JP6396031B2 - Communication device, antenna switching control program, and recording medium - Google Patents

Description

  The present invention relates to a communication apparatus using a diversity technique for switching two antennas according to a communication state.

  In wireless communication, it is performed to determine whether the communication state of an antenna is good and to determine an antenna to be used based on the determination. For example, a subscriber station disclosed in Patent Document 1 is an example of such a communication apparatus.

  In this subscriber station, the antenna selection module performs transmission diversity by switching the antenna connected to the transmitter in accordance with an increase or decrease in power required from the base station. Accordingly, each antenna operates as a transmission / reception antenna that covers both the transmission band and the reception band, and also operates as a diversity reception antenna that covers only the reception band.

JP 2006-510262 Gazette (March 23, 2006)

  For example, consider the case where the subscriber station is used in Band 1 of LTE (Long Term Evolution). In this case, the antenna is used as a transmission / reception antenna (transmission: 1920-1980 MHz / reception: 2110-2170 MHz) and further as a diversity reception antenna (reception: 2110-2170 MHz).

  However, according to the communication frequency band used by the antenna, the subscriber station uses the antenna without being matched with the optimized antenna characteristics. For this reason, there is a problem that the antenna characteristics when used as the diversity reception antenna are deteriorated as compared with the antenna characteristics when optimized for the reception band. Specifically, as shown in FIG. 2B, the wideband antenna characteristics (indicated by a two-dot chain line) adapted to the transmission band Tx and the reception band Rx are narrowband antennas adapted to the reception band Rx. The efficiency peak is lower than the characteristic (shown by the solid line).

  The present invention has been made to solve the above-described problems, and an object of the present invention is to optimize antenna characteristics in accordance with a communication frequency band used in the antenna.

  In order to solve the above problems, a communication device according to one embodiment of the present invention is received by two antennas, a transmission / reception unit that processes signals transmitted / received by one of the antennas, and the other of the antennas. A receiving unit that processes a signal, a switching unit that selectively switches a connection so that one of the antennas is connected to the transmitting / receiving unit and the other is connected to the receiving unit, and the transmitting / receiving unit to be connected And a matching unit that selectively switches an impedance adjustment value so as to match the antenna to each of the receiving unit, and a switching control that controls switching by the switching unit and the matching unit according to a reception state of the antenna And a means.

  According to one embodiment of the present invention, there is an effect that antenna characteristics can be optimized according to a communication frequency band used in an antenna.

It is a block diagram which shows schematic structure of the communication apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the improvement effect of the antenna characteristic of the communication apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows schematic structure of the communication apparatus which concerns on Embodiment 2 of this invention.

Embodiment 1


Embodiment 1 of the present invention will be described below with reference to FIGS. 1 and 2.

  FIG. 1 is a block diagram illustrating a schematic configuration of a communication device 10 according to the present embodiment.

  As illustrated in FIG. 1, the communication device 10 includes a first antenna 1, a second antenna 2, a first matching circuit unit 3, a second matching circuit unit 4, an antenna switching unit 5, and a reception state determination unit 6. An antenna switching controller 7, a transmission / reception circuit 8, and a diversity reception circuit 9.

  In the following description, when the first antenna 1 and the second antenna 2 are not specified, they are simply referred to as antennas.

  In the present embodiment, the communication device 10 switches between two bands (frequency bands), that is, a transmission band Tx (first frequency band) and a reception band Rx (second frequency band) for transmitting and receiving radio signals. Configured to be available. For example, but not limited to this, as an example, the LTE Band 1 band of about 2 GHz (transmission: 1920-1980 MHz / reception: 2110-2170 MHz) includes the transmission band Tx (transmission band) and the reception band Rx (reception). Band) as an example. In addition, this invention is not limited to this, You may be comprised so that three or more bands can be utilized. Each part will be described below.

(Matching circuit)
There are two types of matching circuit units used in the present embodiment: a first matching circuit unit 3 and a second matching circuit unit 4. The first matching circuit unit 3 (matching unit) is connected to the first antenna 1 and the antenna switching unit 5. The second matching circuit unit 4 (matching unit) is connected to the second antenna 2 and the antenna switching unit 5. The first matching circuit unit 3 and the second matching circuit unit 4 are connected to the transmission / reception circuit 8 or the diversity reception circuit 9 via the antenna switching unit 5. In addition, the first matching circuit unit 3 and the second matching circuit unit 4 are matched to a matching state that covers at least a transmission / reception band in one communication band and other matching states (for example, a reception band in the communication band). Is switched as follows, and is configured as follows.

  The first matching circuit unit 3 and the second matching circuit unit 4 respectively set the impedances of the first antenna 1 and the second antenna 2 to the communication frequency band of the connected transmission / reception circuit 8 or diversity receiving circuit 9. Match individually to the appropriate impedance. Specifically, the first matching circuit unit 3 adjusts the impedance of the first antenna 1 according to the communication frequency band of the transmission / reception circuit 8 and the communication frequency band of the diversity reception circuit 9. An adjustment value for adjusting the impedance of one antenna 1 is generated, and one of the adjustment values is selected based on the switching control signal of the antenna switching controller 7. On the other hand, the second matching circuit unit 4 includes the adjustment value for adjusting the impedance of the second antenna 2 according to the communication frequency band of the transmission / reception circuit 8 and the second antenna according to the communication frequency band of the diversity reception circuit 9. 2 is generated, and one of the adjustment values is selected based on the switching control signal.

  Although not shown, the first matching circuit unit 3 and the second matching circuit unit 4 may select either one of two adjustment values using a switch such as SPxT, or may have a variable capacitance. An element may be used to change the capacitance value of the variable capacitance element to a value corresponding to one of the two adjustment values. However, the first matching circuit unit 3 and the second matching circuit unit 4 are not limited to these examples.

(Antenna switching unit 5)
The antenna switching unit 5 (switching unit) is connected to the first matching circuit unit 3 and the second matching circuit unit 4, the transmission / reception circuit 8, and the diversity reception circuit 9. The antenna switching unit 5 receives the first matching circuit unit 3 (first antenna 1) and the second matching circuit unit 4 (second antenna 2) according to an instruction (switching control signal) from an antenna switching controller 7 described later. ) Are selectively switched between the following connection state S1 and connection state S2 so that the other is connected to the transmission / reception circuit 8 and the other is connected to the diversity reception circuit 9. The antenna switching unit 5 selects the connection state S1 and the connection state S2 using a commonly used switch such as DPDT (Double Pole Double Throw).

  As shown in FIG. 1, the connection state S1 is a state in which the transmission / reception circuit 8 is connected to the first matching circuit unit 3, and the diversity receiving circuit 9 is connected to the second matching circuit unit 4. The state S2 is a state in which the diversity receiving circuit 9 is connected to the first matching circuit unit 3 and the transmission / reception circuit 8 is connected to the second matching circuit unit 4.

(Reception state determination unit 6)
The reception state determination unit 6 (determination unit) determines which reception state of the first antenna 1 or the second antenna 2 is good. The reception state determination unit 6 notifies the antenna switching controller 7 of the determination result.

  Examples of a method for determining which reception state of the first antenna 1 or the second antenna 2 is good include the following methods, but are not limited to these methods. For example, the first method determines which reception state of the first antenna 1 or the second antenna 2 is good by comparing the reception levels of the transmission / reception circuit 8 and the diversity reception circuit 9. The second method is a portable terminal in which the communication device 10 is mounted, and a human body (hand, head) is brought close to either the first antenna 1 or the second antenna 2 by a proximity sensor or the like. It is determined that the reception state of the antenna that is not close to the human body is good. Further, the third method determines whether or not the call state of the mobile terminal on which the communication device 10 is mounted is hands-free (a state where the human body is not in proximity to the mobile terminal), and calls that are not hands-free If it is in the state, it is determined that the reception state of the antenna located near the mouth of the mobile terminal (the antenna located away from the human head) of the first antenna 1 and the second antenna 2 is good. To do. As a result, it is possible to identify an antenna having a small influence on the reception state of the human body from among the first antenna 1 and the second antenna 2.

(Antenna switching controller 7)
When the antenna switching controller 7 (switching control means) receives a notification of an antenna having a good reception state from the reception state determining unit 6, the antenna switching controller 7 and the first antenna 1 or the second antenna 2 having a good reception state are received. Is a control unit that outputs a switching control signal to connect the two.

(Transmission / reception circuit 8)
The transmission / reception circuit 8 (transmission / reception unit) is a circuit that performs signal processing (A / D conversion, D / A conversion, modulation / demodulation, multiplexing / separation, etc.) for transmission / reception of radio waves. The transmission / reception circuit 8 covers a wide frequency band including a transmission band and a reception band, and is a circuit capable of a transmission operation and a reception operation.

(Diversity receiving circuit 9)
The diversity receiving circuit 9 (receiving unit) is a circuit that performs signal processing (A / D conversion, D / A conversion, modulation / demodulation, multiplexing / separation, etc.) for radio wave reception. The diversity receiving circuit 9 is a circuit that covers only a narrow receiving frequency band and is capable of receiving operation in order to increase receiving sensitivity.

(Operation of the communication device 10)
An operation of the communication apparatus 10 configured as described above will be described.

  In an initial state such as when the communication device 10 is turned on, the antenna switching unit 5 is in the connection state S <b> 1 by a switching control signal from the antenna switching controller 7. For this reason, the first matching circuit unit 3 is connected to the transmission / reception circuit 8 and the second matching circuit unit 4 is connected to the diversity receiving circuit 9 via the antenna switching unit 5. In this state, the first matching circuit unit 3 selects the adjustment value corresponding to the transmission / reception circuit 8 and the second matching circuit unit 4 selects the adjustment value corresponding to the diversity reception circuit 9 according to the switching control signal. doing. Therefore, the first antenna 1 is matched so as to cover the transmission / reception band of the transmission / reception circuit 8, and the second antenna 2 is matched so as to cover the reception band of the diversity reception circuit 9.

  From this state, when the reception state of the second antenna 2 becomes better than the reception state of the first antenna 1, the reception state determination unit 6 determines that. The antenna switching controller 7 outputs a switching control signal for switching the connection state of the antenna switching unit 5 and the adjustment values of the first matching circuit unit 3 and the second matching circuit unit 4 based on the determination result. To do. The antenna switching unit 5 switches the connection state S1 to the connection state S2 by this switching control signal. As a result, the first matching circuit unit 3 is connected to the diversity receiving circuit 9, and the second matching circuit unit 4 is connected to the transmitting / receiving circuit 8. The first matching circuit unit 3 selects an adjustment value corresponding to the diversity receiving circuit 9, and the second matching circuit unit 4 selects an adjustment value corresponding to the transmission / reception circuit 8. Therefore, the first antenna 1 is matched so as to cover the reception band of the diversity reception circuit 9, and the second antenna 2 is matched so as to cover the transmission / reception band of the transmission / reception circuit 8.

  Further, from this state, when the reception state of the first antenna 1 becomes better than the reception state of the second antenna 2, the reception state determination unit 6 determines that. The antenna switching controller 7 outputs a switching control signal for switching the connection state of the antenna switching unit 5 and the adjustment values of the first matching circuit unit 3 and the second matching circuit unit 4 based on the determination result. To do. The antenna switching unit 5 switches the connection state S2 to the connection state S1 by this switching control signal. Thereby, like the above-mentioned initial state, the first antenna 1 is matched so as to cover the transmission / reception band of the transmission / reception circuit 8, and the second antenna 2 covers the reception band of the diversity reception circuit 9. To be aligned.

(Effects of the communication device 10)
FIG. 2 is a graph showing the effect of improving the antenna characteristics of the communication device.

  As described above, the communication device 10 according to the present embodiment connects the antenna having a good reception state to the transmission / reception circuit 8 and connects the other antenna to the diversity reception circuit 9 based on the determination result of the reception state determination unit 6. Thus, the antenna switching controller 7 performs control. Thereby, the 1st antenna 1 and the 2nd antenna 2 can be switched appropriately according to a receiving state, and it can connect to a transmission / reception part and a receiving part. Further, the communication device 10 selects the adjustment values of the first matching circuit unit 3 and the second matching circuit unit 4 to values according to the transmission / reception circuit 8 and the diversity reception circuit 9 connected thereto. Control is performed by the antenna switching controller 7. Thereby, the impedances of the first antenna 1 and the second antenna 2 are optimally adjusted with respect to the bands (transmission / reception antenna or diversity reception antenna) used respectively.

  Specifically, when the communication apparatus 10 supports the LTE Band 1 band of about 2 GHz, the first antenna 1 and the second antenna 2 can cover the communication band as follows. When the first antenna 1 or the second antenna 2 is connected to the transmission / reception circuit 8, as shown in FIG. 2A, the transmission band Tx (transmission frequency band: 1920-1980 MHz) and the reception band Rx A wide transmission / reception band including (reception frequency band: 2110-2170 MHz) is covered. On the other hand, when the first antenna 1 or the second antenna 2 is connected to the diversity receiving circuit 9, as shown by a solid line in FIG. 2B, a narrow band receiving band including the receiving band Rx. To cover. Therefore, the antenna characteristics of the first antenna 1 and the second antenna 2 connected to the diversity receiving circuit 9 cover the transmission band Tx and the reception band Rx as shown by the solid line in FIG. It can be seen that the efficiency peak is higher than that of the wideband antenna characteristics (shown by a two-dot chain line), which is improved.

[Embodiment 2]
Embodiment 2 of the present invention will be described below with reference to FIG.

  FIG. 3 is a block diagram illustrating a schematic configuration of the communication device 20 according to the present embodiment.

  In the present embodiment, for convenience of explanation, components having the same functions as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As illustrated in FIG. 3, the communication device 20 includes a first antenna 1, a second antenna 2, a first matching circuit unit 3, a second matching circuit unit 4, an antenna switching unit 5, and a reception state determination unit 6. A transmission / reception circuit 8 and a diversity reception circuit 9 are provided. Further, the communication device 20 includes a reception level comparison / determination unit 16 and an antenna switching controller 17.

  In the present embodiment, the communication device 20 also has two bands (frequency bands) for transmitting and receiving radio signals, that is, the transmission band Tx (first frequency band) and the reception, as in LTE, in the same manner as the communication device 10. The band Rx (second frequency band) can be switched and used.

  Reception level comparison and determination unit 16 is provided with reception levels P1 and P2 and gain differences Gd1 and Gd2. The reception level P <b> 1 is information indicating the magnitude of the reception level of the transmission / reception circuit 8 and is acquired from the transmission / reception circuit 8. The reception level P <b> 2 indicates the magnitude of the reception level of the diversity reception circuit 9 and is acquired from the diversity reception circuit 9. The gain difference Gd1 is information on the difference in gain indicated by the reception band in the two matching states of the first antenna 1. The gain difference Gd2 is information on the difference in gain indicated by the reception band in the two matching states of the second antenna 2.

  The reception level comparison / determination unit 16 (determination means) compares the reception level P1 with a value (difference value) obtained by subtracting the gain difference (Gd1 or Gd2) of the antenna connected to the diversity reception circuit 9 from the reception level P2. And determine which is larger. The determination result C1 by the reception level comparison determination unit 16 indicates which of the antenna connected to the transmission / reception circuit 8 or the antenna connected to the diversity reception circuit 9 is in a better reception state. It is given to the controller 7.

  The reception level comparison / determination unit 16 (determination means) compares the reception level P1 with a value (difference value) obtained by subtracting the gain difference (Gd1 or Gd2) of the antenna connected to the diversity reception circuit 9 from the reception level P2. And determine which is larger. The determination result C1 by the reception level comparison determination unit 16 indicates which of the antenna connected to the transmission / reception circuit 8 or the antenna connected to the diversity reception circuit 9 is in a better reception state. It is given to the controller 7.

  The gain difference is set in advance and stored in a storage unit (not shown) of the communication device 20 or the like.

  Here, the reason why the gain difference Gd1 or the gain difference Gd2 is subtracted from the reception level P2 will be described. The reception level P2 is power received by the diversity reception circuit 9. Further, the antenna connected to the diversity receiving circuit 9 (either the first antenna 1 or the second antenna 2) is in a state optimized for the reception band. As a result, the reception level P2 is the level when the antenna is received with a gain state that is higher by a gain difference Gd1 or gain difference Gd2 than when the antenna is optimized for the transmission / reception band. Therefore, by subtracting the higher level from the reception level P2 and comparing it with the reception level P1, it is possible to correct the variation in antenna characteristics due to the matching state.

  Whether the gain difference Gd1 or the gain difference Gd2 is subtracted from the reception level P2 depends on the antenna connected to the diversity receiving circuit 9. That is, when the antenna connected to the diversity reception circuit 9 is the first antenna 1, the gain difference Gd1 is subtracted from the reception level P2, and the antenna connected to the diversity reception circuit 9 is the second antenna 2. If there is, the gain difference Gd2 is subtracted from the reception level P2.

  The antenna switching controller 17 (switching control means) controls the connection state of the antenna switching unit 5 and the selection of the adjustment values of the first matching circuit unit 3 and the second matching circuit unit 4 based on the determination result C1. . Specifically, the antenna switching controller 17 outputs a switching control signal that instructs to connect an antenna in a good reception state to the transmission / reception circuit 8 based on the determination result C1. The antenna switching controller 17 adjusts the first matching circuit unit 3 or the second matching circuit unit 4 so that the antenna connected to the transmission / reception circuit 8 is in a matching state that covers the transmission / reception band. A switching control signal instructing to select a value is output. Furthermore, the antenna switching controller 17 has the first matching circuit unit 3 or the second matching circuit unit 4 so that the antenna connected to the diversity receiving circuit 9 is in a matching state that covers only the reception band. A switching control signal instructing selection of the adjustment value is output.

(Operation of the communication device 20)
The operation of the communication device 20 configured as described above will be described.

  In an initial state such as when the communication device 20 is turned on, the first matching circuit unit 3 is connected to the transmission / reception circuit 8 and the second matching circuit unit 4 is the diversity reception circuit 9 as in the communication device 10 in the first embodiment. It is connected to the. Therefore, the first antenna 1 is matched so as to cover the transmission / reception band of the transmission / reception circuit 8, and the second antenna 2 is matched so as to cover the reception band of the diversity reception circuit 9.

  From this state, when the reception state of the second antenna 2 becomes better than the reception state of the first antenna 1, the reception level comparison determination unit 16 determines that. The antenna switching controller 17 generates a switching control signal for switching between the connection state of the antenna switching unit 5 and the adjustment values of the first matching circuit unit 3 and the second matching circuit unit 4 based on the determination result C1. Output. The antenna switching unit 5 switches the connection state S1 to the connection state S2 by this switching control signal. As a result, the first matching circuit unit 3 is connected to the diversity receiving circuit 9, and the second matching circuit unit 4 is connected to the transmitting / receiving circuit 8. The first matching circuit unit 3 selects an adjustment value corresponding to the diversity receiving circuit 9, and the second matching circuit unit 4 selects an adjustment value corresponding to the transmission / reception circuit 8. Therefore, the first antenna 1 is matched so as to cover the reception band of the diversity reception circuit 9, and the second antenna 2 is matched so as to cover the transmission / reception band of the transmission / reception circuit 8.

  Further, from this state, when the reception state of the first antenna 1 becomes better than the reception state of the second antenna 2, the reception level comparison determination unit 16 determines that. The antenna switching controller 7 generates a switching control signal for switching between the connection state of the antenna switching unit 5 and the adjustment values of the first matching circuit unit 3 and the second matching circuit unit 4 based on the determination result C1. Output. The antenna switching unit 5 switches the connection state S2 to the connection state S1 by this switching control signal. Thereby, like the above-mentioned initial state, the first antenna 1 is matched so as to cover the transmission / reception band of the transmission / reception circuit 8, and the second antenna 2 covers the reception band of the diversity reception circuit 9. To be aligned.

(Effects of the communication device 20)
As described above, the communication device 20 of the present embodiment connects the antenna having a good reception state to the transmission / reception circuit 8 based on the determination result C1 of the reception level comparison determination unit 16 and the other antenna to the diversity reception circuit 9. It controls by the antenna switching controller 17 so that it may connect to. Further, the communication device 20 selects the adjustment values of the first matching circuit unit 3 and the second matching circuit unit 4 to values according to the transmission / reception circuit 8 and the diversity reception circuit 9 connected to each of them. Control is performed by the antenna switching controller 17. Thereby, the impedances of the first antenna 1 and the second antenna 2 are optimally adjusted with respect to the bands (transmission / reception antenna or diversity reception antenna) used respectively.

  Further, in the comparison determination process by the reception level comparison determination unit 16, the difference value obtained by subtracting (subtracting) the gain difference (Gd1 or Gd2) of the antenna connected to the diversity reception circuit 9 from the reception level P1 and the reception level P2. And are used. As a result, since the matching state (adjustment value) is switched before and after switching the antenna, even if the antenna characteristics fluctuate according to the switching of the matching state, the fluctuation is predicted using the gain difference for each antenna. The switching of the antenna can be determined so as to correct. On the other hand, when the difference value is not used, the change in the antenna characteristics before and after the antenna switching is not taken into consideration, and the antenna characteristics deteriorate due to the switching. Therefore, by using the difference value, variation in antenna performance before and after antenna switching is taken into consideration, and antenna characteristics are improved by switching.

[Embodiment 3]
In the present embodiment, an implementation example of the above-described communication apparatuses 10 and 20 by software will be described.

  The control blocks (particularly the reception state determination unit 6, the antenna switching controller 7 and the reception level comparison determination unit 16) of the communication devices 10 and 20 are realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like. Alternatively, it may be realized by software using a CPU (Central Processing Unit).

  In the latter case, the communication devices 10 and 20 include a CPU that executes an instruction of an antenna switching control program that is software for realizing each function, and a ROM (or a computer) that stores the program and various data so that the computer (or CPU) can read the program. A Read Only Memory) or a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) for expanding the program, and the like are provided. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

[Summary]
A communication apparatus (10, 20) according to aspect 1 of the present invention includes two antennas (first antenna 1 and second antenna 2) and a transmission / reception unit that processes a signal transmitted / received by one of the antennas. (Transmission / reception circuit 8), a reception unit (diversity reception circuit 9) that processes a signal received by the other of the antennas, and one of the antennas is connected to the transmission / reception unit, and the other is connected to the reception unit And a switching unit (antenna switching unit 5) for selectively switching the connection, and a matching for selectively switching the impedance adjustment value so as to match the antenna to each of the transmitting / receiving unit and the receiving unit to be connected Switching by the switching unit and the matching unit according to the reception state of the antenna (the first matching circuit unit 3 and the second matching circuit unit 4) and the antenna Gosuru and a switching control unit (antenna switching controller 7 and 17).

  According to said structure, one antenna is connected to a transmission / reception part via a switching part, and the other antenna is connected to a receiving part. Each antenna is matched to the connected transmitting / receiving unit and receiving unit according to the adjustment value selected by the matching unit. Thereby, the antenna characteristics can be optimized according to the communication frequency band.

  The communication device (10) according to aspect 2 of the present invention further includes determination means (reception state determination unit 6) for determining which reception state of the antenna is good in the aspect 1, and the switching control. The means controls the switching unit to connect one of the antennas determined to have a good reception state to the transmitting / receiving unit, and selects the adjustment value that matches the transmitting / receiving unit. In this way, the matching unit may be controlled. Thereby, two antennas can be appropriately switched according to the reception state and connected to the transmission / reception unit and the reception unit.

  The communication device (20) according to aspect 3 of the present invention is the communication apparatus (20) according to aspect 2, in which the determination unit is connected to the gain and the reception unit when each of the antennas is connected to the transmission / reception unit. A gain difference that is a difference from the gain is given, and a connection is made from the first reception level (P1) of the transmission / reception unit and the second reception level (P2) of the reception unit to the reception unit of the antenna It may be determined which reception state of the antenna is good by comparing a value obtained by subtracting any one of the gain differences (gain differences Gd1, Gd2). As a result, the adjustment value is switched before and after the antenna is switched. Therefore, even if the antenna characteristics fluctuate according to the switching of the adjustment value, the antenna switching is performed so that the fluctuation is predicted and corrected using the gain difference of the antenna. Can be determined.

  The communication apparatus according to each aspect of the present invention may be realized by a computer. In this case, the communication apparatus is realized by a computer by causing the computer to operate as each unit included in the communication apparatus. An antenna switching control program and a computer-readable recording medium that records the program also fall within the scope of the present invention.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be used for diversity reception in which two antennas are switched in accordance with reception conditions.

1 First antenna (antenna)
2 Second antenna (antenna)
3 First matching circuit section (matching section)
4 Second matching circuit section (matching section)
5 Antenna switching part (switching part)
6 Reception state determination unit (determination means)
7 Antenna switching controller (switching control means)
8 Transmitter / receiver circuit (transceiver)
9 Diversity receiver circuit (receiver)
10 Communication device 16 Reception level comparison / determination unit (determination means)
17 Antenna switching controller (switching control means)
20 Communication device P1, P2 Reception level

Claims (3)

Two antennas,
A transmission / reception unit for processing a signal transmitted / received by any one of the antennas;
A receiver for processing a signal received by the other of the antennas;
A switching unit that selectively switches connection so that either one of the antennas is connected to the transmitting / receiving unit and the other is connected to the receiving unit;
A matching unit that selectively switches an adjustment value of impedance so as to match the antenna to each of the transmitting and receiving units and the receiving unit connected;
Switching control means for controlling switching by the switching unit and the matching unit according to the reception state of the antenna;
Determination means for determining which reception state of the antenna is good,
The switching control means includes
While controlling the switching unit to connect one of the antennas determined to have a good reception state to the transmission / reception unit,
Controlling the matching unit to select the adjustment value that matches the transceiver unit;
The determination means includes
For each of the antennas, given a gain difference that is the difference between the gain when connected to the transceiver and the gain when connected to the receiver,
The first reception level of the transmission / reception unit is compared with a value obtained by subtracting the gain difference of any one of the antennas connected to the reception unit from the second reception level of the reception unit. Accordingly, it is determined which reception state of the antenna is good. An antenna switching control program for causing a computer to function as the communication device according to claim 1 , wherein the computer functions as each unit. A computer-readable recording medium in which the antenna switching control program according to claim 2 is recorded.

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