Communication device

To eliminate the necessity of providing a special heat insulating structure or heat resisting properties and to simplify wiring. A modulation/demodulation unit, transmission/reception units of active and standby transmission systems, branching units of active and standby transmission systems, and a line switching and monitor control unit are accommodated in one casing. The modulation/demodulation unit and the line switching and monitor control unit, commonly used in the active and standby transmission systems, are incorporated in the lower part of the casing, and the transmission/reception units and the branching units of the active and standby transmission systems are incorporated in the upper part of the casing. The transmission/reception units and the branching units of the active and standby transmission systems are arranged in parallel such that the branching units are positioned at the center thereof.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a communication device composed of a plurality of units, and in particular, to the mounting structure of the respective units.

2. Related Art

FIG. 1is a layout diagram of respective. units in a conventional communication device.FIG. 2is a schematic perspective view of the conventional communication device. Hereinafter, explanation will be given based on these Figures.

A conventional communication device50is so configured that two transmission/reception units521and522of transmission systems for performing transmission and reception with the same polarized wave, a modulation/demodulation unit54, two branching units531and532, and line switching and monitor control unit55are accommodated in one casing51.

Next, the arranging relationship among these units will be described. The transmission/reception units521and522and the branching units531and532, consisting of components which differ depending on the selected radio frequency, are arranged in the upper part of the casing51, and the modulation/demodulation unit54and the link switching and monitor control unit55, consisting of the same components irrespective of the radio frequency, are spaced apart from each other and arranged in the lower part of the casing51.

Further, one branching unit531is electrically connected to one transmission/reception unit521via a transmission signal line561, and is electrically connected to the other transmission/reception unit522via a reception signal line571. The other branching unit532is electrically connected to the other transmission/reception unit522via a transmission signal line562, and is electrically connected to the one transmission/reception unit521via a reception signal line572. Such a communication device50is disclosed in, for example, the Japanese Patent Application Laid-open No. 08-116294 (hereinafter referred to as Patent Document 1).

Here, consideration will be made for the reason why a plurality of units are arranged to be in an arranging relationship shown inFIG. 1. In the initial stage of developing this kind of communication device, the transmission/reception units521and522were large in their structure. Therefore, a communication device might have either an arrangement that the transmission/reception units521and522are placed above and the branching unit531and532are placed below as shown in Patent Document 1, or an arrangement that the transmission/reception units521and522are placed below and the branching unit531and532are placed above as shown inFIG. 1. Next, the arranging relationships shown inFIG. 1and Patent Document 1 will be compared. When comparing the transmission/reception units521and522and the branching units532and532, maintenance is performed less frequently for the branching units531and532. Accordingly, considering from an aspect of maintenance, the arranging relationship shown inFIG. 1where the transmission/reception units521and522are placed below and the branching units531and532are placed above, is most appropriate, comparing with that of Patent Document 1.

However, in the arranging relationship shown inFIG. 1, the branching units531and532are placed above the transmission/reception units521and522with high heating values, whereby the branching units531and532are exposed to the heat of the transmission/reception units521and522. Therefore, it is required to take such countermeasures as addition of discharging items to the transmission/reception units521and522or easing of specification circumstance. This leads to a cost increase and a weak product competitiveness.

In order to avoid such a situation, the transmission/reception units521and522and the branching units531and532may be arranged in parallel. However, considering the mounting area of the casing51, it is impossible to enlarge the size of the casing51. Therefore, it is the current situation that measures against heat must be taken by considering the arranging relationship of the units while keeping the current size of the casing51.

Further, in the case of the arranging relationship between the transmission/reception units521and522and the branching units531and532shown inFIG. 1, the lengths of the transmission signal lines561and562and the reception signal lines571and572, extending from the branching units531and532to the transmission/reception units521and522respectively, are different, whereby a difference of cable loss is caused, which causing a problem that a signal delay occurs between the active transmission system and the standby transmission system. Further, cabling between the active transmission system and the standby transmission system becomes complicated, causing a problem of the high manufacturing cost.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide communication devices in which the conventional problems are solved.

Nowadays, transmission/reception units are miniaturized due to a development in semiconductor devices. The present invention is characterized in that, by using miniaturized transmission/reception units, a plurality of units are built in a casing of the current size while measures against heat are taken by the arranging relationship. Further, the present invention is characterized in that a problem relating to wiring is solved by using the arranging relationship for measures against heat.

In order to achieve such an object, a communication device of the present invention comprises, in a casing: a modulation/demodulation unit having a modulating function for modulating and converting an input baseband signal into an intermediate frequency signal, and a demodulating function for demodulating and converting an intermediate frequency signal into a baseband signal; transmission/reception units of an active transmission system and a standby transmission system, each of which has a transmitting function for converting an intermediate frequency signal from the modulation/demodulation unit into a radio frequency signal and supplying it to an antenna, and a function of converting a radio frequency signal into an intermediate frequency signal and outputting it to the modulation/demodulation unit; branching units for separating a desired radio frequency from an allocated radio frequency and performing provision and reception of a signal with the transmission/reception units; and a line switching and monitor control unit having a line switching function for performing line switching between the active transmission system and the standby transmission system, a line control function for monitoring a line and controlling a switching operation of a line switching part corresponding to the monitored state, and a monitoring function for monitoring and displaying the state of an apparatus. The modulation/demodulation unit and the line switching and monitor control unit, commonly used in the active transmission system and the standby transmission system, are incorporated in the lower part of the casing, and the transmission/reception units and the branching units of the active transmission system and the standby transmission system are incorporated in the upper part of the casing. The transmission/reception units and the branching unit of the active and standby transmission systems are arranged in parallel such that the branching units are positioned at the center thereof.

In general, transmission/reception units have high heating values, and branching units have low heating values. In the present invention, the transmission/reception units of the active transmission system and the standby transmission system and the branching units of the active transmission system and the standby transmission system are incorporated in the upper part of the casing. Further, the transmission/reception units and the branching units of the active and standby transmission systems are arranged in parallel such that the branching units are positioned at the center thereof. Therefore, the branching units will never be exposed to the heat generated by the transmission/reception units. This enables to prevent the characteristics of the branching units from being changed by the heat.

The size of transmission/reception units can be miniaturized when the components consist of semiconductor devices. In the present invention, the transmission/reception units of the active transmission system and the standby transmission system are units comprising components which differ depending on the selected radio frequency, and the components consist of semiconductor devices. Therefore, it is possible to incorporate the branching units and the transmission/reception units in the upper part of the casing with an arranging relationship in which measures against heat are taken, without increasing the current size of the casing.

Further, in the present invention, the transmission/reception units of the active transmission system and the standby transmission system are used with the branching units arranged vertically, all of which are incorporated in the upper part of the casing, and the transmission/reception units and the branching systems of the active and standby transmission systems are arranged in parallel such that the branching units are positioned at the center thereof. Therefore, it is possible to surely prevent the branching units of, the active transmission system and the standby transmission system from being affected by the heat generated from the transmission/reception units of the active transmission system and the standby transmission system.

Further, in the present invention, the transmission/reception units and the branching unit of the active and standby transmission systems are arranged in parallel such that the branching units are positioned at the center thereof, so that wiring routes formed between the branching units and the transmission/reception units are set to have the shortest length. Therefore, a signal delay caused between the active transmission system and the standby transmission system can be solved.

Further, connectors are arranged at positions where the wiring routes formed between the branching units and the transmission/reception units have the shortest length. This makes wiring processing easy.

According to the present invention, air heated by the transmission/reception units do not adversely affect the branching units, whereby no special heat insulating structure or heat-resisting property is required. When a branching unit is connected to each of the two transmission/reception units via a signal line, the length of the signal line becomes the shortest by arranging the branching unit between the transmission/reception units. Thereby, the wiring can be simplified.

As described above, the present invention enables to suppress temperature rise and to improve mounting efficiency and to realize wiring not causing a cable loss to the active system and the standby system, while the transmission/reception units, the branching units, the modulation/demodulation unit, the line switching and monitor control unit and the like are accommodated in one casing. Further, by simplifying cabling, it is possible to improve manufacturing easiness.

PREFERRED EMBODIMENT OF THE INVENTION

FIG. 3is a layout diagram of respective units in a first embodiment of a communication device according to the present invention.FIG. 4is a schematic perspective view showing the first embodiment of the communication device of the present invention. Hereinafter, explanation will be given based on these Figures.

A communication device10of the present embodiment has a 1+1 radio standby switching function provided with an active transmission system and one standby transmission system. In the communication device, a plurality of units, including transmission/reception units121and122of the active and standby transmission systems with high heating values and branching units131and132of the active and standby transmission systems with low heating values, are accommodated in one casing11.

A modulation/demodulation unit14shown inFIG. 3is a unit consisting of components which do not differ depending on radio frequencies, and is commonly used in the active transmission system and the standby transmission system. The modulation/demodulation unit14has a modulating function for modulating and converting an input baseband signal into an intermediate frequency signal, and a demodulating function for demodulating and converting an intermediate frequency signal into a baseband signal.

The transmission/reception units121and122perform transmission and reception with the same polarized wave, and have a transmitting function for converting an intermediate frequency signal from the modulation/demodulation unit14into a radio frequency signals and supplying it to an antenna, and a function of converting a radio frequency signal to an intermediate frequency signal and outputting it to the modulation/demodulation unit14. Further, the transmission/reception units121and122of the active transmission system and the standby transmission system are units consisting of components which differ depending on the selected radio frequency. The components consist of semiconductor devices, and are miniaturized.

The branching units131and132of the active transmission system and the standby transmission system have a function of separating a desired radio frequency from the allocated radio frequency, and performing provision and reception of signals with the transmission/reception units121and122. As for a branching unit, maintenance is performed relatively few times and the failure rate is low, so it is possible to use only one unit of the active transmission system.

The line switching and monitor control unit15is a unit consisting of components which do not differ depending on radio frequencies, and is commonly used in the active transmission system and the standby transmission system. The line switching and monitor control unit15has a line switching function for performing line switching between the active transmission system and the standby transmission system, a line control function for monitoring the line and controlling switching operation of the line switching part corresponding to the monitored state, and a monitoring function for monitoring and displaying the state of the apparatus.

The transmission/reception units121and122of the active and standby transmission systems, the branching units131and132of the active and standby transmission systems, the modulation/demodulation unit14, and the line switching and monitor control unit15are incorporated in one casing11.

Next, an arranging relationship when incorporating the plural units into the casing11will be described.

The modulation/demodulation unit14and the line switching and monitor control unit15, commonly used in both of the active and standby transmission systems, are incorporated in the lower part of the casing11. Here, they are incorporated such that the modulation/demodulation unit14is placed below and the line switching and monitor control unit15is placed above.

The transmission/reception units121and122and the branching units131and132of the active and standby transmission systems are incorporated in the upper part of the casing1. Here, the transmission/reception units121and122and the branching units131and132of the active and standby transmission systems are arranged in parallel such that the branching units131and132are positioned at the center thereof. Since two branching units131and132. are provided, the two branching units131and132are arranged vertically as shown inFIG. 3, and the transmission/reception units121and122and the branching units131and132of the active and standby transmission systems are arranged in parallel such that the two branching units131and132, arranged vertically, are positioned at the center thereof. The casing11is in a lack shape for example, and the respective units are arranged therein by being fitted into or bolted.

Further, with such an arrangement that the transmission/reception units121and122and the branching units131and132of the active and standby transmission systems are arranged in parallel such that the branching units131and132are positioned at the center thereof, wiring routes formed between the branching units131and132and the transmission/reception units121and122are set to have the shortest length. Further, connectors C1to C8are arranged at positions where wiring routes formed between the branching units131and132and the transmission/reception units121and122become the shortest.

Then, the connectors C1, C4, C5and C8of the two transmission/reception units121and122and the connectors C2, C3, C6and C7of the two branching units131and132are connected by the transmission signal lines161and162and the reception signal lines171and172, respectively.

Next, assuming that one transmission/reception unit121and one branching unit131are used as the active transmission system and the other transmission/reception unit122and the other branching unit132are used as the standby transmission system, the operation in the present embodiment of the present invention will be described.

At the time of transmission, when an input baseband signal is inputted into the modulation/demodulation unit14, the modulation/demodulation unit14modulates and converts the input baseband signal into an intermediate frequency signal, and outputs the intermediate frequency signal to the transmission/reception unit121. When the transmission/reception unit121receives the intermediate frequency signal from the modulation/demodulation unit14, the transmission/reception unit121converts the intermediate frequency signal into a radio frequency signal, and transmits the radio frequency signal to the branching unit131via the transmission signal line161.

When the branching unit131receives the radio frequency signal from the transmission/reception unit121, the branching unit131separates a desired radio frequency signal from the allocated radio frequency signal, and transmits the separated radio frequency signal from an antenna not shown.

At the time of reception, when the branching unit132receives the radio frequency signal from the antenna, the branching unit132separates a desired radio frequency signal from the allocated radio frequency signal, and outputs the separated radio frequency signal to the transmission/reception unit121via the reception signal line172. When the transmission/reception unit121receives the radio frequency signal from the branching unit121, the transmission/reception unit.121converts the radio frequency signal into an intermediate frequency signal and outputs the intermediate frequency signal to the modulation/demodulation unit14.

The modulation/demodulation unit14demodulates and converts the intermediate frequency signal from the transmission/reception unit121into a baseband signal.

The line switching and monitor control unit11monitors the line of the active transmission system, and monitors and displays the state of the apparatus. In this monitoring state, when a failure occurs in the line of the active transmission system, the line switching and monitor control unit11outputs an instruction to switch from the active transmission system to the standby transmission system, to the modulation/demodulation unit14, the transmission/reception unit122and the branching units131and132.

When switched to the standby transmission system, the aforementioned transmission and reception are performed by using the modulation/demodulation unit14, the transmission/reception unit122, and the branching units131and132.

If one branching unit131, for example, is failed in the monitoring stage, the line switching and monitor control unit11uses one transmission/reception unit122for transmission and the other transmission/reception unit121for reception. Therefore, an intermediate frequency signal from the modulation/demodulation unit14is signal-processed through the transmission/reception unit122for transmission and the branching unit132, and then transmitted from the antenna. The radio frequency signal received by the antenna is signal-processed through the branching unit131and the transmission/reception unit121for reception, and then outputted to the modulation/demodulation unit14.

When the transmission/reception units121and122are activated and generate large amount of heat, the heat rises toward the upper space within the casing11. In the embodiment of the present invention, the transmission/reception units121and122and the branching units131and132of the active and standby transmission systems are incorporated in the upper part of the casing11, and the transmission/reception units121and122and the branching units131and132of the active and standby transmission systems are arranged in parallel such that the branching units131and132are positioned at the center thereof, whereby no one is exposed to the heat from the transmission units121and122. Accordingly, there is no need to take special measures against heat in the transmission/reception units121and122. Further, since the transmission/reception units121and122and the branching units131and132are not arranged vertically but arranged in parallel, there is no obstacle when the heat generated from the transmission/reception units121and122rises toward the upper space of the casing11, so that the heat naturally moves upward and discharged, whereby the discharging effect is improved comparing with the conventional case.

Further, the transmission/reception units121and122and the branching units131and132of the active and standby transmission systems are arranged in parallel such that the branching units131and132are positioned at the center thereof, and the wiring routes formed between the branching units131and132and the transmission/reception units121and122are set to have the shortest length, and the connectors are arranged at the positions where the wiring routes become the shortest. Therefore, when the transmission signal lines161and162and the reception signal lines171and172for electrically connecting the branching units131and132and the transmission/reception units121and122are cabled, the lengths of the connection cables to the active system and the standby system can be equal, so a difference between the cable losses is reduced. Further, since the wiring is simplified, the manufacturing ease in assembling the communication device10is also improved.