JPH1022757A - Automatic transmission power control circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a variable and high control speed for the automatic transmission power control circuit for a radio equipment and to improve the temperature characteristic. SOLUTION: Part of a transmission output extracted by a directional coupler 5 is rectified and smoothed and converted into a digital signal and it is given to a CPU 17. The CPU 17 provides an output of an error digital value equivalent to a difference between an input value and a reference value read from a memory 11. The output is converted into an analog error voltage and it is given to a power amplifier 4 so as to control the amplifier 4 thereby making the error voltage zero. Temperature information detected by a temperature detection element 18 is given to the CPU 17 to correct the error digital value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission power control circuit in a transmission unit of a radio.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional automatic transmission power control circuit receives an output of an oscillator 1 via a buffer amplifier 2 and a driver amplifier 3 and directionally couples an output voltage of a power amplifier 4 for power amplification. A signal detected by the rectifier 5 and converted to a DC voltage by the rectifier 8 and the smoothing device 9 and an output value of the memory 12 set in advance so as to output a specified output are output from the CPU 13 to obtain a D / A signal. An error output obtained by comparing the DC voltage converted by the converter 11 with the error amplifier 10 passes through a low-pass filter 16 and controls the amplification of the power amplifier 4. Reference numeral 6 denotes a transmission filter for extracting a transmission output of a desired frequency, and reference numeral 7 denotes a transmission antenna.

[0003]

Therefore, the response speed is determined by the time constant of the low-pass filter 16, and it is difficult to change the speed as needed. Further, since the rectifier 8 for output detection has a detection characteristic that fluctuates according to a change in temperature, it is necessary to add a compensating element in order to perform temperature compensation, and the number of components increases.

An object of the present invention is to provide an automatic transmission power control circuit in which a fixed control speed, which is a problem of the prior art, is made variable and, in addition, an improved temperature characteristic which is easily changed by a temperature change is improved. To provide.

[0005]

In order to solve this problem, an automatic transmission power control circuit according to the present invention comprises a CPU,
Means for converting a DC signal obtained by rectifying and smoothing a part of the output of the power amplifier of the transmitter into a digital signal and inputting the digital signal to the CPU, and a memory connected to the CPU and supplying a required reference digital value to the CPU; Converting means for extracting an error digital value corresponding to the difference between the digital signal and the reference digital value from the CPU and converting the error digital value into an analog error voltage; And control means for controlling the power amplifier so that the error voltage becomes zero.

Also, a CPU, a means for converting a DC signal obtained by rectifying and smoothing a part of the output of a power amplifier of a transmitter into a digital signal and inputting the digital signal to the CPU, and a required reference digital value connected to the CPU. To the CPU, conversion means for extracting an error digital value corresponding to the difference between the digital signal and the reference digital value from the CPU, and converting the error digital value to an analog error voltage, Control means for controlling the power amplifier so that the analog error voltage becomes zero in accordance with the analog error voltage from the rectifying and smoothing circuit for extracting the rectified and smoothed DC signal. A temperature detecting element for extracting
Temperature compensating means for shifting the error digital value by a predetermined value for compensating for a change in the detection voltage due to a change in the temperature of the rectifier circuit in response to the detected voltage. Variations in the detection voltage can also be compensated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the DC response detected from the transmission output of a transmitter is digitally processed, so that the control response speed of the transmission output can be changed in a relatively wide variable range. Further, in addition to the digital processing, it is possible to compensate for a change in the detected voltage due to a temperature change of the rectifying / smoothing circuit for detecting the DC voltage from the transmission output.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The control speed, which is one of the problems solved by the present invention, is relatively fast rising / falling such as rising / falling of the transmission output (about 100 μm).
In the case of s), it can be realized by processing the output control signal at high speed by software. When a stable output is to be maintained as in the case of continuous transmission, the output control signal can be set to a low speed by software to prevent output fluctuation due to high-speed load fluctuation or the like.

Also, in the case of a radio using a digital modulation method, especially in the case of a time division multiplex radio, the slot at the time of transmission is usually as short as 10 ms or less. By using the invention, like the previous transmission slot data and the current transmission slot data,
Even when there is a time difference, control is possible, so that a transmission output control circuit can be easily realized.

Another problem to be solved is to improve the temperature characteristics by shifting the value of a memory set in advance so as to output a detection output according to the temperature detected by the temperature detecting element 18. Can be realized by: As shown in FIG. 1, a circuit for realizing these is to combine the transmission power output from the power amplifier 4 with a directional coupler 5 and convert it into a DC signal with a rectifier 8 and a smoother 9.
The signal is converted into a digital signal by the A / D converter 10. Next, data set in the memory 11 is output by the D / A converter 14 to output a specified output according to the digital signal, and the power amplifier 4 and the driver amplifier 3 are controlled by the voltage / current converter 12. Control the output voltage. Further, in order to improve the temperature characteristics, the signal detected by the temperature detecting element 18 is digitally processed by the A / D converter 15.

[0011]

As described above in detail, according to the present invention, a temperature detecting element used for temperature compensation or protection in another part of the radio equipment is diverted, and the temperature compensation of the transmission power is realized without increasing the cost. be able to. In addition, by making the response speed variable, which is difficult with the prior art, it is possible to secure a stable transmission output that is not affected by high-speed rising and falling characteristics, high-speed load fluctuation, and the like.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing a configuration example of the present invention.

FIG. 2 is a circuit configuration diagram showing a configuration example of a conventional automatic transmission power control circuit.

[Explanation of symbols]

 Reference Signs List 1 oscillator 2 buffer amplifier 3 driver amplifier 4 power amplifier 5 directional coupler 6 transmission filter 7 antenna 8 rectifier 9 smoother 10 analog / digital converter 11 memory 12 voltage / current converter 13 battery 14 digital / analog converter 15 analog / digital Converter 16 LPF 17 CPU 18 Temperature detection element

Claims (2)

[Claims] 1. A CPU, means for converting a DC signal obtained by rectifying and smoothing a part of an output of a power amplifier of a transmitter into a digital signal and inputting the digital signal to the CPU, and a required reference digital value connected to the CPU To C
A memory to be supplied to a PU, a conversion unit for extracting an error digital value corresponding to a difference between the digital signal and the reference digital value from the CPU, and converting the error digital value to an analog error voltage; Control means for controlling the power amplifier so that the analog error voltage becomes zero according to the analog error voltage. 2. A CPU, means for converting a DC signal obtained by rectifying and smoothing a part of the output of a power amplifier of a transmitter into a digital signal and inputting the digital signal to the CPU, and a required reference digital value connected to the CPU. To C
A memory to be supplied to a PU, a conversion unit for extracting an error digital value corresponding to a difference between the digital signal and the reference digital value from the CPU, and converting the error digital value to an analog error voltage; Control means for controlling the power amplifier so that the analog error voltage becomes zero according to the analog error voltage; anda temperature detecting element for extracting a detection voltage corresponding to a temperature of a rectifying and smoothing circuit for extracting the rectified and smoothed DC signal. A temperature compensating means for shifting the error digital value by a predetermined value for compensating for a change in the detected voltage due to a change in temperature of the rectifier circuit in accordance with the detected voltage. .