SU1707763A1 - Automatic output-power control for transmitters - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to increase the smoothness of regulation by eliminating outliers and dips in the output signal. For this, the serially connected control signal generator 16 (FUS), reference frequency unit 1, amplitude modulator 2, wideband amplifier 3, tunable power amplifier 4, first amplitude detector 5, control switch 6, first low-pass filter 7 (LPF) , the threshold element 8 and the comparison unit 9, to another input of which a signal is fed from the third amplitude detector 12, the second low pass filter 13 and the direct current amplifier 14 (DCA) are connected in series, produce a signal that controls in the process of automatic control of the FUS 16, the third and fourth outputs of which are connected respectively to the second input of a controlled switch 6, alternately connecting the first 5 and second 10 amplitude detectors to the input of the first low-pass filter 7 and to the second input of the tunable amplifier 4, modifies the gain of the amplitude modulator 2 so that there are no bursts and dips in the output voltage. The first 11 and second 15 bits d (L S

Description

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These switches reduce the voltage at the outputs of the first 7 and second 13 low-pass filters after the transition process, which ends when the tunable power amplifier reaches the output of

signal strength. The fourth and fifth inputs of the FUS 16 are, respectively, an input of information about the tuning frequency and an input of low-frequency signals and information transmitted. 2 Il.

This invention relates to radio engineering and can be used in range radio transmitters.

The aim of the invention is to increase the smoothness of regulation by eliminating outliers and dips in the output signal.

Fig. 1 shows a structural electrical circuit of an automatic transmitter power control device; figure 2 - timing diagrams. deactivating the device.

The device contains a reference frequency unit 1, an amplitude modulator 2, a wideband amplifier 3, a tunable power amplifier (PIP) 4, a first amplitude detector 5, a controllable switch 6, a first low pass filter (LPF) 7, a threshold element 8, a block 9 compare the second amplitude detector 10. the first bit switch 11, the third amplitude detector 12, the second low pass filter 13, the amplifier 14 dc, the second bit switch 15 and the driver control signals (FUS) 16.

The device works as follows.

In the initial state, the signal at the input of the reference frequency block 1 is absent. There is also no signal at the outputs of reference frequency unit 1, amplitude modulator 2, wideband amplifier 3, PIP 4, first amplitude detector 5, second amplitude detector 10, third amplitude detector 12 and, therefore, at the output of direct current amplifier 14 and at the output the threshold element 8. In this case, the output signal of the comparator unit 9 sets the transmission coefficient of the amplitude modulator 2 to a minimum. Capacitors (not shown) of the first 7 and second 13 low-pass filters are discharged,

When a signal is applied to the fourth input of the FUS 16 (FIG. 2, a), the first input of the reference frequency unit 1 is given a signal from the first output of the FUS 16 (FIG. 2, b); At the first output of the reference frequency unit 1, a signal appears with a frequency determined by the signal at the fourth input of the FUS 16, shown in FIG. 2, d conventionally in the form of a radio pulse envelope, and from the second output i the reference

frequency on the first input FUS 16 receives a control signal (figure 2, d). Fifth input FUS 16 is designed to signal information transmitted over the air

(figure 2, c).

At the output of the third amplitude detector 12, a rectified voltage appears (Fig. 2.e) charging the capacitor (not shown) of the second LPF 13 (Fig. 2, g). WITH

the output of the second low-pass filter 13, a signal with a voltage that grows exponentially, with a speed determined by the selected bandwidth of the low-pass filter 13, enters through an amplifier 14 constant

current to the first input of block 9 comparison. The rising signal from the output of the comparator unit 9 begins to increase the gain of the amplitude modulator 2. As the voltage at the output of the amplitude modulator 2 increases, the voltage at the outputs of the broadband amplifier 3, the first amplitude detector 5 and the second amplitude detector 10 (Fig.2, and kl ln m). The signal of the second amplitude detector 10, the passage through normally closed contacts (not shown) of the controlled switch 6, charges the capacitor of the first low-pass filter 7 discharged in the initial state (not shown).

At the output of the first low-pass filter 7, an exponential signal appears (Fig. 2, o). This signal arrives at the threshold element 8. When the threshold level is reached by this signal, the threshold element 8 passes this signal to the second input of the comparator unit 9 (Fig. 2 , P). In block 9 of the comparison, the specified signal is subtracted from the signal arriving at the first input of this block from the amplifier 14 constant

current. As a result, at the output of comparator block 9, the signal decreases and, acting on the amplitude modulator 2, reduces its transmission coefficient. Therefore, the voltage of the output signal I, the amplitude modulator 2 and the wideband amplifier 3 decreases. Upon reaching the nominal level of the signal at the output of the wideband amplifier 3, the first input of the FUS 16 receives a signal indicating the end of the transient process, and the RIGIM of stabilization of the nominal level occurs

the output of the broadband amplifier 3 (figure 2. p).

In this case, from the fourth output of the FUS 16, the PUM 4 tuning commands for the specified frequency are received at the second input of the PUMA A (figure 2, c). At the end of the tuning cycle from the second output of the PUM 4 to the second input of the FUS 16, a signal for the end of the tuning is received (Fig. 2, d).

At the fourth output of the FUS 16, the sequence of pulses is stopped (Fig. 2, s), from the first output of the FUS 16 to the input of the reference frequency unit 1 a locking signal is received, from the second output of the FUS 16 to the control inputs of the first 11 and second 15 bit keys receives a signal that includes them (figure 2, y). A pulse arrives at the second input of the control switch 6, which causes the control switch 6 to be switched to the state when the output of the first amplitude detector 5 is connected to the input of the first low-pass filter 7. At the same time, the first 11 and second 15 bits are lowered to zero. the voltage of the output signals of the first 7 and second 13 low-pass filters, the result of which is the determination of the transmission coefficient of the amplitude modulator 2 to the nominal value.

When the signal is terminated, the settings are completed (Fig. 2, p) at the first and second outputs of the CLC 16, the signals also end (Fig. 2, b and y). This leads to the appearance at the output of block 1 of the reference frequency of the signal of the aesthetic esthete. When ems from the output of the third amplitude detector 12, the signal arrives at the second LPF 13 whose output voltage begins to increase exponentially (Figure 2, f). From the output of the second low-pass filter 13 via the amplifier 14, a direct current signal is connected to the first input of the reference unit 9. The increase in amplitude of the signal with 5lo a comparison (Fig. 2k) is fed to the second input of the amplitude modulator 2, near the E o l i. n: - his is about 11 transmission pattern. The signal at the output of the PUM 4 (Fig. 2, f) and at the output of the first amplitude detector 5 increases accordingly. This signal goes through the controlled switch 6 to the first low-pass filter 7, so the voltage on Ey.-one of the first low-pass filter 7 increases (Fig 2. o). Upon reaching the threshold uroanr signal passes through the threshold element 8 and. arriving at the second input of unit 9 of comparison is subtracted from the signal arriving at the first input of unit 9 of comparison. As a result, the voltage at the output of the comparator unit 9 decreases, which leads to a decrease in the transmission coefficient of the amplitude modulator 2 and a corresponding decrease in the voltage

the outputs of the broadband amplifier 3 and the PIP 4. When the signal at the output of the PIP 4 reaches the nominal level, the circuit goes into the stabilization / nominal level of the signal at the output of the PIP 4.

The decrease in the rate of increase of voltage at the output of the comparator unit 9 as the transition process approaches completion ensures the absence of emissions and dips in the output signal of the transmitter's automatic power control device during the transient process.

Claims (1)

Claims An automatic transmitter output power control device comprising a serially connected driver of control signals, a reference frequency unit, an amplitude modulator, a wideband amplifier, a tunable power amplifier, a first amplitude detector and a control switch, a second amplitude detector, whose input is connected to a wideband output amplifier, and the output of which is connected to the second input of the controlled switch, the first low-pass filter, the comparison unit The first bit switch, the control input of which is connected to the second output of the control signal generator, and the output of which is connected to the common bus, while the output of the tunable power amplifier is the output of the automatic output power control of the transmitter, characterized by what. In order to improve the smoothness of the regulation by eliminating outliers and dips in the output signal, a third amplitude detector, in series, was inputted, the input of which is connected to the output of the reference frequency block of the second Low-pass filter and the DC amplifier whose output is connected to the first input of the comparator, the second bit a single key, the control input of which is connected to the control input of the first bit switch, and a threshold element, the input of which is connected to the output of the first low-pass filter and the signal the input of the first bit switch, while the input of the first low-pass filter is connected to the output of the controlled switch, the output of the threshold element is connected to another input of the comparison unit, the signal input of the second bit switch is connected to the output of the second low-pass filter, the output of the second bit switch is connected to the common bus, the first, second and third inputs of the control signal generator are connected respectively to the second output of the reference frequency block, to the second output of the tunable power amplifier and to the second output the broadband amplifier, the second, third and fourth outputs of the driver control signals are connected respectively to the control input The house of the first bit switch, with the second input of the controlled switch and the second input of the tunable power amplifier, the fourth input of the control signal generator is the input of the transmitter tuning frequency information, and the fifth input of the control signal conditioner is the input of the transmitted information.