This application is based upon and claims the benefit of priority from Japanese patent application No. 2011-064167, filed on Mar. 23, 2011, the disclosure of which is incorporated herein in its entirety by reference.
The present invention relates to a communication device for transmitting and receiving signals using magnetic field coupling type transmitting and receiving elements and to electronic equipment including the communication device.
Relatively large electronic equipment may include a module for each function. In such electronic equipment comprising a plurality of modules, usually, the modules are connected with each other via connectors and cables. For electronic equipment installed outdoors, such as telecommunication equipment used for satellite communications, the connectors and cables through which the modules are connected with each other need to be made waterproof. Because waterproof connectors include sealing gaskets and the like, most of such connectors are large. In addition, for electronic equipment installed outdoors, connectors and cables may need to be protected from falling objects and the like by covering the connectors and cables. As a result, since electronic equipment installed outdoors includes large connectors and covers, the housing of each module tends to be large. Therefore, in order to make such the housing small, the number of connectors and cables needs to be reduced.
As a way to solve such a problem, instead of wiring connections via connectors and cables, wireless technology may be adopted to connect modules with each other. Known examples of such technology include a contactless connector scheme in which signals are transmitted without contact by using a magnetic field.
However, if the electronic equipment installed outdoors comprises a metal housing, contactless connectors that use a magnetic field cannot transfer, through a wall of the housing made of metal, magnetic flux sufficient to transmit signals because the wall interrupts the magnetic field. For this reason, it is necessary to make a hole through the housing or to expose transmitting and receiving elements and make them close to each other. As a result, even in the case of contactless connector schemes, like the above-described connectors through which contacts are mechanically brought into contact with each other, waterproof and protection measures are needed.
To address the problem, for example, Japanese Patent Laid-Open No. 2005-20364 has proposed a technique that enables electromagnetic communications without interruptions caused by a metal cover. The technique described in Japanese Patent Laid-Open No. 2005-20364 enables electromagnetic communications by making the metal layer thin enough to allow electromagnetic communications through electromagnetic induction without losing mechanical protection performance.
However, in relatively large electronic equipment such as telecommunication equipment used for satellite communications, it is necessary to use a metal plate having a thickness of about several millimeters to several centimeters as a housing to ensure adequate strength. For this reason, it is difficult to form housing a thin metal plate like the technique described in Japanese Patent Laid-Open No. 2005-20364. Moreover, if a thick metal plate is adopted, the loss caused by eddy currents generated by the application of a magnetic field becomes considerable, and the distance between transmitting and receiving elements is also relatively increased. Consequently, the amount of current used to generate a magnetic field needed for signal transmission becomes larger, resulting in an increase in the power consumption of the electronic equipment.
Further, consideration is given to using near field communication such as a wireless tag that transmits and receives signals by radio waves for contactless communications between modules. However, because such near field communication requires an antenna for wireless communications to be installed on the outside of the housing, the housing of each module becomes large. Furthermore, in signal transmission by radio waves, because the communication environment may be deteriorated by electromagnetic interference, signals are unfortunately erroneously transmitted and the transmission rate is lowered. Thus, measures against these problems are needed (enhancing error correction, preventing transmission rate from lowering, and the like), resulting in complicated processing to transmit and receive signals. In addition, disadvantageously, transmission efficiency declines.
As described above, in the electronic equipment installed outdoors, a method for transmitting electrical signals needs to be improved in order to reduce the size of the housing. In particular, a method is useful that enables contactless communications and communications with the outside of the housing even if a transmitting and receiving element is installed in the housing. If a transmitting and receiving element can be installed in the housing, the waterproof and protection measures for the transmitting and receiving element may be reduced or eliminated. In addition, electromagnetic interference from external electronic equipment can be reduced. Further, a relatively large connector and cover do not need to be installed on the external wall of housing. As well, if a transmitting and receiving element is installed in an empty space in the housing, the size of the housing can be reduced.
An object of the present invention is to provide a communication device for enabling contactless signal transmission between housings and electronic equipment including the communication device.
To achieve the object, a communication device according to an exemplary aspect of the present invention comprises: a first transmitting and receiving element that generates and detects a magnetic field; and a second transmitting and receiving element that detects a magnetic field generated by the first transmitting and receiving element and generates a magnetic field detectable by the first transmitting and receiving element. The first and second transmitting and receiving elements transmit and receive a signal through magnetic field coupling between ends of the first and second transmitting and receiving elements.
On the other hand, electronic equipment according to an exemplary aspect of the present invention comprises: a first module including the first transmitting and receiving element installed in the inner wall of housing made of a metal plate; and a second module including the second transmitting and receiving element installed in the inner wall of housing made of a metal plate so as to face the first transmitting and receiving element.
The above and other objects, features, and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings, which illustrate examples of the present invention.
Next, the present invention will be described with reference to the drawings.
As illustrated in
Amplifying module housing 2 includes RF control module 5, traveling-wave tube 6, and waveguide 7. Amplifying module housing 2 amplifies high frequency signals input from the outside (input signals) up to high frequency signals of high electric power of, for example, about 100 watts to 1 kilowatt, and outputs the resultant signals.
RF control module 5 smoothes out phase and amplitude characteristics of input signals and outputs the resultant signals to traveling-wave tube 6. RF control module 5 also monitors high frequency signals output from amplifying module housing 2.
Traveling-wave tube 6 amplifies high frequency signals supplied from RF control module 5 up to the required power. The high frequency signals amplified by traveling-wave tube 6 are output to the outside via waveguide 7.
Power supply module housing 1 includes power supply control module 8 and power supply module 9, and supplies amplifying module housing 2 with required power.
Power supply module 9 is supplied with power (AC or DC) from the outside via a connector and a cable not shown and generates predetermined direct-current voltage. Then, power supply module 9 supplies the generated voltage to traveling-wave tube 6 and RF control module 5 included in amplifying module housing 2.
Power supply control module 8 controls the value of voltage supplied from power supply module 9 to amplifying module housing 2 and also controls the supply itself and stopping the supply.
Power supply module housing 1 is connected with amplifying module housing 2 via connector 44, power supply cable 10, and connector 46. Connector 44, power supply cable 10, and connector 46 are mainly used to supply power-supply voltage from power supply module 9 to amplifying module housing 2. Waterproof and protecting cover 45, for example, is attached to connectors 44 and 46, and power supply cable 10, which connects power supply module housing 1 with amplifying module housing 2.
Also, as illustrated in
Since transmitting and receiving element 3 is connected with RF control module 5 and transmitting and receiving element 4 is connected with power supply control module 8, RF control module 5 and power supply control module 8 can transmit and receive signals to and from each other via transmitting and receiving elements 3 and 4.
RF control module 5 monitors, for example, the operation state of traveling-wave tube 6 (voltage, electric current, temperature, etc.) and the quality of signals amplified by traveling-wave tube 6 (output power, a phase, etc.), and notifies power supply control module 8 of the result of the monitoring via transmitting and receiving elements 3 and 4.
Power supply control module 8 controls RF control module 5 and power supply module 9 based on the monitoring result from RF control module 5 to, for example, adjust the phase and amplitude of input signals and change start-stop sequences of traveling-wave tube 6.
As illustrated in
Housing 15 is usually made of a paramagnetic substance such as aluminum to achieve light weight. Thus, for example, magnetic flux 14 that is generated by transmitting and receiving element 3 is emitted from one end of ferromagnetic substance 12 of element 3, penetrates housings 15, and enters one end of ferromagnetic substance 12 of transmitting and receiving element 4. The magnetic flux which enters the one end of ferromagnetic substance 12 of transmitting and receiving element 4 is emitted from the other end, penetrates housings 15, and enters the other end of ferromagnetic substance 12 of transmitting and receiving element 3. A magnetic flux generated by transmitting and receiving element 4 also travels in the same manner. That is, as illustrated in
Transmitting and receiving elements 3 and 4 may be installed on amplifying module housing 2 and power supply module housing 1 illustrated in
Transmitting and receiving elements 3 and 4 that are illustrated in
Therefore, according to the present exemplary embodiment, there is provided a communication device that is useful for contactless signal transmission between housings.
It should be noted that in the example in
In addition, in the example illustrated in
In transmitting and receiving elements 3 and 4 of the first exemplary embodiment, since ferromagnetic substance 12 has a stick shape (see
As illustrated in
In such a configuration, magnetic flux 14a generated by one transmitting and receiving element is guided according to the shape of ferromagnetic substance 16, and emitted from an end of ferromagnetic substance 16 to an end of ferromagnetic substance 16 of the other transmitting and receiving element. In addition, the distance between the ends of ferromagnetic substances 16 is shortened, so that the amount of magnetic flux that does not enter the receiving side from the transmitting side is reduced. As a result, the loss of power required for signal transmission is reduced and transmission efficiency can be improved.
In the configuration with solenoid coils and ferromagnetic substances 16 used as transmitting and receiving elements, magnetic field coupling occurs between the two transmitting and receiving elements mainly at both ends of ferromagnetic substances 16. Thus, the flow of magnetic flux can be controlled by creating the shape of ferromagnetic substance 16 as in the present exemplary embodiment, and the amount of magnetic flux that is not used for signal transmission can be reduced.
It is generally known that non-magnetic substances 17 such as resin less reduce the strength of entering magnetic flux. Thus, as illustrated in
According to the second exemplary embodiment, the amount of magnetic flux that is not used for signal transmission can be reduced more than in the communication device of the first exemplary embodiment, so that the transmission efficiency can be improved.
Generally, in magnetic field coupling type transmitting and receiving elements, when a transmitting element is apart from a receiving element, even if the gap is about several millimeters, the magnetic flux emitted from one end diffuses and the amount of magnetic flux that does not reach the receiving element increases. Further, if the housing is made of metal, eddy currents generated when magnetic flux enters the housing also cause weakened bonding strength between the transmitting and receiving elements, provided by the magnetic field. Eddy currents are electric currents that flow on a metal surface to generate magnetic flux in a direction that cancels out the entering magnetic flux. For this reason, higher power needs to be supplied to the transmitting and receiving element at the transmitting side.
If housing 15 is made of non-magnetic metal such as aluminum, because the relative magnetic permeability of aluminum is almost “1,” there is no significant change in magnetic permeability between the inside and the outside of the portions in which non-magnetic substances 17 such as resin are embedded, as illustrated in
Thus, in a third exemplary embodiment, as illustrated in
It is generally known that ferromagnetic substance 18 concentrates magnetic flux. Thus, in a configuration as illustrated in
According to the third exemplary embodiment, portions that guide a line of magnetic flux (ferromagnetic substances 18) are provided in housings 15, and thereby the amount of magnetic flux that is not used for signal transmission can be reduced more than in the communication device of the second exemplary embodiment.
Furthermore, like the present exemplary embodiment, portions that guide a line of magnetic flux (ferromagnetic substances 18) are provided in housings 15, and thereby a magnetic circuit similar to closed magnetic circuit structure can be formed by ferromagnetic substances 16 included in transmitting and receiving elements 3a and 4a and ferromagnetic substances 18 included in housings 15. Thus, the amount of magnetic flux entering housing 15 is reduced, so that loss caused by eddy currents flowing on housing 15 (eddy-current loss) can also be reduced. Accordingly, signal transmission efficiency of a communication device can be further improved.
As illustrated in
Flux concentrators 21 converts magnetic flux emitted from one transmitting and receiving element into an eddy current, guides the eddy current to the other transmitting and receiving element of the housings, and forms magnetic flux on a surface of the housing at the side of the other transmitting and receiving element by the guided electric current, thereby providing magnetic field coupling between the two transmitting and receiving elements.
As illustrated in
As illustrated in
In such a configuration, if magnetic flux 14a is generated by one transmitting and receiving element illustrated in
On surface 31 of flux concentrator 21 at the side of the other transmitting and receiving element, as illustrated in
That is, like ferromagnetic substance 18 illustrated in
It should be noted that magnetic field distribution A illustrated in
In the example of
In the example of
According to the fourth exemplary embodiment, magnetic flux concentrators 21 that concentrate magnetic flux are provided in housings 19 and 20, and thereby, as in the third exemplary embodiment, the amount of magnetic flux that is not used for signal transmission can be reduced. Accordingly, signal transmission efficiency of a communication device can be further improved.
A fifth exemplary embodiment is an exemplary configuration in which housings 38 and 39 between two transmitting and receiving elements 41 and 42 are relatively thick metal plates.
As illustrated in
According to the fifth exemplary embodiment, even if housings 38 and 39 are relatively thick metal plates, transmitting and receiving elements 41 and 42 can be arranged with the ends of ferromagnetic substance 43 of element 41 and the ends of substance 43 of element 42 close to each other. Thus, the transmission loss caused if the magnetic flux that is emitted from one transmitting and receiving element does not reach the other transmitting and receiving element can be reduced.
It should be noted that the first to the fifth exemplary embodiments described hereinbefore have shown examples in which transmitting and receiving elements 3 and 4 are used for signal transmission, but transmitting and receiving elements 3 and 4 may also be used as proximity sensors.
Transmitting and receiving elements 3 and 4 shown in the first to the fifth exemplary embodiments can normally transmit and receive signals when elements 3 and 4 are close to each other. For example, if power supply module housing 1 illustrated in
Thus, if signal transmission between power supply control module 8 and RF control module 5 is established by using transmitting and receiving elements 3 and 4, it can be confirmed that power supply module housing 1 and amplifying module housing 2 are installed in place. Accordingly, power supply control module 8 can determine whether or not power supply to traveling-wave tube 6 is ready.
While the invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited to these exemplary embodiments. It will be understood by those ordinarily skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims.
Number | Date | Country | Kind |
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2011-064167 | Mar 2011 | JP | national |