CN203942525U - POI flash chamber and dilatation POI system - Google Patents

Abstract

A POI capacity expansion device and a capacity expansion POI system. The capacity expansion bridge of the POI capacity expansion device receives signals sent by the capacity expansion system, and outputs coupling/through signals and direct/coupling signals to the first bridge phase circuit and the second bridge phase circuit respectively. The first phase bridge circuit receives the first broadband signal and the coupling/through signal and outputs a first mixed signal; the second bridge phase circuit receives the second broadband signal and the through/coupling signal and outputs a second mixed signal. Through the first bridge phase circuit and the second bridge phase circuit, the signal that needs to be expanded is filtered and phase-processed to obtain the signal of the required frequency band for expansion, and the original coverage signal is connected to the output together with the processed expanded signal, which is used as the classic The antenna feeder system transmits coverage to realize system expansion. Since there is no need to change the structure of the existing POI equipment, and the expansion can be realized by simplifying complex technical problems, the structure is simple, the operation is convenient and the cost is low.

Description

POI expansion device and expansion POI system

technical field

The utility model relates to the technical field of communication, in particular to a POI capacity expansion device and a capacity expansion POI system.

Background technique

After domestic LTE (Long Term Evolution, long-term evolution) licensing, the number of mainstream mobile communication systems has increased, and the minimum requirement for LTE MIMO (Multi-input Multi-output) coverage is dual-receiver and dual-transmission, and the same coverage area The number of system accesses has further increased.

In addition to conventional mobile communication systems, the access sharing function of POI (Point Of Interface, multi-system access platform) usually includes access to TETRA (Trans European Trunked Radio, Pan-European Trunked Radio), DTV (Digital TV, digital TV ), MOBILE TV (mobile TV), public security and fire protection and other private network systems, the number of systems is increasing, so in the coverage that has been built or is under construction, it has become quite difficult to increase and expand the system.

Traditional POI devices are connected to multiple input systems, receive input signals from multiple systems and output two broadband signals (of course, according to the difference in coverage schemes, some have 4 channels, some have 1 channel, here are two channels for illustration) and pass two antenna feeders System implementation coverage. Due to the structure and working principle of the POI equipment, if the expansion is performed, the structure of the POI equipment needs to be greatly changed. Therefore, the traditional POI equipment has the disadvantage of high expansion cost.

Utility model content

Based on this, it is necessary to provide a POI capacity expansion device and a capacity expansion POI system that can reduce the cost of capacity expansion to address the above problems.

A POI capacity expansion device, comprising a capacity expansion bridge, a first bridge phase circuit and a second bridge phase circuit, the first bridge phase circuit and the second bridge phase circuit are all provided with a capacity expansion input port, a broadband signal port and a combining output port ,

The input port of the expansion bridge is connected to the signal delivered by the expansion system, the first output port of the expansion bridge is connected to the expansion input port of the phase circuit of the first bridge, and the coupling/through signal is transmitted to the first bridge phase circuit;

The second output port of the expansion bridge is connected to the expansion input port of the second bridge phase circuit, and transmits the through/coupling signal to the second bridge phase circuit;

The broadband signal port of the first bridge phase circuit receives the first broadband signal, and the combined output port of the first bridge phase circuit outputs the first mixed signal; the broadband signal port of the second bridge phase circuit receives the second broadband signal. signal, the combined output port of the second bridge phase circuit outputs a second mixed signal.

In the above POI expansion device, the expansion bridge receives the signal transmitted by the expansion system, and outputs the coupling/through signal and the through/coupling signal to the first bridge phase circuit and the second bridge phase circuit respectively. The first phase bridge circuit receives the first broadband signal and the coupling/through signal and outputs a first mixed signal; the second bridge phase circuit receives the second broadband signal and the through/coupling signal and outputs a second mixed signal. Through the first bridge phase circuit and the second bridge phase circuit, the signal to be expanded is filtered and phase-processed to obtain the signal in the frequency band required for expansion, and the original coverage signal is connected to the output together with the processed expanded signal, which is used as the antenna The feeder system transmits and covers to realize system expansion. Since there is no need to change the structure of the existing POI equipment, and the expansion can be realized by simplifying complex technical problems, the structure is simple, the operation is convenient and the cost is low.

An expanded POI system, comprising POI equipment, a first antenna feed system, a second feed system, and the above POI capacity expansion device, the input port of the POI device is connected to a multi-system input signal, and the first output port of the POI device Connect the broadband signal port of the second bridge phase circuit, output the second broadband signal to the second bridge phase circuit, and connect the second output port of the POI device to the broadband signal port of the first bridge phase circuit , output the first broadband signal to the first bridge phase circuit; the combination output port of the first bridge phase circuit is connected to the first antenna feeder system, and the combination output port of the second bridge phase circuit Connect the second feeder system.

The aforementioned capacity expansion POI system, through the aforementioned POI capacity expansion device, has a convenient capacity expansion function, simple structure, convenient operation and low cost.

Description of drawings

Fig. 1 is a structural diagram of a POI expansion device in an embodiment;

Fig. 2 is a schematic diagram of a POI expansion device in an embodiment;

Fig. 3 is a schematic diagram of the phase change of the coupling/through signal flowing through the first bridge phase circuit in an embodiment;

Fig. 4 is a schematic diagram of the phase change of the first broadband signal flowing through the first bridge phase circuit in an embodiment;

Fig. 5 is a structural diagram of an expanded POI system in an embodiment.

Detailed ways

In order to make the above purpose, features and advantages of the present utility model more obvious and understandable, the specific implementation of the present utility model will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a full understanding of the present invention. However, the utility model can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below limit.

It should be noted that when an element is referred to as being “fixed” to another element, it can be directly on the other element or there can also be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of this invention. The terminology used in the description of the utility model herein is only for the purpose of describing specific embodiments, and is not intended to limit the utility model.

A POI capacity expansion device, as shown in Figure 1, the POI capacity expansion device comprises a capacity expansion bridge 110, a first bridge phase circuit 120 and a second bridge phase circuit 130, the first bridge phase circuit 120 and the second bridge phase circuit 130 are all set There are expansion input ports, broadband signal ports and combined output ports.

The input port of the expansion bridge 110 is connected to the signal sent by the expansion system, and the first output port of the expansion bridge 110 is connected to the expansion input port of the first bridge phase circuit 120 to transmit the coupled/through signal to the first bridge phase circuit 120 . The second output port of the expansion bridge 110 is connected to the expansion input port of the second bridge phase circuit 130 to transmit the through/coupling signal to the second bridge phase circuit 130 . It should be noted that transmitting the coupled/through signal to the first bridge phase circuit 120 refers to transmitting the coupled signal or the through signal to the first bridge phase circuit 120 . Sending the through/coupled signal to the second bridge phase circuit 130 refers to sending the through signal or the coupled signal to the second bridge phase circuit 130 .

Specifically, the expansion bridge 110 includes two input terminals and two output terminals, one of which is used as an input port of the expansion bridge 110 , and the other input terminal can be connected to a matching load 210 . Among the two output ends of the capacity expansion bridge 110, the port directly connected to the input port is a through port, which outputs a through signal with the same amplitude as the signal delivered by the capacity expansion system and a phase difference of 180 degrees, and the other port is a coupling port, and the output is connected with the capacity expansion system. The system transmits coupled signals with the same signal amplitude and 90-degree phase difference. In this embodiment, the coupling port of the expansion bridge 110 can be used as the first output port to connect to the first bridge phase circuit 120, and the coupling signal can be sent to the first bridge phase circuit 120, and the through port of the expansion bridge 110 can be used as the second output port. The second bridge phase circuit 130 is connected to deliver the through signal to the second bridge phase circuit 130 . It is also possible to use the through port and the coupled port of the expansion bridge 110 as the first output port and the second output port, and output the through signal and the coupled signal to the first bridge phase circuit 120 and the second bridge phase circuit 130 respectively.

The filter passbands of the first bridge phase circuit 120 and the second bridge phase circuit 130 correspond to the frequency band of the signal that needs to be expanded (which can be called the expansion frequency band), and the coupling/through signal and the through/coupling signal are respectively filtered to realize the corresponding frequency band signal extraction. The broadband signal port of the first bridge phase circuit 120 receives the first broadband signal, and the combined output port of the first bridge phase circuit 120 outputs the first mixed signal. The broadband signal port of the second bridge phase circuit 130 receives the second broadband signal, and the combined output port of the second bridge phase circuit 130 outputs the second mixed signal.

The first broadband signal and the second broadband signal are respectively two broadband signals (ie, original coverage signals) outputted after the POI device accesses multi-system input signals and processes them. The multi-system input signal can specifically be the signal sent by private network systems such as China Mobile, China Unicom, China Telecom, TETRA, DTV, MOBILE TV, public security fire protection, etc. The frequency band of the signal that needs to be expanded is different from the frequency band of the multi-system input signal accessed by POI equipment. Specifically, the first mixed signal includes a signal after filtering the coupled/through signal and a signal corresponding to the first broadband signal; the second mixed signal includes a signal after filtering the through/coupled signal, and a signal corresponding to the first broadband signal. The signals corresponding to the two broadband signals.

The first bridge phase circuit 120 and the second bridge phase circuit 130 filter the signal that needs to be expanded to obtain the signal of the expanded frequency band, and connect the original coverage signal and output the filtered signal together, and use it for coverage through the antenna feeder system. Realize system expansion.

In the aforementioned POI expansion device, the expansion bridge 110 receives the signal sent by the expansion system, and outputs the coupling/through signal and the through/coupling signal to the first bridge phase circuit 120 and the second bridge phase circuit 130 respectively. The first bridge phase circuit 120 receives the first broadband signal and the coupled/through signal and outputs a first mixed signal; the second bridge phase circuit 130 receives the second broadband signal and the through/coupled signal and outputs a second mixed signal. Through the first bridge phase circuit 120 and the second bridge phase circuit 130, the signal to be expanded is filtered and phase-processed to obtain the signal in the frequency band required for expansion, and the original coverage signal is connected to the output together with the processed expanded signal, and used Covering via the antenna feeder system to achieve system expansion, because there is no need to improve the structure of the existing POI equipment, and the expansion can be achieved by simplifying complex technical problems, the structure is simple, the operation is convenient and the cost is low.

In one embodiment, as shown in FIG. 2 , the first bridge phase circuit 120 includes a first quadrature bridge 122 , a second quadrature bridge 124 , a first filter 126 and a second filter 128 .

Orthogonal bridge refers to a bridge whose output ports are out of phase by 90 degrees. The input port of the first quadrature bridge 122 is an expansion input port of the first bridge phase circuit 120 and receives the coupled/through signal. The coupling port of the first quadrature bridge 122 is connected to the first input port of the second quadrature bridge 124 through the first filter 126, and the through port of the first quadrature bridge 122 is connected to the second port through the second filter 128. The second input port of the quadrature bridge 124 is connected. The coupling port of the second quadrature bridge 124 is the broadband signal port of the first bridge phase circuit 120 and receives the first broadband signal. The through port of the second quadrature bridge 124 is the combined output port of the first bridge-phase circuit 120 and outputs the first mixed signal. Specifically, the passbands of the first filter 126 and the second filter 128 are the same, and correspond to the frequency band of the system signal that needs to be expanded, so as to ensure the accuracy of signal extraction.

The first quadrature bridge 122 and the second quadrature bridge 124 also include two ports for inputting signals and two ports for outputting signals. One port of the first quadrature bridge 122 for receiving signals is used as an input port to receive coupled/through signals, and the other port for receiving signals can be connected to a matching load (not shown in the drawings). Among the two output signal ports of the first orthogonal electric bridge 122, the port directly connected to the input port is used as a through port, connected to the second filter 128, and the other output signal port of the first orthogonal electric bridge 122 is used as a coupling port, connected to the first filter 126. The two access signal ports of the second quadrature bridge 124 are used as the first input port and the second input port, respectively connected to the first filter 126 and the second filter 128, and the two ports of the second quadrature bridge 124 Among the ports of the output signal, the port connected to the first input port of the second quadrature bridge 124 is used as a through port to output the first mixed signal, and the port of another output signal of the second quadrature bridge 124 is used as a coupling port, Access the first broadband signal.

The specific working principle of the first bridge phase circuit 120 will be explained below with reference to the accompanying drawings. FIG. 3 and FIG. 4 are schematic diagrams of phase changes of the coupled/through signal and the first broadband signal flowing through the first bridge phase circuit 120 .

As shown in FIG. 3, the coupled/through signal passes through the first quadrature bridge 122, and two signals with a phase difference of 90 degrees are generated at the output port of the first quadrature bridge 122, that is, the phase of one port signal is Ф, then The phase of the other port signal is Ф-90 degrees. For ease of understanding and calculation, it is assumed that the phase of the input coupled/through signal is 0 degrees, and the output port outputs a signal with a phase of -90 degrees (coupled port output) and a signal with a phase of -180 degrees (through port output), two-way The signal passes through the first filter 126 and the second filter 128 respectively, the first filter 126 and the second filter 128 prevent signals outside the expansion frequency band from passing through, and the phases of the two filters are the same, so the The signal phase difference is still 90 degrees, so for the convenience of calculation, it can be assumed that the filter is an ideal filter with a phase of 0 degrees. The -90 degree phase signal reaches the second quadrature bridge 124. Similarly, the signal also produces two signals with a 90 degree phase difference at the output port of the second quadrature bridge 124, which are respectively -180 degree phase signal (coupled port output) and -270 degree phase signal (thru port output). Another -180 phase signal passes through the second quadrature bridge 124 to produce two signals with a phase difference of 90 degrees, which are respectively a -360 degree phase signal (coupling port output) and a -270 degree phase signal ( thru port output). At this time, the coupling port of the second quadrature bridge 124 outputs signals with opposite phases and equal amplitudes of -180 degree phase and -360 degree phase. The through port of the second quadrature bridge 124 outputs two -270-degree phase signals, the amplitudes are the same and the phases are the same, and the signals are superimposed. The power at this time is equal to the power of the coupled/through signal input to the first bridge phase circuit 120, and the output The signal is sent to the antenna feeder system for transmission to complete the system signal coverage that needs to be expanded.

As shown in Figure 4, the first broadband signal (which can be set to 0 degree phase) is input to the coupling port of the second quadrature bridge 124, and two signals with a difference of 90 degrees are also generated, one phase is Ф, and the other The signal phase is Ф-90 degrees. For ease of calculation and understanding, suppose one is a signal with a phase of -90 degrees, and the other is a signal with a phase of -180 degrees. When these two signals are transmitted to the first filter 126 and the second filter 128 respectively, due to the filter The original coverage signal cannot pass through. Here, the two signals are totally reflected, and the phase difference is reversed by 180 degrees, becoming a signal with a phase of -270 degrees and a signal with a phase of -360 degrees (equal to 0 degrees, and 0 is used in Figure 4 degree), after the two signals return to the second quadrature bridge 124, two signals with a phase difference of 90 degrees are generated respectively, and finally 0 degrees and 180 degrees are generated at the port (coupling port) where the original coverage signal is input. Signals with opposite phases and the same amplitude cancel each other out. On the through port of the second quadrature bridge 124, 2 signals with the same phase and the same amplitude at -90 degrees are produced, superimposed on each other, and its power is the same as that of the first broadband signal input, and the original coverage signal output by the through port It is introduced into the antenna feeder system for coverage.

It should be noted that it is not unique for the first filter 126 and the second filter 128 to reverse the signal phase by 180 degrees when the signal is reflected. According to the actual design, it is not necessarily 180 degrees here. For example, the phase is reversed in an open circuit design. 0 degrees, and the phase inversion is 180 degrees in short circuit, but no matter how the design is, the phases of the two filter inversions must remain the same, so that the inversion phase difference during reflection is 0 degrees, that is, the phase difference of the original signal does not change.

In one embodiment, referring to FIG. 2 , the second bridge phase circuit 130 includes a third quadrature bridge 132 , a fourth quadrature bridge 134 , a third filter 136 and a fourth filter 138 .

The input port of the third quadrature bridge 132 is an expansion input port of the second bridge phase circuit 130 and receives the through/coupling signal. The through port of the third quadrature bridge 132 is connected to the first input port of the fourth quadrature bridge 134 through the third filter 136, and the coupling port of the third quadrature bridge 132 is connected to the fourth port through the fourth filter 138. The second input port of the quadrature bridge 134 is connected. The through port of the fourth quadrature bridge 134 is a broadband signal port of the second bridge phase circuit 130 for receiving the second broadband signal. The coupling port of the fourth quadrature bridge 134 is the combined output port of the second bridge phase circuit 130 , and outputs the second mixed signal. Specifically, the passbands of the third filter 136 and the fourth filter 138 are the same, and correspond to the frequency band of the system signal that needs to be expanded, so as to ensure the accuracy of signal extraction.

Both the third quadrature bridge 132 and the fourth quadrature bridge 134 also include two ports for input signals and two ports for output signals. One input signal port of the third quadrature bridge 132 is used as an input port to receive the through/coupling signal, and the other input signal port can be connected to a matching load (not shown in the drawings). Among the two output signal ports of the third quadrature bridge 132, the port directly connected to the input port is used as a through port, connected to the third filter 136, and the port of the other output signal is used as a coupling port, connected to the fourth filter 138 . The two input signal ports of the fourth quadrature bridge 134 serve as a first input port and a second input port, and are respectively connected to the third filter 136 and the fourth filter 138 . Among the two output signal ports of the fourth orthogonal electric bridge 134, the port connected to the first input port of the fourth orthogonal electric bridge 134 is used as a through port to receive the second broadband signal, and the other port is used as a coupled port to output Second mixed signal.

The working principle, signal trend and phase change principle of each device in the second bridge phase circuit 130 are similar to those of the first bridge phase circuit 120 , and will not be repeated here.

Utilizing the quadrature characteristic of the quadrature bridge (the output phase difference is 90 degrees) and the dual output characteristic of equal power, the signal passes through the bridge twice to generate 4 signals with different phases, and the cancellation and summing of the signals are realized by controlling the phase. Superposition, to realize the access transmission of the expansion signal and the access transmission of the original coverage signal, and then transmit through the antenna feeder system to realize system expansion. By selecting filters with different passbands, the system in different frequency bands can be expanded, the structure is simple, the operation is convenient and the cost is low.

This function converts the multi-band-rejection filter, which cannot be realized by the current technology, into an easy-to-implement and mature band-pass filter. Using the reflection characteristics of the filter, the part that needs to be designed as a band-rejection becomes a band-pass, and the original band-pass filter that needs to be designed The passband of the rejection filter becomes the rejection band, thereby realizing the access of broadband signals.

In addition, the POI capacity expansion device can also include a protective shell, and the expansion bridge 110, the first bridge phase circuit 120 and the second bridge phase circuit 130 are housed in the protective shell, and the protective shell can effectively reduce the external force such as impact on the expansion bridge 110, The possibility of damage caused by the first bridge phase circuit 120 and the second bridge phase circuit 130 improves the use safety of the POI expansion device.

An expanded POI system, as shown in Figure 5, the expanded POI system includes a POI device 310, a first feeder system 320, a second feeder system 330, and the above-mentioned POI expansion device 100, and the input port of the POI device 310 is connected to a multi-system The input signal can specifically be the signal sent by private network systems such as China Mobile, China Unicom, China Telecom, TETRA, DTV, MOBILE TV, public security fire protection, etc. In this embodiment, the port ANT1 of the POI device 310 is used as the first output port, connected to the broadband signal port of the second bridge phase circuit 130 in the expansion device 100 , and outputs the second broadband signal to the second bridge phase circuit 130 . The port ANT2 of the POI device 310 is used as the second output port, connected to the broadband signal port of the first bridge phase circuit 120 in the POI expansion device 100 , and outputs the first broadband signal to the first bridge phase circuit 120 . It can be understood that, in other embodiments, the port ANT2 of the POI device 310 can also be used as the first output port, connected to the broadband signal port of the second bridge phase circuit 130, and the port ANT1 of the POI device 310 can be used as the second output port, connected to The broadband signal port of the first bridge phase circuit 120 .

The combined output port of the first bridge-phase circuit 120 is connected to the first antenna feeder system 320 , and outputs the first mixed signal to the first antenna feeder system 320 for transmission. The combined output port of the second bridge-phase circuit 130 is connected to the second feeder system 330 , and outputs the second mixed signal to the second feeder system 330 for transmission.

The POI device 310 can access multi-system input signals and output two-way broadband signals, which can be realized by using the existing multi-system access platform on the market. The POI expansion device 100 receives the signals sent by the expansion system and the two-way broadband signals sent by the POI device 310 , and perform corresponding processing. The specific processing process and principles have been explained in detail above, and will not be repeated here.

In the above expanded POI system, the first bridge phase circuit 120 and the second bridge phase circuit 130 respectively filter the coupling/through signal and the through/coupling signal, the first bridge phase circuit 120 outputs the first mixed signal, and the second bridge phase circuit 130 Output the second mixed signal. Through the first bridge phase circuit 120 and the second bridge phase circuit 130, the signal to be expanded is filtered and phase-processed to obtain the signal of the required frequency band for expansion, and then connected to the original coverage signal output by the POI device 310 and the expanded capacity after processing. The signals are output together, and are transmitted through the two-way antenna feeder system for coverage to realize system expansion. Through the POI capacity expansion device 100 described above, the capacity expansion POI system has a convenient capacity expansion function, simple structure, convenient operation and low cost.

The above-mentioned embodiments only express several implementations of the utility model, and the description thereof is relatively specific and detailed, but it should not be construed as limiting the patent scope of the utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the utility model patent should be based on the appended claims.

Claims (8)

1. A POI expansion device is characterized in that, comprises expansion electric bridge, the first bridge phase circuit and the second bridge phase circuit, described first bridge phase circuit and the second bridge phase circuit are all provided with expansion input port, broadband signal port and combiner output port, The input port of the expansion bridge is connected to the signal delivered by the expansion system, the first output port of the expansion bridge is connected to the expansion input port of the phase circuit of the first bridge, and the coupling/through signal is transmitted to the first bridge phase circuit; The second output port of the expansion bridge is connected to the expansion input port of the second bridge phase circuit, and transmits the through/coupling signal to the second bridge phase circuit; The broadband signal port of the first bridge phase circuit receives the first broadband signal, and the combined output port of the first bridge phase circuit outputs the first mixed signal; the broadband signal port of the second bridge phase circuit receives the second broadband signal. signal, the combined output port of the second bridge phase circuit outputs a second mixed signal. 2. The POI expansion device according to claim 1, wherein the first mixed signal includes a signal obtained by filtering the coupled/through signal and a signal corresponding to the first broadband signal; The second mixed signal includes a signal obtained by filtering the through/coupled signal and a signal corresponding to the second broadband signal. 3. The POI expansion device according to claim 1, wherein the first bridge phase circuit comprises a first orthogonal bridge, a second orthogonal bridge, a first filter and a second filter; The input port of the first quadrature bridge is the expansion input port of the first bridge phase circuit, and the coupling port of the first quadrature bridge is connected to the second quadrature circuit through the first filter. The first input port of the bridge is connected, and the through port of the first quadrature bridge is connected to the second input port of the second quadrature bridge through the second filter; The coupling port of the second quadrature bridge is the broadband signal port of the first bridge phase circuit, and the through port of the second quadrature bridge is the combining output port of the first bridge phase circuit. 4. The POI expansion device according to claim 3, characterized in that the passbands of the first filter and the second filter are the same. 5. The POI expansion device according to claim 1, wherein the second bridge phase circuit comprises a third orthogonal bridge, a fourth orthogonal bridge, a third filter and a fourth filter; The input port of the third quadrature bridge is the expansion input port of the phase circuit of the second bridge, and the through port of the third quadrature bridge communicates with the fourth quadrature circuit through the third filter. The first input port of the bridge is connected, and the coupling port of the third quadrature bridge is connected to the second input port of the fourth quadrature bridge through the fourth filter; The through port of the fourth quadrature bridge is the broadband signal port of the second bridge phase circuit, and the coupling port of the fourth quadrature bridge is the combined output port of the second bridge phase circuit. 6 . The POI expansion device according to claim 5 , wherein the passbands of the third filter and the fourth filter are the same. 7 . The POI expansion device according to claim 1 , further comprising a protective casing, the expansion bridge, the first bridge phase circuit and the second bridge phase circuit are housed in the protective casing. 8 . 8. An expansion POI system, characterized in that it comprises POI equipment, a first antenna feed system, a second feed system and the POI expansion device according to any one of claims 1 to 7, the input port of the POI equipment Access to multi-system input signals, the first output port of the POI device is connected to the broadband signal port of the second bridge phase circuit, and the second broadband signal is output to the second bridge phase circuit, and the POI device The second output port is connected to the broadband signal port of the first bridge phase circuit, and outputs the first broadband signal to the first bridge phase circuit; the combination output port of the first bridge phase circuit is connected to the first In the antenna feeder system, the combined output port of the second bridge phase circuit is connected to the second day feeder system.