JP2003174367A - Portable radio equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide portable radio equipment capable of executing communication always matched with an antenna without being influenced by objects arranged around the antenna. <P>SOLUTION: In the portable radio equipment, the impedance of the antenna is optimized by adjusting a matching circuit connected to the antenna and having an impedance adjusting function on the basis of an antenna reflection phase outputted from a reflection phase detection circuit and a current to be supplied to a transceiver for sending a transmission signal. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless device,
In particular, the present invention relates to a portable wireless device having an integrated antenna, which can reduce the influence of an object arranged around the antenna on the antenna characteristics.

[0002]

2. Description of the Related Art In recent years, portable wireless devices have become smaller and thinner. The portable wireless device is required to be easy to carry and excellent in portability. Therefore, it is very important that the portable wireless device is small and thin.

On the other hand, in the portable wireless device, the influence of the human body on the transmission / reception by the antenna is a problem. The human body absorbs and scatters radio waves of the radio frequency used by the portable radio device. Further, the human body fluctuates the operating impedance of the adjacent antenna. This is because the human body acts as a dielectric having a very high dielectric constant of 50 or more in terms of high frequency. As a result, the radiation characteristics of the antenna deteriorate depending on the human body.

Further, as the size and thickness of wireless devices in recent years are reduced, the ear tends to be closer to the antenna. This proximity makes the deterioration of the antenna characteristics due to the human body even more serious.

Regarding the deterioration of the antenna characteristics due to the human body,
When the inventors of the present invention measured, a measurement result as shown in FIG. 1 was obtained. This experimental data shows the result of measuring the influence on the antenna of the human body by using a portable wireless device with a frequency of 2 GHz as a wireless device model. Here, FIG. 1 shows the amount of deterioration of the antenna gain due to the change of the antenna impedance when the wireless device model is in a call state, using the thickness of the wireless device housing as a parameter. As is clear from FIG. 1, when the thickness of the terminal is less than 20 mm, the ear is likely to come into contact with the antenna, and when the ear is brought into contact with the antenna, the gain of the antenna is significantly deteriorated.

As described above, the cause of this deterioration is that the impedance of the antenna fluctuates due to the influence of the human body. The human body is an object with a very high dielectric constant.
When the antenna approaches such an object, the electrical length of the antenna becomes equivalently long. In such a case, the resonance frequency of the antenna deviates from a desired value, and the impedance of the antenna changes accordingly.

As described above, even if the impedance of the antenna is adjusted to be optimum in the portable wireless device alone,
There is a problem that the impedance value deviates from the optimum value due to the proximity to the human body.

Further, the transmission output of the portable wireless device may be deteriorated due to the change in the impedance of the antenna.
This phenomenon will be described.

In order to radiate radio waves from the antenna,
First, power must be input to the antenna. The optimum condition for power input to the antenna is that the impedance of the feeder line and the impedance of the antenna have the same value.

When the impedance of the antenna fluctuates from the optimum value, the power transmitted through the feeder line is reflected at the input end of the antenna and returns to the transmission amplifier. Therefore, the power output from the amplifier is not input to the antenna.

The electric power reflected in this way deteriorates performance such as operational efficiency and gain of the amplifier, and causes deterioration of transmission performance of the radio device.

As a method for solving this, a method of examining the reflection coefficient between the antenna and the amplifier has been conventionally proposed. In this proposal, there is a power amplification device disclosed in the related art. In this conventional power amplifier, the current consumption value in the power amplifier is detected, and
The electric power reflected from the antenna is detected, and both detection signals are supplied to the control circuit. This control circuit sends a control signal to the variable phase shifter based on both detection signals to correct the phase shift generated between the antenna and the power amplifier.

In this power amplifying device, since the deviation of only the phase is the object of correction, the range of variation of the evaluation amount is narrow, and the phase deviation can be corrected by observing the evaluation amount. However, when the deviation has two vectors, that is, the phase direction and the amplitude direction of the reflection coefficient like the antenna of the mobile phone, there is a problem that the correction is difficult only with the above two evaluation amounts.

On the other hand, even when the communication is not performed, the impedance of the antenna must be checked to start the communication in a state where the communication state is deteriorated at the start of communication, which causes a communication interruption. This is because the portable wireless device has a high probability of changing the surrounding environment at the start of communication. For example, when an incoming call is received from the standby state, the terminal put in the pocket is held in the hand, set in the call state, and then pressed to the head. Here, the environment around the antenna has changed to three states in a short time.

According to the above-mentioned conventional method, the impedance can be checked only during communication depending on the system. For example, in a CDMA system, only reception is performed during standby, and the above operation cannot be performed.
Further, the unnecessary emission of electromagnetic waves except during communication is regulated by the Radio Law, which often causes trouble in other systems.

[0016]

[Patent Document 1] Japanese Patent Laid-Open No. 10-341117

[0017]

As described above,
The conventional portable wireless device has a problem in that the matching between the transmitter and the antenna is deteriorated due to the surrounding environment, particularly the proximity of the human body, and the transmission characteristics of the antenna are deteriorated.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is not influenced by an object arranged around the antenna, and communication which is always matched with the antenna is possible. Providing a portable wireless device.

[0019]

According to the present invention, a power source for supplying electric power, a transmitting circuit which is energized by the electric power to generate a transmission signal, and the electric power supplied to the transmitting / receiving circuit are detected. And a power detection circuit that generates a detected power signal, an antenna that has a certain antenna impedance, and that receives the transmission signal and that generates a reflection signal having a certain phase according to the transmission signal, and a variable impedance. And an impedance matching circuit that adjusts the variable impedance to match the antenna and the transmission circuit,
A phase detection circuit that detects the phase of a reflected signal returned from the antenna and generates a detection phase signal, and a selection circuit that selects one of the phase detection circuit and the transmission circuit and connects the selected one to the antenna. And a control circuit that controls the selection circuit to receive the power detection signal and the detection phase signal, and controls the impedance matching circuit to set a variable impedance depending on the detection phase signal and the power detection signal. A wireless device is provided.

Further, according to the present invention, a power source for supplying electric power, a first transmitting circuit which is energized by the electric power to generate a first transmitting signal, and the first transmitting circuit is supplied. A power detection circuit for detecting the power to generate a detected power signal, an antenna having a certain antenna impedance, and an antenna to which the first transmission signal is supplied, and a variable impedance, and adjusting the variable impedance. And an impedance matching circuit for matching the antenna and the first transmission circuit, and a phase detection circuit for generating a second transmission signal having a first phase and supplying the second transmission signal to the antenna. A transmitter circuit for generating a reflected signal having a second phase dependent on the second transmitted signal; and a second receiving circuit for receiving the second transmitted signal and the reflected signal. A receiving circuit for detecting a phase difference between the first and second phases to generate a phase difference signal; and a delay for the second transmitting signal from the second transmitting circuit to the antenna, A delay line that delays the reflected signal from the receiving circuit to the receiving circuit, and a circulator that distributes the delayed reflected signal to the receiving circuit and distributes the second transmission signal to the delay line and the receiving circuit. A phase detection circuit, a selection circuit that selects one of the phase detection circuit and the transmission circuit and connects the selected one to an antenna, and controls the selection circuit to output the power detection signal and the phase difference signal. And a control circuit for controlling the impedance matching circuit to set a variable impedance depending on the phase difference signal and the power detection signal. That.

Further, according to the present invention, there are provided a power source for supplying power, a transmission circuit which is energized by this power to generate a transmission signal having the first phase, and power supplied to this transmission circuit. A power detection circuit that detects and generates a detection power signal; and an antenna that has a certain antenna impedance and that is supplied with the transmission signal and that generates a reflection signal having a second phase according to the transmission signal Between the impedance matching circuit for adjusting the variable impedance to match the antenna and the transmission circuit, and the first and second phases by receiving the transmission signal and the reflection signal. A receiving circuit for detecting a phase difference and generating a phase difference signal, and a delay for the transmitting signal from the transmitting circuit to the antenna, and a signal from the antenna to the receiving circuit. A delay line for delaying a reflected signal,
A circulator that distributes the delayed reflected signal to the receiving circuit and distributes the transmission signal to the delay line and the receiving circuit,
A selection circuit that selects one of the delay line and the circulator and connects the selected one to an antenna, and controls the selection circuit to receive the power detection signal and the phase difference signal, and to form the impedance matching circuit. There is provided a radio device comprising: a control circuit that controls and sets a variable impedance that depends on the phase difference signal and the power detection signal.

Furthermore, according to the present invention, a power source for supplying a current, a first transmission circuit which is energized by this power to generate a first transmission signal having a first frequency, and the first transmission circuit. A power detection circuit that detects the power supplied to the first transmission circuit to generate a detection power signal, a certain antenna impedance, and an antenna to which the first transmission signal is supplied and a variable impedance. An impedance matching circuit that adjusts the variable impedance to match the antenna and the first transmission circuit, and a phase detection circuit that has a second frequency and a first phase.
A second transmission circuit for generating a transmission signal of and supplying the same to the antenna, wherein the antenna generates a reflection signal having a second phase depending on the second transmission signal. A receiving circuit that receives the second transmission signal and the reflection signal, detects a phase difference between the first and second phases and generates a phase difference signal, and the second transmission circuit to the antenna. Delaying the second transmission signal to
A delay line for delaying the reflected signal from the antenna to the receiving circuit; and a circulator that distributes the delayed reflected signal to the receiving circuit and distributes the second transmission signal to the delay line and the receiving circuit. A phase detection circuit including
The second transmission signal and the reflection signal are allowed to pass through to allow output and input to the antenna and the phase detection circuit, respectively, and a reflection signal is prevented from being input to the first transmission circuit.
And a control circuit for controlling the impedance matching circuit to set a variable impedance depending on the phase difference signal and the power detection signal. A wireless device is provided.

Furthermore, according to the present invention, a current is supplied to generate a transmission signal, the transmission signal is supplied to the antenna through the impedance matching circuit, and the reflection signal returned from the antenna is detected to In the impedance matching circuit that detects the phase, detects the current for the transmission signal, and compares the detected phase signal and the detected current with the reference phase and the current to determine the impedance of the impedance matching circuit and is connected to the antenna. An impedance adjusting method is provided, which comprises adjusting its impedance.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A radio device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram of a portable radio device according to an embodiment of the present invention. As shown in FIG. 1, the antenna 10
1 is connected to a matching circuit 102 having an adjusting function capable of adjusting the impedance of the antenna. The matching circuit 102 is connected to a changeover switch 103, one of the changeover switches 103 is connected to a reflection phase detection circuit 104 that detects the phase of a reflection signal reflected from an antenna, and the other is a transmission / reception unit that generates a transmission signal. Circuit 10
Connected to 5.

The transmission / reception circuit 105 is also connected to a power source 107 via an ammeter 106 for detecting the current value of the supplied power. Further, the control circuit 108 is connected to the reflection phase detection circuit 104 and the ammeter 106 to detect the phase signal and the ammeter 106 detected by the reflection phase detection circuit 104.
The detected current signal from is input. In addition, the control circuit 10
Reference numeral 8 sends a control signal to the matching circuit 102 and the switch circuit 103 to control them.

Here, the matching circuit 102 is composed of an inductance and a variable capacitance element, and the value of the impedance of the antenna 101 can be changed by changing the variable capacitance element by a control signal from the control circuit 108.

The reflected phase detection circuit 104 measures how much the phase of a signal sent from a transmission circuit (not shown) provided therein is changed by the antenna 101 by receiving the reflected signal. . As described above, the reflected signal from the terminal of the antenna 101 is changed depending on the surrounding environment of the antenna 101. This change in the reflected signal occurs based on the change in the input impedance of the antenna as already described in the related art, and can be equivalently regarded as a change in impedance. Therefore, if the correlation between the state where the antenna 101 is placed and the reflection phase Sp is checked in advance, the state where the antenna is placed can be estimated from the value of the reflection phase Sp from the antenna 101. . Also, the measured reflection phase S
From p, the adjustment of the matching circuit 102 can be determined to bring the reflection phase Sp back to the reference state. That is, the impedance of the antenna 101 can be estimated by detecting the reflected signal from the antenna 101. By changing the value of the variable capacitance element of the matching circuit 102 based on the impedance of the antenna 101, the transmission power can be maintained optimally.

Power is supplied from the power supply circuit 107 to the transmission / reception circuit 105, and the supplied power is modulated based on a digital information signal sent from an information signal generating unit (not shown), for example, a sound and an image signal, and , And is converted into a transmission frequency to generate a transmission signal, which is transmitted from the antenna 101. The antenna 101 transmits a transmission signal to the air, and a part of the transmission signal is a reflected wave to the transmission / reception circuit 10.
Returned to side 5. The reflection amount of this reflection signal is the antenna 1
It is changed by the impedance value of 01.

The impedance of the antenna 101 is changed by the environment around the antenna 101, and the reflected signal sent back is also changed. This reflected signal changes the gain and efficiency of the transmission amplifier in the transmission / reception circuit 105. Therefore, the fluctuation of the reflected signal is caused by the transmission / reception circuit 1
This will cause fluctuations in the consumption current of No. 05. The fluctuation of the consumed current is measured by the ammeter 106, and the current level SI is sent to the control circuit 108. The value of this current level SI has a strong correlation with the situation in which the antenna is placed. Therefore, this current level SI can be used as an evaluation function for adjusting the matching circuit.

The received signal received by the antenna 101 is supplied to the transmission / reception circuit 105 through the matching circuit 102 and the changeover switch 103. As for the processing of the received signal, the processing of the ordinary wireless terminal or base station is applied, and therefore the description of the processing of the received signal is omitted.

Next, the operation of the control circuit 108 will be described with reference to the flowchart shown in FIG.

First, the movable contact of the switch 102 is changed to the first fixed contact Sa by the control signal from the control circuit 108.
And a phase detection mode for detecting the phase of the reflected signal is set (step S1). Next, the phase detection circuit 1
A phase detection signal is sent from the transmission circuit (not shown) in 04 to the control circuit 108, and the phase Sp of the reflected signal from the antenna 101 is detected (step S2).

Next, the movable contact of the switch 102 is the second contact.
The current detection mode for connecting to the fixed contact Sb and detecting the transmission current is set (step S3). Therefore, the transmission power is supplied to the transmission / reception circuit 105,
The transmission signal is supplied from the antenna 101 to the ammeter 10
The current level SI of the power supplied to the transmission / reception circuit 105 is detected by 6 (step S4). The phase Sp and the current level SI of the reflected signal are given to the control circuit 108, and the phase Sp and the current level SI are compared with predetermined reference values Sp0 and SI0 (step S).
5). The reference values Sp0 and SI0 are measured in advance in a state where no other object approaches the antenna 101, and are stored in the storage circuit therein.

When the phase Sp and the current level SI deviate from the predetermined reference values Sp0 and SI0, the matching circuit 102 is adjusted. (Step S6) After this adjustment, the phase Sp and the current value SI of the reflected signal are similarly measured, and the evaluation is repeated. This detection phase S
p and the detected current level SI are predetermined reference values Sp
The same adjustment and measurement are repeated until 0 and SI0 are reached, and when the phase Sp and the current level SI reach predetermined reference values Sp0 and SI0, in the transmission / reception mode,
Communication using the transmission / reception circuit 105 is started (step S7).

As described above, since communication is started after the antenna impedance is set to the optimum state, the influence of the surroundings where the wireless terminal is used is reduced, and the communication can be started in the optimum state. it can.

Next, another control method in the circuit shown in FIG. 2 will be described with reference to the flow chart shown in FIG.

First, the movable contact of the switch 102 is connected to the fixed contact Sa by the control signal from the control circuit 108 to set the phase detection mode for detecting the phase of the reflected signal (step S11). Next, the phase detection circuit 110
A transmission signal from a transmission circuit (not shown) is transmitted, a reflection signal from the antenna 101 is detected, and the phase Sp of the reflection signal is detected (step S12).

Next, a method for adjusting the matching circuit 102 is determined based on the value of the detection phase Sp (step S1).
3). In this step 13, when the current level Sp is compared with the reference value Sp0, a method of adjusting the capacitance element of the matching circuit according to the phase amount Sp, that is, whether to increase or decrease the capacitance is determined. When the deviation of the phase Sp of the reflected signal is large depending on the design of the amplifier that constitutes the transmission / reception circuit, when the capacitance of the capacitance element of the matching circuit is increased to approach the reference value, or when the capacitance element of the matching circuit is changed. The capacity may be reduced to a reference value and the method is determined.

When the policy of the adjusting method is determined, the switch 10
The movable contact 3 is connected to the second fixed contact Sb, and the phase detection mode for detecting the phase of the reflected signal is set (step S14). Next, the ammeter 106 detects the current level SI (step S15). Then, each current level SI is compared with the reference value SI0 (step S16). This reference value SI0 is previously measured and stored in a state where no other object approaches the antenna 101 as described above.

If the current level SI deviates from the reference value SI0, the matching circuit 102 is adjusted (step S1).
7) Further, the measurement and evaluation of the current value SI are repeated. This is repeated until the current level SI reaches the reference value SIO.
Communication is started (step S18).

Therefore, in such control, the matching circuit 102 is adjusted by using only the current value SI as the evaluation function. Therefore, the time used for adjustment can be reduced.

As described above, in this embodiment, the communication performance of the wireless device when a human body or other object approaches the antenna can be improved.

FIG. 5 shows a specific circuit configuration of the phase detection circuit 104 of the portable wireless device shown in FIG. 5 is the same as the circuit shown in FIG. 2 except for the phase detection circuit 104, and therefore its explanation is omitted.

As shown in FIG. 5, the phase detection circuit 104 is
A transmission circuit 104-1 for transmitting a signal for measuring the phase of the reflection signal and a reception circuit 104-2 for receiving the reflection signal as a reflected wave reflected from the antenna 101 are provided. The transmitting circuit 104-1 and the receiving circuit 10
4-2 is connected to the circulator 104-3. Further, the circulator 104-3 includes the delay line 104.
It is connected to the switch 103 via -4.

The transmitting circuit 104-1 and the receiving circuit 10
4-2 includes a circuit for phase modulation and demodulation. The circulator 104-3 sends the transmission signal S1 from the transmission circuit 104-1 to the reception circuit 104-2, and also transmits the transmission signal generated from the transmission circuit 104-1 via the delay line 104-4 to the antenna 101. Send, delay line 104-4
The reflected signal reflected from the antenna 101 is supplied to the receiving circuit 104-2 via the. That is, the circulator 10
4-3 selectively receives the transmission signal from the transmission circuit 104-1 and the reflection signal from the antenna 101.
It supplies to 2. Further, the delay line 104-4 uses a device such as a surface acoustic wave filter to give a delay of a relatively long time to a transmission signal toward the antenna 101 and a reflection signal from the antenna.

The receiving circuit 104-2 has a circuit configuration as shown in FIG. 6 as an example. This receiving circuit 104
2 is a demodulation circuit 104 that detects and demodulates a transmission signal or a reflection signal from the circulator 104-3.
-2A, the phase of the transmission signal or the reflection signal demodulated by the demodulation circuit 104-2A is stored in the storage circuit 104-2.
It is stored in B as phase information. The stored phase information of the transmission demodulated signal and the stored phase information of the reflected demodulated signal are given to the comparison circuit 104-2C, and the phase difference between the two is detected.
The detected phase difference signal is supplied to the control circuit 108.

Next, the operations of the receiving circuit 104 and the control circuit 108 having the phase detecting function shown in FIGS. 5 and 6 will be described with reference to the flow chart shown in FIG. The first step is phase detection in the free space state of the antenna 101 to determine the phase reference value. The following operations are executed when there is no object near the antenna.

First, the control signal S from the control circuit 108
The movable contact of the switch 102 is connected to the fixed contact Sa by s, and the phase detection mode for detecting the phase of the reflected signal is set (step S21). Next, the transmission circuit 104-
A transmission signal is transmitted from 1. At this time, the signal is not modulated and the pulse width is set to be half or less of the delay time of the delay line 104-4.

A part of the transmitted signals S1
Circulator 10 so that the remaining transmission signal S2 is sent directly to the receiving circuit 104-2 and to the delay line 104-4 side.
4-3 is adjusted in advance. Receiver circuit 104-2
Detects the transmission signal S1 and demodulates it, collects the phase information P1 thereof, and starts measuring the time from the start of receiving the transmission signal S1 (step S23).

The transmission signal S2 sent to the delay line 104-4
Is the delay line 104-4, the switch 103, the matching circuit 10
2 is sent to the antenna 101. Then, in this antenna 101, the transmission signal is transmitted to the matching circuit 102.
Is reflected according to the impedance difference between the antenna 101 and the antenna 101. The reflected signal S2 is passed through the matching circuit 102, the switch 103, and the delay line 104-4 to the circulator 1
04-3, and is input to the receiving circuit 104-2 by the circulator 104-3. Receiver circuit 104-2
Then, similarly, the reflected signal S2 is detected and demodulated to obtain the phase information P2 of the reflected signal S2 (step S
24).

At this time, in order to confirm that it is the reflected signal S2, the time measured from the time when the transmission signal S1 is received is used. That is, the round-trip delay time given by the delay line 104-4 is measured in advance, and the input signal received after the elapse of the time is determined to be the reflected signal S2 reflected from the antenna. Here, the delay line 104
Since the signal S2 is delayed by -4, no interference occurs between the reflected signal S2 and the transmitted signal S1.

In the comparison circuit 104-2C, the phase information P1 of the transmission signal S1 and the phase information P2 of the reflection signal S2 are obtained.
Are compared and the information P of the phase difference is given to the control circuit 108. The control circuit 108 stores the phase difference P representing the free space state of the antenna in the memory therein as a reference (step S25). The reference is determined as described above. Next, a measurement sequence in an actual state will be described. First, the phase measurement, which is measured in the same way as the reference. Therefore, the description up to S25 is omitted because it is the same. The control circuit compares the measured phase with the reference (step S26).

Next, the policy of the adjusting method of the matching circuit 102 is determined from the compared phase values (step S2).
7). As described above, the policy of this adjustment is to determine the adjustment method of the capacitive element of the matching circuit, that is, whether to increase or decrease the capacitance, according to the phase of the reflected signal in comparison with the reference value of the current value. is there. Depending on the design of the amplifier that configures the transmitter / receiver circuit, when the phase shift of the reflected wave is large, increase the capacitance of the matching circuit's capacitance element to approach the reference value, or reduce the capacitance of the matching circuit's capacitance element. The standard value may be approached and the method is decided.

When the policy is determined, the movable contact of the switch 103 is connected to the fixed contact Sb to set the current detection mode for detecting the transmission current (step S28). Next, the ammeter 106 detects the current level SI (step S29). Then, the current level SI is compared with the reference value SI0 (step S30). This reference value SI0 is measured in advance in the state where no other object approaches the antenna 101 as described above.

If the current level SI deviates from the reference value SI0, the matching circuit 102 is adjusted by Sm (step S31), and the measurement and evaluation of the current value SI are repeated. This is repeated until the current level SI reaches the reference value SIO, and when it reaches the reference value, communication using the transmission / reception circuit 105 in the transmission / reception mode is started (step S3).
2).

In this way, the communication performance of the radio can be improved when a human body or other object approaches the antenna.

The phase detection circuit 108 and the transmission / reception circuit 10
The frequencies used by 5 need not match exactly. The effects of the invention can be obtained if the frequencies are relatively similar.

If the frequency used in the reflection phase detection circuit 108 is the frequency in the IMS band (2.4 GHz), the signal leaked from the antenna 101 does not adversely affect other radios, which is advantageous. Is.

FIG. 8 shows a circuit of a portable terminal according to another embodiment of the present invention, in which the transmission section 104-1 which constitutes the phase detection circuit 104 shown in FIG. 5 is shared by the transmission / reception circuit 105. That is, when the impedance of the antenna 101 is adjusted, the transmission signal from the transmission / reception circuit 105 is used to detect the reflected wave from the antenna.

With such a circuit configuration, the portable wireless device can be downsized.

FIG. 9 shows a circuit of a portable terminal according to still another embodiment of the present invention. In the circuit shown in FIG. 9, a duplexer 110 is used in place of the switch 102 in the portable wireless device shown in FIG. This shared device 110
Is constituted by, for example, a filter, and by making the frequency F1 of the transmission signal SF1 generated from the phase detection circuit 104 and the frequency F2 of the transmission signal SF2 generated from the transmission / reception circuit 105 different, It will have such a function. That is, since the reflected wave generated from the phase detection circuit 104 and reflected from the antenna has the frequency F1, the duplexer 1
The reflected wave that is supplied to the phase detection circuit 104 via 10 and is generated from the transmission / reception circuit 105 and reflected from the antenna has the frequency F2, so is supplied to the phase detection circuit 104 via the duplexer 110. Is prevented. Here, as the operating frequency F1, for example, if a radio device in which the ISM band (2.4 GHz band) is generated from the phase detection circuit 104 is used, the antenna of the radio device does not adversely affect other radio devices. Check the state, matching circuit 1
02 can be adjusted.

Further, FIG. 10 shows a circuit configuration of a portable radio device according to another embodiment of the present invention. In FIG. 10, in addition to the first antenna 101, the second antenna 10
1-2 is provided, and the first antenna 101 and the switch 1 are provided.
2 in place of the matching circuit 102 arranged between
The matching circuit 10 between the antenna 101-2 of the
2 are arranged. The second antenna 101-2 is called a parasitic element, and the second antenna 101-2 is used.
Are electromagnetically coupled to the first antenna 101 by controlling the impedance of the matching circuit 102. This first
If the antenna 101 and the second antenna 101-2 are combined, the characteristics of the second antenna 101-2 are changed. Therefore, even if the antenna 101 shown in FIG. 10 approaches the human body and its antenna characteristics change, the control circuit 108 causes the matching circuit 10 to operate in the same manner as described in the other embodiments.
If 2 is controlled and its impedance is changed, communication is realized with appropriate antenna characteristics. Matching circuit 102
Needs to be between the root of the second antenna 101-2 or the tip of the antenna 101-2 and the ground. In this method, the antenna 101 and the transmission / reception circuit 10
Since the matching circuit 102 does not enter between 5, the matching circuit 10
There is an advantage that the deterioration of gain due to the loss of 2 does not occur.

Although the above-mentioned embodiments describe the portable terminal, it is obvious that the present invention can be applied not only to the portable terminal but also to various radio equipment having an antenna, for example, a base station. Is.

Further, in the above-mentioned embodiment, a single matching circuit is used which is a combination of a capacitor element and an inductance whose capacitance value changes by applying a bias voltage such as a varactor diode. However, the circuit of the wireless device may include a plurality of matching circuits each having a fixed capacitor element and an inductance, and a high frequency switch for switching the matching circuits under the control of the control circuit.
With such a circuit configuration, the same effect as when the matching circuit is controlled can be obtained.

In the above-described embodiment, the ammeter 106 is used.
Is used to evaluate the power supplied to the transceiver circuit 105 which is driven at a substantially constant and relatively low voltage. If the transceiver circuit 105 is driven with a variable voltage instead of this substantially constant and relatively low voltage, then a power meter must be utilized, or the current supplied to the transceiver circuit 105 can be reduced. Not only the ammeter to measure,
It is required that the power be calculated from the voltage and current using a voltmeter that measures the voltage applied to the transceiver circuit 105.

[0067]

As described above, according to the present invention, there is provided a portable wireless device which is not affected by an object arranged around the antenna and is always capable of communicating with the antenna.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between a thickness of a mobile wireless device and an antenna mismatch loss.

FIG. 2 is a block diagram schematically showing a circuit of a portable wireless device according to an embodiment of the present invention.

3 is a flowchart showing an operation of the portable wireless device shown in FIG.

FIG. 4 is another flowchart showing the operation of the portable wireless device shown in FIG.

FIG. 5 is a block diagram schematically showing a circuit of a portable wireless device according to another embodiment of the present invention.

6 is a block diagram schematically showing a circuit example of the receiving circuit shown in FIG.

7 is a flowchart showing an operation of the portable wireless device shown in FIGS. 5 and 6. FIG.

FIG. 8 is a block diagram schematically showing a circuit of a portable wireless device according to still another embodiment of the present invention.

FIG. 9 is a block diagram schematically showing a circuit of a portable wireless device according to still another embodiment of the present invention.

FIG. 10 is a block diagram schematically showing a circuit of a portable wireless device according to still another embodiment of the present invention.

[Explanation of symbols]

101. ． ． antenna 102. ． ． Matching circuit 103. ． ． Changeover switch 102. ． ． switch 104. ． ． Reflection phase detection circuit 104-1. ． ． Transmission circuit 104-2. ． ． Receiver circuit 104-3. ． ． Circulator 104-4. ． ． Delay line 105. ． ． Transceiver circuit 106. ． ． Ammeter 107. ． ． Power supply circuit 108. ． ． Control circuit 110. ． ． Shared device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasushi Murakami             One share at 3-1, Asahigaoka, Hino City, Tokyo             Ceremony Company Toshiba Hino Factory (72) Inventor Kisho Odate             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Kazuhiro Inoue             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Akihiro Tsujimura             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Yuji Iseki             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Keiichi Yamaguchi             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Naoko Ono             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Hiroyuki Kayano             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center F-term (reference) 5K011 DA02 DA29 EA02 EA06 JA01                       KA04                 5K060 CC04 CC12 DD04 HH34 HH39                       JJ03 JJ04 JJ18 JJ21 LL07                       LL28 PP05

Claims (24)

[Claims] 1. A power source for supplying power, a transmission circuit which is energized by the power to generate a transmission signal, and a power detection circuit which detects the power supplied to the transmission / reception circuit and generates a detection power signal. An antenna that has a certain antenna impedance and that generates a reflected signal having a certain phase in response to the transmission signal when the transmission signal is supplied; and an antenna that has a variable impedance, and adjusts the variable impedance to An impedance matching circuit that matches an antenna and the transmission circuit, a phase detection circuit that detects a phase of a reflected signal returned from the antenna to generate a detection phase signal, and one of the phase detection circuit and the transmission circuit is selected. And a selection circuit that connects the selected one to an antenna, and controls the selection circuit to receive the power detection signal and the detection phase signal, And a control circuit for controlling the impedance matching circuit to set a variable impedance depending on the detection phase signal and the power detection signal. 2. The control circuit generates first and second selection signals and supplies the first and second selection signals to the selection circuit, and the selection circuit responds to the first selection signal by controlling the phase of the adjustment circuit. The radio device according to claim 1, wherein the radio circuit is connected to a detection circuit, and the adjustment circuit is connected to the transmission circuit in response to the second selection signal. 3. The control circuit holds a reference phase signal and a reference power signal, and adjusts the adjustment circuit according to a comparison between the detection phase signal and the reference phase signal and a comparison between the reference power signal and the detection power signal. The wireless device according to claim 1, wherein: 4. The control circuit determines an adjusting method of an adjusting circuit according to the comparison between the detected phase signal and the reference phase signal, and compares the detected current value with the reference current value to specify the adjusting circuit. The radio device according to claim 3, wherein impedance is set. 5. The radio device according to claim 4, wherein the adjusting method corresponds to one of an increase and a decrease in impedance. 6. The radio device according to claim 1, further comprising a second antenna connected to the impedance matching circuit, wherein the first and second antennas are electromagnetically coupled. 7. A power source for supplying electric power, a first transmitting circuit which is energized by the electric power to generate a first transmitting signal, and the electric power supplied to the first transmitting circuit is detected. A power detection circuit that generates a detection power signal, an antenna that has a certain antenna impedance and is supplied with the first transmission signal, and a variable impedance, and adjusts the variable impedance to provide the antenna and the antenna. An impedance matching circuit for matching the first transmitting circuit; and a phase detecting circuit, wherein the second transmitting circuit generates a second transmitting signal having a first phase and supplies the second transmitting signal to the antenna, A second transmitting circuit for generating a reflected signal having a second phase in which the antenna has a second phase depending on the second transmitted signal; and the first and second phases for receiving the second transmitted signal and the reflected signal. When A receiver circuit for detecting a phase difference between the two and generating a phase difference signal; and delaying the second transmission signal from the second transmitter circuit to the antenna to reflect the reflection from the antenna to the receiver circuit. A delay line for delaying the signal, and a circulator that distributes the delayed reflected signal to the receiving circuit and distributes the second transmission signal to the delay line and the receiving circuit; A selection circuit for selecting one of a circuit and the transmission circuit and connecting the selected one to an antenna; and controlling the selection circuit to receive the power detection signal and the phase difference signal and control the impedance matching circuit. And a control circuit for setting a variable impedance that depends on the phase difference signal and the power detection signal. 8. The control circuit generates first and second selection signals and supplies the first and second selection signals to the selection circuit, and the selection circuit responds to the first selection signal by controlling the phase of the adjustment circuit. 8. The radio device according to claim 7, wherein the radio circuit is connected to a detection circuit, and the adjustment circuit is connected to the first transmission circuit in response to the second selection signal. 9. The control circuit holds a reference phase difference signal and a reference power signal, and controls the adjustment circuit according to a comparison between the phase difference signal and the reference phase signal and a comparison between the reference power signal and the detected power signal. The radio device according to claim 7, wherein the radio device is adjusted. 10. The control circuit determines an adjusting method of an adjusting circuit according to the comparison between the detected phase difference signal and the reference phase difference signal, compares the detected current value and the reference current value, and adjusts the adjusting circuit. 10. The wireless device according to claim 9, wherein a specific impedance is set for the wireless device. 11. The decision adjustment method corresponds to one of an increase and a decrease in impedance.
Radio. 12. The method according to claim 7, further comprising a second antenna connected to the impedance matching circuit, wherein the first and second antennas are electromagnetically coupled.
Radio. 13. A power source for supplying power, a transmission circuit which is energized by the power to generate a transmission signal having a first phase, and a power signal detected by detecting the power supplied to the transmission circuit. A power detection circuit for generating, an antenna having a certain antenna impedance, being supplied with the transmission signal and generating a reflected signal having a second phase in response to the transmission signal, and having a variable impedance, An impedance matching circuit that adjusts the variable impedance to match the antenna and the transmission circuit, and receives the transmission signal and the reflection signal to detect a phase difference between the first and second phases. A receiving circuit that generates a phase difference signal, delays the transmitting signal from the transmitting circuit to the antenna, and delays the reflected signal from the antenna to the receiving circuit. A delay line, a circulator that distributes the delayed reflected signal to a receiving circuit, and distributes the transmission signal to the delay line and the receiving circuit, and selects one of the delay line and the circulator to select the selected one. A selection circuit connected to an antenna, and the selection circuit is controlled to receive the power detection signal and the phase difference signal, and the impedance matching circuit is controlled to set a variable impedance depending on the phase difference signal and the power detection signal. A radio device comprising: a control circuit for controlling. 14. The control circuit generates first and second selection signals and supplies the first and second selection signals to the selection circuit, and the selection circuit responds to the first selection signal by causing the adjustment circuit to perform the adjustment. 14. The radio device of claim 13, wherein the radio circuit is connected to a delay line, and the adjusting circuit is connected to the circulator in response to the second selection signal. 15. The control circuit holds a reference phase signal and a reference power signal, and adjusts the adjustment circuit according to a comparison between the detection phase signal and the reference phase signal and a comparison between the reference power signal and the detection power signal. 13. The wireless device according to claim 12, wherein 16. The control circuit determines an adjusting method of the adjusting circuit according to the comparison between the detected phase signal difference and the reference phase difference value, compares the detected current value with the reference current value, and determines the current value as the reference value. The specific impedance is set in the adjusting circuit according to the determination adjusting method so that the value becomes a value.
5 radios. 17. The method according to claim 16, wherein the decision adjusting method corresponds to one of an increase and a decrease in impedance.
Radio. 18. The apparatus according to claim 1, further comprising a second antenna connected to the impedance matching circuit, wherein the first and second antennas are electromagnetically coupled.
3 radios. 19. A power source for supplying a current, a first transmission circuit which is energized by the power to generate a first transmission signal having a first frequency, and a first transmission circuit which is supplied to the first transmission circuit. A power detection circuit for detecting the power to generate a detected power signal, an antenna having a certain antenna impedance, and the antenna to which the first transmission signal is supplied, a variable impedance, and adjusting the variable impedance And an impedance matching circuit for matching the antenna with the first transmission circuit, and a phase detection circuit for generating a second transmission signal having a second frequency and a first phase to the antenna. A second transmitter circuit for providing a second transmitter circuit, wherein the antenna is dependent on the second transmitter signal.
A second transmission circuit that generates a reflection signal having a phase of 1 and a second transmission circuit that receives the second transmission signal and the reflection signal
And a receiving circuit for detecting a phase difference between the second phase and a second phase to generate a phase difference signal, delaying the second transmission signal from the second transmitting circuit to the antenna, A delay line for delaying the reflected signal to the receiving circuit; and a circulator that distributes the delayed reflected signal to the receiving circuit and distributes the second transmission signal to the delay line and the receiving circuit. A circuit, allowing the output and the input to the antenna and the phase detection circuit by passing the second transmission signal and the reflection signal, respectively, and blocking the input of the reflection signal to the first transmission circuit;
And a control circuit for controlling the impedance matching circuit to set a variable impedance depending on the phase difference signal and the power detection signal. Radio to do. 20. The control circuit holds a reference phase difference signal and a reference power signal, and controls the adjustment circuit according to a comparison between the phase difference signal and the reference phase signal and a comparison between the reference power signal and the detected power signal. 20. The radio of claim 19, wherein the radio is adjusted. 21. The control circuit determines an adjusting method of an adjusting circuit according to the comparison between the detected phase difference signal and the reference phase difference signal, compares the detected current value with the reference current value, and adjusts the adjusting circuit. 20. The wireless device according to claim 19, wherein a specific impedance is set in the. 22. The decision adjusting method corresponds to one of an increase and a decrease in impedance.
Radio. 23. A second antenna connected to the impedance matching circuit, further comprising a second antenna, wherein the first and second antennas are electromagnetically coupled.
9 radios. 24. An electric current is supplied to generate a transmission signal, the transmission signal is supplied to an antenna through an impedance matching circuit, the reflected signal returned from the antenna is detected, and the phase thereof is detected. For adjusting the impedance in the impedance matching circuit connected to the antenna by determining the impedance of the impedance matching circuit by comparing the detected phase signal and the detected current with the reference phase and the current, respectively. Characteristic impedance adjustment method.