JPH06104776A - Transmission output control circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a transmission output control circuit for suppressing a fluctuation of an output signal due to a fluctuation of a power supply voltage and obtaining a predetermined output. To correct the change in the transmission output of the variable gain amplifying means (1) due to the change in the power supply voltage supplied from the power supply (5), the power supply voltage supplied from the power supply (5) is corrected by the correction voltage generating means ( The desired correction voltage, which is detected by 4) and is necessary for the transmission output to be constant, is applied to the control voltage generating means (3). [Effect] By properly selecting the correction voltage, it is possible to completely compensate the output fluctuation due to the power supply voltage fluctuation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission output control circuit which is mainly used in a transmission section of a portable wireless device or the like and keeps the transmission output constant even when the power supply voltage fluctuates.

[0002]

2. Description of the Related Art FIG. 10 is a functional block diagram showing a configuration of a conventional transmission output control circuit. The variable gain amplifying means 1 is
The gain is varied by the control voltage applied by the control voltage generating means 3. The extraction means 2 extracts a part of the output signal of the variable gain amplification means and outputs it to the control voltage generation means 3. The control voltage generating means 3 generates a control voltage according to the signal output from the extracting means 2 and applies it to the variable gain amplifying means 1. The variable gain amplifying means 1 receives the gain control voltage, determines the gain, and outputs a signal. By repeating the above series of loops, the output becomes stable and constant. Also, the output can be freely changed by changing the internally generated reference voltage. Furthermore, various methods are used to compensate for changes in the output signal due to frequency and changes in temperature. JP-A-2-
In Japanese Patent No. 37844, the frequency change of the output signal is compensated by changing the reference voltage according to the frequency. Further, in Japanese Patent Application Laid-Open No. 4-51721, a temperature characteristic of an output signal is compensated by adding a bias voltage generation circuit having a temperature compensation function to the temperature characteristic of a detection circuit.

[0003]

However, when the power supply voltage is supplied by a battery such as a portable wireless device, there is a problem that the output signal of the variable gain amplifier is decreased due to the decrease of the power supply voltage. The decrease in the output signal due to the decrease in the power supply voltage is large, and the transmission output control circuit may not be able to compensate for it.

An object of the present invention is to provide a transmission output control circuit for suppressing a decrease in output signal due to a decrease in power supply voltage and obtaining a predetermined output.

Another object of the present invention is to provide a transmission output control circuit which compensates for changes in circuit characteristics due to fluctuations in power supply voltage and makes the output constant.

Still another object of the present invention is to provide a portable wireless device provided with a transmission output control circuit for suppressing a decrease in output signal due to a decrease in power supply voltage and obtaining a predetermined output.

[0007]

According to the present invention, a transmission output having a detection circuit capable of giving a reference voltage offset and further provided with a correction voltage generating means for supplying a reference voltage according to a power supply voltage A control circuit is provided.

Further, according to the present invention, there is provided a transmission output control circuit having a correction voltage generating means for supplying a reference voltage according to a power supply voltage and provided with a circuit for adding a detection circuit output and a DC generation circuit output. Provided.

Further, according to the present invention, a transmission output control circuit having a correction voltage generating means for supplying a reference voltage according to the power supply voltage and provided with a circuit for subtracting the output of the voltage comparison circuit and the output of the direct current generation circuit. Will be provided.

[0010]

According to the present invention, by adding or subtracting the DC offset voltage according to the power supply voltage to one point of the loop formed by the transmission output control circuit, the gain control voltage increases as the power supply voltage decreases. Since the operation of changing the DC offset voltage is performed, it is possible to compensate for the decrease in output. Further, by outputting the DC offset voltage from the variable voltage generator according to the decrease in the power amplifier output with respect to the decrease in the power supply voltage, the decrease in output can be completely compensated.

[0011]

FIG. 2 is a functional block diagram showing a configuration example of a transmission output control circuit according to the present invention. Reference numeral 11 denotes a variable gain power amplifier with a gain control terminal, which includes a variable gain driving amplifier 11a for amplifying an input signal with a gain according to a given control voltage, and a power amplifier 11b for outputting an output signal according to the input signal. Composed of. Reference numeral 12 is a signal extraction unit for detecting an output signal, and the high frequency signal extracted here is smoothed by a detection circuit 13 and converted into a DC voltage. When converting to a DC voltage, a DC offset voltage generated by the correction voltage generating means 16 is applied to the detection circuit 13 to offset the output of the detection circuit. This output voltage and reference voltage generation circuit 1
The output of 4 is compared by the voltage comparator 15. The output of the comparator is input as a gain control voltage to the control terminal of the variable gain driving amplifier 11a in the variable gain power amplifier 11. The voltage of each part changes until the error voltage between the output voltage of the detection circuit 13 and the output of the reference voltage generation circuit becomes zero, and stabilizes at a predetermined convergence point. By changing the DC offset voltage by the correction voltage generating means, the curve 203 of the gain control voltage of the transmission output control circuit versus the output signal Pout can be freely moved in accordance with the power supply voltage. When the curve 201 of the gain control voltage of the power amplifier versus the output signal Pout fluctuates due to the fluctuation of the power supply voltage, if the output value of the correction voltage generating means is determined according to the power supply voltage, the curve 203 of the transmission output control circuit will be generated together with the fluctuation of the power supply voltage. It can be changed appropriately and the output signal can be kept constant.

FIG. 3 is a functional block diagram showing another configuration example of the transmission output control circuit according to the present invention. Reference numeral 31 is a variable gain power amplifier with a gain control terminal, which includes a variable gain driving amplifier 31a for amplifying an input signal with a gain according to a given control voltage, and a power amplifier 31b for outputting an output signal according to the input signal. Composed of. Reference numeral 32 denotes a signal extraction unit that detects an output signal, and the high frequency signal extracted here is smoothed by the detection circuit 33 and converted into a DC voltage. After being converted into a DC voltage, a DC offset voltage generated by the correction voltage generating means 36 is added to offset the detection circuit output. The voltage comparator 35 compares this output voltage with the output of the reference voltage generation circuit 34. The comparator output is input to the control terminal of the variable gain driving amplifier 31a in the variable gain power amplifier 31 as a gain control voltage. Detection circuit 33
The voltage of each part changes until the error voltage between the output voltage of 1 and the output of the reference voltage generation circuit becomes zero, and stabilizes when a predetermined convergence point is reached. By changing the DC offset voltage by the correction voltage generating means, the curve 203 of the gain control voltage of the transmission output control circuit versus the output signal Pout can be freely moved in accordance with the power supply voltage. The curve 201 of the gain control voltage of the power amplifier versus the output signal Pout due to the fluctuation of the power supply voltage
If the output value of the correction voltage generating means is determined in accordance with the power supply voltage, the curve 203 of the transmission output control circuit appropriately changes with the power supply voltage fluctuation, and the output signal can be kept constant.

FIG. 4 is a functional block diagram showing still another configuration example of the transmission output control circuit according to the present invention. Reference numeral 41 denotes a variable gain power amplifier with a gain control terminal, which includes a variable gain driving amplifier 41a for amplifying an input signal with a gain according to a given control voltage, and a power amplifier 41b for outputting an output signal according to the input signal. Composed of. Reference numeral 42 is a signal extraction unit for detecting an output signal, and the high frequency signal extracted here is smoothed by a detection circuit 43 and converted into a DC voltage. This output voltage and the output of the reference voltage generating circuit 44 are compared with each other by a voltage comparator 45.
Compare with. Here, the output of the voltage comparator and the DC offset voltage generated by the correction voltage generator 46 are subtracted to offset the output of the detection circuit. This voltage value is input as a gain control voltage to the control terminal of the variable gain driving amplifier 41a in the variable gain power amplifier 41. Detection circuit 4
The voltage of each part changes until the error voltage between the output voltage of 3 and the output of the reference voltage generation circuit becomes zero, and stabilizes when a predetermined convergence point is reached. By changing the DC offset voltage by the correction voltage generating means, the curve 203 of the gain control voltage of the transmission output control circuit versus the output signal Pout can be freely moved in accordance with the power supply voltage. A curve 20 of the gain control voltage of the power amplifier versus the output signal Pout due to the fluctuation of the power supply voltage
When 1 fluctuates, if the output value of the correction voltage generation means is determined according to the power supply voltage, the curve 203 of the transmission output control circuit changes appropriately with the power supply voltage fluctuation, and the output signal can be kept constant.

FIG. 5 is a functional block diagram showing still another configuration example of the transmission output control circuit according to the present invention. The control voltage output from the control voltage generating means 3 is applied to the variable gain amplifying means 1
Not only is it applied to the correction voltage generating means. The correction voltage generating means 4 comprises a control microcomputer, a memory, a power supply voltage detecting means, a control voltage detecting means, and a correction voltage generating means, and a transmission output for the power supply voltage and the gain control voltage of the variable gain amplifying means 1. Store the value in the memory. The power supply voltage supplied from the power supply 5 is detected by the power supply voltage detection means,
Further, the control voltage from the control voltage generating means 3 is detected by the control voltage detecting means. The transmission output value corresponding to the values of the power supply voltage and the control voltage is read from the memory, the transmission output value is processed by the control microcomputer, and the correction voltage required for the transmission output to be constant is output by the correction voltage generating means. FIG. 6 is a diagram for explaining an embodiment in the configuration shown in FIG. 2 or FIG. When the DC offset voltage from the correction voltage generating means is changed (for example, proportionally) in accordance with the power supply voltage, the input / output characteristic of the detection circuit changes due to the change in the DC offset voltage applied to the normal detection circuit output. In the example of FIG. 6, the input / output characteristic 101 at the standard voltage changes like the input / output characteristic 102 at the time when the power supply voltage decreases. This change can change the curve 203 representing the output signal vs. gain control voltage of the transmission output control circuit.

FIG. 7 is a diagram showing the operation of the transmission output control circuit according to the present invention. A curve 201 indicates the characteristic of the output signal Pout with respect to the gain control signal of the variable gain power amplifier at the standard power supply voltage. A curve 203 shows the input / output characteristic of the gain control signal with respect to the output Pout of the variable gain power amplifier of the transmission output control circuit at the standard power supply voltage. Curve 201
The point of intersection of points 203 and 203 is expressed as a convergence point A, and the loop formed by the transmission output control circuit converges to this point at the standard power supply voltage and stabilizes. Here, the curve 201 changes to a curve 202 when the power supply voltage decreases. Since the output of the normal transmission output control circuit does not depend on the power supply voltage, the input / output characteristic of the transmission output control circuit remains the curve 203. Therefore, when the power supply voltage decreases, it converges on the intersection B between the curve 202 and the curve 203 and becomes stable. From FIG. 9, the output signal at the convergence point B is smaller than the output signal at the convergence point A by ΔPout. In order to compensate for this decrease in output, the transmission output control circuit is provided with a power supply voltage detecting means, and the output (gain control voltage) is changed according to the power supply voltage. In other words, the curve showing the input / output characteristics of the transmission output control circuit is moved. In FIG. 7, if the power supply voltage is reduced to converge on the point C, there is no deviation compared with the output signal at the convergence point A at the standard power supply voltage. Similarly, the convergence point may be moved to the point where the deviation of the output signal disappears even when the power supply voltage rises.

FIG. 9 is a diagram for explaining an example of the correction voltage for the power supply voltage and the control state in the configuration shown in FIGS. FIG. 9C shows changes in the output signal with respect to the power supply voltage. If there is a variable gain amplifier whose output drops sharply from a certain point when the power supply voltage is lowered, an example of an appropriate correction voltage by the correction voltage generating means necessary to compensate for this output drop will be shown. Hereinafter, the voltage for the point 308 will be abbreviated as the standard voltage (when the voltage is standard), and the voltage for the point 309 will be abbreviated as the reduced voltage (when the voltage is reduced).

In the conventional transmission power control circuit, the curve 3 in FIG. 9A shows the characteristic at the standard voltage when the power supply is at the standard voltage.
A signal corresponding to the point 301 on 04 is output, this output is converted into a detection voltage corresponding to the point 306 in FIG. 9B, and this detection voltage is output on the curve 314 in FIG. 9E. Point 3
It is converted into a detection voltage + correction voltage corresponding to 16 and output. Further, this output voltage is converted into a control voltage corresponding to the point 311 in FIG. 9D and output, and this control voltage corresponds to the point 301. That is, when the power supply is at the standard voltage, points 301 to
It is stable in the system of 306 to 316 to 311 (each point is called a convergence point). However, when the voltage drops, the curve 304 changes to the curve 305 due to the change in the characteristic of the variable gain amplifier. Due to this change, the convergence point changes, and when the power supply has a low voltage, the system is stabilized at the points 303 to 307 to 317 to 312. As a result, there is a difference in the output signal with respect to each of the convergence points 301 and 303, and this is the decrease in the output signal.

In the transmission output control circuit according to the present invention, a correction voltage generating means is provided in the conventional control circuit, and the correction voltage is changed according to the power supply voltage. An example for compensating the characteristic of the variable gain amplifier having the characteristic as shown in FIG. 9C is shown in FIG. 9F. When the power supply voltage is higher than the standard voltage (point 308), the change in the output signal is small and can be corrected by the conventional transmission output control circuit. Therefore, in FIG. 9 (f), the correction voltage is kept constant in a range where the voltage is larger than the point 319 corresponding to the standard voltage,
Only the constant offset voltage is applied to the detection circuit, and the same operation as the conventional control circuit is performed. Standard voltage (point 308)
In the following, since the output sharply drops, the correction voltage is also changed in accordance with it, as shown in FIG. 9 (f). This point 320
The curve 314 (with respect to the correction voltage va) in FIG.
To curve 315). As a result
The point 317 in (e) moves to the point 318, and the detection voltage + correction voltage corresponding to this point is output, and this voltage is shown in FIG. 9 (d).
The control voltage corresponding to the middle point 313 is converted and output. This control voltage is converted into an output signal corresponding to the point 302 in FIG. 9A and output, and this output signal is converted into a point 306 in FIG. 9B.
Converted into a detection voltage corresponding to and output, and this detection voltage is shown in FIG.
It corresponds to the point 318 in (e). That is, after compensation, the system is stable in the system of points 302 to 306 to 318 to 313. As a result, there is no difference in output between the convergence point 301 at the standard voltage and the point 302 at the time of voltage drop, so that the output signal does not decrease with respect to the power supply voltage. Before compensation (point 30
9) shows the change in the output signal after compensation (point 310).

FIG. 10 is a diagram for explaining an example of the correction voltage for the power supply voltage in the configuration shown in FIG. 4 and the state of control. FIG. 10C shows the change of the output signal with respect to the power supply voltage. If there is a variable gain amplifier whose output drops sharply from a certain point when the power supply voltage is lowered, an example of an appropriate correction voltage by the correction voltage generating means necessary to compensate for this output drop will be shown. Hereinafter, the voltage for the point 308 will be abbreviated as the standard voltage (when the voltage is standard), and the voltage for the point 309 will be abbreviated as the reduced voltage (when the voltage is reduced).

In the conventional transmission power control circuit, when the power supply is at the standard voltage, the signal corresponding to the point 301 on the curve 304 in FIG. 10A showing the characteristic at the standard voltage is output, and this output is shown in FIG. The detected voltage is converted to a detection voltage corresponding to a point 306 in (b), and the detected voltage is converted to a control voltage corresponding to a point 316 on the curve 314 in FIG. It corresponds to. That is, when the power supply is at the standard voltage, the system is stable in the system of points 301 to 306 to 316 (each point is called a convergence point). However, when the voltage drops, the curve 304 becomes the curve 3 due to the change in the characteristic of the variable gain amplifier.
Change to 05. Due to this change, the convergence point changes, and when the power supply has a low voltage, the system is stabilized at the points 303 to 307 to 317. As a result, there is a difference in the output signal with respect to each of the convergence points 301 and 303, and this is the decrease in the output signal.

In the transmission output control circuit according to the present invention, a correction voltage generating means is provided in the conventional control circuit, and the correction voltage is changed according to the power supply voltage. An example for compensating the characteristic of the variable gain amplifier having the characteristic as shown in FIG. 10C is shown in FIG.
Shown in. When the power supply voltage is higher than the standard voltage (point 308), the change in the output signal is small and can be corrected by the conventional transmission output control circuit. Therefore, in FIG. 10 (f), the correction voltage is kept constant in a range where the voltage is larger than the point 319 corresponding to the standard voltage, and only a constant offset voltage is applied to the detection circuit, and the same operation as the conventional control circuit is performed. Standard voltage (point 3
Since the output drops sharply below 08), the correction voltage is also changed as shown in FIG. Due to the change in the correction voltage from this point 320 to the point 321, FIG.
The curve 314 (for the correction voltage va) in (e) changes to the curve 315 (for the correction voltage vb). As a result, the point 317 in FIG. 10E moves to the point 318, and the control voltage corresponding to this point is output. This control voltage is shown in FIG.
Converted into an output signal corresponding to the point 302 in (a) and output,
This output signal is converted into a detection voltage corresponding to a point 306 in FIG. 10B and output, and this detection voltage corresponds to a point 318 in FIG. 10E. In other words, after compensation, point 302-
It is stable in the system of 306 to 318. As a result, there is no difference in output between the convergence point 301 at the standard voltage and the point 302 at the time of voltage drop, so that the output signal does not decrease with respect to the power supply voltage. In FIG. 10C, before compensation (point 309) and after compensation (point 3)
The change of the output signal of 10) is shown.

FIG. 11 is a diagram showing a concrete circuit configuration example of the detection circuit shown in FIG. The output signal is extracted and input from the IN terminal shown in FIG. Diode D1, diode D2, smoothing capacitor C via coupling capacitor C1.
A DC voltage is generated by a voltage doubler half-wave rectifier circuit composed of 2, a grounding capacitor C3, a resistor R1, and a resistor R2. A DC offset voltage of the output of the correction voltage generating means 16 is applied to the AC ground side terminal (anode terminal) of the diode 1 from the SUB terminal via the resistor R3. Here, the voltage may be divided by the resistors R3 and R4, or the resistor R4 may be omitted. Furthermore, it can be considered that the anode terminal and the SUB terminal of the diode 1 are short-circuited, assuming that the configuration of this portion is included in the correction voltage generating means.

FIG. 12 is a diagram showing another specific example of the circuit configuration of the detection circuit shown in FIG. The output signal is extracted and input from the IN terminal shown in FIG. Via the coupling capacitor C1, the diode D1, the diode D2, the smoothing capacitor C2, the grounding capacitor C3, the resistor R1, and the resistor R2.
It becomes a DC voltage by the double voltage half-wave rectification circuit.
The DC offset voltage of the output of the correction voltage generating means 16 is applied to the AC ground side terminal (anode terminal) of the diode 1 as the SUB.
Is added via an emitter follower circuit consisting of a transistor Q, a resistor R5, a resistor R6 and a resistor R7. This makes it possible to add an offset voltage to the output OUT of the detection circuit and simultaneously compensate for the characteristics of the diode of the detection circuit. Further, it can be considered that the anode terminal of the diode 1 and the SUB terminal are short-circuited, assuming that the configuration of this portion is included in the correction voltage generating means.

FIG. 13 shows an example of the configuration of a portable wireless device equipped with a transmission output control circuit according to the present invention. The high frequency signal received by the antenna 501 is sent to the receiving unit by the demultiplexer 502. The RF unit 503 converts the input high frequency signal into an intermediate frequency signal, and the IF unit 504 double-tones the intermediate frequency signal into a voice band signal. After the voice processing unit 505 performs processing such as band limitation, the speaker 506 outputs voice. Further, the voice input from the microphone 507 is subjected to processing such as band limitation in the voice processing unit 505, modulated by the modulator 508, and amplified by the amplifier equipped with the transmission output control circuit according to the present invention. Then, a stable output is radiated from the antenna 501 even when this output is subjected to the fluctuation of the power supply voltage via the duplexer 502.

[0025]

As described above in detail, according to the present invention, a decrease in the output signal due to a decrease in the power supply voltage or a change in the output signal due to a change in the power supply voltage is completely compensated, and stable regardless of the power supply voltage. Can be supplied with an output signal.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration example of a transmission output control circuit according to the present invention.

FIG. 2 is a functional block diagram showing another configuration example of the transmission output control circuit according to the present invention.

FIG. 3 is a functional block diagram showing still another configuration example of the transmission output control circuit according to the present invention.

FIG. 4 is a functional block diagram showing still another configuration example of the transmission output control circuit according to the present invention.

FIG. 5 is a functional block diagram showing still another configuration example of the transmission output control circuit according to the present invention.

FIG. 6 is a diagram illustrating an example of the configuration shown in FIGS. 2 and 3.

FIG. 7 is a diagram showing an operation of a transmission output control circuit according to the present invention.

FIG. 8 is a functional block diagram showing a configuration example of a conventional transmission output control circuit.

FIG. 9 is a diagram illustrating an example of a correction voltage with respect to the power supply voltage in the configurations shown in FIGS. 2 and 3 and a state of control.

10 is a diagram illustrating an example of a correction voltage with respect to the power supply voltage in the configuration shown in FIG. 4 and a state of control.

11 is a diagram showing a specific circuit configuration example of the detection circuit shown in FIG.

12 is a diagram showing another specific example of the circuit configuration of the detection circuit shown in FIG.

FIG. 13 is a functional block diagram showing a configuration example of a mobile wireless device provided with the transmission output control circuit of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Variable gain amplification means, 2 ... Extraction means, 3 ... Control voltage generation means, 4 ... Correction voltage generation means, 5 ... Power supply 11 ... Variable gain power amplifier, 11a ... Variable gain amplifier,
11b ... Power amplifier, 12 ... Signal extraction, 13 ... Detection circuit, 14 ... Reference voltage generation circuit, 15 ... Voltage comparison circuit, 1
6 ... Correction voltage generating means, 17 ... Power supply 31 ... Variable gain power amplifier, 31a ... Variable gain amplifier,
31b ... Power amplifier, 32 ... Signal extraction, 33 ... Detection circuit, 34 ... Reference voltage generation circuit, 35 ... Voltage comparison circuit, 3
6 ... Correction voltage generating means, 37 ... Power supply 41 ... Variable gain power amplifier, 41a ... Variable gain amplifier,
41b ... Power amplifier, 42 ... Signal extraction, 43 ... Detection circuit, 44 ... Reference voltage generation circuit, 45 ... Voltage comparison circuit, 4
6 ... Correction voltage generating means, 47 ... Power supply 101 ... Output of detection circuit at standard power supply voltage, 102 ... Output of detection circuit at decrease of power supply voltage 201 ... Power amplifier output for gain control voltage at standard power supply voltage, 202 ... Power amplifier output for gain control voltage when power supply voltage decreases, 203 ... Gain control voltage output for power amplifier output when standard power supply voltage, 204 ... Gain control voltage output for power amplifier output when power supply voltage decreases 301 ... Standard voltage Convergence point, 302 ... Convergence point at voltage drop (with compensation), 303 ... Convergence point at voltage drop (without compensation), 304 ... Characteristic of variable gain amplifier at standard voltage, 3
05 ... Characteristics of variable gain amplifier when voltage drops, 306 ... convergence point at standard voltage, 307 ... convergence point when voltage drops, 30
8 ... Convergence point at standard voltage, 309 ... Convergence point at voltage drop (without compensation), 310 ... Convergence point at voltage drop (with compensation) 311 ... Convergence point at standard voltage, 312 ... Convergence at voltage drop Point (without compensation), 313 ... Convergence point when voltage drops (with compensation) 314 ... Characteristics without correction, 315 ... Characteristics with correction, 3
16 ... Convergence point at standard voltage, 317 ... Convergence point at voltage drop (without compensation), 318 ... Characteristics at voltage drop (with compensation),
319 ... Convergence point at standard voltage, 320 ... Convergence point at voltage drop (without compensation), 321 ... Convergence point at voltage drop (with compensation) 501 ... Antenna, 502 ... Divider, 503 ... RF section,
504 ... IF unit, 505 ... Voice processing unit, 506 ... Speed
F, 507 ... Microphone, 508 ... Modulator, 509 ... Variable gain amplification means, 510 ... Extraction means, 511 ... Control voltage generation means, 512 ... Correction voltage generation means, 513 ... Power supply, 51
4 ... Transmission output control circuit according to the present invention

Claims (7)

[Claims] 1. A transmission output control comprising at least a variable gain amplifying means (1), an extracting means (2), a control voltage generating means (3), a correction voltage generating means (4), and a power source (5). In the circuit, the power source (5) supplies a voltage to the variable gain amplifying means (1) and the correction voltage generating means (4), and the extracting means (2) includes the variable gain amplifying means (1). The output is input, a part of the output signal is extracted and output to the control voltage generating means (3), and the control voltage generating means (3) outputs the output of the extracting means (2) and the correction voltage generating means. The output of (4) is input, a control voltage corresponding to the input is applied to the variable gain control means (1), and the correction voltage generation means (4) changes the voltage supplied from the power supply (5). Regardless of the correction voltage such that the output of the variable gain amplifying means (1) becomes constant. Transmission output control circuit, characterized in that applied to the control voltage generating means. 2. At least a variable gain power amplifier (11)
A signal extractor (12), a detection circuit (13), a reference voltage generation circuit (14), a voltage comparator (15), and a correction voltage generation means (16). The extraction (12) is performed by the variable gain power amplifier (1
1) is provided in the output section to extract a part of the output signal, the correction voltage generating means (16) generates a reference offset voltage according to the power supply voltage, and the detection circuit (13) extracts the signal. The high frequency signal extracted by the converter (12) is converted into a smoothed voltage, a detection output is output from the smoothed voltage and the reference offset voltage, and the reference voltage generation circuit (14)
Generates a reference voltage required to obtain a desired transmission output, and the voltage comparator (15) outputs the detection circuit (13).
Transmission output control characterized by inputting an output in a reverse phase and a reference voltage from the reference voltage generating circuit (14) in a positive phase for comparison and applying the output to the variable gain power amplifier (11) circuit. 3. At least a variable gain power amplifier (31)
In a transmission circuit comprising a signal extractor (32), a detection circuit (33), a reference voltage generation circuit (34), a voltage comparator (35), a correction voltage generation means (36) and an adder , The signal extractor (32) is provided at the output part of the variable gain power amplifier (31) to extract a part of the output signal, and the detection circuit (33) is provided for the signal extractor (32).
The high-frequency signal extracted by the above is converted into a smoothed voltage and output, the correction voltage generating means (36) generates a reference offset voltage according to the power supply voltage, and the adder causes the smoothed voltage from the detection circuit and the correction voltage. The reference offset voltage from the voltage generating means (36) is added, the reference voltage generating circuit (34) generates a reference voltage required to obtain a desired transmission output, and the voltage comparator (35) A transmission characterized in that the output of the adder circuit is input in the reverse phase and the reference voltage from the reference voltage generation circuit (34) is input in the positive phase for comparison, and the output is applied to the variable gain power amplifier (31). Output control circuit. 4. At least a variable gain power amplifier (41)
In a transmission circuit including a signal extractor (42), a detection circuit (43), a reference voltage generation circuit (44), a voltage comparator (45), a correction voltage generation means (46) and a subtractor , The signal extractor (42) is provided at an output part of the variable gain power amplifier (41) to extract a part of the output signal, and the detection circuit (43) includes the signal extractor (42).
The high-frequency signal extracted by the above is converted into a smoothed voltage and output, and the reference voltage generation circuit (44) generates a reference voltage required to obtain a desired transmission output, and the voltage comparator (45).
Is the smoothed voltage from the signal extractor (42) in reverse phase,
The reference voltage from the reference voltage generation circuit (44) is input to the positive phase and compared, the correction voltage generation means (46) generates a reference offset voltage according to the power supply voltage, and the subtractor is A transmission output control circuit characterized by subtracting an output of a voltage comparator (45) and a reference offset voltage from the correction voltage generating means (46) and applying the output to the variable gain power amplifier (41). 5. The transmission output control circuit according to claim 1, wherein the control voltage outputted from the control voltage generating means (3) is applied not only to the variable gain amplifying means (1) but also to the correction voltage generating means. Then, the correction voltage generating means (4) is composed of a control microcomputer, a memory, a power supply voltage detecting means, a control voltage detecting means, and a correction voltage generating means, and the power source of the variable gain amplifying means (1). The transmission output values for the voltage and the gain control voltage are stored in the memory, the power supply voltage supplied from the power supply (5) is detected by the power supply voltage detecting means, and the control from the control voltage generating means (3) is performed. A voltage is detected by the control voltage detecting means, a transmission output value corresponding to the value of the power supply voltage and the control voltage is read from the memory, the transmission output value is processed by the control microcomputer, and the transmission output becomes constant. For Transmission output control circuit for causing output the required correction voltages in the correction voltage generating means. 6. A transmission output control circuit configured to correct a change in gain of the variable gain amplifying means with respect to a fluctuation in power supply voltage. 7. A radio equipment comprising the transmission output control circuit according to claim 1, 2, 3, 4, 5, 6.