JP2001217624A - Radio communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication device which can prevent the gain of an antenna from decreasing as much as possible, even when the use state is changed. SOLUTION: When a touch sensor detects a housing 2, being gripped in the hand of a user, a control circuit 8 switches switches 15 and 16 from a matching circuit 17 which has matched the impedance with a free space to a matching circuit 18, which has matched the impedance with the state. Furthermore, when a voice processing part detects the user who is in a calling state, the control circuit switches the switches 15 and 16, so that an antenna 7 is connected to a matching circuit 19 having been matched the impedance to the state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication device which is configured to be portable and performs communication using radio signals.

[0002]

2. Description of the Related Art In such a mobile communication device, for example, a portable telephone device, a main body is provided with, for example, two antennas in order to secure a better communication state, and radio waves transmitted from a base station are respectively transmitted by the antennas. It is a common practice to compare the reception levels when receiving, and to make a call using the antenna with the higher reception level at that time (diversity reception). Such antennas are adjusted in advance so as to match impedances (matching) so that the reception gain in the used frequency band is maximized.

[0003] In this case, two conditions of a free space (Free Mode) and a talk state (Talk Mode) are mainly considered as conditions for matching the impedance of the antenna. In the former case, it is difficult to assume a specific matching condition because the use state of the mobile phone device is extremely diverse, so that the matching is first performed on a free space. In the latter case, the matching condition is limited to the talking state, and the impedance of the antenna is matched in consideration of the impedance of the transmission line in a state where the user holds the main body of the mobile phone device by hand and approaches the head. It is made to let.

[0004]

However, in the former case, the portable telephone device cannot be placed in free space as an actual use condition, and as a result, the impedance of the antenna is matched in any use condition. Can not be achieved enough.

[0005] In the latter case, impedance matching in an assumed call state is sufficient, but other states are not assumed, such as a state in which the user is wearing a portable telephone device and waiting for an incoming call. However, in a state in which the user tries to make a call while holding the mobile phone device in his hand, the matching becomes insufficient. Therefore, in either case, there is a problem that a state in which the gain of the antenna is reduced is caused.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radio communication device that can prevent a decrease in antenna gain as much as possible even when the use state changes.

[0007]

According to the wireless communication apparatus of the present invention, the connection switching means switches the antenna when the change of the environmental state outside the main body is detected by the state detecting means. Since the switching is performed so as to connect to the matching circuit corresponding to the state, the impedance of the antenna is matched according to the changed environmental state by the switched connection circuit. Therefore, when the environmental condition outside the main body changes, it is possible to prevent the impedance of the antenna from being mismatched and the gain from decreasing as much as possible, and to always maintain a good communication condition.

According to the second aspect of the present invention, when the holding state detecting means as the state detecting means detects the state in which the main body is held by the hand of the user, the connection switching means sets the antenna to a corresponding matching state. Switch to connect to the circuit.

That is, for example, when the impedance of the antenna is previously adjusted to match the free space, if the user grips the main body of the wireless communication device, the impedance of the transmission path is affected. If it is left as it is, the impedance of the antenna will be mismatched. Therefore, the connection switching means switches the antenna to be connected to the matching circuit corresponding to the state, so that the impedance of the antenna can be readjusted so as to be matched according to the change in the state.

According to the third aspect of the present invention, when the communication state detection means as the state detection means detects that the user is in the communication state, the connection switching means connects the antenna to the corresponding matching circuit. Switch to connect.

That is, when the wireless communication device is configured to be able to communicate by radio signals, for example, as in a portable telephone device, the user holds the main body with his / her hand and performs a call when making a call. As described above, if the impedance of the antenna is adjusted so as to be matched by assuming another state as described above, the impedance of the antenna will be mismatched. Therefore, by switching the antenna to be connected to a matching circuit corresponding to a case where the user is in a talking state, the impedance of the antenna can be matched according to a change in the state.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. FIG. 3 is a perspective view showing the appearance of the mobile phone device. In FIG. 3, a call start key, a call end key, a redial key, numeric keys "0" to "9", * (asterisk) are provided on a front portion of a housing 2 constituting a mobile phone device (wireless communication device) 1. ) Key, a # (sharp) key, a scroll key, and various other keys, a microphone 4, a speaker 5, and a display (LCD) 6 for displaying a telephone number. A telescopic rod antenna (hereinafter simply referred to as an antenna) 7 is arranged on the upper surface of the housing (main body) 2.

FIG. 2 is a functional block diagram showing an electrical configuration of the mobile phone 1. In FIG. 2, the mobile phone device 1 is mainly configured with a control circuit (connection switching means) 8 including a microcomputer or the like, and an operation signal from the key operation unit 3 is given to the control circuit 8. It has become. Further, the control circuit 8 controls the display on the display unit 6.

When the audio signal input to the microphone 4 is applied to an audio processing unit (communication state detecting means) 9 and A / D converted, the data conversion unit 10 performs, for example, π / 4 shift DQPSK (Differential Quadrature). Phase Shift K
eying) signal. And D
The transmission data converted (digitally modulated) into a QPSK signal is supplied to the transmission / reception unit 11 and quadrature-modulated by a 1.5 GHz-band carrier signal.
The signal is transmitted to the outside as a radio signal from the antenna 7 via the antenna 2.

When the antenna 7 receives a radio signal, the received signal is transmitted to the transmitting / receiving section 11 and the data converting section 1.
The signal is demodulated at 0 and supplied to the audio processing unit 9. When D / A conversion is performed in the audio processing unit 9, the audio signal is output from the speaker 5 as an audio signal.

The control circuit 8 controls the audio processing unit 9, the data conversion unit 10, the transmission / reception unit 11, and the impedance matching unit 12. On the other hand, information such as detection of an incoming signal and a detected value of a transmission signal or a reception signal level is given from the transmission / reception unit 11 to the control circuit 8.

Further, the portable telephone device 1 is provided with a touch sensor (grip state detecting means) 13 inside the housing 2.
The touch sensor 13 allows the user to operate the housing 2 of the mobile phone device 1.
Is a sensor for detecting whether or not the user has grasped the device with his / her hand. For example, the detection is performed based on a change in the resistance value of the housing 2 or the like. The detection signal of the touch sensor 13 is provided to the control circuit 8.

The antenna 7 is a main antenna of the mobile phone 1, and the mobile phone 1 also has a sub-antenna such as a pattern antenna or an inverted F antenna for diversity reception, but is not shown. are doing.

FIG. 1 shows a detailed electrical configuration of the impedance matching unit 12. The transmission / reception unit 11 includes a shared circuit 14 represented by a symbol of a changeover switch. The fixed contact 14a of the shared circuit 14 is connected to the transmission line of the transmission system, and the fixed contact 14b is connected to the transmission line of the reception system. The movable contact 14c is connected to a front-stage switch (connection switching unit) 15 of the impedance matching unit 12.
Is connected via a power supply line L to the movable contact 15d.
The switching of the movable contact 14 c in the shared circuit 14 of the transmitting and receiving unit 11 causes transmission and reception signals to be transmitted to and from the impedance matching unit 12.

In the impedance matching section 12, a front-stage switch 15 and a rear-stage switch (connection switching means) 16
Between three matching circuits (matching circuits) 17 and 18
And 19 are arranged. The front-stage switch 15 and the rear-stage switch 16 each include three fixed contacts 15a, 15
b, 15c and 16a, 16b, 16c, a three-point changeover switch. Both ends of a matching circuit 17 are connected to fixed contacts 15a, 16a. Both ends of a matching circuit 18 are connected to fixed contacts 15b, 16b.
Are connected to fixed contacts 15c, 16c. The movable contact 16 d of the rear switch 16 is connected to the antenna 7.

The matching circuit 17 is a circuit for matching the impedance of the antenna 7 in a state where the portable telephone device 1 is in a free space.
This is a circuit that matches the impedance of the antenna 7 when the user holds the mobile phone device 1 with his / her hand. In addition, the matching circuit 19 controls the antenna 7 when the user is talking using the mobile phone device 1.
This is a circuit in which the impedances of the two are matched.

The switching of the front-stage switch 15 and the rear-stage switch 16 is controlled by control signals 1 and 2 output from a control circuit 8. The output states of the control signals 1 and 2 and the switches 15 and 1
The switching state of No. 6 (to which of the fixed contacts the movable contacts 15d and 16d are connected) is as follows. Control signal Connected fixed contact No output 15a, 16a Signal 1 output 15b, 16b Signal 2 output 15c, 16c

That is, in a default state in which no control signal is output, the movable contacts 15d and 16d of the switches 15 and 16 are connected to the fixed contacts 15a and 16a, and the matching circuit 17 includes the antenna 7 and the feed line L. Connected to the transmission line. When the control signal 1 is output, the movable contacts 15d and 16d
d is connected to the fixed contacts 15b and 16b, the matching circuit 18 is connected to the transmission line, and the control signal 2
Is output, the movable contacts 15d and 16d are connected to the fixed contacts 15c and 16c, and the matching circuit 1
9 is connected to the transmission line.

Next, the operation of this embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing the control contents of the portion related to the impedance matching unit 12 by the control circuit 8. The control circuit 8 first controls the touch sensor 13
It is determined whether or not the detection signal has been output (step S1). If the detection signal has not been output (“NO”), both of the control signals 1 and 2 match the impedance matching unit 1.
2 is not output (step S2).

That is, in this case, the mobile phone 1 can be assumed to be in a state where the casing 2 is not gripped by hand, such as in a standby state or a hands-free communication state. A matching circuit 17 that matches the impedance of the antenna 7 is connected to the antenna 7 and the feed line L with 1 in free space. Therefore, as long as the detection signal is not output by the touch sensor 13, the control circuit 8 waits around the loop of steps S1 and S2.

The external environment of the housing 2 of the mobile phone 1 in such a case is extremely diverse. The mobile phone device 1 may be placed on a table or the like, for example, or may be put in a user's pocket or bag by a user. Therefore, it is difficult to assume a specific environment.

When the casing 2 of the portable telephone device 1 is gripped by the user's hand while the control circuit 8 is in the loop of steps S1 and S2, the control circuit 8 returns "YES" in step S2. Judge and proceed to step S3.

In step S3, the control circuit 8 determines whether the level of the audio signal input to the microphone 4 via the audio processing unit 9 is equal to or higher than a predetermined value and it is assumed that the user is talking. Determine whether or not. If the input level of the audio signal is less than the predetermined value, the control circuit 8 determines "NO" and outputs the control signal 1 to the impedance matching unit 12 (step S4). Then, the movable contacts 15d and 16d of the switches 15 and 16 are connected to the fixed contact 1
Switching from 5a and 16a to fixed contacts 15b and 16b causes the matching circuit 18 to be connected to the antenna 7 and the feed line L.

That is, in this case, the user holds the casing 2 of the mobile phone device 1 but does not talk, and the only external factor affecting the impedance of the transmission line is the user's hand. Is assumed. Accordingly, a matching circuit 18 that matches the impedance of the antenna 7 is connected to the transmission line while the user holds the mobile phone device 1.

[0030] From the above state, the user sets the portable telephone device 1
When a call is started with the housing 2 of the
, A user's voice is input. Then
In the audio processing unit 9, since the input level of the audio signal is equal to or higher than the predetermined value, the control circuit 8 determines "YES" in step S3, and outputs the control signal 2 to the impedance matching unit 12 (step S5). . Then, the movable contacts 15d and 16d of the switches 15 and 16
Is connected from the fixed contacts 15b and 16b to the fixed contacts 15b.
Since the mode is switched to c and 16c, the matching circuit 19 is connected to the antenna 7 and the feed line L.

That is, as described above, the user can use the portable telephone 1
In a state where a telephone call is being made, the external factors that affect the impedance of the transmission line are assumed to be the user's hand and head. Therefore, in that state, a matching circuit 19 that matches the impedance of the antenna 7 is connected to the transmission line.

When the user ends the telephone conversation with the portable telephone 1, the input level of the audio signal in the audio processing unit 9 becomes lower than the predetermined value again.
It is determined as “NO” in Step S3, and the control signal 1 is output to the impedance matching unit 12 (Step S5). Further, if the user releases the housing 2 from his / her hand and places it on a table, for example, the output of the detection signal by the touch sensor 13 is also stopped.
It is determined as "NO" in step S1, and the output of the control signal is stopped (step S2), and the process returns to the initial state.

Here, FIG. 5 shows the case where the impedance of the antenna is matched with the free space (A), the case where the communication condition is maintained with the matching conditions (B), and the impedance of the antenna is matched in the communication state. (C) In each case, the VSWR (Vo in the transmission line including the antenna)
It shows an example of a measurement result of a ltage standing wave ratio (voltage standing wave ratio). The measurement frequency band is 1.5G
In the vicinity of Hz, the measurement span is about 150 MHz.

That is, (A)
On the other hand, in (B) in the talking state, the VSWR in the measurement frequency band is largely increased because the resonance point of the antenna is shifted to a lower frequency. As a result, reflection on the transmission line increases, and the gain of the antenna decreases.

[0035] In contrast to (B), in (C), which is matched to the call state, the antenna has a lower resonance point because the resonance point of the antenna has returned to the higher frequency side. In this case, the impedance in the matching circuit is changed by increasing or decreasing the capacitance or inductance of the matching circuit so as to move the resonance point of the antenna to a higher frequency.

As described above, according to the present embodiment, when the touch sensor 13 detects that the housing 2 is gripped by the user's hand, the control circuit 8 sets the antenna 7 to its external environment state. Is switched to connect to the matching circuit 18 that has performed impedance matching in accordance with
The impedance of the antenna 7 is matched according to the changed environmental condition by the matching circuit 18 which is switched and connected. Therefore, even if the environmental condition outside the housing 2 changes, it is possible to prevent the impedance of the antenna 7 from being mismatched and the gain from being reduced due to reflection loss or the like as much as possible, and to maintain a good communication condition. Can be.

When the voice processing unit 9 detects that the user is in a talking state, the control circuit 8 switches to connect the antenna 7 to a matching circuit 19 that has been matched in accordance with the state. Therefore, it is possible to readjust the impedance of the antenna 7 in accordance with the state change so as to achieve the impedance matching. Therefore, even if the external environment of the housing 2 of the mobile phone device 1 changes variously, it is possible to match the impedance of the antenna 7 as much as possible according to the state. can do.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. I will explain only. FIG. 6 is a diagram corresponding to FIG. 1, but in the impedance matching unit 20 instead of the impedance matching unit 12, the rear switch 16 is omitted, and the connection of each of the matching circuits 17 to 19 is switched only by the front switch 15. It has become. One end of each of the matching circuits 17 to 19 is connected to a line (connection switching means).
Commonly connected to the antenna 7 via 21a to 21c.

These lines 21a to 21c are connected, for example, when the matching circuit 17 is connected to the feed line L.
The other two matching circuits 1 as seen from the antenna 7
8 and 19 (fixed contact 15 of switch 15)
b, 15c) are arranged so as to be equal to an apparently open state with respect to the antenna 7 via the lines 21b, 21c.

That is, even if one end of each of the matching circuits 17 to 19 is commonly connected to the antenna 7 via the lines 21a to 21c, the antenna 7 is connected to a matching circuit other than the one connected to the feed line L. Is not affected. Other configurations are the same as in the first embodiment.

According to the second embodiment configured as described above, each matching circuit 1 is controlled only by the front-stage switch 15.
Since connection switching can be performed for the transmission lines 7 to 19, the configuration can be performed at lower cost.

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications or extensions are possible. Only one of the gripping state detecting means and the talking state detecting means may be provided, and two matching circuits may be provided. The grip state detecting means is not limited to the one that detects a change in the resistance value. The state detecting means is not limited to the gripping state detecting means and the talking state detecting means, but may be any as long as it detects that the state of the external environment of the housing 2 has changed. Therefore, three or more state detection means may be provided, or four or more matching circuits may be provided. The present invention is not limited to the mobile phone device 1 and may be applied to a PHS (Personal Handyphone System). Further, even a device such as a data communication device that does not make a call can be applied as long as it is configured to be portable.

[Brief description of the drawings]

FIG. 1 is a first embodiment in which the present invention is applied to a mobile phone device, and is a diagram showing a detailed electrical configuration centering on an impedance matching section inside the mobile phone device;

FIG. 2 is a functional block diagram showing an electrical configuration of the mobile phone device.

FIG. 3 is a perspective view showing an appearance of the mobile phone device.

FIG. 4 is a flowchart showing control contents of a control circuit.

FIG. 5 is a diagram illustrating an example of a measurement result of VSWR in a transmission line including an antenna.

FIG. 6 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

[Explanation of symbols]

1 is a mobile telephone device (wireless telephone device), 2 is a housing (main body), 8 is a control circuit (connection switching means), 9 is a voice processing unit (communication state detecting means), and 13 is a touch sensor (gripping state detecting means). ), 15 are front switches (connection switching means), 16 are rear switches (connection switching means), 17 to 17
19 is a matching circuit (matching circuit), 21a, 21b,
Reference numeral 21c denotes a line (connection switching means).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04M 1/725 H04B 7/26 BF Term (Reference) 5J021 AA01 AB03 CA06 DB04 EA04 GA08 HA05 HA10 JA02 5J047 AA01 AA02 AA03 AB06 FA12 FC05 FD01 5K011 DA02 EA06 GA05 GA06 JA01 KA13 5K027 AA11 BB03 CC08 5K067 AA23 BB04 EE02 KK00 KK01

Claims (3)

[Claims] 1. A wireless communication device which is configured to be portable and communicates with a wireless signal transmitted and received via an antenna, wherein the wireless communication device is arranged on a power supply line and matches the impedance of the antenna according to an environmental state outside the main body. A plurality of matching circuits for detecting a change in the environmental state; and at least one state detecting means for detecting a change in the environmental state. A wireless communication device comprising: connection switching means for switching connection to a matching circuit corresponding to a state. 2. The apparatus according to claim 2, wherein said state detecting means includes a gripping state detecting means for detecting a state in which the main body is gripped by a user's hand, and said connection switching means determines whether said state is gripped by said gripping state detecting means. 2. The wireless communication device according to claim 1, wherein when detected, the antenna is switched to connect to the corresponding matching circuit. 3. The communication control apparatus according to claim 2, wherein said connection switching includes a communication state detection unit configured to detect that a user is in a state of talking, said communication unit being configured to enable communication by a wireless signal. 3. The wireless communication apparatus according to claim 1, wherein the means switches the antenna to be connected to a corresponding matching circuit when the communication state is detected by the communication state detection means.