KR200343490Y1 - A remote control system for an antenna - Google Patents

Abstract

The present invention relates to a system for remotely controlling a tilting angle of an antenna by controlling a tilting angle adjusting means mounted at one side of an antenna for a base station at a remote location. The control system according to the present invention includes one RF cable. The antenna tilt angle can be remotely controlled by transmitting a low RF signal, a DC power for driving the motor, and a sensing signal obtained by frequency-modulating the motor rotation speed or the tilt angle of the antenna.

The present invention eliminates the need for a separate cable for power supply to the motor and the transmission and reception of motor control signals, simplifying the configuration of the system, and rotating the motor in a state in which the power supply to the motor is cut off and the motor does not operate. It has the effect of detecting the number or the tilting angle of the antenna. It also has the effect that reliable communication is achieved by frequency modulation of the sensing signal by the voltage-frequency converter.

Description

Tilting angle remote control system of base station antenna

The present invention relates to a system for remotely controlling a tilting angle of an antenna by controlling a tilting angle adjusting means mounted at one side of an antenna for a base station at a remote location, and more specifically, using a single RF cable. The present invention relates to a system for remotely controlling a tilting angle by transmitting a signal, a DC power, and a sensing signal together.

In a cellular mobile communication system, the position of an antenna mounted on a base station when designing a cell becomes an important variable for determining coverage of a corresponding cell. In general, when the antenna is mounted on a structure such as a steel tower, the antenna main beam is mounted toward the horizon to increase cell coverage. However, the tilting angle is gradually lowered and adjusted in consideration of cross interference between the neighboring base station and the neighboring base station cell coverage where relatively weak radio waves arrive.

The method for adjusting the tilting angle is a method of mechanically adjusting the vertical beam of the antenna by using a tilting angle adjusting means of a clamping device attached to the rear side of the antenna and electrically using a phase shifter. There is a method of adjusting the tilting angle by distributing and feeding signals having different phases to the radiating element, but nowadays, the electric tuning method having better tilting characteristics is more preferred.

On the other hand, domestic and overseas mobile communication companies are studying ways to adjust this remotely by using a rotational force providing means such as a motor in order to reduce the hassle and risk that the installer has to climb directly on the steel tower to adjust the tilt angle of the antenna. . The AISG (Antenna Interface Standard Group) is a group of domestic and international operators to conduct and standardize such research. The group offers two options in Draft 8. The first is to send and receive RF signal, motor power, and motor control signal with one coaxial cable. Secondly, it is a cable for RS-485 communication to provide motor control and power supply separately from the coaxial cable for transmitting and receiving RF signals.

The present invention provides a tilting angle remote control system that can be more simply and reliably controlled on a motor mounted on one side of the antenna for the base station to adjust the tilting angle of the antenna, unlike the above schemes. It is a task.

1 is a block diagram of a preferred embodiment of a tilting angle remote control system of an antenna for a base station according to the present invention;

Figure 2 is a block diagram showing the configuration of another embodiment according to the present invention.

<Description of the symbols for the main parts of the drawings>

101, 201: RF cable 102, 202: first bias-t

103, 203: second bias tee 104: rotational force generating means

105: rotation speed detection device 106: signal generator

107: signal detection device 108, 214: signal processing means

109, 212: DC power supply

204: first filter 205: first voltage control means

206: motor 207: rectifier circuit

208: second voltage control means 209: variable resistor

210: voltage-frequency converter 211: second filter

213: frequency-voltage inverter

The present invention for solving the above technical problem is a system for remotely controlling the tilting angle of the antenna by controlling the tilting (tilting) adjustment means mounted on one side of the antenna at a remote location, the power supply from the remote site to the antenna (RF) cable for feeding; and a first bias tee and a second bias tee provided at one end of the antenna and one end of the RF cable respectively; and the second bias tee DC power supply for supplying a; and DC power supply from the DC power supply through the first bias, the rotational force generating means for adjusting the tilting angle by transmitting a corresponding rotational force to the tilting angle adjusting means And a rotation speed detection device interlocked with the rotation axis of the rotation force generating means and configured to detect the amount of rotation; and the rotation speed detection device. A signal generator for receiving a signal from a signal and generating a signal having a frequency corresponding thereto and transmitting the signal to the first bias; and a signal generated from the signal generator from the second bias and corresponding to the signal frequency. A signal detection device for outputting a detection signal; And signal processing means for controlling the rotational force generating means by receiving a signal from the signal sensing device and reading the signal to control the DC power supply device.

Hereinafter, exemplary embodiments of a tilting angle remote control system of a base station antenna according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a preferred embodiment of a tilting angle remote control system of an antenna for a base station according to the present invention.

The remote and base station antennas are connected by RF cable 101. The RF signal received by the antenna is transmitted to the remote via the RF cable 101, or vice versa, the RF signal transmitted from the remote is copied to the antenna via the RF cable 101.

Both ends of the RF cable 101 are provided with a first bias tee 102 and a second bias tee 103. DC power supplied from a remote DC power supply 109 is transferred to the first bias tee 102 via the second bias tee 103 and the RF cable 101. The first bias tee is configured to generate a rotational force for adjusting the tilting value of the antenna by applying the received DC power to the rotational force generating means 104.

The transmitted DC power activates the rotational force generating means 104, and rotates by varying the rotational direction according to its polarity. For example, when power having a positive polarity is applied, the motor rotates in a clockwise direction, and when power having a negative polarity is transmitted, the rotation force generating means 104 is rotated counterclockwise. It is spinning.

A part of the DC power transmitted to the rotational force generating means 104 is input to the rotation speed detecting device 105. The rotation speed detecting device 105 is interlocked with the rotational force generating means 104. When the rotational force is generated according to the DC power transmitted to the rotational force generating means 104, the interlocking speed detecting device 105 is It detects the number of revolutions and outputs the information in signal form.

The output detection signal is input to the signal generator 106. The signal generator converts an input signal so that a signal corresponding to the input detection signal can be transmitted to a remote location via the first bias tee 102, the RF cable 101, and the second bias tee 103. And print it out.

The converted signal output through the second bias 103 located at a remote location is detected by the signal sensing device 107 and again in a suitable form that can be recognized by the signal processing means 108 connected to the output port. The output is converted.

The signal processing means 108 reads out the input signal and calculates the rotation speed of the rotation force generating means 104. In addition, it is determined from the calculated rotational speed that is less than or exceeds the desired rotational speed, and the DC power supply 109 is controlled accordingly. In detail, when it approaches the desired rotational speed, the power supply to the rotational force generating means 104 is stopped, and if it does not reach, the power supply is not interrupted so that it can rotate slightly. In addition, when the desired rotational speed is exceeded, the rotational force generating means 104 is reversely rotated so as to obtain a desired rotational speed by supplying power of opposite polarity. In this way, the rotational force generating means 104 is controlled and, ultimately, the tilting angle of the associated antenna is adjusted.

Figure 2 is a block diagram showing the configuration of another embodiment according to the present invention.

The RF signal from a remote site is fed to the antenna via the second bias 203, the RF cable 201, and the first bias 202, and radiated into the space. On the contrary, the RF signal received through the antenna is transmitted to the remote via the first bias 202, the RF cable 201, and the second bias 203.

The motor 206 provided as one side of the antenna is fastened to a tilting angle adjusting means (not shown), and adjusts the tilting angle of the antenna by providing the generated rotational force to the tilting angle adjusting means.

The DC power supply 212 supplies power to the motor 206 to generate a rotational force for adjusting the tilting angle. The power supply from the DC power supply 212 to the motor 206 is supplied to the second filter 211, the second bias 203, the RF cable 201, the first bias 202, and the first filter ( 204, the second bias 203 allows the RF signal and the DC power to be transmitted together through one RF cable 201. In addition, the first bias 202 extracts only the DC power from the RF cable channel 201 to allow power to be supplied to the motor 206.

The front end of the motor 206 may be provided with a first voltage control means 205. The first voltage control means such as a regulator provides a stable power so that the motor can perform a normal function.

A part of the DC power output from the first filter 204 is input to the variable resistor 209 and the voltage-frequency converter 210.

The variable resistor 209 allows the motor 206 to know the rotation speed. The output resistance value of the variable resistor 209 can be varied as the motor rotates (rotates) by linking the control lever of the variable resistor to the rotation shaft of the motor 206. For example, the variable resistor selects one of the DAEJUNG ELECTRONICS DJRV series or the DJRP series, which has a gear in a circular shape, and attaches a gear body to the rotating shaft of the motor so as to be linked thereto. . The control lever of the variable resistor 209 interlocked with the rotating shaft of the motor 206 through the gear body rotates as the motor rotates, and the resistance value of the resistor connected thereto is changed. Therefore, the motor rotates in a clockwise or counterclockwise direction according to the polarity of the supplied electric power, and the variable resistor 209 is interlocked with the motor to detect the rotational speed of the motor 206 by increasing or decreasing its resistance value. To give.

On the other hand, the number of revolutions (information) of the motor represented by a specific resistance value must be converted into a signal for transmission to a remote location. First, as described above, part of the DC power supplied from the first filter 204 is input to the variable resistor 209, and the supplied DC power is voltage-divided according to the output resistance value. Therefore, the rotation speed (information) of the motor, which has been expressed as a specific resistance value, is converted into a specific voltage value and expressed.

At this time, it is important to ensure that a constant voltage is supplied to the variable resistor 209, because the voltage value distributed by the output resistance value of the variable resistor is also not constant because a constant voltage is not applied. . For example, if the motor is rotated 10 times and is expressed at 5 volts at one moment and at 4.8 volts at the next moment, incorrect information (motor revolutions) is transmitted and eventually the tilt angle of the antenna has an unwanted value. will be. Therefore, in order to prevent this, a second voltage control means 208 such as a regulator is required at the front end of the variable resistor 209.

In addition, a rectifier circuit 207 such as a bridge circuit is added to the front end so that a positive power voltage is always applied to the variable resistor 209 and the voltage-frequency converter 210. . When supplying power to the motor 206, a positive voltage for clockwise rotation and a negative voltage for counterclockwise rotation were applied. When a negative power supply voltage is applied, the variable voltage is applied. Since a negative power is applied to the resistor 209 and the voltage-frequency converter, the power-frequency converter 210 may not operate. The rectifier circuit 207 solves this.

The output resistance value of the variable resistor 209 that is variable in conjunction with the rotating shaft of the motor 206 divides the applied voltage and outputs the divided voltage, and the output divided voltage value is input to the voltage-frequency converter 210. A voltage-frequency converter such as National Semiconductor's LM231 outputs a signal with a frequency corresponding to the input voltage value. The frequency of the output signal may be transmitted to the frequency-to-voltage converter 213 through the first bias 202 and the second bias 203 and should be low frequency so that the signal does not leak toward the remote or antenna. do.

The signal output from the voltage-frequency converter 210 is input to the first bias 202 via the first filter 204, the first filter 204 is the first bias 202 DC power input from the output to only the port connected to the motor 206, it is designed to output only the low-frequency signal to the port to the first bias 202.

The signal output from the voltage-frequency converter 210 is input to the frequency-voltage converter 213 via the RF cable 201. The frequency-voltage converter 213 is opposite in function to the voltage-frequency converter 210. Outputs a signal of voltage value corresponding to the input signal frequency.

The second filter 211 allows DC power from the DC power supply 212 to be output only to a port of the second bias 203 side, and outputs a signal output from the voltage-frequency converter 210. It is designed to be output only to the port to the frequency-voltage converter 213.

Since the signal processing means 214 performs the same function as the signal processing means 108 of FIG. 1, the above description will be made with reference to the above description.

If the motor 206 rotates clockwise 10 times, the tilting value of the antenna increases by 1 degree, and conversely, if the motor rotates 10 counterclockwise, the tilting value of the antenna decreases by 1 degree. When the tilting value of the antenna is to be increased by 5 degrees, the signal processing means 214 controls the DC power supply 212 so that required power can be applied to the motor 206. The powered motor 206 is started and its rotational speed is sensed by the variable resistor 209. The detected rotational speed is converted into a low frequency signal through the voltage-frequency converter 210 and transmitted to the remote place through the RF cable 201. The transmitted signal is converted into a specific voltage value again through the frequency-voltage converter 213 and input to the signal processing means 214. The signal processing means 214 reads this out and reads out the rotation speed of the motor 206. When reading that the rotation is about 50 rotations, the DC power supply 212 is cut off to stop the rotation of the motor 206. Conversely, if the tilting value of the antenna is to be reduced by about 3 degrees from the current position, the signal processing means 214 applies a negative power value to the motor 206 so that the motor can be rotated counterclockwise. The DC power supply 212 is controlled. The rotation speed of the motor 206 to be reversely rotated is input again through the frequency-voltage converter 213 as described above, and rotated about 30 revolutions to cut off the power supply of the DC power supply 212. Just do it.

In addition, as described above, the output resistance value of the variable resistor 209 may be changed according to a change in the tilting value of the antenna without changing the output resistance value according to the rotation speed of the motor. In detail, the tilting value of the antenna is changed to a range of 0 degrees to 10 degrees due to the rotational force of the motor 206, and the variable resistor 209 is also designed to vary from 0 ohms to 100 ohms in conjunction with this. When the tilting value of the antenna is changed from 3 degrees to 7 degrees according to the rotation of the motor, the output resistance value of the variable resistor is changed from 30 ohms to 70 ohms, which changes the distribution voltage value to the voltage-frequency converter 210. By generating a low frequency signal of a corresponding frequency. When the frequency-signal converter 213 receives this and outputs a voltage value corresponding to the frequency, the signal processing means 214 refers to the predetermined tilting value (7 degrees) with reference to the predetermined voltage-tilting value table. Read out. The DC power supply 212 is controlled according to the read result so that the antenna has a desired tilting value.

However, as described above, when the signal processing unit 214 obtains the desired rotational speed or tilting angle, the control method of cutting off the power supply of the DC power supply device 212 is performed in a state in which the motor 206 does not rotate. It has the disadvantage that it is impossible to know the rotation speed or tilt angle. Therefore, since the rotation speed or tilting angle is not known before the motor starts or after the power supply to the motor is stopped, reliable control cannot be obtained.

In order to solve this problem, the rated input voltage value of the motor 206 and the rated input voltage value of the second voltage control means 208 should be different from each other. For example, using the motor 206 having a rated voltage of 24 volts and using the second voltage control means 208 having a 10 volt rated input voltage value. When the signal processing means 214 detects the current rotation speed or tilting value of the antenna from the frequency-voltage converter 213 and determines that the motor rotation should be stopped, the motor 206 is different from the power supply stopping method described above. ) And the supply voltage to the second voltage control means 208 to 10 volts, the motor stops rotating and the voltage-frequency converter 210 continuously transmits the current rotation speed or tilting value of the antenna. Therefore, it is possible to detect the rotation speed or the tilting value in the state in which the motor is stopped, rather than detecting the rotation speed or the tilting value in the motor's rotation state.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, changes, and modifications are possible within the scope without departing from the technical idea of the present invention. It will be apparent to those of ordinary skill in the art.

As described above, the tilting angle remote control system of the antenna for the base station according to the present invention does not require a separate cable for power supply to the motor and transmission and reception of the motor control signal, thereby simplifying the configuration of the system, Since the power supply is cut off, the rotation speed of the motor or the tilting angle of the antenna can be detected while the motor is not operating. It also has the effect that reliable communication is achieved by frequency modulation of the sensing signal by the voltage-frequency converter.

Claims (6)

In a system for remotely controlling the tilting angle of the antenna by controlling a tilting angle adjusting means mounted on one side of the antenna at a remote place, RF cable for feeding from the remote to the antenna; A first bias tee and a second bias tee provided at one end of the antenna and one end of the RF cable, respectively; A DC power supply for supplying DC power to the second bias tea; Rotational force generating means for receiving DC power from the DC power supply through the first bias and transmitting a corresponding rotational force to the tilting angle adjusting means to adjust the tilting angle; A rotation speed detection device interlocked with the rotation shaft of the rotation force generating means and capable of sensing the amount of rotation; A signal generator for receiving a signal from the rotation speed sensor and generating a signal having a frequency corresponding thereto and transmitting the signal to the first bias; A signal sensing device which receives a signal generated from the signal generating device from the second bias and outputs a sensing signal corresponding to the signal frequency; And Signal processing means for controlling the rotational force generating means by receiving a signal from the signal sensing device and reading the signal to control the DC power supply; Tilting angle remote control system of the base station antenna is configured to include. In a system for remotely controlling the tilting angle of the antenna by controlling a tilting angle adjusting means mounted on one side of the antenna at a remote place, RF cable for feeding from the remote to the antenna; A first bias tee and a second bias tee provided at one end of the antenna and one end of the RF cable, respectively; A DC power supply for supplying DC power to the second bias tea; A motor for receiving DC power from the DC power supply device through the first bias and transmitting a corresponding rotational force to the tilting angle adjusting means to adjust the tilting angle; A variable resistor interlocked with the rotating shaft of the motor and varying a resistance value according to the number of rotations thereof; A voltage-frequency conversion device for receiving the voltage value distributed by the variable resistor from the DC power supplied from the first bias, generating a signal having a frequency corresponding thereto, and transmitting the generated signal to the first bias; A frequency-voltage converter configured to receive a signal generated from the voltage-frequency converter from the second bias and generate a voltage corresponding to a signal frequency; And And a microcontroller for controlling the motor by receiving a voltage signal from the frequency-voltage converter and reading the voltage signal, thereby controlling the DC power supply device. The method according to claim 1 or 2, A tilting angle remote control system of a base station antenna, characterized in that it further comprises a rectifier circuit in front of the rotation speed detection device (variable resistor). The method of claim 3, wherein A tilting angle remote control system of a base station antenna, characterized in that it further comprises a voltage stabilization means at the rear end of the rectifier circuit. The method of claim 4, wherein A tilting angle remote control system of an antenna for a base station, characterized in that the rated input voltage of the torque generating device (motor) and the voltage stabilization means are different from each other. The method of claim 5, wherein At the rear end of the first bias tee, DC power input from the first bias tee is output only to a port connected to the rotation force generating means (motor), and the signal generator (voltage) is connected to the port of the first bias tee. A first filter passing only the output signal from the frequency converter); and At the rear end of the second bias tee, DC power from the DC power supply is output only to the port of the second bias tee, and a signal output from the signal generator (voltage-frequency converter) is output to the signal sensing device. A tilting angle remote control system of a base station antenna, characterized in that it further comprises; a second filter to be output only to the (frequency-voltage converter) side port.