JP3896708B2 - Wireless communication device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radio communication apparatus that includes a main antenna that protrudes from a casing and a sub antenna that is built in the casing, and is configured to receive diversity by using the main antenna and the sub antenna.
[0002]
[Problems to be solved by the invention]
In recent years, with the advancement of telecommunications technology, wireless communication devices such as mobile phone devices have become widespread. By the way, the cellular phone device generally includes a whip antenna provided so as to protrude from the housing and a flat plate antenna built in the housing, and the whip antenna is used for both transmission and reception for radiating and capturing radio waves. The flat antenna acts as a reception-only sub-antenna for capturing radio waves. The mobile phone device is configured to receive diversity using the whip antenna and the flat antenna.
[0003]
However, the conventional device has a structure in which the whip antenna acting as the main antenna is provided so as to protrude from the housing, so that, for example, the user keeps the mobile phone device in the back pocket of the pants. If the user sits down, the whip antenna may bend and break down. In this case, the whip antenna cannot radiate and capture radio waves satisfactorily, and as a result, there is a problem that communication cannot be performed.
[0004]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wireless communication apparatus that enables communication even when a main antenna that radiates and captures radio waves breaks down. There is.
[0005]
[Means for Solving the Problems]
According to the wireless communication device of the first aspect, when the main antenna breaks down, the impedance on the main antenna side viewed from the transmission circuit side becomes infinite, and accordingly, the control means uses the level detection means. When it is detected that the level of the reflected wave of the detected transmission wave has changed from less than a predetermined value to a predetermined value or more, the transmission switching means is controlled to switch from the first transmission switching state to the second transmission switching state. As a result, the transmission wave output from the transmission circuit is not given to the main antenna, but is given to the sub-antenna.
[0006]
Here, since the sub-antenna is originally configured to be able to capture radio waves, when the transmission wave output from the transmission circuit is given due to the reversibility of the antenna, the transmission wave can be radiated as a radio wave. . Therefore, even when the main antenna breaks down, radio waves can be radiated and captured by the sub antenna, and communication can be executed.
[0007]
According to the wireless communication device of claim 2, when the control unit detects that the level of the reflected wave of the transmission wave detected by the level detection unit has changed from less than a predetermined value to more than a predetermined value, as described above. The transmission switching means is controlled to switch from the first transmission switching state to the second transmission switching state, and the reception switching means is controlled to switch from the first reception switching state to the second reception switching state. As a result, diversity reception is not performed by the main antenna and the sub-antenna, that is, radio waves captured by the failed main antenna are not given as reception waves to the receiving circuit, and radio waves captured by the sub-antenna are not received. Is given to the receiving circuit as a received wave, so that the radio wave can be satisfactorily received by the sub-antenna.
[0008]
According to the wireless communication device of the third aspect, when the control unit detects that the level of the reflected wave of the transmission wave detected by the level detection unit has changed from less than the predetermined value to more than the predetermined value, as described above. The transmission switching unit is switched from the first transmission switching state to the second transmission switching state, the reception switching unit is switched from the first reception switching state to the second reception switching state, and the notification unit is activated. . Thereby, the user can recognize that the main antenna has failed by outputting predetermined notification information from the notification means.
[0009]
According to the wireless communication device of the fourth aspect, when the main antenna recovers from a failure, the impedance on the main antenna side viewed from the transmission circuit side returns to a normal value, and accordingly, the control means When detecting that the level of the reflected wave of the transmission wave detected by the level detection means has changed from a predetermined value or more to less than a predetermined value, the transmission switching means is changed from the second transmission switching state to the first transmission switching state. Switching control is performed. Thereby, it is possible to quickly return to the state before the failure, that is, radio waves can be radiated and captured by the main antenna, and communication can be performed satisfactorily.
[0010]
According to the wireless communication device of the fifth aspect, since the level detection means is mainly composed of the envelope detection circuit, the envelope detection circuit is a well-known configuration with high versatility, and therefore the level detection means is simply configured. I can.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a mobile phone device will be described with reference to the drawings.
First, in FIG. 2, on the front side of the housing 2 in the cellular phone device 1, a call start key, a redial key, a call end key, numeric keys "0" to "9", * (asterisk) key, Keypad 3 on which various keys such as # (sharp) key and F (function) key are arranged, display 4 (notification means in the present invention) for displaying the telephone number of the other party, and a transmission signal are input. There are provided a microphone (transmitter) 5 that performs, a speaker (receiver) 6 that outputs a reception signal, and an LED 7 that blinks when an incoming call is received.
[0012]
An antenna case portion 2a is integrally provided on the upper side of the housing 2 so as to protrude upward, and a whip antenna 8 is provided inside the antenna case portion 2a. Further, a flat plate antenna 9 is disposed on the back side of the housing 2. The whip antenna 8 and the flat antenna 9 are fed from a feeding unit (not shown), and in a normal usage pattern, the whip antenna 8 is used as a main antenna for transmitting and receiving radio waves. In operation, the flat antenna 9 acts as a reception-only sub-antenna for capturing radio waves.
[0013]
Next, the main part of the electrical configuration of the cellular phone device 1 will be described with reference to FIG.
Whip antenna 8 is connected to one fixed contact 11a of reception changeover switch 11 (reception changeover means in the present invention) via antenna duplexer 10, and flat antenna 9 is fixed to the other of reception changeover switch 11. It is connected to the contact 11b. The movable contact 11 c of the reception changeover switch 11 is connected to the reception circuit 12.
[0014]
Thereby, when the fixed contact 11a and the movable contact 11c are connected in the reception changeover switch 11 (in the state shown by the solid line in FIG. 1, in the first reception changeover state in the present invention), The radio wave captured by the whip antenna 8 is given to the receiving circuit 12 as a received wave. On the other hand, when the fixed contact 11b and the movable contact 11c are connected in the reception changeover switch 11 (in the state indicated by the broken line in FIG. 1, in the second reception changeover state in the present invention), the flat plate The radio wave captured by the antenna 9 is given to the receiving circuit 12 as a received wave.
[0015]
The transmission circuit 13 is connected via a circulator 14 to a movable contact 15a of a transmission changeover switch 15 (transmission changeover means in the present invention). One fixed contact 15b of the transmission changeover switch 15 is connected to the whip antenna 8 via the antenna duplexer 10, and the other fixed contact 15c of the transmission changeover switch 15 is connected to the flat plate antenna 9. Yes.
[0016]
As a result, when the movable contact 15a and the fixed contact 15b are connected in the transmission changeover switch 15 (in the state indicated by the solid line in FIG. 1, in the first transmission changeover state referred to in the present invention), The transmission wave output from the transmission circuit 13 is supplied to the whip antenna 8 and is emitted from the whip antenna 8 as a radio wave. On the other hand, when the movable contact 15a and the fixed contact 15c are connected in the transmission changeover switch 15 (in the state indicated by the broken line in FIG. 1, in the second transmission switching state in the present invention), the transmission is performed. The transmission wave output from the circuit 13 is supplied to the flat antenna 9.
[0017]
Here, as described above, the flat antenna 9 functions as a reception-only antenna that captures radio waves in a normal usage pattern. Therefore, when a transmission wave is given due to the reversibility of the antenna, the flat antenna 9 is given. The transmitted wave is radiated as a radio wave.
[0018]
The circulator 14 has three terminals, one of which is connected to the termination resistor 16. In this case, the portion between the circulator 14 and the termination resistor 16 is electromagnetically coupled to the input side of the envelope detection circuit 20 (level detection means in the present invention) including the diode 17, the resistor 18, and the capacitor 19. It has become. Thereby, a part of the transmission wave output from the transmission circuit 13 is reflected by the whip antenna 8 to become a reflected wave, and when the reflected wave flows toward the terminating resistor 16 via the circulator 14, the current of the reflected wave is reflected. A leakage current corresponding to the current flows through the envelope detection circuit 20.
[0019]
The output side of the envelope detection circuit 20 is connected to the non-inverting input terminal of the operational amplifier 21. The output terminal of the operational amplifier 21 is connected to the determination circuit 22 and negatively connected to the inverting input terminal. That is, the operational amplifier 21 constitutes a voltage follower circuit 23, whereby impedance is matched between the output side of the envelope detection circuit 20 and the input side of the determination circuit 22, and the operation of the determination circuit 22 is stable. It is supposed to be.
[0020]
The determination circuit 22 compares the current level given from the envelope detection circuit 20 via the voltage follower circuit 23 with a preset threshold value (predetermined value in the present invention), and the comparison result Is output to the control circuit 24 (control means in the present invention).
[0021]
When the comparison result is given from the determination circuit 22, the control circuit 24 controls the reception changeover switch 11 and the transmission changeover switch 15 based on the comparison result. Specifically, when the control circuit 24 detects that the current level output from the envelope detection circuit 20 to the determination circuit 22 is less than the threshold based on the comparison result given from the determination circuit 22, the reception circuit The reception changeover switch 11 is controlled to switch between the first reception changeover state and the second reception changeover state on the basis of the reception intensity of the received wave given to 12, and the transmission changeover switch 15 is changed to the first transmission changeover state. Switching control is performed.
[0022]
On the other hand, when the control circuit 24 detects that the current level output from the envelope detection circuit 20 to the determination circuit 22 is greater than or equal to the threshold value based on the comparison result given from the determination circuit 22, the control circuit 24 turns the reception changeover switch 11 on. The transmission switching switch 15 is controlled to be switched to the second transmission switching state and the transmission switching switch 15 is switched to the second transmission switching state. At this time, the control circuit 24 outputs a display control signal to the display control unit 25 to display predetermined display information (notification information in the present invention) on the display 4.
[0023]
Next, the operation of the above configuration will be described with reference to FIG.
First, when normal, that is, when the whip antenna 8 is normal, the impedance on the whip antenna 8 side viewed from the transmission circuit 13 side is a normal value, and the current output from the envelope detection circuit 20 to the determination circuit 22 The level is below the threshold and never exceeds the threshold.
[0024]
At this time, as described above, the control circuit 24 switches the reception changeover switch 11 between the first reception changeover state and the second reception changeover state based on the reception intensity of the reception wave applied to the reception circuit 12. By controlling, diversity reception is controlled so that the higher reception strength of the radio wave captured by the whip antenna 8 and the radio wave captured by the flat antenna 9 is given to the reception circuit 12 as a reception wave, and transmission switching By switching the switch 15 to the first transmission switching state, transmission is controlled so that the transmission wave output from the transmission circuit 13 is radiated from the whip antenna 8 as a radio wave.
[0025]
Now, consider a case where the whip antenna 8 has failed for some reason. When the whip antenna 8 breaks down, the impedance on the whip antenna 8 side viewed from the transmission circuit 13 side becomes infinite, and most of the transmission wave output from the transmission circuit 13 is reflected by the whip antenna 8, and envelope detection is performed. The current level output from the circuit 20 to the determination circuit 22 is equal to or greater than the threshold value.
[0026]
At this time, the control circuit 24 controls the reception so that the radio wave captured by the flat plate antenna 9 is given as a reception wave to the reception circuit 12 by switching the reception selector switch 11 to the second reception switching state. Further, by controlling the transmission changeover switch 15 to the second transmission switching state, the transmission is controlled so that the transmission wave output from the transmission circuit 13 is radiated from the flat antenna 9 as a radio wave, and the display control unit 25. By outputting a display control signal, display information “Whip antenna pepper” is displayed on the display 4 (see FIG. 3).
[0027]
In this case, the control circuit 24 switches and controls the reception changeover switch 11 and the transmission changeover switch 15 at a predetermined reception timing and transmission timing corresponding to the TDMA operation, whereby the transmission output from the transmission circuit 13 is performed. Waves are not applied to the receiving circuit 12.
[0028]
When the whip antenna 8 returns from the failure, the impedance on the whip antenna 8 side viewed from the transmission circuit 13 side returns to a normal value, and the current level output from the envelope detection circuit 20 to the determination circuit 22 is less than the threshold value. At this time, the control circuit 24 controls diversity reception by the whip antenna 8 and the flat plate antenna 9 and controls transmission by the whip antenna 8 as described above.
[0029]
Thus, according to the present embodiment, when the whip antenna 8 fails, the transmission changeover switch 15 is controlled to be switched from the first transmission changeover state to the second transmission changeover state. The output transmission wave is not given to the whip antenna 8 but given to the flat antenna 9 and is radiated as a radio wave from the flat antenna 9. Therefore, even when the whip antenna 8 breaks down, radio waves can be radiated and captured by the flat antenna 9 and communication can be executed.
[0030]
At this time, since the reception changeover switch 11 is controlled to be switched from the first reception changeover state to the second reception changeover state, diversity reception is not performed by the whip antenna 8 and the flat antenna 9. The radio wave captured by the failed whip antenna 8 is not given to the reception circuit 12 as a reception wave, and the radio wave captured by the flat plate antenna 9 is given to the reception circuit 12 as a reception wave. Can be received.
[0031]
At this time, the display information “Whipped antenna pepper” is displayed on the display 4, so that the user can recognize that the whip antenna 8 is broken by this display information.
[0032]
Further, when the whip antenna 8 returns from the failure, the transmission changeover switch 15 is controlled to be switched from the second transmission switching state to the first transmission switching state, so that the state before the whip antenna 8 breaks down. It is possible to quickly return and radiate / capture the radio wave by the whip antenna 8 so that the communication can be performed satisfactorily.
[0033]
Further, since the circuit as the level detection means for detecting whether or not the whip antenna 8 is broken is mainly composed of the envelope detection circuit 20, the envelope detection circuit 20 is a well-known configuration with high versatility. The detection means can be configured easily.
[0034]
The present invention is not limited to the above-described embodiments, and can be modified or expanded as follows.
The wireless communication device is not limited to the mobile phone device, and may be another communication device as long as it has a main antenna for both transmission and reception and a sub antenna dedicated for reception.
[0035]
The input side of the envelope detection circuit is not limited to the electromagnetic coupling configuration, and may be a capacitive coupling configuration.
When the main antenna breaks down, the LED may turn on or the speaker may sound. In addition, the display information displayed on the display is not limited to kana display, but may be kana kanji display such as “Whipping antenna is faulty”, and the display information message may be other messages. May be.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is an external perspective view. FIG. 3 is a diagram showing a display on a display.
In the drawings, 1 is a cellular phone device (wireless communication device), 2 is a case, 4 is a display (notification means), 8 is a whip antenna (main antenna), 9 is a flat plate antenna (sub antenna), and 11 is a reception changeover switch. (Reception switching means), 12 is a reception circuit, 13 is a transmission circuit, 15 is a transmission switch (transmission switching means), 20 is an envelope detection circuit (level detection means), and 24 is a control circuit (control means).

Claims (5)

A main antenna that protrudes from the casing and can radiate a transmission wave output from the transmission circuit as a radio wave and can capture the radio wave; a sub-antenna that is built in the casing and can capture the radio wave; and the main antenna It is possible to switch between a first reception switching state in which the radio wave captured by the sub-antenna is applied as a reception wave to the reception circuit and a second reception switching state in which the radio wave captured by the sub-antenna is applied to the reception circuit as a reception wave. In a wireless communication apparatus configured to receive diversity by the main antenna and the sub antenna by switching control of the reception switching means, the reception switching means,
Provided separately from the reception switching means, the first transmission switching state in which the transmission wave output from the transmission circuit is applied to the main antenna and the transmission wave output from the transmission circuit are applied to the main antenna. A transmission switching means capable of switching between the second transmission switching state given to the sub-antenna without being controlled and always controlled to be switched to the first transmission switching state;
Level detection means for detecting the level of the reflected wave of the transmission wave output from the transmission circuit;
When the reflected wave level of the transmission wave detected by the level detection means changes from less than a predetermined value to a predetermined value or more, the transmission switching means is switched from the first transmission switching state to the second transmission switching state. And a control means for controlling the wireless communication apparatus.   The control means switches the reception switching means to the second reception switching state when the reflected wave level of the transmission wave detected by the level detection means changes from less than a predetermined value to a predetermined value or more. The wireless communication apparatus according to claim 1. A notification means for outputting predetermined notification information;
The control means is configured to activate the notification means when the level of the reflected wave of the transmission wave detected by the level detection means changes from less than a predetermined value to a predetermined value or more. The wireless communication apparatus according to claim 1 or 2.   The control means changes the transmission switching means from the second transmission switching state to the first transmission when the level of the reflected wave of the transmission wave detected by the level detection means changes from a predetermined value to less than a predetermined value. 4. The wireless communication apparatus according to claim 1, wherein switching control is performed in a switching state.   The wireless communication apparatus according to claim 1, wherein the level detection unit is configured mainly with an envelope detection circuit.

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