JP5615324B2 - Mobile communication terminal - Google Patents

Description

  The present invention relates to a mobile communication terminal that performs communication using two frequency bands simultaneously.

  As a mobile radio device sharing a high-frequency circuit of a mobile device of a digital automobile telephone system (FDD) using a transmission band a and a reception band b and a digital cordless telephone system (TDD) using a band c for transmission and reception, Patent Document 1, Two mobile radios are known. These mobile radios use two antennas and switches, and share a high-frequency circuit.

  In addition, mobile communication terminals are required to support MIMO (Multiple Input Multiple Output) and to introduce multiple frequency simultaneous communication (CA: Carrier Aggregation) due to demands for further improvement in communication speed and ensuring communication quality. ing.

JP-A-9-116458 JP-A-9-18397

  CA is useful for improving the communication speed, but it becomes a factor that complicates the configuration of the RF circuit of the mobile communication terminal. For example, since a mobile communication terminal transmits signals in two frequency bands, there is a concern that one transmission signal leaks into the other receiving circuit and deteriorates reception sensitivity. As a method for preventing such deterioration of reception sensitivity, a method of inserting a diplexer to block signal leakage by an RF circuit, or a method of spatially attenuating signal leakage by dividing a transmission antenna can be considered. However, each has advantages and disadvantages.

  When the transmission power of the mobile communication terminal is small, the leakage of the transmission signal is also small. Therefore, since a signal leaked sufficiently by the diplexer can be removed, a method using the diplexer is desirable. On the other hand, when the transmission power of the mobile communication terminal is large, the leaked signal becomes large, and therefore, a method of separating the transmission antennas is preferable. However, there has been no means for properly using the two methods according to transmission power and reception performance.

  An object of the present invention is to provide a mobile communication terminal that changes a method of attenuating transmission signal leakage in accordance with transmission power and reception performance when communication is performed in two frequency bands.

  The first mobile communication terminal of the present invention performs communication in two frequency bands, a first frequency band and a second frequency band. A main antenna, a sub antenna, a first main front end, a first sub front end, a second main front end, a second sub front end, a main diplexer, a sub diplexer, a first switch unit, and a second switch unit are provided. The main antenna and the sub-antenna can transmit and receive in the two frequency bands. The first main front end performs transmission / reception in the first frequency band. The first subfront end performs reception in the first frequency band. The second main front end performs transmission / reception in the second frequency band. The second subfront end performs reception in the second frequency band. The main diplexer has a first main input / output unit, a second main input / output unit, and a main antenna input / output unit, and signals in the first frequency band are between the first main input / output unit and the main antenna input / output unit. The signal in the second frequency band is transmitted between the second main input / output unit and the main antenna input / output unit, and the main antenna input / output unit is connected to the main antenna. The sub-diplexer has a first sub input / output unit, a second sub input / output unit, and a sub antenna input / output unit, and a signal in the first frequency band is between the first sub input / output unit and the sub antenna input / output unit. The second frequency band signal passes between the second sub input / output unit and the sub antenna input / output unit, and the sub antenna input / output unit is connected to the sub antenna. The first switch unit includes a first straight state in which the first main input / output unit is connected to the first main front end, the first sub input / output unit is connected to the first sub front end, and the first main input / output unit is connected to the first main input / output unit. The first sub front end is connected to switch to the first cross state in which the first sub input / output unit is connected to the first main front end. The second switch unit has a second straight state in which the second main input / output unit is connected to the second main front end, the second sub input / output unit is connected to the second sub front end, and the second main input / output unit is connected to the second main input / output unit. The second sub front end is connected, and the second cross input / output unit is switched to the second cross state connected to the second main front end. Then, the mobile communication terminal changes the state of the first switch unit and the second switch unit according to the transmission power of the first frequency band, the transmission power of the second frequency band, the reception performance of the first frequency band, and the reception of the second frequency band. Decide based on performance.

  The second mobile communication terminal of the present invention also performs communication in two frequency bands, the first frequency band and the second frequency band. A main antenna, a sub antenna, a first main front end, a first sub front end, a second main front end, a second sub front end, a main diplexer, a sub diplexer, and a switch unit are provided. The main antenna and the sub-antenna can transmit and receive in the two frequency bands. The first main front end performs transmission / reception in the first frequency band. The first subfront end performs reception in the first frequency band. The second main front end performs transmission / reception in the second frequency band. The second subfront end performs reception in the second frequency band. The main diplexer has a first main input / output unit, a second main input / output unit, and a main antenna input / output unit, and signals in the first frequency band are between the first main input / output unit and the main antenna input / output unit. The second frequency band signal passes between the second main input / output unit and the main antenna input / output unit, and the main antenna input / output unit is connected to the main antenna. The sub-diplexer has a first sub input / output unit, a second sub input / output unit, and a sub antenna input / output unit, and a signal in the first frequency band is between the first sub input / output unit and the sub antenna input / output unit. And the signal of the second frequency band is transmitted between the second sub input / output unit and the sub antenna input / output unit, and the sub antenna input / output unit is connected to the sub antenna. The switch unit has a straight state in which the second main input / output unit is connected to the second main front end, the second sub input / output unit is connected to the second sub front end, and the second main input / output unit is connected to the second sub front end. Connect to the end and switch to the cross state in which the second sub input / output unit is connected to the second main front end. The first main input / output unit and the first main front end are connected, and the first sub input / output unit and the first sub front end are connected. The mobile communication terminal also determines the state of the switch unit based on the transmission power of the first frequency band, the transmission power of the second frequency band, the reception performance of the first frequency band, and the reception performance of the second frequency band.

  The third mobile communication terminal of the present invention also performs communication in two frequency bands, the first frequency band and the second frequency band. A main antenna, a sub antenna, a first main front end, a first sub front end, a second main front end, a second sub front end, a main diplexer, a sub diplexer, and a switch unit are provided. The main antenna and the sub-antenna can transmit and receive in the two frequency bands. The first main front end performs transmission / reception in the first frequency band. The first subfront end performs reception in the first frequency band. The second main front end performs transmission / reception in the second frequency band. The second subfront end performs reception in the second frequency band. The main diplexer has a first main input / output unit, a second main input / output unit, and a main antenna input / output unit, and signals in the first frequency band are between the first main input / output unit and the main antenna input / output unit. The second frequency band signal passes between the second main input / output unit and the main antenna input / output unit, and the main antenna input / output unit is connected to the main antenna. The sub-diplexer has a first sub input / output unit, a second sub input / output unit, and a sub antenna input / output unit, and a signal in the first frequency band is between the first sub input / output unit and the sub antenna input / output unit. The second frequency band signal is transmitted between the second sub input / output unit and the sub antenna input / output unit, the first sub input / output unit is connected to the first sub front end, and the second sub input / output unit is connected. The output unit is connected to the second subfront end. The switch unit connects the second main input / output unit to the second main front end, connects the sub antenna to the sub antenna input / output unit, and connects the second main input / output unit to the sub antenna input / output unit. And switching to the cross state in which the sub antenna is connected to the second main front end. The first main input / output unit and the first main front end are connected. The mobile communication terminal also determines the state of the switch unit based on the transmission power of the first frequency band, the transmission power of the second frequency band, the reception performance of the first frequency band, and the reception performance of the second frequency band.

  According to the mobile communication terminal of the present invention, when communication is performed in two frequency bands, a method for attenuating transmission signal leakage can be changed according to transmission power and reception performance. Therefore, it is possible to select an appropriate method according to the environment in which the mobile communication terminal is used.

The figure which shows the structure from the antenna of the mobile communication terminal of Example 1 to a front end. The figure which shows the structural example of a switch part. The figure which shows another structural example of a switch part. The figure which shows the structure from the antenna of the mobile communication terminal of Example 2 to a front end. The figure which shows the structure from the antenna of the mobile communication terminal of Example 3 to a front end.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, the same number is attached | subjected to the structure part which has the same function, and duplication description is abbreviate | omitted.

  FIG. 1 shows the configuration from the antenna to the front end of the mobile communication terminal of the first embodiment. The mobile communication terminal 100 includes a main antenna 110, a sub antenna 210, a first main front end 150, a first sub front end 160, a second main front end 250, a second sub front end 260, a main diplexer 120, a sub diplexer 220, A first switch unit 130 and a second switch unit 230 are provided, and communication is performed in two frequency bands, a first frequency band and a second frequency band.

  The main antenna 110 and the sub-antenna 210 can transmit and receive in the first frequency band and the second frequency band. For example, the first frequency band may be 1.7 GHz, 2 GHz, or 2.6 GHz, and the second frequency may be 2.4 GHz or 2.5 GHz. However, it is not necessary to limit to these frequencies, and it may be two frequencies that can be transmitted and received by one antenna. The main antenna 110 and the sub antenna 210 may be the same antenna, or the main antenna 110 may be an antenna having better characteristics. Alternatively, the main antenna 110 may be an antenna that prioritizes characteristics in the first frequency band, and the sub-antenna 210 may be an antenna that prioritizes characteristics in the second frequency band.

  The first main front end 150 performs transmission / reception in the first frequency band. For example, the first main front end 150 may include a transmission unit 151 and a reception unit 152 for the first frequency band, and a duplexer 155 that multiplexes and demultiplexes the transmission signal and the reception signal of the first frequency band. Good. The first subfront end 160 performs reception in the first frequency band. For example, the first subfront end 160 may be used when performing communication by MIMO in the first frequency band. The first subfront end 160 may be configured to include the first frequency band receiving unit 162, for example.

  The second main front end 250 performs transmission / reception in the second frequency band. If the second main front end 250 includes, for example, a transmission unit 251 and a reception unit 252 for the second frequency band, and a duplexer 255 that multiplexes and demultiplexes the transmission signal and the reception signal of the second frequency band. Good. The second subfront end 260 performs reception in the second frequency band. For example, the second subfront end 260 may be used when performing communication by MIMO in the second frequency band. The second subfront end 260 may be configured to include a second frequency band receiving unit 262, for example.

  The main diplexer 120 includes a first main input / output unit 121, a second main input / output unit 122, and a main antenna input / output unit 125. The signal in the first frequency band is transmitted between the first main input / output unit 121 and the main antenna input / output unit 125, and between the second main input / output unit 122 and the main antenna input / output unit 125 and Attenuation occurs between the first main input / output unit 121 and the second main input / output unit 122. The signal in the second frequency band is transmitted between the second main input / output unit and the main antenna input / output unit, and between the first main input / output unit 121 and the main antenna input / output unit 125 and the first main. Attenuation occurs between the input / output unit 121 and the second main input / output unit 122. The main antenna input / output unit 125 is connected to the main antenna 110.

  The sub diplexer 220 includes a first sub input / output unit 221, a second sub input / output unit 222, and a sub antenna input / output unit 225. The signal in the first frequency band is transmitted between the first sub input / output unit 221 and the sub antenna input / output unit 225, and between the second sub input / output unit 222 and the sub antenna input / output unit 225 and Attenuation occurs between the first sub input / output unit 221 and the second sub input / output unit 222. Further, the signal in the second frequency band is transmitted between the second sub input / output unit 222 and the sub antenna input / output unit 225, and between the first sub input / output unit 221 and the sub antenna input / output unit 225 and Attenuation occurs between the first sub input / output unit 221 and the second sub input / output unit 222. The sub antenna input / output unit 225 is connected to the sub antenna 210.

  The first switch unit 130 includes a first straight state in which the first main input / output unit 121 is connected to the first main front end 150 and the first sub input / output unit 221 is connected to the first sub front end 160; The main input / output unit 121 is connected to the first sub front end 160, and the first cross state in which the first sub input / output unit 221 is connected to the first main front end 150 is switched. For example, the first switch unit 130 includes terminals 131, 132, 133, and 134, the terminal 131 is connected to the first main input / output unit 121, the terminal 132 is connected to the first sub input / output unit 221, and the terminal 133 is connected. The first main front end 150 is connected, and the terminal 134 is connected to the first sub front end 160. Then, the state where the terminal 131 and the terminal 133 are connected, the state where the terminal 132 and the terminal 134 are connected is the first straight state, the state where the terminal 131 and the terminal 134 are connected, and the state where the terminal 132 and the terminal 133 are connected is the first cross state. do it.

  The second switch unit 230 includes a second straight state in which the second main input / output unit 122 is connected to the second main front end 250 and the second sub input / output unit 222 is connected to the second sub front end 260; The main input / output unit 122 is connected to the second sub front end 260, and the second cross state in which the second sub input / output unit 222 is connected to the second main front end 250 is switched. For example, the second switch unit 230 includes terminals 231, 232, 233, and 234, the terminal 231 is connected to the second main input / output unit 122, the terminal 232 is connected to the second sub input / output unit 222, and the terminal 233 is connected. The second main front end 250 is connected, and the terminal 234 is connected to the second sub front end 260. Then, the terminal 231 and the terminal 233 are connected, the terminal 232 and the terminal 234 are connected in the second straight state, the terminal 231 and the terminal 234 are connected, and the terminal 232 and the terminal 233 are connected in the second cross state. do it.

  Then, the mobile communication terminal 100 changes the states of the first switch unit 130 and the second switch unit 230 according to the transmission power of the first frequency band, the transmission power of the second frequency band, and the reception performance (BER: Bit). Error Rate) and the reception performance (BER) of the second frequency band. A specific determination method will be described below.

  A first range indicating that the transmission power of the first frequency band is low and a second range indicating that the transmission power of the second frequency band is low are determined in advance. Specifically, a first threshold value for the first frequency band and a second threshold value for the second frequency band may be determined, and the first threshold value or less may be set as the first range, and the second threshold value or less may be set as the second range. However, it is not necessary to limit to this, the less than the first threshold may be the first range, and the less than the second threshold may be the second range, and the first and second thresholds may be varied from information such as past transmission power. Alternatively, the first threshold value and the second threshold value may be the same or different values.

<First control method>
In this control method, it is assumed that the first frequency band is more important than the second frequency band, and that the main antenna 110 and the sub antenna 210 have the same characteristics or the main antenna 110 has better characteristics. doing. In this control method, control is divided into three cases.

(1) When transmission power in the first frequency band is in the first range and transmission power in the second frequency band is in the second range (when transmission power is low in both the first frequency band and the second frequency band)
The mobile communication terminal 100 sets the first switch unit 130 in the first straight state and the second switch unit 230 in the second straight state. With this connection, the main antenna 110 transmits and receives both the first frequency band and the second frequency band. At this time, since there are few leaked transmission signals, the leaked transmission signals are removed by a method using a diplexer. Since the transmission power is controlled according to the radio wave condition, it indicates that the radio wave condition is good when the transmission power is small. Therefore, both the first frequency band and the second frequency band indicate that the radio wave state is good.

(2) When transmission power in the first frequency band is not in the first range (when transmission power in the first frequency band is large)
The mobile communication terminal 100 determines whether the first switch unit 130 is in the first straight state and the second switch unit 230 is in the second straight state or the second cross state based on the reception performance of the second frequency band. Decide (select the one with better reception performance in the second frequency band). At this time, it is necessary to prevent the transmission signal of the first frequency band from leaking into the second main front end 250. Therefore, the second main front end 250 is connected to the sub-antenna 210 to attenuate the transmission signal leaking by separating the antennas, or the second main front end 250 is connected to the main antenna 110 and leaked from the main diplexer 120. Whether to attenuate the transmitted signal is determined based on the reception performance. At this time, the first frequency band is more important than the second frequency band, and the radio wave condition of the first frequency band is poor. Therefore, the main antenna having good characteristics regardless of the radio wave condition of the second frequency band. 110 is assigned to the first frequency band.

(3) When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range (the transmission power of the first frequency band is small but the transmission power of the second frequency band Is large)
The mobile communication terminal 100 sets whether the second switch unit 230 is in the second straight state and whether the first switch unit 130 is in the first straight state or the first cross state based on the reception performance of the first frequency band. Decide (select the one with better reception performance in the first frequency band). At this time, it is necessary to prevent the transmission signal in the second frequency band from leaking into the first main front end 150. Therefore, the first main front end 150 is connected to the sub-antenna 210 to attenuate the transmission signal leaking by separating the antennas, or the first main front end 150 is connected to the main antenna 110 and leaked by the main diplexer 120. Whether to attenuate the transmitted signal is determined based on the reception performance. At this time, since the radio wave condition of the first frequency band is good and the radio wave condition of the second frequency band is bad, the main antenna 110 having good characteristics is assigned to the second frequency band.

<Second control method>
In this control method, it is assumed that there is no superiority or inferiority in the first frequency band and the second frequency band, and the main antenna 110 and the sub antenna 210 have the same characteristics, or the main antenna 110 has better characteristics. Yes. In this control method, control is divided into four cases.

(1) When transmission power in the first frequency band is in the first range and transmission power in the second frequency band is in the second range (when transmission power is low in both the first frequency band and the second frequency band)
The mobile communication terminal 100 sets the first switch unit 130 in the first straight state and the second switch unit 230 in the second straight state. The reason for this state is the same as (1) of the first control method.

(2) When the transmission power of the first frequency band is not in the first range and the transmission power of the second frequency band is in the second range (the transmission power of the first frequency band is large and the transmission power of the second frequency band is small) When)
The mobile communication terminal 100 determines whether the first switch unit 130 is in the first straight state and the second switch unit 230 is in the second straight state or the second cross state based on the reception performance of the second frequency band. Decide (select the one with better reception performance in the second frequency band). Since the premise of this control method is that there is no superiority or inferiority in the first frequency band and the second frequency band, after confirming that the radio wave condition in the second frequency band is good, the first frequency band in which the radio wave condition is bad is set. The main antenna 110 having good characteristics is assigned.

(3) When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range (the transmission power of the first frequency band is small and the transmission power of the second frequency band is When big)
The mobile communication terminal 100 sets whether the second switch unit 230 is in the second straight state and whether the first switch unit 130 is in the first straight state or the first cross state based on the reception performance of the first frequency band. Decide (select the one with better reception performance in the first frequency band). The reason for this state is the same as (3) of the first control method.

(4) When transmission power in the first frequency band is not in the first range and transmission power in the second frequency band is not in the second range (when transmission power is high in both the first frequency band and the second frequency band)
The states of the first switch unit 130 and the second switch unit 230 are determined based on the reception performance of the first frequency band and the reception performance of the second frequency band. For example, when the first switch unit 130 is in the first straight state and the second switch unit 230 is in the second straight state, the average of the reception performance of the first frequency band and the reception performance of the second frequency band, and the first switch unit When 130 is in the first straight state and the second switch unit 230 is in the second cross state, the reception performance in the first frequency band and the average reception performance in the second frequency band, and the first switch unit 130 in the first cross state The average of the reception performance of the first frequency band and the reception performance of the second frequency band when the second switch unit 230 is in the second straight state, the first switch unit 130 in the first cross state, and the second switch unit 230 What is necessary is just to select the combination with the best average reception performance by comparing the reception performance of the first frequency band and the average of the reception performance of the second frequency band in the second cross state. At this time, it is considered that the radio wave condition is poor in both the first frequency band and the second frequency band, and since there is no superiority or inferiority in either frequency band, four combinations are confirmed. Since both transmission powers are large, it may be decided to separate the antennas. In that case, the average of the reception performance of the first frequency band and the reception performance of the second frequency band when the first switch unit 130 is in the first straight state and the second switch unit 230 is in the second cross state, Compare the average of the reception performance of the first frequency band and the reception performance of the second frequency band when the switch unit 130 is in the first cross state and the second switch unit 230 is in the second straight state. Just choose.

<Configuration of first switch unit and second switch unit>
Next, more specific configurations of the first switch unit 130 and the second switch unit 230 will be described. FIG. 2 shows a configuration example of the first switch unit 130. The second switch unit 230 may have the same configuration. The first switch unit 130 includes four switch elements: a first switch element 135, a second switch element 136, a third switch element 137, and a fourth switch element 138. Each of the four switch elements has three terminals, and the first terminals 1351, 1361, 1371, and 1381 are connected to the second terminals 1352, 1362, 1372, and 1382 and the third terminal 1353, respectively. , 1363, 1373, 1383.

  The first terminal 1351 of the first switch element 135 is connected to the terminal 131 (or the terminal 1351 is the terminal 131), and the first terminal 1361 of the second switch element 136 is connected to the terminal 132 (or the terminal 1361 is the terminal 132), the first terminal 1371 of the third switch element 137 is connected to the terminal 133 (or the terminal 1371 is the terminal 133), and the first terminal 1381 of the fourth switch element 138 is the terminal 134. (Or the terminal 1381 is the terminal 134). Also, the second terminal 1352 of the first switch element 135 and the second terminal 1372 of the third switch element 137 are connected, and the second terminal 1362 of the second switch element 136 and the second terminal of the fourth switch element 138 are connected. The terminal 1382 is connected, the third terminal 1353 of the first switch element 135 and the third terminal 1383 of the fourth switch element 138 are connected, and the third terminal 1363 and the third switch element 137 of the second switch element 136 are connected. The third terminal 1373 is connected.

  The states of the first switch element 135, the second switch element 136, the third switch element 137, and the fourth switch element 138 shown by solid lines in FIG. 2 indicate a straight state, and the states indicated by dotted lines indicate a cross state. ing. If the switch elements are arranged and connected as described above and each switch element is operated, the straight state and the cross state can be switched.

  Furthermore, FIG. 3 shows another configuration example of the first switch unit 130. The second switch unit 230 may have the same configuration. The first switch unit 130 includes four switch elements: a first switch element 235, a second switch element 236, a third switch element 237, and a fourth switch element 238. The first switch element 235 and the second switch element 236 each have three terminals, and the first terminals 2351 and 2361 are connected to the second terminals 2352 and 2362 and the third terminals 2353 and 2353, respectively. 2363 is a switching element to be selected from 2363. The third switch element 237 and the fourth switch element 238 are switch elements that switch between a connected state and a disconnected state between the terminals 2371, 2381 and the terminals 2372, 2382.

  Then, the first terminal 2351 of the first switch element 235 is connected to the terminal 131 (or the terminal 2351 is the terminal 131), and the first terminal 2361 of the second switch element 236 is connected to the terminal 132 (or the terminal). 2361 is the terminal 132), the third terminal 2363 of the second switch element 236 is connected to the terminal 133 (or the terminal 2363 is the terminal 133), and the third terminal 2353 of the first switch element 235 is the terminal 134. (Or the terminal 2353 is the terminal 134). Further, the terminal 2371 of the third switch element 237 is connected to the second terminal 2352 of the first switch element 235, and the terminal 2372 of the third switch element 237 is connected to the third terminal 2363 of the second switch element. The terminal 2381 of the fourth switch element 238 is connected to the third terminal 2353 of the first switch element 235, and the terminal 2382 of the fourth switch element 238 is connected to the second terminal 2362 of the second switch element 236.

  The state of the first switch element 335, the second switch element 236, the third switch element 237, and the fourth switch element 238 indicated by solid lines in FIG. 3 indicates a straight state, and the state indicated by a dotted line indicates a cross state. ing. If the switch elements are arranged and connected as described above and each switch element is operated, the straight state and the cross state can be switched. Note that the third switch element 237 and the fourth switch element 238 have a bad effect on the characteristics of the mobile communication terminal because the wiring between the first switch element 335 and the second switch element 236 becomes a bridge tap. Provided to prevent. If there is no problem in the characteristics of the mobile communication terminal, it is not necessary.

  According to the mobile communication terminal 100 of the first embodiment, when communication is performed in two frequency bands, a method for attenuating transmission signal leakage can be changed according to transmission power and reception performance. Therefore, it is possible to select an appropriate method according to the environment in which the mobile communication terminal is used. Further, since the first subfront end 160 and the second subfront end 260 can receive the signal regardless of the state of the first switch unit 130 and the second switch unit 230, the communication in the MIMO is theoretically possible in either frequency band. (However, in practice, it is possible that communication by MIMO cannot be performed due to leakage of a transmission signal in the other frequency band.)

  In the second embodiment, an embodiment in which the importance of the first frequency band is clearly higher than that of the second frequency band is shown. FIG. 4 shows a configuration from the antenna to the front end of the mobile communication terminal of the second embodiment. The difference from the first embodiment is that there is no switch corresponding to the first switch unit 130. In other words, this corresponds to the first switch unit 130 being always in the first straight state, and transmission of the first frequency band is always performed by the main antenna 110 (the first main front end 150 is always connected to the main antenna 110). )

  The mobile communication terminal 300 includes a main antenna 110, a sub antenna 210, a first main front end 150, a first sub front end 160, a second main front end 250, a second sub front end 260, a main diplexer 120, a sub diplexer 220, A switch unit 330 is provided and performs communication in two frequency bands, a first frequency band and a second frequency band.

  The main antenna 110, the sub antenna 210, the first main front end 150, the first sub front end 160, the second main front end 250, the second sub front end 260, the main diplexer 120, and the sub diplexer 220 are the same as in the first embodiment. is there. However, the first main input / output unit 121 and the first main front end 150 are connected, and the first sub input / output unit 221 and the first sub front end 160 are connected.

  The switch unit 330 includes a straight state in which the second main input / output unit 122 is connected to the second main front end 250, and the second sub input / output unit 222 is connected to the second sub front end 260. 122 is connected to the second sub front end 260, and the second sub input / output unit 222 is switched to the cross state in which the second main front end 250 is connected. For example, the switch unit 330 includes terminals 331, 332, 333, and 334, the terminal 331 is connected to the second main input / output unit 122, the terminal 332 is connected to the second sub input / output unit 222, and the terminal 333 is connected to the second The main front end 250 is connected, and the terminal 334 is connected to the second sub front end 260. Then, the terminal 331 and the terminal 333 are connected, the terminal 332 and the terminal 334 are connected in a straight state, the terminal 331 and the terminal 334 are connected, and the terminal 332 and the terminal 333 are connected in a cross state. Note that the switch unit 330 can be realized by adopting the configuration shown in FIG. 2 or FIG. 3 as in the first embodiment.

  Then, the mobile communication terminal 300 determines the state of the switch unit 330 based on the transmission power of the first frequency band, the transmission power of the second frequency band, the reception performance of the first frequency band, and the reception performance of the second frequency band. To do. A specific determination method will be described below. The concept of the first range and the second range is the same as that of the first embodiment.

<Control method>
In this control method, the first frequency band is much more important than the second frequency band, and the main antenna 110 and the sub-antenna 210 have equivalent characteristics, or the main antenna 110 has better characteristics. Is assumed. In this control method, control is divided into three cases.

(1) When transmission power in the first frequency band is in the first range and transmission power in the second frequency band is in the second range (when transmission power is low in both the first frequency band and the second frequency band)
The mobile communication terminal 300 sets the switch unit 330 in a straight state. The reason is the same as (1) in the first control method of the first embodiment.

(2) When transmission power in the first frequency band is not in the first range (when transmission power in the first frequency band is large)
The mobile communication terminal 300 determines whether the switch unit 330 is set to the straight state or the cross state based on the reception performance of the second frequency band. The reason is the same as (2) in the first control method of the first embodiment.

(3) When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range (the transmission power of the first frequency band is small but the transmission power of the second frequency band Is large)
The mobile communication terminal 300 determines whether the switch unit 330 is set to the straight state or the cross state based on the reception performance of the first frequency band. The reason is the same as (3) of the first control method of the first embodiment.

  Since the mobile communication terminal 300 of the second embodiment controls in this way, the same effect as the mobile communication terminal of the first embodiment can be obtained while treating the first frequency band as a particularly important frequency band.

  Example 3 also shows an example in which the importance of the first frequency band is clearly higher than that of the second frequency band. FIG. 5 shows a configuration from the antenna to the front end of the mobile communication terminal of the third embodiment. The difference from the second embodiment is that the sub diplexer is arranged on the sub front end side with respect to the switch unit. Also in this embodiment, transmission in the first frequency band is always performed by the main antenna 110 (the first main front end 150 is always connected to the main antenna 110).

  The mobile communication terminal 400 includes a main antenna 110, a sub antenna 210, a first main front end 150, a first sub front end 160, a second main front end 250, a second sub front end 260, a main diplexer 120, a sub diplexer 220, A switch unit 430 is provided and performs communication in two frequency bands, a first frequency band and a second frequency band.

  The main antenna 110, the sub antenna 210, the first main front end 150, the first sub front end 160, the second main front end 250, the second sub front end 260, and the main diplexer 120 are the same as in the first and second embodiments. . However, the first main input / output unit 121 and the first main front end 150 are connected.

  The sub-diplexer 220 has the same configuration as in the first and second embodiments, but has a different connection relationship with the outside. The first sub input / output unit 221 is connected to the first sub front end 160, the second sub input / output unit 222 is connected to the second sub front end 260, and the sub antenna input / output unit 225 is connected to the switch unit 430. Yes.

  The switch unit 430 has a straight state in which the second main input / output unit 122 is connected to the second main front end 250 and the sub antenna 210 is connected to the sub antenna input / output unit 225, and the second main input / output unit 122 is connected to the sub antenna. It is connected to the input / output unit 225 and switched to the cross state in which the sub antenna 210 is connected to the second main front end 250. For example, the switch unit 430 includes terminals 431, 432, 433, 434, the terminal 431 is connected to the second main input / output unit 122, the terminal 432 is connected to the sub-antenna 210, and the terminal 433 is connected to the second main front end 250. And the terminal 434 is connected to the sub-antenna input / output unit 225. Then, the terminal 431 and the terminal 433 are connected, the terminal 432 and the terminal 434 are connected in a straight state, the terminal 431 and the terminal 434 are connected, and the terminal 432 and the terminal 433 are connected in a cross state. The switch unit 430 can be realized by using the configuration shown in FIG. 2 or FIG. 3 as in the first embodiment.

  Then, the mobile communication terminal 400 determines the state of the switch unit 430 based on the transmission power of the first frequency band, the transmission power of the second frequency band, the reception performance of the first frequency band, and the reception performance of the second frequency band. To do. A specific determination method will be described below. The concept of the first range and the second range is the same as that of the first embodiment.

<Control method>
Even in this control method, the first frequency band is much more important than the second frequency band as in the second embodiment, and the main antenna 110 and the sub antenna 210 have the same characteristics, or the main antenna 110 However, it is assumed that the characteristics are better. In this control method, control is divided into three cases.

(1) When transmission power in the first frequency band is in the first range and transmission power in the second frequency band is in the second range (when transmission power is low in both the first frequency band and the second frequency band)
The mobile communication terminal 400 sets the switch unit 430 to a straight state. The reason is the same as (1) in the first control method of the first embodiment.

(2) When transmission power in the first frequency band is not in the first range (when transmission power in the first frequency band is large)
The mobile communication terminal 400 determines whether the switch unit 430 is in the straight state or the cross state based on the reception performance of the second frequency band. The reason is the same as (2) in the first control method of the first embodiment. When the switch unit 430 is set to the cross state, the main diplexer 120 attenuates the first frequency band signal, so that the first frequency band reception signal hardly reaches the first subfront end 160. Therefore, MIMO communication in the first frequency band cannot be performed. However, since the radio wave condition in the first frequency band is poor in the first place, it is considered that there is almost no demerit due to the fact that communication by MIMO cannot be performed.

(3) When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range (the transmission power of the first frequency band is small but the transmission power of the second frequency band Is large)
The mobile communication terminal 400 determines whether the switch unit 430 is set to the straight state or the cross state based on the reception performance of the first frequency band. The reason is the same as (3) of the first control method of the first embodiment. When the switch unit 430 is set to the cross state, the main diplexer 120 attenuates the first frequency band signal, so that the first frequency band reception signal hardly reaches the first subfront end 160. Therefore, MIMO communication in the first frequency band cannot be performed. However, it is considered that the merit by preventing leakage of the transmission signal of the second frequency band to the first main front end 150 is greater.

  According to the mobile communication terminal 400 of the third embodiment, when communication is performed in two frequency bands, a method for attenuating transmission signal leakage can be changed according to transmission power and reception performance. Therefore, it is possible to select an appropriate method according to the environment in which the mobile communication terminal is used. Further, when the switch unit 430 is set in the cross state, MIMO communication in the first frequency band cannot be performed, but it is considered that there is almost no substantial demerit.

100, 300, 400 Mobile communication terminal 110 Main antenna 120 Main diplexer 121 First main input / output unit 122 Second main input / output unit 125 Main antenna input / output unit 130 First switch unit 150 First main front end 151, 251 Transmitter 152, 162, 252, 262 Receivers 155, 255 Duplexer 160 First sub front end 210 Sub antenna 220 Sub diplexer 221 First sub input / output unit 222 Second sub input / output unit 225 Sub antenna input / output unit 230 Second switch unit 250 Second main front end 260 Second sub front end 300 Mobile communication terminal 330, 430 Switch unit

Claims (13)

A mobile communication terminal that performs communication in two frequency bands, a first frequency band and a second frequency band,
A main antenna capable of transmitting and receiving in the two frequency bands;
A sub-antenna capable of transmitting and receiving in the two frequency bands;
A first main front end for transmitting and receiving in the first frequency band;
A first subfront end that performs reception in the first frequency band;
A second main front end for transmitting and receiving in the second frequency band;
A second subfront end for receiving in the second frequency band;
A first main input / output unit, a second main input / output unit, and a main antenna input / output unit; and a signal in the first frequency band is transmitted between the first main input / output unit and the main antenna input / output unit. A main diplexer in which the second frequency band signal is transmitted between the second main input / output unit and the main antenna input / output unit, and the main antenna input / output unit is connected to the main antenna;
A first sub input / output unit, a second sub input / output unit, and a sub antenna input / output unit, and a signal in the first frequency band is transmitted between the first sub input / output unit and the sub antenna input / output unit. A subdiplexer, wherein the second frequency band signal is transmitted between the second sub input / output unit and the sub antenna input / output unit, and the sub antenna input / output unit is connected to the sub antenna;
A first straight state in which the first main input / output unit is connected to the first main front end, the first sub input / output unit is connected to the first sub front end, and the first main input / output unit is connected to the first main input / output unit. A first switch unit connected to a first sub front end and switching between a first cross state in which the first sub input / output unit is connected to the first main front end;
A second straight state in which the second main input / output unit is connected to the second main front end, the second sub input / output unit is connected to the second sub front end, and the second main input / output unit is connected to the second main front end. A second switch unit connected to a second sub front end and switching between a second cross state in which the second sub input / output unit is connected to the second main front end;
With
The states of the first switch unit and the second switch unit are set as follows: transmission power of the first frequency band, transmission power of the second frequency band, reception performance of the first frequency band, reception performance of the second frequency band. A mobile communication terminal characterized by being determined based on The mobile communication terminal according to claim 1, wherein
In the first range indicating that the transmission power of the first frequency band is small and in the second range indicating that the transmission power of the second frequency band is small, the first switch unit is in the first straight state, The second switch portion is in the second straight state,
When the transmission power of the first frequency band is not in the first range, the first switch unit is set to the first straight state, and the second switch unit is set to either the second straight state or the second cross state. Is determined based on the reception performance of the second frequency band,
When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range, the second switch unit is set to the second straight state, and the first switch The mobile communication terminal is characterized by deciding whether to set the first straight state or the first cross state based on reception performance of the first frequency band. The mobile communication terminal according to claim 1, wherein
In the first range indicating that the transmission power of the first frequency band is small and in the second range indicating that the transmission power of the second frequency band is small, the first switch unit is in the first straight state, The second switch portion is in the second straight state,
When the transmission power of the first frequency band is not in the first range and the transmission power of the second frequency band is in the second range, the first switch unit is in a first straight state, and the second switch unit is Deciding whether to be in the second straight state or the second cross state based on the reception performance of the second frequency band,
When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range, the second switch unit is set to the second straight state, and the first switch Determine whether to set the first straight state or the first cross state based on the reception performance of the first frequency band,
When the transmission power of the first frequency band is not in the first range and the transmission power of the second frequency band is not in the second range, the states of the first switch unit and the second switch unit are The mobile communication terminal is determined based on reception performance of one frequency band and reception performance of the second frequency band. The mobile communication terminal according to any one of claims 1 to 3,
The first switch unit is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The four switch elements are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
The first terminal of the first switch element is connected to the first main input / output unit, the first terminal of the second switch element is connected to the first sub input / output unit, and the third switch element A first terminal is connected to the first main front end, a first terminal of the fourth switch element is connected to the first sub front end,
The second terminal of the first switch element and the second terminal of the third switch element are connected, the second terminal of the second switch element and the second terminal of the fourth switch element are connected,
The third terminal of the first switch element and the third terminal of the fourth switch element are connected, and the third terminal of the second switch element and the third terminal of the third switch element are connected. ,
Or
The second switch part is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The four switch elements are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
A first terminal of the first switch element is connected to the second main input / output unit; a first terminal of the second switch element is connected to the second sub input / output unit; A first terminal is connected to the second main front end, and a first terminal of the fourth switch element is connected to the second subfront end;
The second terminal of the first switch element and the second terminal of the third switch element are connected, the second terminal of the second switch element and the second terminal of the fourth switch element are connected,
The third terminal of the first switch element and the third terminal of the fourth switch element are connected, and the third terminal of the second switch element and the third terminal of the third switch element are connected. ,
A mobile communication terminal characterized by the above. The mobile communication terminal according to any one of claims 1 to 3,
The first switch unit is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The first switch element and the second switch element are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
The third switch element and the fourth switch element are switch elements that switch connection and disconnection between two terminals,
A first terminal of the first switch element is connected to the first main input / output unit, a first terminal of the second switch element is connected to the first sub input / output unit, and A third terminal is connected to the first main front end, a third terminal of the first switch element is connected to the first subfront end,
One terminal of the third switch element is connected to a second terminal of the first switch element, and another terminal of the third switch element is connected to a third terminal of the second switch element;
One terminal of the fourth switch element is connected to a third terminal of the first switch element, and another terminal of the fourth switch element is connected to a second terminal of the second switch element;
Or
The second switch part is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The first switch element and the second switch element are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
The third switch element and the fourth switch element are switch elements that switch connection and disconnection between two terminals,
A first terminal of the first switch element is connected to the second main input / output unit; a first terminal of the second switch element is connected to the second sub input / output unit; A third terminal is connected to the second main front end, and a third terminal of the first switch element is connected to the second subfront end;
One terminal of the third switch element is connected to a second terminal of the first switch element, and another terminal of the third switch element is connected to a third terminal of the second switch element;
One terminal of the fourth switch element is connected to a third terminal of the first switch element, and another terminal of the fourth switch element is connected to a second terminal of the second switch element;
A mobile communication terminal characterized by the above. A mobile communication terminal that performs communication in two frequency bands, a first frequency band and a second frequency band,
A main antenna capable of transmitting and receiving in the two frequency bands;
A sub-antenna capable of transmitting and receiving in the two frequency bands;
A first main front end for transmitting and receiving in the first frequency band;
A first subfront end that performs reception in the first frequency band;
A second main front end for transmitting and receiving in the second frequency band;
A second subfront end for receiving in the second frequency band;
A first main input / output unit, a second main input / output unit, and a main antenna input / output unit; A main diplexer in which the second frequency band signal is transmitted between the second main input / output unit and the main antenna input / output unit, and the main antenna input / output unit is connected to the main antenna;
A first sub-input / output unit, a second sub-input / output unit, and a sub-antenna input / output unit; A subdiplexer, wherein the second frequency band signal is transmitted between the second sub input / output unit and the sub antenna input / output unit, and the sub antenna input / output unit is connected to the sub antenna;
A straight state in which the second main input / output unit is connected to the second main front end, the second sub input / output unit is connected to the second sub front end, and the second main input / output unit is connected to the second main front end. A switch unit that connects to a sub front end and switches between a cross state in which the second sub input / output unit is connected to the second main front end;
With
The first main input / output unit and the first main front end are connected, the first sub input / output unit and the first sub front end are connected,
The state of the switch unit is determined based on transmission power of the first frequency band, transmission power of the second frequency band, reception performance of the first frequency band, and reception performance of the second frequency band. Mobile communication terminal. The mobile communication terminal according to claim 6, wherein
In the first range indicating that the transmission power of the first frequency band is small, and in the second range indicating that the transmission power of the second frequency band is small, the switch unit is in the straight state,
When the transmission power of the first frequency band is not in the first range, determine whether the switch unit is in the straight state or the cross state based on the reception performance of the second frequency band,
When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range, whether the switch unit is in the straight state or the cross state The mobile communication terminal is determined based on reception performance of the first frequency band. The mobile communication terminal according to claim 6 or 7, wherein
The switch part is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The four switch elements are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
A first terminal of the first switch element is connected to the second main input / output unit; a first terminal of the second switch element is connected to the second sub input / output unit; A first terminal is connected to the second main front end, and a first terminal of the fourth switch element is connected to the second subfront end;
The second terminal of the first switch element and the second terminal of the third switch element are connected, the second terminal of the second switch element and the second terminal of the fourth switch element are connected,
The third terminal of the first switch element and the third terminal of the fourth switch element are connected, and the third terminal of the second switch element and the third terminal of the third switch element are connected. ,
A mobile communication terminal characterized by the above. The mobile communication terminal according to claim 6 or 7, wherein
The switch part is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The first switch element and the second switch element are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
The third switch element and the fourth switch element are switch elements that switch connection and disconnection between two terminals,
A first terminal of the first switch element is connected to the second main input / output unit; a first terminal of the second switch element is connected to the second sub input / output unit; A third terminal is connected to the second main front end, and a third terminal of the first switch element is connected to the second subfront end;
One terminal of the third switch element is connected to a second terminal of the first switch element, and another terminal of the third switch element is connected to a third terminal of the second switch element;
One terminal of the fourth switch element is connected to a third terminal of the first switch element, and another terminal of the fourth switch element is connected to a second terminal of the second switch element;
A mobile communication terminal characterized by the above. A mobile communication terminal that performs communication in two frequency bands, a first frequency band and a second frequency band,
A main antenna capable of transmitting and receiving in the two frequency bands;
A sub-antenna capable of transmitting and receiving in the two frequency bands;
A first main front end for transmitting and receiving in the first frequency band;
A first subfront end that performs reception in the first frequency band;
A second main front end for transmitting and receiving in the second frequency band;
A second subfront end for receiving in the second frequency band;
A first main input / output unit, a second main input / output unit, and a main antenna input / output unit; and a signal in the first frequency band is transmitted between the first main input / output unit and the main antenna input / output unit. A main diplexer in which the second frequency band signal is transmitted between the second main input / output unit and the main antenna input / output unit, and the main antenna input / output unit is connected to the main antenna;
A first sub input / output unit, a second sub input / output unit, and a sub antenna input / output unit, and a signal in the first frequency band is transmitted between the first sub input / output unit and the sub antenna input / output unit. The second frequency band signal is transmitted between the second sub input / output unit and the sub antenna input / output unit, and the first sub input / output unit is connected to the first sub front end. A subdiplexer in which the second sub input / output unit is connected to the second subfront end;
A straight state in which the second main input / output unit is connected to the second main front end and the sub antenna is connected to the sub antenna input / output unit, and the second main input / output unit is connected to the sub antenna input / output unit. A switch unit that connects and switches between a cross state in which the sub antenna is connected to the second main front end;
With
The first main input / output unit and the first main front end are connected,
The state of the switch unit is determined based on transmission power of the first frequency band, transmission power of the second frequency band, reception performance of the first frequency band, and reception performance of the second frequency band. Mobile communication terminal. The mobile communication terminal according to claim 10, wherein
In the first range indicating that the transmission power of the first frequency band is small, and in the second range indicating that the transmission power of the second frequency band is small, the switch unit is in the straight state,
When the transmission power of the first frequency band is not in the first range, determine whether the switch unit is in the straight state or the cross state based on the reception performance of the second frequency band,
When the transmission power of the first frequency band is in the first range and the transmission power of the second frequency band is not in the second range, whether the switch unit is in the straight state or the cross state, The mobile communication terminal, wherein the mobile communication terminal is determined based on reception performance of the first frequency band. The mobile communication terminal according to claim 10 or 11,
The switch part is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The four switch elements are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
The first terminal of the first switch element is connected to the second main output section, a first terminal of the second switching element is pre connected to hexa Buantena, first of the third switch element A terminal is connected to the second main front end, and a first terminal of the fourth switch element is connected to the sub-antenna input / output unit;
The second terminal of the first switch element and the second terminal of the third switch element are connected, the second terminal of the second switch element and the second terminal of the fourth switch element are connected,
The third terminal of the first switch element and the third terminal of the fourth switch element are connected, and the third terminal of the second switch element and the third terminal of the third switch element are connected. ,
A mobile communication terminal characterized by the above. The mobile communication terminal according to claim 10 or 11,
The switch part is
Comprising four switch elements, a first switch element, a second switch element, a third switch element, and a fourth switch element;
The first switch element and the second switch element are respectively
A switch element having three terminals, and selecting a connection destination of the first terminal from the second terminal and the third terminal,
The third switch element and the fourth switch element are switch elements that switch connection and disconnection between two terminals,
A first terminal of the first switch element is connected to the second main input / output unit, a first terminal of the second switch element is connected to the sub-antenna, and a third terminal of the second switch element Is connected to the second main front end, a third terminal of the first switch element is connected to the sub-antenna input / output unit,
One terminal of the third switch element is connected to a second terminal of the first switch element, and another terminal of the third switch element is connected to a third terminal of the second switch element;
One terminal of the fourth switch element is connected to a third terminal of the first switch element, and another terminal of the fourth switch element is connected to a second terminal of the second switch element;
A mobile communication terminal characterized by the above.

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