JP5189881B2 - Variable circuit, communication system - Google Patents

Description

  The present invention relates to a variable circuit, a communication apparatus, a mobile communication apparatus, and a communication system that have different characteristics depending on the mechanical state of a device having a mechanical operation mechanism.

A MEMS (Micro Electro Mechanical Systems) device is a device having a minute mechanical operation mechanism, and is used in portable game machines, liquid crystal projectors, car navigation systems, and the like. In recent years, MEMS devices having low loss characteristics in a radio frequency band have been developed, and application to radio (RF) circuits such as filters and amplifiers is also being studied. For example, Non-Patent Document 1 describes a multiband amplifier that can operate optimally at a plurality of frequencies by taking advantage of good characteristics in the radio frequency band of the MEMS switch. In this document, a MEMS switch is provided in the matching circuit, and the circuit constant is changed by switching the state of the switch. Here, the MEMS switch is an ultra-compact relay having a side of several mm or less. And it switches to an ON state or an OFF state by mechanically driving at least one contact. Therefore, it is possible to achieve low loss and high isolation characteristics over a wide band as compared with conventional semiconductor switches. In Non-Patent Document 1, the state of the switch is changed when the frequency characteristic is changed.
2004 IEICE General Conference C-24 Multiband Power Amplifier Using MEMS Switches

  In the multiband amplifier of Non-Patent Document 1, the device is a MEMS switch, and operates at a predetermined frequency by turning on the MEMS switch. When the multiband amplifier is operated at that frequency for a long time, the MEMS switch in the ON state is always kept ON during that time. However, in the case of a structure having a mechanical operation mechanism such as a relay, if it is stored for a long period of time, a phenomenon such as mechanical deformation or contact portion fixing may occur due to baking or the like. As a result, there arises a problem of causing a malfunction such as the MEMS switch not operating. Furthermore, the MEMS switch uses a mechanical drive mechanism, and each component is very small or thin. Therefore, compared to a general size machine, a phenomenon such as mechanical deformation or contact portion fixing may occur in a short period of time. When such a phenomenon occurs, for example, the MEMS switch described in Non-Patent Document 1 cannot be switched in frequency, and problems such as failure to obtain designed characteristics at a desired frequency occur.

  An object of the present invention is to provide a variable circuit, a communication device, a mobile communication device, and a communication system in which a device such as a mounted MEMS switch does not cause a phenomenon such as mechanical deformation or contact portion fixation.

The present invention is a variable circuit having a device whose mechanical state is changed and having different characteristics by changing the mechanical state of the device. The variable circuit includes a control unit and a trigger transmission unit. The control unit changes the current state that is the current mechanical state of the device to a different state that is different from the current state, and returns the current state to the current state. The trigger transmission unit transmits a first trigger for changing the device from the current state to the different state to the control unit.
Further, a timer may be provided that measures the time and causes the trigger transmission unit to transmit the first trigger each time a predetermined first elapsed time elapses.

Further, the trigger transmission unit may also transmit a second trigger for returning from a different state of the device to the current state to the control unit. In this case, the timer causes the trigger transmission unit to also transmit the second trigger when a predetermined second elapsed time has elapsed from when the current state is changed to the different state.
Further, the timer may measure the time with respect to the first elapsed time from when the current state is changed to the current state.
The variable circuit may be applied to a communication device. In this case, the trigger transmission unit may not transmit the first trigger during communication.

The variable circuit may be applied to a mobile communication device. In this case, the trigger transmission unit may not transmit the first trigger during communication except at the timing when the base station as the communication partner is switched.
In order to determine the timing at which the base station is switched, for example, a measurement unit that measures reception levels of reception signals from a plurality of base stations may be provided. In this case, the measurement means determines when the reception level of the currently communicating base station is smaller than a predetermined threshold and when the reception level from another base station is larger than a predetermined threshold. It is determined that the station is switched.

Or you may have a measurement means to measure the reception level of the received signal from the base station of a communicating party, for example. In this case, the measurement unit determines that the timing at which the base station is switched when the reception level is less than a predetermined threshold.
Furthermore, a silence state detecting means for detecting a silence state during communication may be provided. In this case, the trigger transmission unit does not transmit the first trigger during communication except when the silent state detecting means determines that the silent state is in effect.
Further, the trigger transmission unit may transmit the first trigger at the start of communication or at the end of communication.

  Furthermore, it is good also as a communication system provided with the 1st communication apparatus provided with the said variable circuit, and the 2nd communication apparatus which sends a periodic signal regularly. In this case, the timer of the first communication device measures time with a periodic signal. Moreover, the trigger transmission part of a 1st communication apparatus does not transmit the said 1st trigger except the timing which received a regular signal.

  With the above configuration, the mechanical state of the device is changed at various timings that do not interfere with the processing, so there are phenomena such as mechanical deformation and sticking due to the device being stored for a long time. Can be prevented.

  The best mode for carrying out the invention will be described below. In addition, the same number is attached | subjected to the process which performs the structure part with the same function, or the same process, and abbreviate | omits description.

  FIG. 1 illustrates a functional configuration example of the variable circuit 5 according to the first embodiment. Hereinafter, a case where a device having a mechanical operation mechanism is a MEMS switch will be described. The current mechanical state (hereinafter referred to as “current state”) is set to the ON state, and the state different from the current state (hereinafter referred to as “different state”) is set to the OFF state. In the drawing, the MEMS switch is simplified and displayed as a switch. The variable circuit 5 is an example of an RF circuit element, and includes a multiband power amplifier 3 and a control mechanism 28. The multiband power amplifier 3 includes a single band PA 18, an input side matching circuit 14, and an output side matching circuit 16. The single band PA 18 operates at a single frequency. An input side matching circuit 14 and an output side matching circuit 16 are added to both ends of the single band PA 18. The input side matching circuit 14 includes a switch 2, a line 6, and a line 10. The output side matching circuit 16 includes a switch 4, a line 8, and a line 12. The frequency characteristics of the input side matching circuit 14 and the output side matching circuit 16 can be changed by the switch 2 and the switch 4, respectively. The multiband power amplifier 3 operates at the frequency f2 when both the switch 2 and the switch 4 are in the ON state, and operates at the frequency f1 when both the switch 2 and the switch 4 are in the OFF state. When the voltage V is applied to the control terminals (not shown) of the switches 2 and 4, the switch is turned on (current state), and when not applied, the switch is turned off (different state). Further, the lines 6, 8, 10, and 12 are designed to match at the frequency f2. The details of the design method of the multiband power amplifier 3 are described in Non-Patent Document 1.

  Next, the control mechanism 28 will be described. The control mechanism 28 includes a switch 24, a switch 26, a control unit 20, and a trigger transmission unit 22. The control unit 20 changes the switch 2 and the switch 4 from the ON state to the OFF state, or returns from the OFF state to the ON state. The trigger transmission unit 22 transmits to the control unit 20 a first trigger that changes the switch 2 and the switch 4 from the ON state to the OFF state when a predetermined condition is satisfied. Note that the “predetermined condition” is a condition such as that a certain period of time has elapsed or that there has been an input from the outside. When receiving the first trigger, the control unit 20 transmits a command signal to the switch 24 and the switch 26. The command signals transmitted to the switch 24 and the switch 26 may be the same signal or different signals.

  FIG. 2 is a detailed view of the switch 24. The switch 24 includes, for example, two fixed electrodes 202 and 204 and one movable electrode 206. In the ON state, the movable electrode 206 is electrically connected to the fixed electrode 202, applies a voltage V to the control terminal of the switch 2, and the multiband power amplifier 3 operates at f2. When the switch 24 receives the command signal, the movable electrode 206 is electrically connected to the fixed electrode 204. Then, the switch 24 stops applying voltage to the control terminal of the switch 2, and the switch 2 is turned off. Therefore, the multiband power amplifier 3 operates at f1. The configuration of the switch 26 is the same as the configuration of the switch 24. That is, when the control unit 20 receives the first trigger and transmits a command signal to the switch 24 and the switch 26, the switch 2 and the switch 4 are switched from the ON state to the OFF state.

[Modification 1]
FIG. 3 shows a functional configuration example of a variable circuit 5-1 that is a first modification of the first embodiment. The variable circuit 5-1 is different from the variable circuit 5 in that the control mechanism 28-1 has a timer 30. The timer 30 causes the trigger transmission unit 22 to transmit a first trigger every time a predetermined first elapsed time ΔT elapses. That is, every time the first elapsed time ΔT elapses, the switch 2 and the switch 4 are switched from the ON state to the OFF state. If the variable circuit 5 is not used, it may remain in the OFF state. By adopting such a configuration, the switches 2 and 4 are not turned on for a long time, and the switches 2 and 4 are not fixed.

FIG. 4 shows a functional configuration example of the variable circuit 5-2 of the second embodiment. The variable circuit 5-2 is different from the variable circuit 5-1, in that the trigger transmission unit 22 in the control mechanism 28-2 also transmits the second trigger to the control unit 20. Upon receiving the second trigger, the control unit 20 controls the switch 2 and the switch 4 with the command signal, and returns the switch 2 and the switch 4 from the OFF state to the ON state. The timer 30 causes the trigger transmission unit 22 to transmit the second trigger when a predetermined second elapsed time δt has elapsed since the timer 30 was changed from the ON state to the OFF state.
FIG. 5 is a diagram showing the relationship between the ON and OFF states of the switches 2 and 4 and the first elapsed time ΔT and the second elapsed time δt. During the first elapsed time ΔT from an arbitrary time point, the control unit 20 transmits a control signal to the switches 24 and 26, that is, the switches 2 and 4 are in the ON state. When the first elapsed time ΔT elapses (time point a), the trigger transmission unit 22 transmits the first trigger to the control unit 20, and the control unit 20 turns off the switches 2 and 4. Here, the first elapsed time ΔT is preferably shorter than the fixing time R from when the switches 2 and 4 are turned on to when the switches 2 and 4 are fixed, for example. Thus, since the mechanical state of the switch is changed at an interval shorter than the fixing time R, problems such as the switches 2 and 4 sticking can be prevented.

  However, since the switches 2 and 4 are in the OFF state after the time point a, the multiband power amplifier 3 is in the f1 mode, and optimal characteristics cannot be obtained at the frequency f2. Therefore, the timer 30 further causes the trigger transmitter 22 to transmit the second trigger when the second elapsed time δt has elapsed (time point b). The control unit 20 controls the switches 2 and 4 by the command signal to return from the OFF state to the ON state (actuate at the frequency f2). Therefore, the multiband power amplifier 3 can obtain optimum characteristics. Here, the second elapsed time δt is preferably set to a time that is short enough not to affect the transfer characteristics of the variable circuit 5-2.

Furthermore, the timer 30 may measure the time with respect to the first elapsed time ΔT from when the state is changed from the OFF state to the ON state (time point b). With this configuration, the variable circuit can be operated without affecting the transfer characteristics as shown in FIG.
With the configuration of the variable circuit of the second embodiment, the control unit 20 controls the state of the switches 2 and 4 from the ON state to the OFF state after the first elapsed time ΔT has elapsed. In addition, the control unit 20 returns to the ON state again after the second elapsed time δt has elapsed since the OFF state. In this way, the switches 2 and 4 can be prevented from sticking without affecting the transmission characteristics.

[Modification 1]
A variable circuit 5-2 ′ according to the first modification of the second embodiment will be described. The variable circuit 5-2 ′ uses both the use frequency bands f1 and f2. An example of the functional configuration of the variable circuit of Modification 1 is the same as that in FIG. 4, and FIG. When the used frequency band is f2, when the first elapsed time ΔT has elapsed (at time a), the switches 2 and 4 are turned off under the control of the control unit 20. When the second elapsed time δt elapses (time point b), the switches 2 and 4 are turned on again. Then, the use frequency band is switched from f2 to f1 (time point c). At the time point c, the time measurement of the timer 30 is reset. Again, when the use frequency band is switched from f1 to f2 (time point d), the timer 30 starts measuring time again. When the first elapsed time ΔT has elapsed (time e), the switches 2 and 4 are turned off under the control of the control unit 20. Even when two types of use frequency bands f1 and f2 are used as in the variable circuit 5-2 ′, it is possible to prevent the switches 2 and 4 from being stuck by the timer 30, the trigger transmission unit 22, and the control unit 20. .

[Modification 2]
FIG. 7 shows a functional configuration example of the variable circuit 5-2 ″ of the second modification of the second embodiment. The multiband power amplifier 41 includes a line 102, a line 104, a line 106, a line 108, a line 110, a line 112, a line 114, a line 116, a line 118, a line 120, a switch 58, a switch 59, a switch 62, a switch 64, a single It is composed of a band PA18. Lines 102, 104, 106, 108, 110, 112, 114, 116, 118, 120 are the same as lines 10, 12 (see FIG. 1), and switches 58, 59, 62, 64 are switches 2. 4 is the same.

  Lines 102, 104, and 106 for adjusting the frequency band are arranged on the input side of the single band PA18. Also, lines 108, 110, and 112 for adjusting the frequency band are arranged on the output side of the single band PA18. The controller 20 controls the switches 59 and 62 by controlling the switches 68 and 69 with the command signal α. The control unit 20 controls the switches 66 and 72 by the command signal β to control the switches 58 and 64. When the switches 59 and 62 are in the ON state, the multiband power amplifier 41 operates at f1. When the switches 58 and 64 are in the ON state, the multiband power amplifier 41 operates at f2.

In FIG. 8, when the variable circuit 5-2 ″ uses only the frequency band f1, the ON state, the OFF state, the first elapsed time ΔT, and the second elapsed time δt of the switches 58, 59, 62, and 64 The relationship is shown. As shown in FIG. 8, in the control when the switches 59 and 62 are in the ON state, the control unit 20 sets the switches 59 and 62 to the OFF state for each first elapsed time ΔT. When the second elapsed time δt elapses from the OFF state, it returns to the ON state again. In this case, since the frequency band f2 is not used, the control unit 20 does not transmit the control signal β.
FIG. 9 shows the relationship between the ON and OFF states of the switches 59 and 62 and the first elapsed time ΔT and the second elapsed time δt when the variable circuit 5-2 ″ uses the frequency bands f1 and f2. Show. As illustrated in FIG. 9, when the switches 58 and 64 are in the ON state, when the first elapsed time ΔT has elapsed (time point g), the control unit 20 turns the switches 58 and 64 into the OFF state. When the second elapsed time δt elapses from the time when the switch becomes OFF, the switches 58 and 64 return to the ON state again (time point h). The control unit 20 transmits the command signal α without transmitting the command signal β, and switches the use frequency band from f2 to f1 (at time i). The switches 59 and 62 are turned off every first elapsed time ΔT. When the second elapsed time δt elapses from the OFF state, it returns to the ON state again.

  In the third embodiment, a communication device 50 including a variable circuit obtained by modifying the variable circuit described in the first and second embodiments will be described. FIG. 10 shows a functional configuration example of the communication apparatus 50 according to the third embodiment. The communication device 50 includes a control mechanism 54, a reception circuit 36, a transmission circuit 38, a switch 2, a switch 4, a line 6, a line 8, a duplexer 42, and an antenna 40. The reception circuit 36 receives a reception signal. The transmission circuit 38 generates a transmission signal. The antenna 40 transmits a transmission signal and receives a reception signal. The duplexer 42 prevents a transmission signal from being input to the reception circuit and a reception signal from being input to the transmission circuit.

Here, in the first and second embodiments, the timer 30 causes the trigger transmitter 22 to transmit the first trigger. However, the communication device 50 (control mechanism 54) does not have the timer 30, and the trigger transmission unit 52 is characterized in that the first trigger is not transmitted while the communication device 50 is communicating. That is, the trigger transmission unit 52 mainly transmits the first trigger to the control unit 20 when the communication device 50 is not communicating.
For example, consider packet communication. FIG. 11 is a schematic diagram showing the relationship between packet transmission and time. The horizontal axis indicates time. The square part is the time during which the packet is transmitted. By setting the time during which packets are not transmitted (indicated as “packet untransmitted time” in FIG. 11) to be the second elapsed time δt, the switches 2 and 4 are turned off without causing any trouble in packet transmission processing. Thus, it is possible to prevent the switches 2 and 4 from sticking.

Next, the mobile communication device 60 of Example 4 will be described. The mobile communication device 60 transmits with a plurality of base stations. The mobile communication device is, for example, a mobile phone. The functional configuration example of the mobile communication device 60 is the same as that shown in FIG. As shown in FIG. 12, it is assumed that the mobile communication device 60 currently belongs to the communication area _{RA of} the base station A and is communicating with the base station A. Then, the mobile communication device 60 is moving, belongs to the communication area R _B of the base station B, and the was communicating base station A and switched to the base station B. The trigger transmission unit 52 does not transmit the first trigger to the control unit 20 except at the timing when the base station is switched. That is, mainly, the trigger transmission unit 52 transmits the first trigger to the control unit 20 at the timing when the base station is switched.

Furthermore, the mobile communication device 70 in which the configuration of the mobile communication device 60 is made more specific will be described. An example of the functional configuration of the mobile communication device 70 is shown in FIG. The receiving circuit 36 has measuring means 44. The measuring means 44 measures received signals from a plurality of base stations. The measuring means 44, it falls below a threshold L _R of the reception level L _A is a predetermined base station A currently in communication (see FIG. 12), and the reception level of the other base stations B L _B is the threshold L _R When it becomes larger, it is determined as the timing at which the base station switches. When the measurement unit 44 makes the determination, the measurement unit 44 causes the trigger transmission unit 22 to transmit the first trigger to the control unit 20.

The measurement unit 44 may determine the timing of the base station is switched when the reception level L _A for the base station A currently in communication becomes less than the threshold L _R determined in advance. Moreover, the fact that L _A becomes lower than the threshold L _R is also likely that becomes out of range of the communication area R _A of the base station A. When the measuring unit 44 makes the determination, that is, when the base station is switched or out of the base station area, the measuring unit 44 transmits the first trigger to the trigger transmitting unit 22 toward the control unit 20. Let

[Modification 1]
Next, a mobile communication device 75 that is Modification 1 of the mobile communication device 70 will be described. FIG. 14 is a partial functional configuration example of the mobile communication device 75. The mobile communication device 75 includes the variable circuit described in the first and second embodiments, and an antenna and the like are not shown in FIG. The mobile communication device 75 has a measuring means 44 in the control mechanism 28-4. The measuring means 44 measures the output signal from the output side matching circuit. Even with the configuration of the mobile communication device 75, the same effect as the mobile communication device 70 can be obtained.

[Modification 2]
Next, a mobile communication device 80 that is a second modification of the mobile communication device 70 will be described. FIG. 15 shows a functional configuration example of the mobile communication device 80. The mobile communication device 80 includes a signal processing circuit 34 in addition to the variable circuit described in the first and second embodiments. The signal processing circuit 34 detects switching information indicating that the base station has been switched. When the signal processing circuit 34 detects the switching information, the trigger transmission unit 22 transmits the first trigger to the control unit 20.
With such a configuration, the switches 2 and 4 can be turned off without interfering with communication between the base station and the mobile communication device, and phenomena such as sticking of the switches 2 and 4 can be prevented.

FIG. 16 shows a functional configuration example of the mobile communication device 90 according to the fifth embodiment. The mobile communication device 90 differs from the mobile communication device 60 (see FIG. 10) in that it has a silent state detection means 46 between the antenna 40 and the duplexer 42. The silent state detection means 46 detects a state during communication. The trigger transmission unit 22 does not transmit the first trigger during communication except when the silent state detecting means 46 determines that the silent state is in effect. That is, mainly, during transmission, the trigger transmission unit 22 transmits the first trigger when the silent state detecting unit 46 determines that the silent state is present.
With such a configuration, even during communication, the switches 2 and 4 can be turned off without interfering with communication processing, and a phenomenon such as sticking of the switches 2 and 4 can be prevented.

  A mobile communication apparatus according to the sixth embodiment will be described with reference to FIG. The trigger transmission unit 52 transmits the first trigger at the start of communication or at the end of communication. Specifically, for example, when the reception circuit 36 receives a reception signal or the transmission circuit 38 transmits a transmission signal (indicated by a dashed arrow in FIG. 10), the trigger transmission unit 52 to decide. Then, when the trigger transmission unit 52 stops detecting the reception signal and the transmission signal, the trigger transmission unit 52 determines that the communication is finished. As described above, the trigger transmission unit 52 transmits the first trigger when it is determined that the communication starts or ends. With such a configuration, the switches 2 and 4 can be turned off without hindering communication processing, and a phenomenon such as the sticking of the switches 2 and 4 can be prevented.

  Next, the communication system 100 of Example 7 is demonstrated. FIG. 17 is a diagram illustrating a functional configuration example of the communication system 100. The communication system 100 includes a first communication device 92 and a second communication device 94. The first communication device 92 includes, for example, the variable circuit 5-1 (see FIG. 3) and the variable circuit 5-2 (see FIG. 4) described in the first embodiment. The second communication device 94 includes a periodic signal transmission unit 96 that periodically transmits a periodic signal to the first communication device 92. The timer 30 in the first communication device measures the time based on the periodic signal, and the trigger transmission unit 22 of the first communication device 92 does not transmit the first trigger except at the timing when the periodic signal is received. That is, mainly, the trigger transmission unit 22 transmits the first trigger at the timing when the periodic signal is received.

[Modification of switch]
The switches 2 and 4 described above are single-pole single-throw switches. However, the switches 2 and 4 (see FIG. 1) may be modified as follows (hereinafter referred to as “switch 2 ′”). FIG. 18A shows a functional configuration example of the switch 2 ′. The switch 2 ′ has two fixed electrodes 202 and 204 and one movable electrode 206. As shown in FIG. 18B, when the switch 2 ′ does not receive the voltage V from the control mechanism, it is turned off. When the switch 2 ′ receives the voltage V, the movable electrode 206 is in electrical contact with one of the fixed electrodes 202 and 204. When the movable electrode 206 is in contact with the fixed electrode 202 as shown in FIG. 18C (hereinafter referred to as “ON state 1”), or when the movable electrode 206 is in contact with the fixed electrode 204 as shown in FIG. In either case of “ON state 2”), the switch 2 ′ is in the ON state. When the switch 2 ′ is used, the time for switching from the ON state 1 to the ON state 2 or the time for switching from the ON state 2 to the ON state 1 becomes the OFF state of the switch 2 ′. If the switches 2 and 4 have such a configuration, the load on the fixed electrode can be reduced, and switching between the ON state and the OFF state can be performed smoothly.

Further, another modification of the switches 2 and 4 is shown in FIG. 19 (hereinafter referred to as “switch 22 ′”). The switch 22 ′ is a switch having a configuration in which two single-pole single-throw switches 212 and 214 are arranged in parallel as shown in FIG. In this configuration, the switches 212 and 214 are both opened as shown in FIG. 19B to be turned off, and at least one of the switches 212 and 214 is closed as shown in C, D, and E of FIG. Will be in the ON state. For example, when the initial current state is the ON state in FIG. 19C, the control unit of the control mechanism first switches to the ON state in FIG. 19D, which is a different state by the first trigger. Next, the second trigger is used to shift to the ON state in FIG. 19 which is the current state of the next period, and then the first trigger is used to shift to the ON state in FIG. 19D which is a different state. Control is performed so as to shift to the ON state of C in FIG. 19 which is the initial current state by the trigger. That is, in this case, the ON state is maintained while the switches are sequentially switched. Further, when the initial current state is the OFF state of B in FIG. 19, the control unit of the control mechanism shifts to the ON state of D in FIG. 19 which is a different state by the first trigger, and in the current state by the second trigger. Control is performed so as to shift to the OFF state of B in FIG.
In this way, the switch 22 'is applied to a circuit that needs to keep the ON state for a long time in particular, so that even if the ON state continues for a long time, two switches are operated sequentially like MBB (Make Before Break). Therefore, a phenomenon such as sticking can be prevented without instantaneous interruption.

  The present invention is not limited to the embodiments described above. For example, in the above-described embodiment, a configuration in which a stub by a line is used for frequency matching is shown. However, a configuration in which a lumped constant type reactance element is applied may be used. In this case, a reactance element is connected to the switches 2 and 4 instead of the line conductor stub shown in the above embodiment. In addition, it can change suitably in the range which does not deviate from the meaning of this invention. In the above embodiment, an example in which the frequency band is two bands is shown. However, when the number of switches is increased or the combination of the ON / OFF states of the switches is changed, the switches 2 and 4 are fixed by the same control. Can be prevented.

  As an application field of the present invention, an RF circuit element used in a communication device used in a wide band, for example, a mobile phone terminal device used in a multiband can be exemplified.

The figure which showed the function structural example of the variable circuit 5. FIG. FIG. The figure which showed the function structural example of the variable circuit 5-1. The figure which showed the function structural example of the variable circuit 5-2. The figure which showed the relationship between the state of a switch, and time when the use frequency band is the same. The figure which showed the relationship between the state of a switch when use frequency bands differ, and time. The figure which showed the function structural example of the variable circuit 5-2 ". The figure which showed the relationship between the state of a switch, and time when the use frequency band of variable circuit 5-2 '' is the same. The figure which showed the relationship between the state of a switch, and time when the use frequency bands of variable circuit 5-2 '' differ. The figure which showed the function structural example of the communication apparatus 50 and the mobile communication apparatus 60. FIG. The figure which showed packet transmission time etc. The figure which shows that the communication base station of the mobile communication apparatus 60 switches. FIG. 3 is a diagram illustrating an example of a functional configuration of a mobile communication device 70. The figure which shows the function structural example of the mobile communication apparatus 75. FIG. 3 is a diagram illustrating an example of a functional configuration of a mobile communication device 80. FIG. 3 is a diagram illustrating an example of a functional configuration of a mobile communication device 90. 1 is a diagram illustrating a functional configuration example of a communication system 100. FIG. A is a detailed view of the switch 2 ′, B is an OFF state of the switch 2 ′, C is an ON state 1 of the switch 2 ′, and D is an ON state 2 of the switch 2 ′. A is a detailed view of the switch 22 ′, B is an OFF state of the switch 22 ′, and C, D, and E are views showing an ON state of the switch 22 ′.

Claims (3)

A variable circuit having a switch whose mechanical state changes, and having different characteristics by changing the mechanical state of the switch,
The switch is switched from a current state that is a mechanical state of the switch corresponding to a current characteristic of the variable circuit to a different state that is a mechanical state of the switch corresponding to a characteristic different from the current characteristic of the variable circuit. And a control unit for returning from the different state to the current state,
A trigger transmitting unit that transmits a first trigger for changing the switch from the current state to the different state to the control unit, and a second trigger for returning the switch from the different state to the current state to the control unit. When,
A timer for measuring a time with respect to a first elapsed time from when the use frequency band is switched, and causing the trigger transmission unit to transmit the first trigger each time a predetermined first elapsed time elapses. A variable circuit comprising: A variable circuit having a switch whose mechanical state changes, and having different characteristics by changing the mechanical state of the switch,
The switch includes a movable electrode, a first fixed electrode, and a second fixed electrode, and the movable electrode contacts the second fixed electrode even when the movable electrode is in a mechanical state where the movable electrode contacts the first fixed electrode. In the mechanical state, the characteristics of the variable circuit are the same as the current state. In the mechanical state where the movable electrode is not in contact with any fixed electrode, the characteristics of the variable circuit are different from the current state. State
A control unit for changing the current state to the different state and returning from the different state to the current state;
A trigger transmitting unit that transmits a first trigger for returning the current state from the different state to the current state after changing the switch from the current state to the different state;
A timer for measuring a time with respect to a first elapsed time from when the use frequency band is switched, and causing the trigger transmission unit to transmit the first trigger each time a predetermined first elapsed time elapses. A variable circuit comprising: A first communication apparatus including the variable circuit according to claim 1 or 2, wherein,
A second communication device for periodically sending a periodic signal;
A communication system comprising:
The timer of the first communication device measures time according to the periodic signal;
The communication system in which the trigger transmission unit of the first communication device does not transmit the first trigger except at the timing when the regular signal is received.

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