WO2017158910A1

WO2017158910A1 - Active antenna system

Info

Publication number: WO2017158910A1
Application number: PCT/JP2016/082388
Authority: WO
Inventors: 修一西村
Original assignee: 住友電気工業株式会社
Priority date: 2016-03-18
Filing date: 2016-11-01
Publication date: 2017-09-21
Also published as: JP2017169173A

Abstract

Provided is an active antenna system that comprises a plurality of antenna elements, a plurality of signal processing units that perform processing on radio signals that are to be respectively transmitted by the plurality of antenna elements, and a casing that accommodates the plurality of antenna elements and the plurality of signal processing units, wherein the active antenna system is provided with the following: a plurality of signal obtaining units that obtain from the respective signal processing units transmission signals that are to be output to the corresponding antenna elements; and an inspection port that is provided in the casing and can output the obtained transmission signals to outside the casing.

Description

Active antenna system

The present invention relates to an active antenna system.
This application claims priority based on Japanese Patent Application No. 2016-055414 filed on Mar. 18, 2016, and incorporates all the content described in the above Japanese application.

Conventionally, in a base station apparatus used in a wireless communication system such as a mobile phone, a radio transmission / reception unit (RRH; Remote Radio Head) that processes a signal of a radio frequency and a baseband signal processing unit that performs processing related to a baseband signal ( The structure which isolate | separated BBU; Base | Band | Unit | Unit) is employ | adopted.

An antenna system installed outdoors is connected to the RRH via a coaxial cable or the like. A radio frequency transmission / reception signal transmitted / received by the antenna system is transmitted between the RRH and the antenna system via a coaxial cable or the like.
The RRH and the BBU are connected by an optical fiber cable or the like, and a digital baseband signal is transmitted between the two by optical communication or the like.

Normally, BBU is installed indoors and RRH is installed directly under the outdoor antenna system. Thus, by separating the transmission / reception function of the base station device into BBU and RRH, and installing RRH in the vicinity of the antenna system, the length of the coaxial cable connecting the antenna system and RRH is made as short as possible, The coaxial cable suppresses attenuation of radio frequency transmission / reception signals.

The RRH is provided with a maintenance port to which a cable for communication with the outside is connected by a connection method compliant with Ethernet (registered trademark), RC232C, or the like (see, for example, Patent Document 1). Thus, for example, by preparing a port connected to an external measuring instrument as a maintenance port through a cable, the radio performance of the RRH is examined and the radio wave law is observed, Inspection work to confirm that the equipment is operating normally can be performed. Hereinafter, this port is referred to as an inspection port.

JP 2011-254415 A (see FIG. 2)

The active antenna system according to the present disclosure includes a plurality of antenna elements, a plurality of signal processing units that process radio signals transmitted by the plurality of antenna elements, and the plurality of antenna elements and the plurality of signal processing units. A plurality of signal extraction units that extract transmission signals output to the corresponding antenna elements from each of the signal processing units, and provided in the case. And an inspection port capable of outputting the extracted transmission signal to the outside of the housing.

It is a block diagram which shows a part of base station apparatus provided with the active antenna system which concerns on 1st Embodiment of this invention. It is a block diagram of an active antenna system. It is a block block diagram of a signal processing module. It is a block diagram of the active antenna system which concerns on 2nd Embodiment of this invention. It is a block diagram of the active antenna system which concerns on 3rd Embodiment of this invention. It is a block diagram which shows a part of base station apparatus provided with the active antenna system which concerns on 4th Embodiment of this invention. It is a block diagram which shows a part of base station apparatus provided with the active antenna system which concerns on 5th Embodiment of this invention.

[Problems to be solved by the present disclosure]
In recent years, with the spread of smartphones and the like in wireless communication systems, there has been a growing demand for expansion of communication areas and expansion of communication capacity, and application of active antenna systems incorporating RRH functions to base station devices has been proposed. ing.
The active antenna system includes a plurality of antenna elements and a plurality of radio transmission / reception units (corresponding to conventional RRHs) provided corresponding to the plurality of antenna elements. For this reason, the radio signal transmitted / received for each antenna element can be controlled, and the controllability is excellent, and it is possible to provide a new service that can improve the communication environment using this excellent controllability.

However, the active antenna system has a structure in which the wireless transmission / reception unit and the antenna element are integrated in the casing. For this reason, as with conventional RRHs, if the quality of the radio signal is confirmed at the output unit of the radio transmission / reception unit, the output unit of the radio transmission / reception unit cannot be easily accessed from the outside of the housing during inspection work. Problems arise.

In addition, when a coaxial cable is connected to an inspection port provided in each of a plurality of wireless transmission / reception units and a signal is taken out from each wireless transmission / reception unit to perform an inspection operation, an operation of connecting the coaxial cable to each of a large number of inspection ports Therefore, workability becomes extremely difficult. There is also a need to check the output of the combined antenna element as a whole, not the output of a single wireless transmission / reception unit for each antenna element.

Therefore, an object of the present invention is to provide an active antenna system that can easily perform inspection work.

[Effects of the present disclosure]
According to the present disclosure, the inspection work can be easily performed.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
(1) An active antenna system according to an embodiment of the present invention includes a plurality of antenna elements, a plurality of signal processing units that process radio signals transmitted by the plurality of antenna elements, the plurality of antenna elements, An active antenna system including a plurality of signal processing units, and a plurality of signal extraction units that extract transmission signals output to the corresponding antenna elements from the signal processing units. An inspection port provided in the casing and capable of outputting the extracted transmission signal to the outside of the casing.

According to the above active antenna system, the inspection port that can output the transmission signal to the antenna element taken out by the signal extraction unit is provided in the housing in which the antenna element and the signal processing unit are accommodated. By connecting a cable of an external device such as a measuring instrument to the inspection port, the signal processing unit can be easily accessed from the outside of the housing. Thereby, the inspection work of an active antenna system can be performed easily.

(2) It is preferable that the active antenna system further includes a combiner that combines two or more transmission signals extracted by the signal extraction units different from each other and outputs the combined signals to the inspection port.
In this case, since two or more transmission signals extracted by different signal extraction units are synthesized by the combiner and output to the inspection port, a signal equivalent to an actual radio signal radiated from the two or more antenna elements. Can be output from the inspection port to the outside for confirmation.

(3) It is preferable that the active antenna system further includes a plurality of switches provided on paths connecting the signal extraction units and the combiner, and connecting and disconnecting the paths.
In this case, by turning on only one of the switches and turning off all of the other switches, the transmission signal extracted from each signal extraction unit can be output to the outside from the inspection port via the combiner. it can. As a result, it is possible to easily identify the faulty signal processing unit and the aged deterioration state of each signal processing unit. In addition, by turning on a predetermined number of switches of 2 or more and turning off the other switches, it is possible to synthesize an arbitrary predetermined number of transmission signals by a synthesizer and output it from the inspection port to the outside. .

(4) It is preferable that the active antenna system further includes a control unit that individually controls the plurality of switches.
In this case, the signal output from the inspection port to the outside can be easily changed by individually controlling the plurality of switches by the control unit.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, you may combine arbitrarily at least one part of embodiment described below.
[First Embodiment]
<About base station equipment>
FIG. 1 is a block diagram illustrating a part of a base station apparatus including an active antenna system according to the first embodiment of the present invention. The base station apparatus 1 is used as a base station apparatus in a wireless communication system for mobile phones to which LTE (Long Term Evolution) is applied, for example, and is connected to a plurality of mobile terminals (not shown) such as mobile phones and MIMO. (Multiple Input Multiple Output) It has a function of performing wireless communication by transmission.

The base station apparatus 1 includes a baseband unit (BBU) 2, a remote radio head (RRH) 3, and an active antenna system 4 (hereinafter also simply referred to as an antenna system 4).
The BBU 2 is connected to the RRH 3 via a signal transmission line 5 such as an optical fiber cable, and has a function of transmitting and receiving a frame (CPRI frame) compliant with the CPRI (Common Public Radio Interface) to the RRH 3. ing.
Specifically, the BBU 2 acquires a reception baseband signal (I / Q signal) that is a digital signal from the RRH 3 via the signal transmission path 5. And BBU2 has a function which produces | generates reception data by performing a digital demodulation process with respect to a reception baseband signal, and gives the produced | generated reception data to a high-order network.

The BBU 2 has a function of generating a transmission baseband signal by performing digital modulation processing on transmission data given from an upper network (not shown). The BBU 2 gives a digital transmission baseband signal obtained by modulating transmission data to the RRH 3 via the signal transmission path 5.

The RRH 3 is connected to the antenna system 4 by connecting the coaxial cables 6 and 7 extending from the RRH 3 to

connection ports

6a and 7a provided in the casing 11 of the antenna system 4, and transmits and receives transmission / reception signals. Signal processing. Although a part of the

connection ports

6a and 7a of this embodiment is not shown in FIG. 1, a plurality of (for example, four)

connection ports

6a and 7a are provided on the bottom surface 11a of the housing 11, respectively. The same number of coaxial cables 6 and 7 extending from the RRH 3 are respectively connected to 7a.

The RRH 3 has a function of converting it into an analog radio frequency signal by performing various signal processing on the transmission baseband signal given from the BBU 2. The RRH 3 supplies the converted analog radio frequency transmission signal to the antenna system 4 via the coaxial cable 6.
The RRH 3 has a function of converting a radio frequency reception signal supplied from the antenna system 4 through the coaxial cable 7 into a digital reception signal by performing various signal processing. The RRH 3 gives the converted digital reception signal to the BBU 2.

The antenna system 4 is installed higher than the RRH 3 (such as on the roof of a building or on a steel tower). The antenna system 4 includes a plurality of antenna elements 10 housed in a housing 11 for transmitting and receiving radio frequency signals. When the base station apparatus 1 performs wireless communication with a mobile terminal, It has a function of transmitting and receiving wireless signals related to the wireless communication. The antenna system 4 of the present embodiment includes 4 × N antenna elements 10 (N is an integer equal to or greater than 1), with two antenna elements 10 having polarization directions orthogonal to each other as a set.

The antenna system 4 distributes a radio frequency transmission signal provided from the RRH 3 corresponding to each of the plurality of antenna elements 10 and transmits the radio signals from the antenna elements 10 as radio signals. In addition, the antenna system 4 synthesizes radio frequency reception signals received by the plurality of antenna elements 10 as radio signals, and gives the synthesized radio frequency signal to the RRH 3.
In this way, the base station apparatus 1 converts a digital transmission signal into a radio frequency signal and transmits it to the mobile terminal, receives the radio frequency signal transmitted by the mobile terminal, and receives the received signal from the mobile terminal. get.

<About the antenna system>
FIG. 2 is a block diagram of the antenna system 4. The antenna system 4 includes the casing 11 and a plurality of antenna elements 10, a plurality of distribution / combiners 12, a plurality of signal processing modules 13, a control unit 14, and a combiner 15.
The distribution synthesizers 12 are provided in the casing 11 in the same number as the connection ports 6a (7a). Each distribution synthesizer 12 is connected to a set of

connection ports

6 a and 7 a and is connected to a plurality of signal processing modules 13. The plurality of signal processing modules 13 are respectively connected to the antenna elements 10 having the same polarization direction.

With the above configuration, one distribution synthesizer 12, a plurality of signal processing modules 13 to which the distribution synthesizer 12 is connected, and a plurality of antenna elements to which the plurality of signal processing modules 13 are respectively connected. One branch is configured. Therefore, the antenna system 4 of this embodiment has a 4-branch MIMO function.

The distribution synthesizer 12 distributes the radio frequency transmission signal given from the RRH 3 via the connection port 6 a to each of the plurality of signal processing modules 13, and gives the distributed transmission signal to each signal processing module 13.
The distribution synthesizer 12 synthesizes reception signals received as radio signals by the plurality of antenna elements 10 and provides the synthesized radio frequency reception signal to the RRH 3 from the connection port 7a.

<Signal processing module>
FIG. 3 is a block diagram of the signal processing module 13. The signal processing module 13 includes two

duplexers

21 and 22 and a signal processing unit 23.
The signal processing unit 23 includes a first phase shifter 27 and a first amplifier 28 in order to process a radio frequency signal (radio signal) transmitted by the antenna element 10 connected to the signal processing module 13. Have. In addition, the signal processing unit 23 includes a second phase shifter 29 and a second amplifier 30 in order to process a radio signal received by the antenna element 10 connected to the signal processing module 13.

One duplexer 21 is connected to the first phase shifter 27 and the second phase shifter 29 and is also connected to the distribution synthesizer 12 (see FIG. 2). The other duplexer 22 is connected to the first amplifier 28 and the second amplifier 30 and to the antenna element 10 (see FIG. 2).

The duplexer 21 provides the first phase shifter 27 with the radio signal (radio frequency transmission signal) input from the distribution synthesizer 12. The first phase shifter 27 adjusts the phase of the transmission signal given from the duplexer 21. The first phase shifter 27 provides the first amplifier 28 with the transmission signal whose phase has been adjusted.
The first amplifier 28 amplifies the power of the transmission signal given from the first phase shifter 27 and passes the amplified transmission signal to the duplexer 22 through the signal extraction unit 25. The duplexer 22 outputs the transmission signal given from the first amplifier 28 to the antenna element 10.

On the other hand, a radio signal (radio frequency received signal) received by the antenna element 10 is given to the duplexer 22. The duplexer 22 provides the input received signal to the second amplifier 30. The second amplifier 30 amplifies the power of the input reception signal and supplies the second phase shifter 29 with the transmission signal whose power has been amplified.
The second phase shifter 29 adjusts the phase of the reception signal supplied from the second amplifier 30 and supplies the reception signal with the adjusted phase to the duplexer 21. The duplexer 21 outputs the received signal given from the second phase shifter 29 to the distribution synthesizer 12.

In this manner, each signal processing module 13 functions as an active antenna that can perform processing such as phase adjustment and power amplification on the transmission / reception signals transmitted and received by the plurality of antenna elements 10 for each antenna element 10. Processing can be performed.

The signal processing module 13 further includes a signal extraction unit 25 and a switch 26. The signal extraction unit 25 is composed of, for example, a directional coupler, and is provided between the first amplifier 28 and the duplexer 22. The signal extraction unit 25 extracts a transmission signal output from the signal processing unit 23 toward the antenna element 10. Specifically, the signal extraction unit 25 extracts a transmission signal whose power is amplified by the first amplifier 28 of the signal processing unit 23, and provides the transmission signal to the synthesizer 15 (see FIG. 2).

The switch 26 is provided on a path connecting the signal extraction unit 25 and the combiner 15, and connects and disconnects the path. The switch 26 of the present embodiment is composed of, for example, a multi-port high-frequency switch, and has an a contact, a b contact, and a c contact. The switch 26 is controlled by the control unit 14 (see FIG. 2) so as to be in one of an off state in which the a contact is connected to the b contact and an on state in which the a contact is connected to the c contact. Is done.
The contact a of the switch 26 is connected to the signal extraction unit 25. Further, for example, a terminator 31 is connected to the b contact of the switch 26, and the c contact of the switch 26 is connected to the synthesizer 15 (see FIG. 2).

With the above configuration, when a transmission signal is output from the signal processing unit 23 to the antenna element 10, the control unit 14 turns off the switch 26 (a contact is connected to the b contact) and terminates the signal extraction unit 25. Connected to the device 31.
When the transmission signal output from the signal processing unit 23 is taken out of the signal processing module 13 from this state, the control unit 14 switches on the switch 26 (a state where the a contact is connected to the c contact). The signal extraction unit 25 is connected to the combiner 15.

<About the control port and inspection port>
1 and 2, the control unit 14 is provided in the housing 11 and has a function of individually controlling the switches 26 of the signal processing modules 13. The control unit 14 is connected to a control port 8 a provided on the bottom surface 11 a of the housing 11. The control port 8a is a port compliant with, for example, Ethernet (registered trademark), and is connected to a control cable 8 extending from an external device 50 such as a measuring instrument or a notebook personal computer.

Control information for controlling the switch 26 of one or a plurality of signal processing modules 13 is input to the control unit 14 from the external device 50 through the control cable 8 and the control port 8a. Accordingly, the control unit 14 of the present embodiment individually controls the switch 26 of each signal processing module 13 based on the control information input from the external device 50 by connecting the control cable 8 to the control port 8a. It is like that.

The synthesizer 15 is provided in the housing 11 and has a function of synthesizing transmission signals extracted by the signal extraction units 25 of two or more different signal processing modules 13. Only one synthesizer 15 according to this embodiment is provided in the casing 11 and synthesizes transmission signals extracted from all the signal processing modules 13.

The synthesizer 15 is connected to a single inspection port 9a provided on the bottom surface (outer surface) 11a of the casing 11, and outputs the synthesized transmission signal to the inspection port 9a. Further, when the transmission signal extracted from the single signal processing module 13 is given, the synthesizer 15 outputs the transmission signal as it is to the inspection port 9a.

The inspection port 9a is a port compliant with, for example, Ethernet (registered trademark), and is connected to an inspection cable 9 extending from the external device 50 (see FIG. 1). Thus, by connecting the inspection cable 9 to the inspection port 9 a, the transmission signal synthesized by the combiner 15 can be output to the external device 50 that is outside the housing 11.

As described above, in the present embodiment, the inspection port that can output the transmission signal to the antenna element 10 extracted by the signal extraction unit 25 to the outside in the casing 11 in which the antenna element 10 and the signal processing unit 23 are accommodated. Since 9a is provided, the signal processing unit 23 can be easily accessed from the outside of the housing 11 by connecting the inspection cable 9 of the external device 50 to the inspection port 9a. Thereby, the inspection work of the antenna system 4 can be performed easily.

In addition, since two or more transmission signals extracted by different signal extraction units 25 are combined by the combiner 15 and output to the inspection port 9a, the actual radio signals radiated from the two or more antenna elements 10 and An equivalent signal can be output from the inspection port 9a to the external device 50 for confirmation.

Further, a switch 26 for connecting / disconnecting the path is provided on a path connecting each signal extraction unit 25 and the combiner 15. For this reason, by turning on only one of the switches 26 and turning off all the other switches, the transmission signals taken out from the signal take-out sections 25 are sent from the inspection port 9a to the outside via the synthesizer 15. Can be output.

As a result, it is possible to easily identify the faulty signal processing unit 23 and the aged deterioration status of each signal processing unit 23. Also, by turning on two or more predetermined number of switches 26 and turning off other switches 26, an arbitrary predetermined number of transmission signals are synthesized by the synthesizer 15 and output to the outside from the inspection port 9a. Is also possible.
In addition, since the plurality of switches 26 can be individually controlled by the control unit 14, the signal output to the outside from the inspection port 9a can be easily changed.

[Second Embodiment]
FIG. 4 is a block diagram of an antenna system 4 according to the second embodiment of the present invention. The main difference between the antenna system 4 of the present embodiment and the first embodiment is that the synthesizer 15 (see FIG. 2) is not provided. For this reason, the antenna system 4 of this embodiment includes the same number of inspection ports 9 a as the signal processing module 13. Thereby, the transmission signal taken out from each signal processing module 13 is individually output to the outside from the corresponding inspection port 9a. Since the other structure of this embodiment is the same as that of 1st Embodiment, description is abbreviate | omitted.

As mentioned above, according to the antenna system 4 which concerns on 2nd Embodiment, while there exists an effect similar to 1st Embodiment, there exist the following effects. That is, by connecting the inspection cable 9 of the external device 50 to the inspection port 9a corresponding to the signal processing unit 23 of each signal processing module 13, each signal processing unit 23 can be easily accessed from the outside of the housing 11. be able to.

In this embodiment, the switch 26 (see FIG. 3) is provided in the signal processing module 13, but a terminator may be detachably connected to each inspection port 9a instead of the switch 26. In this case, when connecting the inspection cable 9 to the inspection port 9a, it is only necessary to remove the terminator and connect the inspection cable 9.

[Third Embodiment]
FIG. 5 is a block diagram of an antenna system 4 according to the third embodiment of the present invention. The main difference between the antenna system 4 of the present embodiment and the first embodiment is that a plurality of combiners 15 and a plurality of inspection ports 9a are provided.
In FIG. 5, the antenna system 4 of the present embodiment includes the same number (four) of combiners 15 and inspection ports 9a as the number of MIMO branches.

Each synthesizer 15 synthesizes the transmission signals extracted from the signal extraction units 25 of the plurality of signal processing modules 13 constituting one branch. Each combiner 15 is connected to a single inspection port 9a, and outputs the combined transmission signal to the inspection port 9a. Each synthesizer 15 receives the transmission signal extracted from any one of the signal processing modules 13 among the plurality of signal processing modules 13, and the inspection signal 9a corresponding to the transmission signal as it is. Output to. Since the other structure of this embodiment is the same as that of 1st Embodiment, description is abbreviate | omitted.

As mentioned above, according to the antenna system 4 which concerns on 3rd Embodiment, while there exists an effect similar to 1st Embodiment, there exist the following effects. That is, by turning on the switch 26 of each signal processing module 13 constituting any one branch of MIMO and turning off all the switches 26 of the signal processing module 13 constituting other branches, the radiation is emitted from each branch. A signal equivalent to the wireless signal can be output from the inspection port 9a to the external device 50. Thereby, it can be easily confirmed that the radio signal radiated from each branch is radiated in a desired direction.

The antenna system 4 of the present embodiment includes a combiner 15 and an inspection port 9a for each MIMO branch. However, the combiner 15 and an inspection port are provided for each of two orthogonal polarization directions of the antenna element 10. A port 9a may be provided. For example, in FIG. 5, a plurality of signal processing modules 13 arranged on the right side and the left side are output to the antenna elements 10 having the same polarization direction. For this reason, the transmission signals extracted from the plurality of signal processing modules 13 on the right side are combined by one synthesizer 15, and the transmission signals extracted from the plurality of signal processing modules 13 on the left side are combined by one other synthesizer 15. You may synthesize.

[Fourth Embodiment]
FIG. 6 is a block diagram showing a part of the base station apparatus 1 including the antenna system 4 according to the fourth embodiment of the present invention. The main difference between the antenna system 4 of the present embodiment and the first embodiment is that the upstream end of the control cable 8 is connected to the RRH 3. In FIG. 6, in the antenna system 4 of the present embodiment, the control cable 8 extending from the RRH 3 is connected to the control port 8 a of the housing 11.

The RRH 3 controls information for controlling the switch 26 of one or a plurality of signal processing modules 13 with respect to the control unit 14 (see FIG. 2) in the housing 11 via the control cable 8 and the control port 8a. give. Thereby, the control part 14 of this embodiment controls the switch 26 of each signal processing module 13 with the control information input from RRH3 by connecting the control cable 8 to the control port 8a. Since the other structure of this embodiment is the same as that of 1st Embodiment, description is abbreviate | omitted.
As described above, the antenna system 4 according to the fourth embodiment also has the same effects as the first embodiment.

[Fifth Embodiment]
FIG. 7 is a block diagram showing a part of the base station apparatus 1 including the active antenna system 4 according to the fifth embodiment of the present invention. The antenna system 4 of the present embodiment is a modification of the fourth embodiment, and is mainly different from the fourth embodiment in that the antenna system 4 and the BBU 2 are directly connected without using the RRH 3. is there.

7, the BBU 2 of the present embodiment is connected to a connection port 17 provided in the housing 11 of the antenna system 4 via a signal transmission path 5 such as an optical fiber cable. The connection port 17 is connected to an interface unit (not shown) for transmitting and receiving a frame conforming to the CPRI in the housing 11.

The BBU 2 gives a transmission baseband signal obtained by modulating transmission data given from an upper network (not shown) to the antenna system 4 via the signal transmission path 5.
Further, the BBU 2 acquires a reception baseband signal (I / Q signal) that is a digital signal given from the antenna system 4 via the signal transmission path 5, and performs digital demodulation processing on the reception baseband signal. And has a function of generating received data. The BBU 2 gives received data obtained by demodulating the received baseband signal to the upper network.

Further, the BBU 2 gives control information for controlling the switches 26 of the one or more signal processing modules 13 to the control unit 14 (see FIG. 2) in the housing 11 via the signal transmission path 5. Thereby, the control part 14 of this embodiment controls the switch 26 of each signal processing module 13 with the control information input from BBU2. Since the other structure of this embodiment is the same as that of 1st Embodiment, description is abbreviate | omitted.
As described above, the antenna system 4 according to the fifth embodiment also has the same effects as the first embodiment.

In addition, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined not by the above-described meaning but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

1 Base station device 2 Baseband unit (BBU)
3 Remote Radio Head (RRH)
DESCRIPTION OF SYMBOLS 4 Active antenna system 5 Signal transmission path 6 Coaxial cable 6a Connection port 7 Coaxial cable 7a Connection port 8 Control cable 8a Connection port 9 Inspection cable 9a Inspection port 10 Antenna element 11 Case 11a Bottom surface 12 Divider / Synthesizer 13 Signal processing Module 14 Control unit 15 Synthesizer 17 Connection port 21 Duplexer 22 Duplexer 23 Signal processing unit 25 Signal extraction unit 26 Switch 27 First phase shifter 28 First amplifier 29 Second phase shifter 30 Second amplifier 31 Terminator 50 External device

Claims

A plurality of antenna elements;
A plurality of signal processing units for processing radio signals transmitted by each of the plurality of antenna elements;
A housing in which the plurality of antenna elements and the plurality of signal processing units are housed, and an active antenna system comprising:
A plurality of signal extraction units that extract transmission signals output to the corresponding antenna elements from the signal processing units;
An active antenna system comprising: an inspection port provided in the casing and capable of outputting the extracted transmission signal to the outside of the casing.
The active antenna system according to claim 1, further comprising a combiner that combines two or more of the transmission signals extracted by the signal extraction units different from each other and outputs the combined signal to the inspection port.
The active antenna system according to claim 2, further comprising a plurality of switches provided on paths connecting the signal extraction units and the combiner, and connecting and disconnecting the paths.
The active antenna system according to claim 3, further comprising a control unit that individually controls the plurality of switches.