JPH0969787A - Radio equipment and transmission output control method for radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the operation time or a radio equipment by extending the use time of a battery without extremely the current quantity of the current which is made flow at the time of reduction of the voltage value of the battery. SOLUTION: This method is provided with a voltage detection means 21, which detects one of plural arbitrarily determined voltage values of the battery, and a storage means 22, which stores plural battery voltage data corresponding to arbitrarily determined voltage values of the battery and reads out battery voltage data corresponding to the voltage value detected at present, and consists of a reference voltage generation means 23 which selectively generates a reference level corresponding to read-out battery voltage data, an error voltage detection means 13 which compares the generated reference level and the value of a low frequency signal obtained from the transmission output to output the difference, and means 14, 10, and 11 which control the transmission output based on the difference and transmit it. Thus, the value of the transmission output is changed and set to a value corresponding to each value of the reference level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless device such as a mobile phone, and more particularly to a wireless device which controls a transmission output when the voltage of a battery used decreases.

[0002]

2. Description of the Related Art Conventionally, as a radio device for controlling the transmission output when the battery voltage drops, there is a radio device as shown in FIGS. FIG. 3 is a block diagram showing a configuration of a wireless device having a conventional transmission output control means, and FIG. 4 is a graph diagram of a battery voltage of the wireless device shown in FIG.

In FIG. 3, reference numeral 51 is a wireless device such as a mobile phone, 10 is a power amplifier for amplifying the power of the second high frequency signal 31 to be transmitted, and outputting a third high frequency signal (transmission wave) 32, and 11 is A directional coupler that propagates the third high-frequency signal (transmission wave) 32 received from the power amplifier 10 only in the direction in which it is transmitted from the antenna 16 and outputs a part thereof as a fourth high-frequency signal 33 for feedback. Reference numeral 12 is a detection means for separating the fourth high frequency signal 33 into a low frequency signal and a carrier wave and outputting a low frequency signal 34, 13
Is an error voltage detecting means for comparing the voltages of the low-frequency signal 34 and the reference signal 36 (described later), producing the difference, amplifying the difference, and outputting the error component signal 35.

Further, 14 is a gain control means for amplifying the voltage of the first high frequency signal (modulation wave) 30 based on the control of the error component signal 35, and 15 is a low frequency signal such as voice to be transmitted and a carrier wave. Modulating means for synthesizing or modulating and outputting the first high-frequency signal 30, 16 is an antenna for radiating the third high-frequency signal 32 to be transmitted from the wireless device 51 to the free space, and 17 is a constant voltage power supply means such as a voltage regulator. A reference voltage generating means for generating a reference signal 36 having a predetermined reference voltage value for the error voltage detecting means 13 including
Is a battery that supplies electric power to drive the wireless device 51. The detection unit 12, the error voltage detection unit 13, the gain control unit 14, and the reference voltage generation unit 17 form a transmission output control unit that responds to the voltage drop of the battery.

Next, in FIG. 4, V1 is a wireless device 51.
Is the maximum operating voltage value within the range of the voltage value of the battery 20 that can operate the V.sub.2, and V2 is the minimum operating voltage value. When the voltage value of the battery 20 is within the range of the maximum operating voltage value V1 and the minimum operating voltage value V2, I1 is a set value for each unit in the wireless device 51, and I1 is a value when the battery voltage is the maximum operating voltage value V1. The amount of current flowing through the power amplifier 10,
I2 is the amount of current flowing through the power amplifier 10 when the battery voltage is the minimum operating voltage value V2, and P1 is the reference voltage generating means 17
The transmission output of the third high frequency signal (transmission wave) 32 output from the antenna 16 corresponding to the reference level 1 when the value of the reference signal 36 output from the reference level 1 is shown.

Next, with reference to FIGS. 3 and 4, the operation of the conventional wireless device 51 will be described. First, battery 2
A case where 0 is the fully charged state, that is, a case where the voltage value of the battery 20 is the maximum operating voltage value V1 will be described. The first high-frequency signal (modulation wave) 30 generated by combining or modulating a low-frequency signal such as a voice signal and a data signal and a carrier signal in the modulator 15 is amplified in the gain controller 11 by a voltage. Second high frequency signal 31
Is converted to The power of the second high frequency signal 31 is amplified by the power amplifier 10 and converted into a third high frequency signal (transmission wave) 32. This third high frequency signal (transmitted wave) 32 is transmitted via the directional coupler 11 to the antenna 1
Radiation from 6 to free space.

On the other hand, the directional coupler 11 includes an antenna 16
The fourth high-frequency signal 33 having a minute level that does not affect the transmission output of the third high-frequency signal (transmission wave) 32 radiated from the output is output to the detection means 12. This fourth
The transmission of the high frequency signal 33 is for negative feedback in order to keep the transmission output of the third high frequency signal (transmission wave) 32 constant, as described later. The detection means 12 that has received the fourth high-frequency signal 33 causes the fourth high-frequency signal 3
3 is separated into a low frequency signal 34 and a carrier wave, and the low frequency signal 3
4 is sent to the error voltage detecting means 13.

On the other hand, the reference voltage generating means 17 generates the reference signal 36 of the reference level 1 having a predetermined value with respect to the transmission output of the third high frequency signal (transmission wave) 32 generated by the voltage regulator or the like. It is output to the error voltage detection means 13. The error voltage detection means 13 compares the low frequency signal 34 with the reference signal 36, amplifies the difference, and outputs the error component signal 3
5 is output to the gain control means 14. The gain control means 14 controls the voltage gain by the antenna 16
The value of the transmission output of the third high-frequency signal (transmission wave) 32 radiated from is adjusted to be held at P1. As a result, the amount of current flowing into the power amplifier 10 at that time is I1.
Becomes

Next, the case where the voltage value of the battery 20 drops from the maximum operating voltage value V1 to the minimum operating voltage value V2 will be described. At this time, the value of the transmission output of the third high frequency signal (transmission wave) 32 output from the antenna 16 temporarily decreases. However, in the error voltage detecting means 13, when the value of the low frequency signal 34 from the detecting means 12 whose value has decreased and the value of the reference level 1 of the reference signal 36 are compared, the difference increases. Therefore, the value of the error component signal 35 output from the error voltage detection means 13 becomes high. The value of the voltage gain of the gain control means 14 that receives the increased error component signal 35 also increases, and the amount of current flowing into the power amplifier 10 increases to I2.

As a result, the transmission output of the third high frequency signal (transmission wave) 32 radiated from the antenna 16 is held at P1. That is, when the voltage value of the battery 20 drops from the maximum operating voltage value V1 to the minimum operating voltage value V2, the amount of current flowing into the power amplifier 10 increases from I1 to I2, and the third high frequency signal (transmission wave) 32 Send output as P1
Try to keep constant.

[0011]

However, in the above-described conventional wireless device, when the voltage value of the battery is lowered, the third high frequency signal (transmitted wave) radiated from the antenna is transmitted.
The reference level to be compared with the low-frequency signal value fed back from the transmission output in order to keep the transmission output of (1) constant (P1) was always constant. Therefore, the amount of current flowing into the power amplifier is increased from I1 to I2 to correspond to it. Therefore, when the voltage value of the battery decreases, the amount of current flowing into the power amplifier correspondingly increases in inverse proportion to the decrease in the voltage value. There was a problem that the operating time was also shortened.

The present invention has been made in view of the conventional problems described above, and does not excessively increase the amount of current flowing into the power amplifier even when the voltage value of the battery decreases.
An object of the present invention is to provide a wireless device whose operating time is improved by extending the usable time of the battery.

[0013]

In order to achieve the above-mentioned object, a wireless device according to the present invention has a power amplifier for amplifying the power of a high frequency signal and a power amplifier for propagating the high frequency signal in a transmission direction and for feedback. A directional coupler for outputting a high frequency signal, a detection means for separating a fed back high frequency signal into a low frequency signal and a carrier wave, and an error component signal composed of the difference between the low frequency signal and the reference level of the reference signal. Error voltage detection means, a modulation means for synthesizing a low frequency signal such as voice and a carrier wave and outputting a high frequency signal (modulation wave), and the high frequency signal (modulation wave) based on the control of the error component signal. Gain control means for controlling the voltage gain that amplifies the voltage of the power amplifier to control the current flowing through the power amplifier, an antenna that radiates a high frequency signal (transmission wave) to the free space, and power. A wireless device including a battery to be supplied, further including reference level changing means for changing the reference level in response to a voltage drop of the battery, when the voltage value of the battery reaches any predetermined value. The reference level is changed to reduce the output power of the high frequency signal output from the directional coupler.

In the wireless device according to the present invention, in order to achieve the above-mentioned object, the reference level changing means detects the voltage value of the battery, and a plurality of arbitrarily determined voltage values of the battery. Storage means for storing a plurality of battery voltage data corresponding to each and reading battery voltage data corresponding to the detected voltage value in response to detection of one of the arbitrarily determined voltage values; A reference voltage generating means for outputting a reference signal of a reference level corresponding to the voltage data, and changing the reference level when the voltage value of the battery reaches one of the predetermined values. It is a feature.

Further, in order to achieve the above-mentioned object, the method for controlling the transmission output of a wireless device according to the present invention detects one of a plurality of arbitrarily determined battery voltage values, and selects any of the stored batteries. Reads the battery voltage data corresponding to the voltage value detected from the multiple battery voltage data corresponding to each voltage value specified in, and supports the battery voltage data read from each reference level corresponding to the multiple battery voltage data. The selected reference level is generated, the generated reference level is compared with the value of the low-frequency signal obtained from the transmission output, the difference is output, and the transmission output is controlled based on the difference. The transmission output value is changed and set to a value corresponding to each value of the reference level.

That is, in order to achieve the above-mentioned object, the wireless device according to the present invention propagates only the power amplifier for amplifying the power of the high frequency signal and the direction of transmitting the high frequency signal from the antenna, and feeds back a part thereof. A directional coupler for outputting, a detection means for separating the high frequency signal into a low frequency signal and a carrier wave and outputting the low frequency signal,
An error voltage detecting means for comparing the voltage of the input low frequency signal and the voltage of the reference signal, outputting the difference and amplifying the difference to output an error component signal, and a low frequency signal such as voice and a carrier wave for synthesizing a high frequency signal (modulation). Wave), a gain control means for amplifying the voltage of the high frequency signal (modulated wave) to control the current flowing through the power amplifier based on the control of the error component signal, and a high frequency signal to be transmitted from the wireless device. An antenna that radiates (transmitted wave) to a free space, and a battery that supplies power to drive a wireless device,

Further, voltage detecting means for detecting a voltage value of the battery and outputting a voltage detection signal including voltage value data corresponding to each of the plurality of voltage values, and a battery corresponding to each of the plurality of voltage value data. A storage unit that stores the voltage data and reads out the battery voltage data corresponding to the received voltage detection signal and outputs it to the reference voltage generation unit, and a predetermined reference level for each of a plurality of voltage values to be detected by the battery ( Configured to select or set the reference voltage value)
A reference voltage generating means for selecting or setting a reference signal having a reference level corresponding to the battery voltage data based on the battery voltage data received from the storage means and outputting the reference signal to the error voltage detecting means; Or, when it drops, the battery voltage data corresponding to the changed voltage value is read from the storage means and supplied to the reference voltage generating means, and the reference voltage of the reference level corresponding to the battery voltage data is detected from the reference voltage generating means as the error voltage. The transmission output of the high frequency signal supplied to the means and radiated from the antenna is controlled.

The wireless device according to the present invention is configured as described above, and when the voltage value of the battery fluctuates or drops, the reference level of the reference signal is changed or changed in response to the fluctuation or drop of the voltage value. By lowering the amount of current flowing into the power amplifier and reducing the transmission output of the high frequency signal radiated from the antenna within the allowable range, the amount of current flowing out of the battery is reduced and the consumption of the battery is suppressed, The usable time of the wireless device can be extended and the operating time can be improved.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the accompanying drawings and FIGS. 1 and 2.
FIG. 1 is a block diagram showing the configuration of a wireless device having transmission output control means according to an embodiment of the present invention, and FIG. 2 is FIG.
FIG. 3 is a graph of battery voltage vs. current flowing through a power amplifier and transmission output of the wireless device shown in FIG.

First, the configuration of a radio apparatus according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, 1
Is a wireless device such as a mobile phone having a transmission output control means (described later) according to the present invention, and includes a power amplifier 10,
Directional coupler 11, detection means 12, error voltage detection means 1
3, the gain control means 14, the modulation means 15, the antenna 16, the battery 20 and the like are the same as those of the conventional one.

The present embodiment further includes a voltage detection means 21, a storage means 22, and a reference voltage generation means 23, and the voltage detection means 21 detects the voltage value of the battery and sets a plurality of predetermined values. Output a voltage detection signal 37 including any voltage value data corresponding to each of the voltage values, and the storage means 22 stores the battery voltage data 38 corresponding to each of a plurality of predetermined voltage values of the battery. The battery voltage data 38 corresponding to the received voltage detection signal 37 is read and output to the reference voltage generating means 23, and the reference voltage generating means 23 determines a reference voltage value predetermined for each voltage value of the battery to be detected. Alternatively, the reference level may be selected, switched, or set (which may be any constant voltage power source such as a voltage regulator), and the electric power received from the storage means 22 may be received. Outputs a reference level of the reference signal 39 corresponding to the battery voltage data 38 based on the voltage data 38 to the error voltage detector 13.

Further, in the present embodiment, the detection means 12, the error voltage detection means 13, the gain control means 14, the voltage detection means 21, the storage means 22 and the reference voltage generation means 23 are used for transmission in response to the voltage drop of the battery. The output control means constitutes a reference level changing means for changing the reference level of the reference signal in response to the voltage drop of the battery by the voltage detecting means 21, the storage means 22 and the reference voltage generating means 23.

In the present embodiment, the voltage detecting means 21 has at least three arbitrary voltage values (V1, V2 and V3) of the battery 20, as described below in FIG.
Voltage value data corresponding to each of the three voltage values, for example, a digital value "0" for a voltage between the voltage values V1 and V3, a voltage value V3 exceeding V2 to V2. A voltage detection signal 37 indicating a digital value "1" with respect to the voltage is output (in the case of detecting a larger number of voltage values, it is configured to output a wider variety of digital values). It should be noted that any value exceeding the voltage value V3 may be used.

The storage means 22 may be composed of any device such as a latch, and stores a plurality of battery voltage data corresponding to each voltage value of the battery 20 to be detected (or a voltage detection signal). When 37 is input, it may be stored and output as the battery voltage data 38), and the voltage value detected by the voltage detection means 21 (value exceeding V1 to V3 and V3 to V2). When the voltage detection signal 37 having the corresponding voltage value data (digital value 0, 1) is received, the corresponding battery voltage data 38 is read and output to the reference voltage generating means 23, and the reference voltage generating means 23 outputs the battery. Reference levels 1 and 2 corresponding to the voltage data 38 (for example, the reference level 1 for the voltage values V1 to V3 and the bases for the voltage values from the value V2 exceeding the voltage value V3 to the voltage value V2). The reference signal 39 of the quasi level 2, which is the relationship of reference level 1> reference level 2 in the present embodiment) is output to the error voltage detection means 13.

Then, for example, when the voltage value exceeds V3, the reference level to be compared with the low-frequency signal 34 input thereto is changed from the reference level 1 to the reference level 2 to lower the comparison level. To do. Of course, the voltage detecting means 21 detects a plurality of three or more voltage values, outputs voltage value data (for example, a digital value or an analog value) corresponding to each of these voltage values, and then outputs each value. The corresponding reference level may be output.

Next, in FIG. 2, V1 is the maximum operating voltage value, V2 is the minimum operating voltage value, and V3 is the maximum operating voltage within the range of the voltage value of the battery 20 at which the wireless device 1 can be operated. Any intermediate operating voltage value between the value V1 and the minimum operating voltage value V2, V2 <V3 <V
Have a relationship of 1.

When the voltage value of the battery 20 is within the range of the maximum operating voltage value V1 to the intermediate operating voltage value V3, I1 is a set value for each means in the radio apparatus 1 when I1 is the maximum operating voltage value V1 of the battery voltage. The amount of current flowing in the power amplifier 10, I3 is the amount of current flowing in the power amplifier 10 when the battery voltage is the intermediate operating voltage value V3, and the battery voltage data 38 output from the storage means 22 within this voltage range.
Is the battery voltage data 381, and P1 is the antenna 16 corresponding to the reference level 1 when the value of the reference signal 39 output from the reference voltage generating means 23 is the reference level 1.
The transmission output of the third high-frequency signal (transmission wave) 32 output from

Within the range in which the voltage value of the battery 20 exceeds the intermediate operating voltage value V3 to the minimum operating voltage value V2, I1 is set as the set value for each means in the wireless device 1.
-1 is the amount of current flowing through the power amplifier 10 when the battery voltage exceeds the intermediate operating voltage value V3, I3-1 is the amount of current flowing through the power amplifier 10 when the battery voltage is at the minimum operating voltage value V2, and Within the voltage range, the storage means 22
The battery voltage data 38 output from the battery voltage data 38
2 and P2 is a third high frequency signal (transmitted wave) output from the antenna 16 corresponding to the reference level 2 when the value of the reference signal 39 output from the reference voltage generating means 23 is set to the reference level 2. The transmission output of 32 is shown.
Therefore, there is a relation of reference level 1> reference level 2.

Next, with reference to FIGS. 1 and 2, the operation of the radio apparatus 1 in the present embodiment will be described.
First, when the battery 20 is fully charged, that is, the battery 2
A case where the voltage value of 0 is the maximum operating voltage value V1 will be described. The first high-frequency signal (modulation wave) 30 generated by synthesizing or modulating a low-frequency signal such as a voice signal and a data signal and a carrier signal in the modulating means 15 is amplified in voltage by the gain control means 11 and 2 is converted into a high frequency signal 31. The power of the second high frequency signal 31 is amplified by the power amplifier 10 and converted into a third high frequency signal (transmission wave) 32. This third high frequency signal (transmitted wave) 32 is transmitted via the directional coupler 11 to the antenna 1
Radiation from 6 to free space.

On the other hand, the directional coupler 11 includes an antenna 16
The fourth high-frequency signal 33 having a minute level that does not affect the transmission output of the third high-frequency signal (transmission wave) 32 radiated from the output is output to the detection means 12. This fourth
The transmission of the high frequency signal 33 is for negative feedback in order to keep the transmission output of the third high frequency signal (transmission wave) 32 constant, as described later. The detection means 12 that has received the fourth high-frequency signal 33 causes the fourth high-frequency signal 3
3 is separated into a low frequency signal 34 and a carrier wave, and the low frequency signal 3
4 is sent to the error voltage detecting means 13 and is compared with the reference signal 39 as described later.

At this time, since the voltage value of the battery 20 is the maximum operating voltage value V1, the voltage value data of the voltage detection signal 37 output from the voltage detection means 21 is the digital 0 as described above, and therefore is stored. Since the value of the battery voltage data 38 read from the means 22 is the battery voltage data 381, the value of the reference signal 39 from the reference voltage generating means 23 corresponding to the battery voltage data 381 is the reference level 1. Therefore, the error voltage detecting means 13 compares the value of the input low frequency signal 34 with the reference level 1 to calculate an error or difference, amplifies the error or difference, and outputs it to the gain controlling means 14 as an error component signal 35.

The gain control means 14 adjusts the voltage gain by controlling the error component signal 35 so that the value of the transmission output of the third high frequency signal (transmission wave) 32 radiated from the antenna 16 is held at P1. . Thereby,
At that time, the amount of current flowing into the power amplifier 10 becomes I1.

Next, the case where the voltage value of the battery 20 drops from the maximum operating voltage value V1 to the intermediate operating voltage value V3 will be described. At this time, the voltage detection unit 21 detects that the voltage value of the battery 20 has dropped, but since the voltage value is still the intermediate operating voltage value V3, the voltage value of the voltage detection signal 37 output from the voltage detection unit 21. The data remains 0.
Therefore, since the battery voltage data 38 read from the storage means 22 is the battery voltage data 381 similar to the above, the reference voltage generation means 2 corresponding to this battery voltage data 381.
The value of the reference signal 39 from 3 is the reference level 1. Third high frequency signal (transmitted wave) 3 corresponding to the reference level 1
Since the value of the transmission output of 2 is P1, the wireless device 1 operates as follows.

When the voltage value of the battery 20 drops from the maximum operating voltage value V1 to the intermediate operating voltage value V3, the value of the transmission output of the third high frequency signal (transmission wave) 32 output from the antenna 16 is temporarily. descend. However, in the error voltage detection means 13, when the value of the low frequency signal 34 from the detection means 12 whose value has decreased and the value of the reference level 1 of the reference signal 39 are compared, the difference increases. Therefore, the value of the error component signal 35 output from the error voltage detection means 13 becomes high. The value of the voltage gain of the gain control means 14 that receives the increased error component signal 35 also increases, and the amount of current flowing into the power amplifier 10 increases to I3.

As a result, the transmission output of the third high frequency signal (transmission wave) 32 radiated from the antenna 16 is held at P1. That is, when the voltage value of the battery 20 drops from the maximum operating voltage value V1 to the intermediate operating voltage value V3, the amount of current flowing into the power amplifier 10 increases from I1 to I3, and the third high frequency signal (transmission wave) 32 Send output as P1
Try to keep constant.

Next, a case will be described in which the voltage value of the battery 20 exceeds the intermediate operating voltage value V3 and further decreases toward the minimum operating voltage value V2. In this case, the voltage detecting means 21
Detects that the voltage value of the battery 20 has dropped below the intermediate operating voltage value V3, and changes the voltage value data of the voltage detection signal 37 to be output to digital 1. Therefore, the battery voltage data 38 read from the storage unit 22 is changed from the battery voltage data 381 to the battery voltage data 382. Reference voltage generating means 2 corresponding to the battery voltage data 382
The value of the reference signal 39 from 3 is reference level 2. Third high frequency signal (transmitted wave) 3 corresponding to the reference level 2
The value of the transmission output of 2 is P2 (FIG. 2), and the wireless device 1 operates as follows.

When the voltage value of the battery 20 drops to the minimum operating voltage value V2 from the intermediate operating voltage value V3, the antenna 1
The value of the transmission output of the third high-frequency signal (transmission wave) 32 output from 6 temporarily decreases. However, since the error voltage detection means 13 compares the value of the low-frequency signal 34 from the detection means 12 whose value has decreased with the value of the reference level 2 of the reference signal 39 whose value has decreased, the difference is The voltage value of the battery 20 is lower than that in the case where the maximum operating voltage value V1 to the intermediate operating voltage value V3. Therefore, the value of the error component signal 35 output from the error voltage detection means 13 becomes low. The value of the voltage gain of the gain control means 14 that has received the lowered error component signal 35 is also lowered, and the amount of current flowing into the power amplifier 10 is lowered to I1-1.

As a result, the transmission output of the third high frequency signal (transmission wave) 32 radiated from the antenna 16 is reduced to P2 and held at that value. That is, when the voltage value of the battery 20 decreases from the intermediate operating voltage value V3 toward the minimum operating voltage value V2, the amount of current flowing into the power amplifier 10 is I3.
To I1-1 from the third high frequency signal (transmitted wave)
It operates to lower the transmission output of 32 from P1 to P2 and hold it there.

Furthermore, when the voltage value of the battery 20 exceeds the intermediate operating voltage value V3 and drops to the minimum operating voltage value V2, the wireless device 1 operates in such a manner that the above-mentioned voltage value of the battery 20 changes from the maximum operating voltage value V1 to the intermediate operating voltage value V1. The same operation as described for the case where the voltage value is reduced to V3 is performed, the amount of current flowing into the power amplifier 10 is increased from I1-1 to I3-1 (shown in FIG. 2), and the third high-frequency signal (transmitted wave) is transmitted. ) P is the transmission output of 32
2 Operates to keep constant.

In this way, when the battery 20 is exhausted and its voltage value drops to a certain value, for example, when a battery alarm indicating a voltage drop is given, or when the voltage level exceeds another set voltage level, etc. (Not necessarily at the same time), by suppressing the increase in the amount of current flowing into the power amplifier 10 that controls the transmission output of the third high-frequency signal (transmission wave) 32 by the control of the transmission output control means (described above), the battery 20
It is possible to increase the operating time of the wireless device 1 by reducing the decrease (consumption) of the voltage value of 1. That is,
As shown by the dotted line in FIG. 2, in the case of the above-described conventional example, when the battery voltage drops, the transmission output from the antenna is kept constant at P1, so that the amount of current flowing into the power amplifier 10 is increased to I2. However, in the present embodiment, the amount of current is suppressed to I3-1, so that battery consumption can be reduced.

However, in the battery voltage data 38 stored in the storage means 22, the transmission output from the power amplifier 10 is a value specified by law in consideration of fluctuations due to temperature characteristics and variations due to errors of each component. It is necessary to set a value that satisfies Further, although the reference voltage generating means 23 is separately provided in the present embodiment, this function may be provided in another means, for example, the error voltage detecting means 13.

It should be noted that the number of battery voltage data 38 stored in the storage means 22 is increased to three or more to increase the number of reference levels of the reference signal, thereby increasing the types of the transmission output P and increasing the power amplifier. By further reducing the amount of current flowing into 10, the consumption of the battery can be suppressed. Further, even if the transmission output of the third high frequency signal (transmission wave) 32 by the error component signal 35 is controlled not only to the gain control means 11 but also to the power amplifier 10, the same effect is obtained. Can be achieved.

[0043]

The wireless device according to the present invention is configured as described above, and in particular, when the voltage value of the battery decreases,
Corresponding to the decrease in the voltage value, the reference level of the reference signal to be compared with the low frequency signal fed back from the transmission output is lowered to reduce the amount of current flowing into the power amplifier and transmit the high frequency signal radiated from the antenna. By reducing the output within the allowable range, it is possible to reduce the amount of current flowing out from the battery, suppress battery consumption, extend the usable time of the wireless device, and improve the operation time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a wireless device having a transmission output control unit according to an embodiment of the present invention.

2 is a graph of battery voltage vs. current flowing through a power amplifier and transmission output of the wireless device shown in FIG.

FIG. 3 is a block diagram showing a configuration of a wireless device having a conventional transmission output control means.

4 is a graph of battery voltage vs. current flowing through a power amplifier and transmission output of the wireless device shown in FIG.

[Explanation of symbols]

1,51 wireless device 10 power amplifier 11 directional coupler 12 detection means 13 error voltage detection means 14 gain control means 15 modulation means 16 antennas 17,23 reference voltage generation means 20 battery 21 voltage detection means 22 storage means 30 first High frequency signal (modulated wave) 31 Second high frequency signal 32 Third high frequency signal (transmitted wave) 33 Fourth high frequency signal 34 Low frequency signal 35 Error component signal 36, 39 Reference signal 37 Voltage detection signal 38 Battery voltage data V1 , V2, V3 Battery voltage values I1, I2, I3, I1-1, I3-1 Current flowing in power amplifier P1, P2 Transmission output

Claims (3)

[Claims] 1. A power amplifier for amplifying the power of a high-frequency signal, a directional coupler for propagating the high-frequency signal in a transmission direction and outputting a part thereof for feedback, and a high-frequency signal fed back to the directional coupler. Detecting means for separating the low frequency signal and carrier wave, error voltage detecting means for comparing the low frequency signal and the reference level of the reference signal and outputting an error component signal consisting of the difference between them, and a low frequency signal such as voice And a carrier for synthesizing a carrier wave to output a high frequency signal, and a gain control means for controlling a voltage gain for amplifying the voltage of the high frequency signal based on the control of the error component signal to control a current flowing through a power amplifier. A wireless device including an antenna for radiating the high-frequency signal to a free space and a battery for supplying electric power, which further corresponds to a voltage drop of the battery. The reference level changing means for changing the reference level is included, and when the voltage value of the battery reaches any predetermined value, the reference level is changed to change the reference level of the high frequency signal output from the directional coupler. A wireless device characterized in that output power is reduced. 2. The reference level changing means stores a voltage detecting means for detecting a voltage value of the battery and a plurality of battery voltage data corresponding to a plurality of arbitrarily determined voltage values of the battery, and stores the plurality of battery voltage data. Storage means for reading out battery voltage data corresponding to the detected voltage value in response to detection of one of arbitrarily determined voltage values, and outputting a reference signal of a reference level corresponding to the read battery voltage data 2. The wireless device according to claim 1, further comprising: a reference voltage generating unit for changing the reference level when the voltage value of the battery reaches any one of predetermined values. . 3. One of a plurality of arbitrarily determined battery voltage values
One of the plurality of battery voltage data is read out from the plurality of battery voltage data corresponding to each arbitrarily determined voltage value of the battery stored, and the battery voltage data corresponding to the detected voltage value is read. A reference level corresponding to the read battery voltage data is selected from the corresponding reference levels and generated, and the generated reference level is compared with the value of the low-frequency signal obtained from the transmission output to determine the difference. A transmission output control method for a wireless device, comprising: each step of outputting and controlling the transmission output based on the difference, and changing and setting the value of the transmission output to a value corresponding to each value of the reference level.