JPH05172879A - Monitoring device for antenna and electricity feeding system for antenna - Google Patents

Abstract

PURPOSE:To correctly monitor an antenna and an electricity feeding system for antenna by preventing the erroneous detection due to the turning around from the antenna of other system. CONSTITUTION:As for a monitoring device 100, a direction type joint device 12 detects the intensity Et of the transmission wave and the intensity Er of the reflection wave by the joining with a transmission line for an antenna 13 from a combiner 11. The wave detection circuits 14 and 15 outputs the wave detection signals Vt and Vr corresponding to each intensity. The voltage signal Vo corresponding to the reflection coefficient is obtained from the ratio of the wave detection signal Vr of the reflection wave for the wave detection signal Vt of the transmission wave. When the reflection coefficient exceeds a certain value, a comparator 19 outputs the level of a logic 1, and when the wave detection signal Vt of the transmission wave exceeds a certain value, a comparator 21 outputs the level of the logic 1. The logic sum of the comparators 19 and 21 is obtained by an AND circuit 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device for an antenna and an antenna feeding system provided in, for example, a base station in a mobile communication system.

[0002]

2. Description of the Related Art In recent years, with the development of wireless communication technology, mobile communication systems such as car telephones have been put into practical use. As an example of this type of mobile communication system, a system called a cellular system is shown in FIG.

In the cellular mobile communication system shown in FIG. 2, a base station 2 is arranged in each small zone 1 which divides a service area, and a mobile station 3 and a base station 2 in the small zone 1 are arranged. In between, communication is performed via the control channel 5 and the communication channel 4 including the call signal. Each of the base stations 2 is connected via a switching control station 6 and a switching control subsystem 7 to a fixed telephone network 9 to which a fixed telephone 8 is connected.

As shown in FIG. 5, a plurality of transmitters TX1, ... TXi, ... TXn, a combiner 11, and an antenna 13 which output carrier waves having mutually different frequencies f1 to fn are output to the base station. Equipped with. Transmitter T
Each output of X1, ..., TXi, ..., TXn is input to the combiner 11. Each of the inputs of the combiner 11 is provided with an isolator I1, ... Ii, ... In consisting of a three-terminal type circulator terminated at one end, and the outputs of the circulators are bandpass filters F1 ,.
i, ..., Fn are provided, and the outputs of the band pass filters are combined.

The output of the combiner 11 is connected to the antenna 13 via a transmission line.

By the way, the base station 2 constantly monitors the states of the antenna feeding system from the combiner 11 to the antenna 13 and the state of the antenna 13 in order to secure the reliability of communication and prevent the occurrence of radio interference. There is. Conventionally, a monitoring device 100 for an antenna and an antenna feeding system is provided to perform this type of monitoring.

In the monitoring apparatus 100 of FIG. 5, the directional coupler 12 is provided on the transmission line between the antenna 13 and the combiner 11, and detects the transmitted wave to the antenna 13 and the reflected wave from the antenna 13. Detection circuit 14
And 15 are transmitted waves E output from the directional coupler 12.
The t and the reflected wave Er are respectively detected to obtain DC voltages Vt and Vr which are proportional to the voltages of the transmitted wave and the reflected wave. The arithmetic circuit 16 is based on the detection signal of the transmitted wave and the detection signal of the reflected wave, the high frequency power radiated from the antenna 13 to the space, the voltage standing in the antenna from the directional coupler 12 to the antenna 13 and the antenna feeding system. The wave ratio (hereinafter referred to as VSWR) is calculated, and the result is displayed on the display device 17.

In the structure of FIG. 5, for example, a disconnection may occur in the transmission line from the combiner 11 to the antenna 13, contact failure may occur in the connector portion, or a part of the antenna 13 may be damaged or bent. Occurs, the reflection coefficient or VSWR increases. Therefore, the monitoring device 100 can be used to monitor the antenna or the antenna feeding system by monitoring the impedance matching state between the transmission circuit system and the antenna circuit system.

[0009]

By the way, in a cellular mobile communication system, the number of channels increases as the number of subscribers increases, and even in the same base station, a plurality of sets of antennas composed of combinations of different channels are provided. A common system may be provided. In this case, a plurality of antenna sharing systems as shown in FIG. 5 are provided, and the respective antennas are arranged close to each other. Therefore, the antenna sharing system using the antenna 13 may receive interference (wraparound) from another antenna 24 close to the antenna 13. The interference wave from the other antenna is detected as a reflected wave Er by the directional coupler 12. In this way, the level of the original reflected wave fluctuates due to the wraparound from other antennas, so not only the accurate reflection coefficient and VSWR cannot be measured, but also the system itself (shared antenna system) is in the power-off state. When monitoring device 10
0 will malfunction. That is, in the power-off state of the own system, the detection signal Et of the transmitted wave to the antenna 13 is 0, and thus the detection signal Vt thereof is also almost 0. At this time, if the antenna 13 is sneak from another system, the interference wave signal is detected as Er, and the detected signal is output as Vr. Therefore, Vr / Vt≈∞, and it is erroneously detected that a serious failure has occurred in the antenna or the antenna feeding system.

An object of the present invention is to solve the above-mentioned problems that occur when the intensity of the transmitted wave to the antenna is 0 or low, and to always monitor the antenna and the antenna feeding system correctly. To provide a monitoring device.

[0011]

A monitoring device for an antenna and an antenna feeding system according to claim 1 of the present invention feeds a transmission signal output from a transmitter to the antenna and transmits the transmission signal from the antenna to a space. A monitoring device for an antenna and an antenna feeding system in a radiating wireless transmission system, which is provided in a transmission line for feeding a transmission signal to the antenna, and coupling means for detecting a transmitted wave and a reflected wave of the transmission signal, respectively, Detection means for respectively detecting the transmitted wave and the reflected wave of the transmission signal detected by the coupling means and outputting each detection signal, and a reflection coefficient or a function of the reflection coefficient based on each detection signal output from the detection means Is compared with a measurement value detecting means for detecting a measurement value representing the reflection coefficient or the function of the reflection coefficient with respect to a reference value, and the reflection coefficient or the function of the reflection coefficient is compared. When the above-mentioned reference value is exceeded, a first comparing means for outputting a first detection signal is compared with the detected signal strength of the transmitted wave to a reference strength, and when the detected signal strength of the transmitted wave exceeds the reference strength. It is characterized by further comprising a second comparing means for outputting a second detection signal and a logical product means for obtaining a logical product of the first detection signal and the second detection signal.

According to a second aspect of the present invention, there is provided an antenna and a monitoring device for an antenna feeding system in which a transmitting signal output from a transmitter is fed to the antenna and the transmitting signal is radiated into space from the antenna. And a monitoring device for an antenna feeding system, which is provided in a transmission line for feeding a transmission signal to an antenna, and which detects a transmitted wave and a reflected wave of the transmission signal, respectively, and the coupling means detected by the coupling means. Detecting means for respectively detecting the transmitted wave and the reflected wave of the transmission signal and outputting each detected signal, and detecting a measurement value representing a reflection coefficient or a function of the reflection coefficient based on each detected signal output from the detecting means. Measured value detection means and the detected signal strength of the transmitted wave are compared with a reference strength, and a detection signal is detected when the detected signal strength of the transmitted wave exceeds the reference strength. Comparison means for outputting a, characterized by comprising the measurement selection output means for outputting the measured values at the time of the detection signal generated.

Further, the monitoring device for the antenna and the antenna feeding system according to claim 3 is characterized in that the measured value selection output means according to claim 2 reports the measured value at a level representing the degree of an abnormal state. ..

[0014]

In the monitoring device for the antenna and the antenna feeding system according to the first aspect of the present invention, the coupling means detects the transmitted wave and the reflected wave to the antenna, respectively, and the detection means detects the transmitted wave and the reflected wave, respectively. And outputs each detected signal, and the measured value detecting means detects a measured value representing a reflection coefficient or a function of the reflection coefficient based on each detected signal. The first comparing means compares the reflection coefficient or the function of the reflection coefficient with a reference value, outputs a first detection signal when the reflection coefficient or the function of the reflection coefficient exceeds the reference value, and the second comparing means The detected signal intensity of the transmitted wave is compared with the reference intensity, and the second detection signal is output when the detected signal intensity of the transmitted wave exceeds the reference intensity. Then, the logical product means obtains the logical product of the first detection signal and the second detection signal. Therefore, by using the result of the logical product means as the monitoring result, the comparison of the measured value representing the reflection coefficient or the function of the reflection coefficient with respect to the reference value only under the condition that the intensity of the transmitted wave to the antenna exceeds the predetermined reference intensity The result is valid. Even if the measured value representing the reflection coefficient or the function of the reflection coefficient quasi exceeds the reference value due to wraparound from other antennas when the transmission power from the antenna is low, It is not regarded as an abnormal state of the power feeding system.

Further, in the monitoring device for the antenna and the antenna feeding system according to the second aspect, the coupling means detects the transmitted wave and the reflected wave to the antenna, respectively, and the detection means detects the transmitted wave and the reflected wave, respectively. Each detection signal is output, and the measurement value detection means detects a measurement value representing a reflection coefficient or a function of the reflection coefficient based on each detection signal. The comparison means compares the detected signal intensity of the transmitted wave with the reference intensity and outputs a detection signal when the detected signal intensity of the transmitted wave exceeds the reference intensity. Then, the measurement value selection output means outputs the measurement value when the detection signal is generated. Therefore, when the comparison means does not generate the detection signal, the measured value selection output means does not output the measured value. In this way, the obtained measured value is valid only under the condition that the intensity of the transmitted wave to the antenna exceeds the predetermined reference intensity. If the transmission power from the antenna is low,
Even if the measured value that represents the reflection coefficient or the function of the reflection coefficient exceeds the reference value in a pseudo manner due to the wraparound from other antennas, the measured value is not output and the antenna or the antenna feeding system is in an abnormal state. There is no mistake.

Further, in the monitoring device for the antenna and the antenna feeding system according to claim 3, in the monitoring device according to claim 2, the measured value is notified at a level indicating the degree of the abnormal state. Therefore, the degree of the abnormal state of the antenna and the antenna feeding system can be easily grasped from this display.

[0017]

1 is a block diagram showing the configuration of a transmission sharing system in a base station equipped with an antenna and a monitoring device for an antenna feeding system according to a first embodiment of the present invention. In FIG. 1, 11 is a plurality of transmitters TX1, ... TXi, ...
-A combiner for inputting and multiplexing TXn transmission signals,
Reference numeral 100 is a monitoring device inserted in the transmission line from the output of the combiner 11 to the antenna 13. To the combiner 11, isolators I1, ... Ii, ... In each consisting of a three-terminal circulator for inputting the transmission signals of the transmitters TX1 ,. .. Fn, which pass band-pass filters F1, ... Fi, ... Fn, and the outputs of the band-pass filters are multiplexed and output. In the monitoring device 100, the directional coupler 12 is the combiner 11
To the transmission line for the antenna 13 to detect the transmitted wave signal Et and the reflected wave signal Er to the antenna.
The detection circuits 14 and 15 output a detection signal Vt which is a DC voltage according to the intensity of the transmitted wave signal Et, and the detection circuit 15 has a detection signal V which is a DC voltage according to the intensity of the reflected wave signal Er.
Output r. The division circuit 18 obtains Vr / Vt and outputs it as a voltage signal Vo representing the reflection coefficient. The comparator 19 is a circuit that compares the output voltage Vo of the division circuit 18 with the output voltage of the reference voltage setting circuit 20 as a reference, and corresponds to the first comparison means according to the present invention. This comparator 19 sets its output to the logic 1 level when the value of Vo exceeds the reference voltage, and sets it to the logic 0 voltage level when it is below the reference voltage. The comparator 21 is a circuit that compares the transmitted wave detection signal Vt, which is the output signal of the detection circuit 14, with the output voltage of the reference voltage setting circuit 22 as a reference, and corresponds to the second comparison means according to the present invention. The comparator 21 sets its output to a logic 1 level when Vt exceeds the reference voltage, and sets its output to a logic 0 level when Vt is less than or equal to the reference voltage. The AND circuit 23 obtains a logical product result of the outputs of the comparator 19 and the comparator 21. When the outputs of the comparators 19 and 21 are both at the logic 1 level, the outputs are at the logic 1 level, and under other conditions, at the logic 0 level.

In the monitoring device 100 shown in FIG. 1, the reference voltage setting circuit 22 sets the output of the comparator 21 to be in the logic 1 state when the transmission power from the antenna 13 exceeds a predetermined constant value. .. Further, the reference voltage setting circuit 20 sets the output of the comparator 19 to the level of logic 1 when the reflection coefficient becomes abnormal.
With this configuration, when the system itself is in a power-off state and the intensity of the transmitted wave to the antenna 13 is extremely low, Vo ( = Vr / Vt) exceeds the reference voltage Vs1 and the output of the comparator 19 becomes the level of logic 1, but the detection signal Vt of the transmitted wave becomes the reference voltage Vs2 or less, and the output of the comparator 21 becomes logic 0.
It becomes the level of. Therefore, the output of the AND circuit 23 remains logic 0. Even if the intensity of the transmitted wave to the antenna 13 is not low and the detected signal Vt of the transmitted wave exceeds the reference voltage Vs2, if the reflection coefficient of the antenna or the antenna feeding system is sufficiently small, Vo is the reference voltage Vs1. After that, the output of the AND circuit 23 maintains the logic 0 level. If the intensity of the transmitted wave to the antenna 13 is not low and the reflection coefficient is high due to the obstacle of the antenna or the antenna feeding system, the outputs of the comparators 19 and 21 both become the level of logic 1 and the AND circuit 23 outputs. The output will also be at a logic one level. From this, the abnormal state of the antenna or the antenna feeding system can be correctly detected.

In the first embodiment, the detection circuit 1 for the detection signal Vt of the transmitted wave output from the detection circuit 14
Although the ratio of the detection signal Vr of the reflected wave output from 5 is obtained by the division circuit 18 and the reflection coefficient is obtained by this, the function of the reflection coefficient may be obtained without directly obtaining the reflection coefficient. For example, the VSWR may be further obtained from the reflection coefficient and the VSWR may be compared with a reference value. Further, for example, the detection circuits 14 and 15 are configured as a square-law detection circuit using diodes to detect the power component of the input signal and to compare the power ratio of the reflected wave to the power of the transmitted wave with a reference value. Good. Further, in the first embodiment, the division circuit 18 and the comparator 1
The circuits 9 and 21 and the AND circuit 23 are respectively constituted. For example, the detection signal Vt of the transmitted wave and the detection signal Vr of the reflected wave are respectively A / D converted, and the reflection coefficient or the function of the reflection coefficient is converted by digital arithmetic processing. The extraction, the magnitude comparison of the reflection coefficient or the function of the reflection coefficient with respect to the reference value, the magnitude comparison of the detection signal intensity of the transmitted wave with respect to the reference value, and the logical product calculation may be performed. Further, in the first embodiment, the output of the AND circuit 23 is at the level of logic 1 or logic 0, and whether the normal state or the abnormal state is present depends on the level of the observer's eyes. Alternatively, as in the second and third embodiments described below, the signal level is 0 in the normal state, and the level signal according to the seriousness of the abnormal state in the abnormal state. May be generated, and the level of visual or / and auditory appeal of the observer may be changed accordingly.

Next, FIGS. 3 and 4 show second and third examples of outputting the measured value representing the reflection coefficient as the measurement result.

FIG. 3 is a partial block diagram of the monitoring device provided in the transmission sharing system in the base station, and shows only parts different from the structure shown in FIG. 1 is different from the monitoring device 100 shown in FIG. 1 in that a multiplication circuit 25 that multiplies the output of the division circuit 18 and the output of the comparator 21 is provided, and that a meter 26 that displays the measured value in an analog manner is provided. is there. If the output of the comparator 21 is logic 1, the output of the multiplication circuit 25 is the same as the output of the division circuit 18. If the output of the comparator 21 is logic 0, the output of the multiplication circuit 25 is 0. With this configuration, when the system is in the power-off state and the intensity of the transmitted wave to the antenna is extremely low, when it is sneak-in from the antenna of another system, the output of the division circuit Shows a voltage Vo representing a pseudo large reflection coefficient, but since the output of the comparator 21 becomes the level of logic 0, the pointer of the meter 26 does not move. If the intensity of the transmitted wave to the antenna is not low and the reflection coefficient is high due to the obstacle of the antenna or the antenna feeding system, the output of the comparator 21 becomes the logic 1 level and the meter 26 responds to Vo. Will refer to the value. From this, the abnormal state of the antenna or the antenna feeding system can be correctly detected. An LED indicator may be used instead of the meter 26 in the example of FIG.

Further, in this case, a circuit is constructed such that the power of the meter 26 is turned on under the condition that the output of the comparator 21 is logic 1, while the meter 26 is output according to the output of the division circuit 18 without passing through the multiplication circuit 25. The same operation as described above can be obtained even if oscillates.

FIG. 4 is another partial configuration diagram of the monitoring device provided in the transmission sharing system in the base station, and shows only the parts different from the configuration shown in FIG. Monitoring device 10 shown in FIG.
The difference from 0 in the configuration is that a switch circuit 27 for selectively outputting the output of the divider circuit 18 to the display device 28 by the output of the comparator 21 is provided. Further, although the meter 26 may be used, the display device 28 uses, for example, an LED indicator that indicates the degree of the abnormal state in a plurality of stages according to the level of the measured value Vo. The switch circuit 27 outputs the output of the division circuit 18 to the display device 28 when the output of the comparator 21 is at the logic 1 level, but outputs the 0 potential when the output of the comparator 21 is at the logic 0 level. With this configuration, the display according to Vo is performed only when the intensity of the transmitted wave to the antenna is not low. Moreover, since the display is made according to the degree of the abnormal state, it becomes possible to easily grasp the degree of the abnormal state of the antenna or the antenna feeding system.

[0024]

According to the present invention, when there is no obstacle in the antenna or the antenna feeding system, even if the sneak from the antenna of another system occurs in a state where the transmission power is extremely low such as the power off state of the own system, The abnormal state of the antenna or the antenna feeding system will not be erroneously detected. This not only eliminates the need for maintenance and inspection work due to false failure detection, but also eliminates the occurrence of secondary failures due to maintenance and inspection.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a transmission common system to which a monitoring device for an antenna and an antenna feeding system according to a first embodiment of the present invention is applied.

FIG. 2 is a block diagram showing a general configuration of a cellular mobile communication system.

FIG. 3 is a block diagram showing a partial configuration of a monitoring device for an antenna and an antenna feeding system according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a partial configuration of an antenna and an antenna feeding system monitoring apparatus according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a transmission sharing system in a base station to which a conventional monitoring device is applied.

[Explanation of symbols]

 11-combiner 12-directional coupler 13-antenna 14,15-detection circuit 19,21-comparator 23-AND circuit 24-antenna of other system 100-antenna and antenna feeding system monitoring device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshito Shoto, 2 26-10 Tenjin, Tenjin, Nagaokakyo, Kyoto Murata Manufacturing Co., Ltd.

Claims (3)

[Claims] 1. A monitoring device for an antenna and an antenna feeding system in a wireless transmission system for feeding a transmission signal output from a transmitter to an antenna and radiating the transmission signal from the antenna to a space. Coupling means provided on the transmission line for power feeding, each detecting a transmitted wave and a reflected wave of the transmission signal, and a transmission wave and a reflected wave of the transmission signal detected by the coupling means are respectively detected and detected. A detection unit that outputs a signal, a measurement value detection unit that detects a measurement value representing a reflection coefficient or a function of the reflection coefficient based on each detection signal output from the detection unit, and the reflection coefficient or the function of the reflection coefficient. Compared to the standard value,
First comparing means for outputting a first detection signal when the reflection coefficient or the function of the reflection coefficient exceeds the reference value; and comparing the detected signal strength of the transmitted wave with a reference strength to detect the transmitted wave. It is characterized by further comprising a second comparing means for outputting a second detection signal when the intensity exceeds the reference intensity, and a logical product means for obtaining a logical product of the first detection signal and the second detection signal. Monitoring device for antenna and antenna feeding system. 2. A monitoring device for an antenna and an antenna feeding system in a wireless transmission system for feeding a transmission signal output from a transmitter to an antenna and radiating the transmission signal from the antenna to a space, wherein the transmission signal to the antenna is provided. Coupling means provided on the transmission line for power feeding, each detecting a transmitted wave and a reflected wave of the transmission signal, and a transmission wave and a reflected wave of the transmission signal detected by the coupling means are respectively detected and detected. A detection unit that outputs a signal, a measurement value detection unit that detects a measurement value representing a reflection coefficient or a function of the reflection coefficient based on each detection signal output from the detection unit, and a detection signal intensity of the transmitted wave as a reference. Comparing means for outputting a detection signal when the detected signal strength of the transmitted wave exceeds the reference strength; and a means for outputting the measured value when the detection signal is generated. Further comprising a measurement value selection output means for antenna and antenna feed system of the monitoring device and said. 3. The monitoring device for an antenna and an antenna feeding system according to claim 2, wherein the measured value selection output means reports the measured value at a level indicating the degree of an abnormal state.