 200 through a pair of SBTs 600.

Here, a bottom SBT adjacent to the controller 300 and the controller 300 may be connected through an AISG cable C200 and the antenna phase conversion device 200 and a top SBT adjacent to the antenna phase conversion device 200 may be connected through an AISG cable C200. Here, an RF cable C100 may be used to connect the top SBT and the bottom SBT to each other.

In the configuration of the antenna phase conversion system shown in FIG. 2, an SBT instead of a general bias tee needs to be used for conversion between On-Off Keying (OOK) signals and RS485 signals although an inexpensive RF cable C100 instead of an AISG cable C200 may be used to connect the top SBT and the bottom SBT to each other and therefore configuration complexity and device costs are increased.

An antenna phase conversion system of the present invention can solve such problems. An antenna phase conversion system according to an embodiment of the present invention is described below.

FIG. 3 illustrates an antenna phase conversion system according to an embodiment of the present invention. As shown in FIG. 3, the antenna phase conversion system includes an antenna 100, an antenna phase conversion device 200 coupled to the antenna 100, a controller 300 that transmits a control signal to the antenna phase conversion device 200, and a management terminal 400 for manipulating the controller 300.

The antenna 100 may be connected to a base station 500 to emit an RF signal to the outside or receive an RF signal from the outside. Specifically, the antenna 100 may be connected to the base station 500 using an RF cable C100 and may perform communication with the base station 500 using a pair of RF cables C100 including a reception (Rx) cable for receiving an RF signal from the base station 500 and a transmission (Tx) cable for transmitting an RF signal received from the outside to the base station 500.

The antenna 100 may electrically down-tilt the phase of an antenna beam in order to secure an appropriate coverage or to minimize interference caused by an adjacent base station. To accomplish this, the antenna 100 may internally include a phase shifter 110 as shown in FIG. 4. The phase shifter 110 may be physically connected to a drive unit 280 in the antenna phase conversion device 200, which will be described later, through a knob and may be controlled so as to have a desired phase according to a control signal.

The antenna phase conversion device 200 may be connected to the antenna 100 such that it is possible to adjust the phase of the antenna beam to a desired phase by controlling the phase shifter 110 of the antenna 100. Specifically, the antenna phase conversion device 200 may adjust the phase down by -2°, -4°, -6°, or -8° by controlling the phase shifter 110 without changing the characteristic impedance of the antenna 100. For example, the antenna phase conversion device 200 of Fig. 3 may down-tilt the phase of the antenna beam from P1 to P2 by manipulating the phase shifter 110.

The antenna phase conversion device 200 may use both an RS485 control signal and an OOK control signal as control signals. To accomplish this, the antenna phase conversion device 200 includes both an interface for an AISG cable for transmitting an RS485 signal and an interface for an RF cable for transmitting an OOK control signal.

When the antenna phase conversion system is implemented as a system using RS485 control signals, the antenna phase conversion device 200 and the controller 300 may be connected directly to each other using an AISG cable C200 similar to the configuration of the antenna phase conversion system shown in FIG. 1.

When the antenna phase conversion system is implemented as a system using OOK control signals, the antenna phase conversion device 200 and the controller 300 may be connected to each other through an RF cable C100. Here, a Bias Tee (BT) 700 instead of an SBT may be used to connect the antenna phase conversion device 200 and the controller 300 to each other and therefore an additional AISG cable C200 is unnecessary.

A detailed configuration of the antenna phase conversion device 200 is described below in detail with reference to FIG. 4.

FIG. 4 illustrates a detailed configuration of the antenna phase conversion device 200 according to an embodiment of the present invention.

As shown in FIG. 4, the antenna phase conversion device 200 includes an AISG interface 210, an RF cable interface 240, a switching unit 230, a conversion unit 260, a control unit 270, and a drive unit 280. The antenna phase conversion device 200 may further include a first DC filter 220, a second DC filter 250, and a sensing unit 290.

The AISG interface 210 may be connected to an AISG cable C200 to receive a control signal and DC power from the controller 300 (see the configuration of FIG. 1).

Here, the control signal received from the controller 300 through the AISG interface 210 may be an RS485 signal. In this case, a first DC filter 220 for separating the received RS485 signal and DC power may be added at a rear side of the AISG interface 210. The DC power separated by the first DC filter 220 may be used as drive power of an internal circuit of the antenna phase conversion device 200 or may be provided to the drive unit 280.

The switching unit 230 may be located at a rear side of the first DC filter 220. When an RS485 signal input through the AISG interface 210 is applied to the switching unit 230, the switching unit 230 connects a circuit including the AISG interface 210 and the first DC filter 220 to the control unit 270. Here, the input RS485 signal may be transmitted to the control unit 270 connected to the switching unit 230 to be used as a control signal for controlling operation of the drive unit 280.

The antenna phase conversion device 200 may include an RF cable interface 240 in addition to the AISG interface 210 to receive a control signal and DC power from the controller 300 through an RF cable C100 connected to the RF cable interface 240 (see the configuration of FIG. 3).

Here, a control signal received from the controller 300 through the RF cable interface 240 may be an OOK signal. In this case, a second DC filter 250 for separating an OOK signal and DC power may be added at a rear side of the RF cable interface 240. Here, the second DC filter 250 may function as an RF filter. The DC power separated by the second DC filter 250 may be used as drive power of an internal circuit of the antenna phase conversion device 200 or may be used as drive power of the drive unit 280.

The OOK signal received through the RF cable interface 240 may be converted to an RS485 signal and the RS485 signal may then be transferred to the switching unit 230.

When the RS485 signal produced through conversion by the conversion unit 260 is input to the switching unit 230, the switching unit 230 connects a circuit including the RF cable interface 240 and the conversion unit 260 to the control unit 270. Here, the converted RS485 signal may be transmitted to the control unit 270 through the switching unit 230 to be used as a control signal for controlling the drive unit 280.

The drive unit 280 may be an actuator such as a stepper motor and may be driven according to a control signal from the control unit 270 to rotate the phase shifter 110 of the antenna 100, which is physically connected to the drive unit 280, horizontally or vertically. The antenna phase conversion system may further include a sensing unit 290 for sensing an operation of the drive unit 280 and feeding the sensed operation back to the control unit 270.

In the above configuration, the switching unit 230 may selectively switch on a first path that extends from the AISG interface 210 to the switching unit 230 or a second path that extends from the RF cable interface 240 to the switching unit 230 via the conversion unit 260 and may connect the selected path to which a control signal has been input to the control unit 270.

Accordingly, it is possible to transmit a control signal from the controller 300 to the control unit 270 regardless of whether the antenna phase conversion system is configured such that the antenna phase conversion device 200 is connected directly to the controller 300 using an AISG cable C200 as shown in FIG. 1 or the antenna phase conversion system is configured such that the antenna phase conversion device 200 is connected to the controller 300 using an RF cable and a pair of BTs 700 as shown in FIG. 3.

FIG. 5 illustrates control signal flow when the antenna phase conversion system is configured such that the antenna phase conversion device 200 and the controller 300 are connected directly to each other using an AISG cable C200 as shown in FIG. 1.

As shown in FIG. 5, a control signal generated by the controller 300, together with DC power, is input to the AISG interface 210 of the antenna phase conversion device 200 through the AISG cable C200 and is then transmitted to the control unit 270 through the switching unit 230. The control unit 270 controls the drive unit 280 according to the received RS485 control signal to adjust the beam phase of the antenna 100 to a desired phase angle.

FIG. 6 illustrates control signal flow when the antenna phase conversion system is configured such that the antenna phase conversion device 200 and the controller 300 are connected directly to each other using a pair of BTs 700 and an RF cable C100 as shown in FIG. 3.

As shown in FIG. 6, a control signal generated by the controller 300, together with DC power, is input to the bottom BT 700 through an RF cable C100 and the control signal is combined with an RF signal transmitted from the base station 500 at the bottom BT 700 and the combined signal is then transmitted to the top BT 700 through an RF cable C100. An OOK control signal and DC power are separated from an RF signal at the top BT 700 and are then input to the RF cable interface 240 of the antenna phase conversion device 200 and thereafter the OOK control signal is converted to an RS485 control signal through the conversion unit 260 and the RS485 control signal is then transferred to the control unit 270 through the switching unit 230. The control unit 270 controls the drive unit 280 according to the RS485 control signal to adjust the beam phase of the antenna 100 to a desired phase angle.

As is apparent from the above description, according to the present invention, it is possible to provide an antenna phase conversion device which includes both an AISG cable interface and an RF cable interface such that it is possible to implement an antenna phase conversion system with various configurations.

In addition, it is possible to implement an antenna phase conversion system so as to satisfy AISG standards regardless of the type of a connection cable between an antenna phase conversion device and a controller.

Further, it is possible to control a phase shifter of an antenna regardless of the type of an input control signal.

Although exemplary embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible without departing from essential characteristics of the invention.

Thus, the embodiments described herein are explanatory without limiting the technical spirit of the invention and should not be used to limit the scope of the invention.

The scope of the invention should be determined by reasonable interpretation of the appended claims and all changes coming within the equivalency range of the invention are intended to be embraced in the scope of the invention.

Claims

An antenna phase conversion system comprising:

an antenna for emitting a beam, the antenna including a phase shifter;

a phase conversion device connected to the phase shifter to change a phase of the beam; and

a controller for generating a control signal for remotely controlling the phase conversion device and transmitting the generated control signal to the phase conversion device,

wherein the control signal is one of an RS485 signal or an On-Off Keying (OOK) signal, and

the phase conversion device controls the phase shifter based on an input control signal from among the RS485 signal or the OOK signal.
The antenna phase conversion system according to claim 1, wherein the phase conversion device includes:

an Antenna Interface Standards Group (AISG) interface connected to an AISG cable to receive the RS485 signal;

an RF cable interface connected to an RF cable to receive the OOK signal;

a drive unit for controlling the phase shifter connected to the drive unit through a knob to change the phase of the beam; and

a control unit for controlling the drive unit based on one of the RS485 signal or the OOK signal.
The antenna phase conversion system according to claim 2, wherein the phase conversion device further includes a switching unit for selectively connecting the AISG interface or the RF cable interface to the control unit.
The antenna phase conversion system according to claim 3, wherein the phase conversion device further includes a conversion unit that is located between the RF cable interface and the switching unit and that converts the OOK signal input through the RF cable interface to an RS485 signal.
The antenna phase conversion system according to claim 1, wherein the phase conversion device is connected to the controller using an AISG cable and receives the RS485 signal from the controller.
The antenna phase conversion system according to claim 1, wherein the phase conversion device is connected to the controller using an RF cable and receives the OOK signal from the controller.
The antenna phase conversion system according to claim 6, wherein the phase conversion device is connected to the controller via a pair of bias tees connected through an RF cable.
An antenna phase conversion device comprising:

a drive unit connected to a phase shifter of an antenna to adjust a phase of an antenna beam;

a control unit for controlling operation of the drive unit based on a control signal received from an external controller; and

a cable interface connected to the controller to receive the control signal from the controller,

wherein the cable interface includes an Antenna Interface Standards Group (AISG) interface connected to an AISG cable and an RF cable interface connected to an RF cable.
The antenna phase conversion device according to claim 8, further comprising a switching unit for selecting and connecting one of the AISG interface and the RF cable interface to the control unit and transferring the received control signal to the control unit.
The antenna phase conversion device according to claim 8, wherein the control signal is one of an RS485 signal or an On-Off keying (OOK) signal.
The antenna phase conversion device according to claim 10, wherein the control signal is the RS485 signal when the AISG cable is connected to the AISG interface.
The antenna phase conversion device according to claim 10, wherein the control signal is the OOK signal when the RF cable is connected to the RF cable interface.
The antenna phase conversion device according to claim 12, wherein the RF cable interface is connected to the controller via a pair of bias tees connected through an RF cable.
The antenna phase conversion device according to claim 12, further comprising a conversion unit that is located between the RF cable interface and the switching unit and that converts the OOK signal input through the RF cable interface to an RS485 signal.