JPS59181832A - Automatic power controller of transmitter - Google Patents

Abstract

PURPOSE:To prevent an excess transmission signal from being transmitted even if a transmission signal is intermitted by zeroing substantially the fluctuation of a transmission level when the transmission is restarted. CONSTITUTION:When the transmission signal is stopped, a contact of a relay 7 is opened so as to open an automatic power control system S. When the transmission is restarted, an alarm control circuit 5 detects the start of transmission by an output voltage of a comparator amplifier 3, and when the transmission level is increased more than the transmission level decided by a reference voltage source 4, the contact of the relay 7 is closed. In designing the response speed of a voltage current converter 9 remarkably faster than the time constant of a low pass filter 6, since the voltage current converter 9 is operated so as to keep the output current zero, the output voltage of the converter 9 is coincident with the level control voltage of a voltage control attenuator 24 before the fluctuation of the level control voltage of the voltage control attenuator 24 is detected, thereby zeroing substantially the fluctuation in the transmission level.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic power control device that provides a stable control response even when a C1 transmission signal is interrupted in a communication device that transmits data intermittently.

Automatic power control devices are often used to suppress fluctuations in transmitter amplification due to fluctuations in ambient temperature or primary voltage, but in communication devices that transmit signals intermittently, when transmission stops, The negative feedback loop that performs automatic power control is
In order to maximize the transmitter's amplification in order to increase the total output level as much as possible, if transmission is restarted in this state, the transmitter's amplification at the beginning will be excessive and much higher than the specified transmit level. It will send out a level signal. Excessive transmission level is undesirable because it may interfere with other communications and may cause deterioration of the transmitting tube or semiconductor element due to a saturation of the transmitter.

[Explanation of conventional example]

The operation of the conventional automatic power control device will be described below with reference to FIG.

The transmission signal supplied to the input terminal 26 is attenuated by the voltage controlled attenuator 24 and then transmitted to the transmission power amplifier 23! l) Amplified and directional coupler 22f: via the antenna 2
1 is radiated into space. The amount of attenuation of the voltage controlled attenuator 24 is controlled by the output voltage of the fixed bias source 25 when the automatic power control loop L (described later) is disconnected.

A part of the transmission signal branched out by the directional coupler 22 is detected by the wave detector 1 and becomes a DC voltage signal according to the transmission level. The DC voltage signal from the detector 1 and the output signal from the first reference voltage source 2 are compared by a comparator amplifier 3, and the eye difference signal e is 11! ! 2 amplifier 13 to low pass filter 6. Through the contact of the relay 7, the output voltage of the fixed bias source 25 located ahead of C1 is I-plus-converted and negatively fed back to the voltage-controlled attenuator 24.

The transmission output level in steady state is determined by the output voltage of the first reference voltage source 2.

Further, the alarm control circuit 5 outputs the output signal e of the comparator amplifier 3 and the second
and the output voltage of the second reference voltage source 4, and if the transmission level becomes lower than the value determined by the output voltage of the second reference voltage source 4, the contact of the relay 7 is opened to disconnect the automatic power control loop L. do.

Although this conventional automatic power control device operates stably in a steady state, when the transmission signal is intermittent as described above, the comparator amplifier 3
The output error signal eI7:1 voltage becomes the voltage that minimizes the amount of attenuation of the voltage-controlled attenuator 24, and the capacitor in the low-pass filter 6 is charged with this voltage.・The moment the alarm control circuit 5 cancels the alarm and closes the contacts of the relay 7, the attenuation ml of the attenuator 24 becomes the minimum, and excessive transmission power is radiated from the antenna 21. I had a good time.

[Description of the invention]

The present invention is based on the above considerations and aims to provide an automatic power control device that does not radiate excessive transmission power from an antenna even when there is a fire.

Below, using FIG. 2, automatic power supply according to the present invention? An embodiment of the li control device will be described in detail.

The device according to the present invention supplies an intermittent transmission signal supplied to an input terminal 26 to a voltage-controlled attenuator 24, performs level control, and then amplifies the same signal by a transmission power amplifier 23. The antenna 21 radiates the light into space through the antenna 21. Further, the amount of attenuation of the voltage-controlled attenuator 24 when the automatic power control system S (described later) is open is determined by the output voltage of the fixed bias source 25. The above operation is almost the same as that of a conventional automatic power control device.

In the device according to the present invention, a part of the transmitted signal is taken out by the directional coupler 22, detected by the detector 1, and a tally output signal and the output signal of the first reference voltage source 2 are supplied to the soft amplifier 3. Then, the difference between the two is amplified by a certain value. The amplified signal e is supplied from the specific soft amplifier 3 to the voltage-current converter 9 whose output current changes according to the magnitude and polarity of the input voltage via the resistor 8, and the output current of the voltage-current converter 9 is further increased. The output signal of the fixed bias source 25 is multiplied by M through the contact point of the first relay 7 and the low-pass filter 6, and the negative signal is returned to the voltage controlled attenuator 24 to set the transmitter output level to the first reference. Voltage source 2
Stabilizes to a constant value determined by .

Now, considering the situation where the transmitting (g) signal has stopped, first, a decrease in the transmitting signal level changes the output voltage e of the detector 1 and the comparison/amplifier 3. This change causes the information control circuit 5 to When the signal is transmitted and the transmission level falls below a certain value determined by the second reference car pressure 4, the wheel axle control circuit 5 opens the contacts of the first relay 7 and opens the automatic power control system S, and at the same time lowers the voltage. The input terminal of the power/L converter 90 is grounded using the contact of the second relay 10.

When transmission is restarted next time, the automatic power control system S is open, so the transmission force becomes a value determined by the attenuation amount of the voltage controlled attenuator 24 controlled by the fixed bias source 25.

The alarm control circuit 5 detects the start of transmission using the output voltage C of the comparator amplifier 3, and when the transmission level becomes higher than the transmission level determined by the second reference voltage source 4, the alarm control circuit 5 activates the first relay 7. Close the contacts.

The output voltage of the voltage-current converter 9 at the point 11J when the contact is closed is 岑, which is not equal to the voltage Vi appearing at the input terminal of the low-pass filter 56 because it is the output voltage of the fixed bias source 25, and theoretically the contact is At the moment of closing 1ii1, *θIL flows from the low-pass filter 6 toward the piezoelectric L converter 9, resulting in a voltage! The level control voltage of the tjiJ control attenuator 240 changes, and therefore the transmission level changes with respect to the transmission level when transmission is restarted.

However, if the response speed of the voltage-current converter 9 is designed to be significantly faster than the time constant of the low-pass filter 6, the voltage-current converter 9 will operate to maintain its output voltage b'1↑ at a constant level. In order to
Setting the output voltage to zero in accordance with the level control voltage of 1 means equalizing the voltages at both ends. ), the fluctuation in the transmission level becomes essentially zero.

The tube shaft control circuit 5 further opens the contacts of the second relay 10 after a certain period of time determined by the delay circuit 11. From this point on, the automatic power control loop L begins to operate, and the transmission output level converges to a certain value determined by the first reference voltage source 2. In this case, the transmission level when the automatic power control loop L is disconnected is determined by the output voltage of the fixed bias source 25.
When the transmission level is higher than the transmission level determined by the first reference voltage source 2, the voltage frost one-current converter 9 sinks the output current of the constant bias source 25, and conversely when it is lower than the transmission level, it discharges the output current.

As described above, the present invention provides an automatic power control device suitable for a line that transmits signals intermittently, but the present invention also provides an automatic power control device suitable for a line that transmits signals intermittently. When applied to cases where a momentary interruption of the transmission wave occurs, such as during switching, it is possible to prevent the radiation of excessive force when transmission is resumed, resulting in a great effect.

In the configuration of this device, a detector was used as a detector for the transmitted @information level, but it is also possible to use a 'trajectory cap' using a thermocouple, thermistor, etc. that detects the signal level. The same effect can be obtained.

+ of the sweet circuit? I explained using a mechanical relay for l++, but it is also possible to replace the relay with another semiconductor element.
1. Of course it can be done simply.

[Absorption of the present invention]

To avoid invention here, the transmission signal is supplied to the transmission power amplifier via a voltage controlled attenuator whose attenuation is controlled by fixed biases, and the amplifier In , a part of the output signal of the transmission power amplifier is taken out by a directional coupler 17, and this is detected by a detector, and the obtained constituent output signal and the output signal of the first reference voltage source are supplied to a comparison amplifier. After amplifying the voltage difference between the two, the output voltage is converted into a current by a 5-voltage L converter,
Through the first relay contact and the low-pass filter, the current is multiplied by M to the output signal of the previously made Bobbias filter and fed back to the voltage controlled attenuator, and the superstition output level is set to the first reference voltage. A constant value determined by the output voltage of the source (automatic power control iron stabilized by IM (alarm output No. 16 of the C1 comparator amplifier and output signal of the second reference voltage source)! 1) connected to the control circuit C,
*If the transmission signal is stopped by the signal control circuit, open the first relay contact and at the same time ground the input terminal of the voltage-current converter through the second relay contact and stop the transmission. In this case, at the same time as closing the first relay contact, after a certain period of time determined by the delay circuit, the input terminal of the voltage-current converter is grounded, and the second relay is connected to the transmitter 1b. It is an automatic power control product that has the feature of not sending out a large groove transmission signal even if the No. 1 U+Top is performed.

[Brief explanation of drawings]

Figure 1 is a system diagram of a conventional automatic power control device.
The figure is a thread diagram of an automatic power control device according to the invention. 23°・°・Pacific signal power amplifier, 2...First reference voltage source, e...°°・° difference voltage, error signal, output number, 3......Ratio Soft amplifier, 7...Relay, 1st loop, 1 notch, 6...Low pass filter, 4...2nd reference voltage source , 5°°°° Ankarashin 12 City 1'' control circuit, 9... Voltage current conversion, -
, Figure 1■ Figure 2

Claims (1)

[Claims] A transmitter that transmits a transmission signal through a voltage control attenuation means and a transmission power amplifier, the difference voltage between a detected output signal taken out from the transmission power amplifier etc. and an output signal of a first reference voltage source. a comparator amplifier for obtaining a voltage difference from the comparator amplifier; means for feeding back a differential voltage from the comparator amplifier to the voltage control attenuation means via the first switch means and a low-pass filter; When the transmission signal of n11 Ht stops by comparing the output signal of the source, the above first
In an automatic force control device having a transport/shaft control circuit surrounding the switch means, a voltage-current converter converts the above-mentioned differential voltage into a current and sends it to the above-mentioned first switch means;
When the transmission IC signal is stopped, the voltage difference is grounded simultaneously with the switching means; when the transmission signal is resumed, the first switch means is closed, and then, An automatic power control device for a transmitter, characterized in that it is completely equipped with a second switch means that disconnects the voltage difference after a certain period of time has elapsed.