JP2784873B2 - Power control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to power (level) used for digital modulation (such as .pi. / 4 QPSK) with amplitude change.
It relates to a control device.

[0002]

2. Description of the Related Art Generally, various power control devices are already known. A plurality of examples are described in JP-A-4-157,927. The prior art power control device in this publication includes an IF
The signal is mixed with a local oscillation signal in advance and supplied as an RF signal. The improved power control device disclosed herein is supplied directly with an IF signal. This improved power control device provides a controlled level of R
Outputs F signal.

On the other hand, the transition from analog communication to digital communication has recently been advancing rapidly. Digital modulation with amplitude changes is also widely used in communication networks. For example, π / 4 QPSK modulation and demodulation has begun to be implemented in mobile phones or other communication networks.

In general, a power control device is supplied with a device input signal, and outputs a device output signal of control, that is, a predetermined output power (level). The present inventor has invented a novel power (level) control device for use in digital modulation with amplitude change, and has disclosed it in Japanese Patent Application No. 4-145302, which has not been published. In describing the present invention, Japanese Patent Application No. 4-1
Use the novel power control device disclosed in US Pat. No. 45,302 as an indication of the state of the art.

With reference to FIG. 4, the above-mentioned novel power control device will be described first. This is to facilitate understanding of the invention of this application. This power control device shall be used for a TDM modulation system. TDM modulation is digital modulation accompanied by amplitude change, and is typically π / 4 QPSK modulation by TDM.

In FIG. 4, a power control device is a device input signal S used in a TDM modulation system.
(I), and outputs a device output signal S which is an RF signal of control, ie, a predetermined output power (level).
(O) is output. Even if the device input signal is an IF signal,
The F signal may be used. For convenience of explanation, unless otherwise noted that an RF signal is used, a device input signal is assumed to be an IF signal throughout the following. The variable attenuator 11 supplied with the device input signal outputs an attenuator output signal of an attenuation level. Upconverter 13
A local oscillator (not shown) for outputting a local signal, and the local signal and the attenuator output signal are mixed to produce an RF signal.
A mixer (not shown) serving as an intermediate signal. The power amplifier 15 amplifies the RF mediation signal to obtain an amplified signal of an amplified level. Since the amplified signal is output in this way, the amplified level is related to the attenuation level.

The amplified signal, as will be described shortly,
It is coupled to a level detector 17. The level detector 17 detects the amplified signal and outputs a detection signal of a detection voltage related to the amplified level and thus the attenuation level.

[0008] Specifically, the level detector 17 includes a first capacitor C1 to which an amplified signal is supplied. The first or detection diode CD1 and the second capacitor C2
The rectifier circuit is connected in series between the capacitor C1 and the ground and outputs a half-wave rectified signal. The connection point between the detection diode CD1 and the second capacitor C2 is grounded by a series circuit of the first resistor R1 and the third capacitor C3. This series circuit functions as a smoothing circuit for removing a change in amplitude from the half-wave rectified signal. The detection signal is the first resistor R
It is obtained at the connection point between the first and third capacitor C3 and the second resistor R2.

The combination of the up-converter 13, the power amplifier 15, and the level detector 17 functions as a level detection unit that detects an attenuator output signal and outputs a detection signal. When an RF signal is used as a device input signal, the level detection unit uses an up converter 13
Not included. In such a case, the level detection unit directly amplifies the attenuator output signal into an amplified signal, converts the amplified signal to an amplified signal, and then outputs a detection signal.

The control signal generator 19 is supplied with a generator input signal. Then, an attenuation control signal of an attenuation control level is output. The generator input signal has a level (value) referred to herein as an input level. In the example just described, the detection signal is the generator input signal. The detection voltage gives the input level.

A connection line serving as an attenuation control signal supply means 21 supplies an attenuation control signal to the variable attenuator 11. Controlled according to the attenuation control level, the variable attenuator 13 controls the attenuation level. The amplified level and the detection voltage are controlled accordingly.

The control signal generator 19 includes an AD converter (A / D) 23 supplied with a generator input signal and converting an input level into a digital value. The control, that is, the reference value considering the predetermined output level is stored in the processor, that is, the central processing unit (CPU) 25 in advance.

A processor 25 connected to the A / D converter 23 compares the digital value with the reference value and outputs a processed signal of a processed level (value) that changes according to the input level in relation to the reference value. . Upon receiving the processed signal, the DA converter (D / A) 27 processes the signal,
The value is converted to an analog value, and an attenuation control signal having the analog value as an attenuation control level is output.

A transmitter (not shown) and a level detector 1
7 directional coupler 2 connected to the first capacitor C1
After 9, the amplified signal is output as a device output signal. Since the amplified level is controlled by the attenuation control level, it has an output level controlled by the device output signal. In this way,
The attenuator output signal becomes a device output signal.

Controlled by the attenuation control signal, the variable attenuator can use the attenuator output signal as the device output signal. The reference value is easily determined by the controlled output level. The device input signal may be an IF signal or an RF signal.

When used for time division multiplexing (TDM) modulation, the new level control works well. TDM
Modulation is desirable for efficient use of the channel.

[0017]

Turning to FIG. 5 and also to FIG. 4, the voltage is plotted in volts on the vertical axis. The controlled power (level) is shown on the horizontal axis, labeled W.

As mentioned previously, the detection diode CD1 of the level detector 17 has a high internal resistance when the attenuation level and thus the controlled output level is low. Therefore, the detected voltage varies according to the controlled output level, as illustrated by the real curve labeled V (d).

The internal resistance changes with temperature. Therefore, the detection voltage changes according to the temperature change. When the controlled level is low, for example not higher than +10 dB, this variation will cause an error in the attenuation control level. As a result, the controlled level has a non-negligible temperature error.

In FIG. 1, the AD and DA converters 23
And 27 have unavoidable conversion errors. This results in a non-negligible converter error in the attenuation control level and thus the controlled output level when the controlled output level is low as in the example above.

Next, turning to FIG. 6 and referring to FIG. 4, the attenuation control level is plotted on the horizontal axis as the control voltage V (c). In the variable attenuator 11, the attenuation control signal gives the attenuation ATT illustrated on the vertical axis to the device input signal. The variable attenuator 11 has an attenuation characteristic exemplified by a linear axis.

Specifically, the amount of attenuation changes with the nonlinearity in relation to the attenuation control level, and must be increased when the controlled output level is lowered. For this purpose, the attenuation control signal must have a considerably lower attenuation control level. When the controlled output level is low as exemplified above, this non-linearity gives the controlled output level a non-negligible uncertainty. In addition, a conversion error of the AD or DA converter 23 or 27 causes a considerable converter error at this low attenuation control level.

Referring back to FIGS. 4-6, the power control device just described is excellent in function, as described in the introduction. However, this power control device suffers from instability resulting from operational instability and uncertainty resulting from temperature and converter errors.

A first object of the present invention is to provide a stable and accurate power control device used for TDM modulation.

A second object of the present invention is to provide a power control device which is stable against temperature changes.

A third object of the present invention is to operate an analog circuit.
An object of the present invention is to provide a power control device which is hardly affected by a digital conversion error.

[0027]

According to the present invention, a TDM is provided.
Used for modulation, receives device input signal, and
In a power control device for outputting a device output signal of a controlled output level, a variable attenuator for outputting an attenuator output signal of an attenuated level in response to the supply of the device input signal, and a bias for generating a bias current A current source, and alternately outputs a detection voltage related to the attenuated level and a bias voltage related to the bias current in a detection signal obtained by detecting the attenuator output signal controlled by the bias current. Level detection means, a control signal generator for generating an attenuation control signal of an attenuation control level from a detection signal and a reference value from the level detection means,
Attenuation control signal supply means for supplying the attenuator control signal to the variable attenuator so that the attenuator output signal can be used as the device output signal.The control signal generator includes: The detection voltage and the bias voltage in the detection signal are converted into a digital value substantially independent of temperature, and an analog value used as the attenuation control level by comparing the digital value with the reference value. Wherein the power control device is further connected between the level detection means and the control signal generator, and wherein the controlled output level of the detection signal from the level detection means is low. The higher the level, the higher the gain Amplifying means for supplying an attenuation control signal to the control signal generator, wherein the attenuation control signal supply means corresponds to the attenuation control level of the attenuation control signal from the control signal generator to the high gain. A power control device characterized by having a damping means for providing a large amount of attenuation to attenuate and supplying the attenuation to the variable attenuator.

In a preferred embodiment of the present invention, in the power control device, the bias current source controls the bias current so that the bias voltage has a substantially constant difference from the detection voltage regardless of a temperature change. Occur.

According to the present invention, in a power control apparatus used for TDM modulation, receiving a device input signal, and outputting a device output signal having a controlled output level, the power control device supplies the device input signal. A variable attenuator that outputs an attenuator output signal of an attenuated level, a bias current source that generates a bias current, and a detection obtained by detecting the attenuator output signal controlled by the bias current. Level detection means for alternately outputting a detection voltage related to the attenuated level and a bias voltage related to the bias current in the signal; and an attenuation control level based on a detection signal and a reference value from the level detection means. A controller that generates an attenuation control signal A roll signal generator, and an attenuation control signal supply means for supplying the attenuation control signal to the variable attenuator so that the attenuator output signal can be used as the device output signal. The power control device further amplifies the detection signal with a variable gain to obtain an amplifier output, and provides the amplifier output with an amplification voltage related to the detection voltage and an amplification bias related to the generated bias voltage. And a gain controller that controls the variable gain in accordance with the attenuation control signal, wherein the bias current source has a substantially constant difference between the bias voltage and the detection voltage regardless of a temperature change. Generate the bias current as above Control signal generator, using said amplified signal as said detection signal,
The amplified voltage and the amplified bias voltage are converted into a digital value that is substantially independent of temperature, and a digital processor output value proportional to the digital value that is independent of temperature is compared with the digital value and the reference value. Outputting a processor output signal, converting the digital processor value into an analog value used as the attenuation control level, and supplying the processor output signal to the gain controller as the device control signal. A power control device is obtained.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, a description will be given of a power control apparatus according to a preferred embodiment of the present invention.
In the power control apparatus of FIG. 1, the same members as those shown in FIG. 4 are denoted by the same reference numerals or symbols, and have the same reference numerals and the same named levels (values). Work on the signal. As described above, it is assumed that the device input signal S (i) is an IF signal. Upconverter 13 is not shown for simplicity only.

Since the structure of the level detector 17 is the same, the inside is not shown. However, the level detector 17 has a bias current source 31 connected to the connection point between the first capacitor C1 and the detection diode CD1 shown in FIG.

The bias current source 31 includes a power supply 33 illustrated as a battery. The power supply voltage of this power supply 33 is typically 5 volts. In the future, diodes, resistors, and capacitors will be numbered sequentially from those used for level detector 17.

A series circuit of a third resistor R3 and a first coil L1 is connected between the power supply 33 and a connection point of the first capacitor C1 and the detection diode CD1. The fourth capacitor C4 and the fourth resistor R4 are connected in parallel between the connection point between the third resistor and the first coil and the ground.

The bias current is supplied to the second resistor R2 (FIG. 4)
Both generate a bias voltage at the connection point between the first resistor R1 and the third capacitor C3 shown in FIG. The bias current has a bias current value that includes the power supply voltage of the power supply 33 and is determined by the circuit constants of the level detector 17 and the bias current source 31.

As shown by the dashed line labeled V (b) in FIG. 5, the bias voltage does not change appreciably depending on the controlled output level, but the temperature depends on the temperature dependence of the circuit constants. Changes like a detection voltage.

Turning to FIG. 2 for a while and continuing with reference to FIG. 1, the temperature is shown on the horizontal axis in degrees Celsius. The voltage is shown on the vertical axis in V units. Let the detected voltage change as shown by the straight line labeled V (d).

According to the present invention, the bias current is selected such that the bias voltage changes as illustrated by another straight line labeled V (b) in FIG. Specifically, the circuit constant is selected so that the bias voltage has a substantially constant difference from the detection voltage regardless of the temperature.

Returning to FIG. 1, note that this power control device is used for a TDM modulation system. Each of the device input and output signals is a series of bursts. The detection voltage from the level detector 17 has a detection voltage related to the attenuation level, that is, the controlled output level when the burst is on. The detection level at the time of burst off is a bias voltage.

Suppose for a while that the detection signal is supplied directly to the control signal generator 19. The input level changes between the detection voltage and the bias voltage.

In the control signal generator 19, A
The D converter 23 converts the detection voltage and the bias voltage into first and second digital values. Processor 25 subtracts the second digital value from the first digital value to produce a difference digital value that is substantially independent of temperature changes. The processor 25 then compares the difference digital value with the reference value to produce a digital control value which is the processed level described above and produces a processor output signal having a digital processor output value proportional to the digital control value. DA converter 27
Converts the digital control value into an analog value, and outputs an attenuation control signal having the analog value as an attenuation control level.

As a result, the attenuation control level is substantially independent of temperature changes. In addition, digital values that are largely independent of temperature are useful in eliminating small errors that may appear in controlled output levels when the bias voltage does not have a completely constant difference from the sensed voltage. In this way, temperature errors that would otherwise occur in the controlled output power (level) can be eliminated.

In the above description, the most preferable case is described in which the bias voltage has a substantially constant difference from the detection voltage irrespective of the temperature, but the temperature change of the bias voltage and the temperature change of the detection voltage have been described. Temperature error can be made much smaller than in the conventional method in which only the detected voltage is compared with the reference value. The reason for this is
In the present invention, a difference digital value which is a difference between a bias voltage and a detection voltage is generated, and a processor output signal of a digital processor output value proportional to a digital control value obtained by comparing the difference digital value with a reference value is generated. This is because the attenuator is controlled by the attenuation control signal obtained by DA-converting the output signal.

In FIG. 1, a detection signal is supplied to a control signal generator 19, not directly, but to a variable amplifier 35 having a + and-input terminal and an output terminal and having a variable gain.
It is preferably fed via a single operational amplifier that acts as The detection voltage is supplied to the + input terminal, and the variable amplifier 35 outputs the amplifier output from the output terminal to the control signal generator 19.
To supply.

Depending on the variable gain, the amplifier output has a sensed voltage, ie, an amplified voltage related to the controlled output level and bias voltage. Since the bias voltage of the amplified voltage has a substantially constant difference from the detection voltage, the control signal generator 19 operates in the same manner as described above. However, the control signal generator 19 additionally outputs the processor output signal from the processor 25.

The gain controller 37 includes a grounded analog multiplexer (MPX) 39 and a fifth resistor R5 connected to the negative input terminal and the output terminal of the variable amplifier 35. This output terminal is grounded via a fifth capacitor C5. In the example just described, the fourth to ninth resistors R6, R7, R8 and R9 are connected in parallel between the-input terminal and the multiplexer 39. Controlled by the processor output signal, the multiplexer 39 grounds the-input terminal via the selected one of the four resistors R6 to R9 and itself.
Since the selected resistor is one of four, the processor output signal is two bits.

The gain controller 37 is a processor 25
The variable amplifier 35 controlled by the processor output signal from the
As the controlled output level is lower, the detection signal is amplified with a larger gain. As a result, the influence of a converter error of the AD converter 23 when the data is taken into the processor 25 can be reduced. The attenuation control unit 21 attenuates the attenuation control level of the attenuation control signal from the control signal generator 19 by giving a large amount of attenuation corresponding to the high gain. And a damping means for supplying to the In this way, the attenuation means varies the dynamic range of the attenuation control level in accordance with the amount of attenuation of the variable attenuator 11, whereby the attenuation control signal output from the processor 25 is converted into a digital signal. The effect of the converter error of the converter 27 can be reduced.

In FIG. 1, the variable attenuator 11 includes first and second attenuator diodes as second and third diodes CD2 and CD3. These diodes CD2 and CD3 are typically PIN
They are connected in series with diodes, and have a series connection point between them.
The combination of the second and third diodes has an input terminal of the variable attenuator 11 to which a device input signal is supplied and an attenuator output terminal for outputting an attenuator output signal.

The attenuation control unit serving as the attenuation control signal supply means 21 is given the same reference numeral,
9 is shared with the gain controller 37. In the attenuation control unit 21, an attenuation control signal is supplied to one end of the tenth resistor R10. The other end of the tenth resistor R10 is grounded via an eleventh resistor R11.

The operational amplifier member 41 has + and-input terminals and an output terminal. Tenth and eleventh resistors R10
The connection point between R11 and R11 is connected to the + input terminal. The twelfth to fifteenth resistors R12, R13,
R14 to R15 are connected in parallel between the-input terminal and the multiplexer 39. Controlled by the processor output signal, multiplexer 39 grounds one of four resistors R12-R15 via itself.
The operational amplifier member 41 and a selected one of the four resistors form a constant current circuit, and compensate for the temperature error of the attenuator diodes CD2 and CD3. further,
Each of the four resistors R12-R15 reduces the nonlinearity of the attenuation characteristics.

The sixth capacitor C6 is an operational amplifier member 41.
Is connected between the input terminal and the output terminal. The second coil L2 is connected between the output terminal of the variable attenuator 11 and the-input terminal of the operational amplifier member 41. Seventh
The capacitor C7 includes the second coil L2 and the operational amplifier member 41.
To the-input terminal.

The third coil L3 is a variable attenuator 1
1 and an output terminal of the operational amplifier member 41. An eighth capacitor C8 is connected between the connection point between the output terminal and the third coil L3 and the ground. A sixteenth resistor R16 connects to the series connection of the second and third diodes CD2 and CD3. This sixteenth resistor is grounded by a ninth capacitor C9.

[0052]

Referring to FIG. 3 in addition to FIG. 1, assume that processor 25 controls control signal generator 19. It is assumed that the detection signal is sent directly from the level detector 17 to the control signal generator 19, for the sake of simplicity.

In a first step 51, the processor 25
Knows the burst off. In the second step 52, A
The D converter 23 changes the bias voltage to a second digital value. In a third step 53, the processor 25 knows burst on. In a fourth step 54, the AD converter 23 changes the detection voltage to a first digital value.

In a fifth step 55, the processor subtracts the second digital value from the first digital value to create a difference digital value. In the sixth step 56, the processor 25 generates various control values for controlling the present level control device.

In the seventh step 57, the processor 25
Checks whether the difference digital value is correct. This is a measure of whether the controlled output power (level) is correct. If the controlled output level is correct,
The seventh step 57 returns to the first step 51.

If the controlled output level is not correct in the seventh step 57, the processor 25 determines in a eighth step 58 whether the controlled output level is too high. If too high, processor 25
Increases the attenuation control level and lowers the controlled output level in the ninth step 59. If the controlled output level is low, processor 2
5 increases the controlled output level in a tenth step 60. 9th step 59 or 10th step 6
0 returns to the first step 51.

A review of FIGS. 1 to 3 reveals the following. This power control works great.
By way of example only, it is assumed that this power control device is used in a cellular mobile communication system. When the minimum level of the transmission signal is not higher than -4 dB, the conventional power control apparatus has a detection error of ± 6 dB. In the controlled output level, conversion errors of ± 5 dB and 10 dB were generated by the AD and DA converters.

When the power control device just described is used, the detection error is reduced to ± 0.4 dB. The conversion error by the AD converter 23 and the DA converter 24 is ± 0.5
dB and 0.4 dB. At worst, the output error of the controlled output power (level) was only ± 1.3 dB. Usually, four resistors R6 to R9 or R12 to R15 are sufficient.

While the invention has been described with respect to only one embodiment, those skilled in the art will readily be able to implement the invention in various ways. For example, a variable amplifier is a variable attenuator 11
Is equivalent to The level detector 17 may be modified.

[0061]

According to the power control device of the present invention, T
Used for DM modulation, operation is stable and accurate.

Further, the power control device of the present invention is stable against temperature changes. Further, the operation of the power control device of the present invention is hardly adversely affected by the analog-to-digital conversion error.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a power control device according to one embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a detection voltage and a bias voltage in the power control device shown in FIG.

FIG. 3 is a flowchart for explaining the operation of the power control device shown in FIG. 1;

FIG. 4 is a block diagram showing a power control device known to the present inventors.

FIG. 5 is a diagram showing characteristics of a level detector in the power control device shown in FIG.

6 is a diagram showing characteristics of a variable attenuator in the power control device shown in FIG.

[Explanation of symbols]

 11 Variable Attenuator 13 Up Converter 15 Power Amplifier 17 Level Detector 19 Control Signal Generator 21 Attenuation Control Unit 23 AD Converter 25 Processor 27 DA Converter 29 Directional Coupler 31 Bias Current Source 35 Variable Amplifier 37 Gain Controller 39 Multiplexer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H03G 3/20 H04B 3/06 H04B 1/04

Claims (10)

(57) [Claims] 1. A power control device used for TDM modulation, receiving a supply of a device input signal and outputting a device output signal having a controlled output level, the level of which is attenuated by the supply of the device input signal. A variable attenuator for outputting an attenuator output signal; a bias current source for generating a bias current; and the attenuated detection signal obtained by detecting the attenuator output signal controlled by the bias current. Level detection means for alternately outputting a detection voltage related to the detected level and a bias voltage related to the bias current, and an attenuation control signal of an attenuation control level based on a detection signal from the level detection means and a reference value. Generate control signal And an attenuation control signal supply means for supplying the attenuation control signal to the variable attenuator so that the attenuator output signal can be used as the device output signal. The control signal generator Converts the detection voltage and the bias voltage in the detection signal into a digital value substantially independent of temperature, and uses the digital value and the reference value as the attenuation control level. The power control device is further connected between the level detection means and the control signal generator, and outputs the detected signal from the level detection means to the controlled output level. The lower the level, the higher the gain Attenuating control signal supply means for supplying the attenuation control signal of the attenuation control signal from the control signal generator to the high gain. A power control device comprising: a damping unit that attenuates by providing a large amount of attenuation corresponding to the variable attenuator and supplies the variable attenuator with the attenuation. 2. The power control device according to claim 1, wherein the bias current source generates the bias current such that the bias voltage has a substantially constant difference from the detection voltage regardless of a temperature change. A power control device, characterized in that: 3. The power control device according to claim 1, wherein the device input signal is an IF signal,
The level detecting means includes an upconverter for converting the attenuator output signal into an RF signal, a power amplifier for amplifying the RF signal to an amplified signal having an amplified level related to the attenuated level, A level detector that supplies a signal and is controlled by the bias current to output the detection signal so that the detection voltage is related to the amplified level, and the amplified signal is used as the device output signal. A power control device, characterized in that: 4. The power control device according to claim 1, wherein the device input signal is an RF signal,
The level detecting means includes: a power amplifier for amplifying the attenuator output signal to an amplified signal of an amplified level; and a supply of the amplified signal, the detection signal being controlled by the bias current, and causing the detection voltage to amplify the detection signal. A level detector for outputting a signal related to the level, and the amplified signal is used as the device output signal. 5. The power control device according to claim 1, wherein the control signal generator converts the detection voltage and the bias voltage into first and second bias values, and the second control signal generator includes: A processor for generating a difference digital value by subtracting a bias value from the first bias value to generate a processor output signal of a digital processor output value proportional to the difference digital value by comparing the difference digital value with the reference value; And a DA converter for converting an output value into the analog value. 6. A power control device used for TDM modulation, receiving a supply of a device input signal and outputting a device output signal having a controlled output level, wherein a level attenuated by the supply of the device input signal is provided. A variable attenuator for outputting an attenuator output signal; a bias current source for generating a bias current; and the attenuated detection signal obtained by detecting the attenuator output signal controlled by the bias current. A level detection means for alternately outputting a detection voltage related to the level and a bias voltage related to the bias current; and an attenuation control signal of an attenuation control level from the detection signal and the reference value from the level detection means. Generated control signal generator Attenuation control signal supply means for supplying the attenuation control signal to the variable attenuator so that the attenuator output signal can be used as the device output signal. Further, the detection signal is amplified by a variable gain to obtain an amplifier output,
A variable gain amplifier that provides an amplification voltage related to the detection voltage and an amplification bias related to the generated bias voltage to the amplifier output; and a gain controller that controls the variable gain according to the attenuation control signal. The bias current source generates the bias current so that the bias voltage has a substantially constant difference from the detection voltage regardless of a temperature change, and the control signal generator generates the bias signal. Used as the detection signal, the amplified voltage and the amplified bias voltage are converted to a digital value substantially independent of temperature,
By comparing the digital value with the reference value, a processor output signal of a digital processor output value proportional to the digital value irrelevant to the temperature is output, and the digital processor value is converted to an analog value used as the attenuation control level. A power control device for converting and supplying the processor output signal to the gain controller as the device control signal. 7. The power control device according to claim 6, wherein the device input signal is an IF signal,
The level detecting means includes an upconverter that converts the attenuator output signal into an RF signal, a power amplifier that amplifies the RF signal into an amplified signal having an amplified level related to the attenuation level, A detector that is supplied and controlled by the bias current and outputs the detection signal so that the detection voltage is related to the amplified level, and the amplified signal is used as the device output signal. Power control device characterized by the following. 8. The power control device according to claim 6, wherein the device input signal is an RF signal,
A power amplifier for amplifying the attenuator output signal to an amplified signal of an amplified level;
A level detector that supplies the amplified signal and is controlled by the bias current and outputs the detection signal so that the detection voltage is related to the amplified level; and
A power control device, wherein the amplified signal is used as the device output signal. 9. The power control device according to claim 6, wherein the control signal generator converts the amplified voltage and the bias voltage into first and second digital values, and the second digital signal. Value first
A processor that subtracts the digital value to produce a difference digital value as the substantially temperature-independent digital value, generates a digital processor output value by comparing the difference digital value with the reference value, and outputs the processor output signal. And a DA converter for converting the digital processor output value to the analog value. 10. The power control device according to claim 6, wherein said attenuator control signal supply means receives said attenuation control signal and is controlled by said processor output signal to set said attenuation control level. A power control device comprising an attenuation control unit for controlling.