KR100938832B1 - Auto level and gain control apparatus for communication and broadcasting equipments - Google Patents

Abstract

The present invention provides an automatic level control device and an automatic gain control to simultaneously perform auto level control (ALC) and auto gain control (AGC) for signal amplification in an electronic device for communication and broadcasting. The present invention relates to an automatic level and automatic gain control apparatus for communication and broadcasting equipment in which the apparatus is integrally formed.

An input detector for detecting a voltage level of the input signal, having an input signal controller, an amplifier, and a controller for outputting a reference level signal for automatic level control; An output detector for detecting a voltage level of the output signal of the amplifier; After generating a difference signal between the input signal voltage level of the input detector and the reference level input from the controller, the difference signal is added to the voltage level of the input signal, and the difference signal between the summed signal and the voltage level of the output signal. An automatic level control unit for outputting an automatic level control signal; An automatic gain control reference level output unit for outputting the automatic gain control reference level to the automatic gain control unit; And an automatic gain control unit configured to add the output signal of the automatic level control unit and the automatic gain control reference level to output the automatic gain control signal to which the automatic level control is performed to the input signal controller.

Automatic level control, automatic gain control, power transmitter, power amplification, RF power amplification

Description

AUTO LEVEL AND GAIN CONTROL APPARATUS FOR COMMUNICATION AND BROADCASTING EQUIPMENTS}

The present invention provides an automatic level control device and an automatic gain control to simultaneously perform auto level control (ALC) and auto gain control (AGC) for signal amplification in an electronic device for communication and broadcasting. The present invention relates to an automatic level and automatic gain control apparatus for communication and broadcasting equipment in which the apparatus is formed integrally.

FIG. 1 is a block diagram of a controller 60 of an RF power amplifier for transmitting an RF signal of a general communication device. As shown in FIG. 1, a power amplifier of the prior art outputs an input signal and detects an input signal signal. An input signal detector 10 for outputting to the automatic gain controller and the automatic level controller AGC, ALC; A variable attenuator 20 which receives the output signal of the input signal detector 10 and varies the magnitude of the input signal according to the gain and level control signals of the automatic level and automatic gain controllers AGC and ALC; An RF power amplifier 30 for the variable attenuator 20 to amplify the output signal into a signal having a constant gain and level; An output signal detector 40 for outputting the output signal level signal detected from the reference level signal and the output signal of the RF power amplifier 30 to the automatic level and automatic gain controller 60; A power supply unit 50 for supplying the drive power adjusted to the automatic level and the automatic gain to the RF power amplifier 30; After receiving the reference level signal input from the output signal detector 40 and the output signal signal of the RF power amplifier 30, generate the automatic gain adjustment and automatic level adjustment signal and output to the power supply unit 50 and automatic gain A controller 60; The isolator 70 is configured to isolate the output signal of the RF power amplifier 30 to the RF signal transmitting end while isolating the signal of the RF power supply terminal from flowing into the RF power amplifier 30.

The RF power amplifier of the general communication and broadcasting electronic apparatus of the related art having the above-described configuration amplifies the output signal to have a certain gain in order to improve the efficiency of signal transmission and then outputs the amplified output signal. At this time, the gain and level by the signal amplification should be controlled so that the output signal has a set normal output signal, and when this condition is satisfied, an optimal signal transmission effect can be obtained. Therefore, in the above-described power amplifier of the prior art, the gain GAIN for power amplification becomes an important factor, and a circuit for controlling the gain constant by such a gain signal may be essential.

Accordingly, in the case of the communication and broadcasting electronic device of the prior art, the automatic level and automatic gain controller for automatic gain control (AGC) and automatic level control (ALC) in order to optimally amplify the signal as shown in FIG. (60) must be provided.

In this case, in the case of the aforementioned automatic level and automatic gain controller 60, the automatic gain controller and the automatic level controller are generally implemented as separate devices.

In this case, when using the digital method, the CPU detects and compares the amplitude of the digital sample signal generated through the A / D converter, and converts the voltage gain control signal to the D / A converter so as to be at a desired level or area. Is configured to control the level of the analog input signal, and is configured to control the automatic gain controller using a step of the D / A converter. In the case of using the analog method, circuits such as a detector and a direct current amplifier are included.

However, the prior art as described above has the following problems.

First, in the case of the digital method, a technology for processing a signal through the A / D converter as described above is difficult to control in response to changes according to the performance of the processor processing the signal, and according to the step of the D / A converter. Gain GAIN also has a disadvantage of having a step. In addition, the operation of the automatic level control (ALC) and automatic gain control (AGC) has a problem that the processing speed is lower than the analog method.

Next, in the case of the analog system, since a circuit such as a detector or a direct current amplifier must be included, the configuration of the analog circuit is complicated.

In the conventional automatic level and automatic gain controller 60, the automatic level controller and the automatic gain controller are implemented as separate devices, so that a separate circuit must be configured, and accordingly, there is a problem in that a large cost is required. .

Therefore, the present invention is to solve the above-mentioned problems of the prior art, using an operational amplifier (OP amplifier: OPAMP) and resistors and capacitors, the circuit configuration is simpler than the conventional analog automatic gain and level controller, automatic level controller It is an object of the present invention to provide an automatic level and automatic gain control device for communication and broadcasting equipment, which enables the automatic gain controller and the automatic gain controller to be integrated.

In addition, the present invention implements a device that feeds back (OPAMP) in order to properly control the gain of the average output signal level within the range of the input signal level (OPAMP), even in the excessive input signal It is an object of the present invention to provide an automatic level and automatic gain control device for communication and broadcasting equipment that restricts the output and protects the power amplifier even from an input having a capacity or more.

The automatic level and automatic gain control apparatus for communication and broadcasting equipment of the present invention for achieving the above object comprises an amplifying unit for amplifying an output signal of the input signal control unit and the input signal control unit and a reference level signal for automatic level control. An automatic level and automatic gain control device having a control unit for outputting, comprising: an input detector for detecting a voltage level of the input signal and outputting the detected voltage level to the control unit, the delay unit, and the automatic level control unit; An output detector for detecting a voltage level of the output signal of the amplifier and outputting the voltage to the controller and the automatic level controller; A controller connected in parallel with the delay unit at an output terminal of the input detector and receiving a voltage level of the input signal and an output signal voltage level of the output detector and inputting a reference level for automatic level control to the automatic level controller; By comparing the voltage level of the input signal input from the input detection unit and the reference level input from the control unit generates an input signal voltage level adjustment signal so that the input signal has a maximum voltage level, and the voltage level adjustment signal of the input signal and An automatic level control unit for generating and outputting a difference signal of a voltage level of the output signal; An automatic gain control reference level output unit for outputting the automatic gain control reference level to the automatic gain control unit; And an automatic gain control unit for comparing the output signal of the automatic level control unit with the automatic gain control reference level and outputting the automatic gain control signal on which the automatic level control is performed to the input signal controller.

The input detection unit may include a delay unit located in front of the automatic level control unit and delaying the detected input signal to have the same phase as the output signal.

The automatic level control unit includes: a first OP amplifier for inputting an input signal voltage level input from the input detection unit to a non-inverting terminal, and inputting the automatic level control reference level to an inverting terminal and outputting a difference signal; The first diode D1 and the second diode D2 are connected to the output terminal of the OP amplifier and the cathode is connected to the non-inverting terminal of the second OP amplifier of the first adder and the anode of the second diode grounded with the cathode. A first subtractor having a diode portion comprising; And a second OP amplifier for inputting an output signal of the first subtractor and an automatic level control reference level of the controller, and a voltage level of the input signal to a non-inverting terminal to output the sum signal. A first adder; And a second subtractor comprising a third OP amplifier configured to receive the first adder output level as an inverting terminal and receive the voltage level of the output signal of the output detector as a non-inverting terminal and output the difference signal. It is characterized in that the configuration.

The automatic gain control unit may include a second adder having a fourth OP amplifier configured to add and output the output signal of the automatic level control unit and the automatic gain control reference level as non-inverting terminals.

The automatic gain control unit is configured to sequentially connect the integrator and the buffer to the output terminal of the adder to improve the stability of the output signal of the fourth OP amplifier.

The automatic level and automatic gain control device of the present invention having the above-described configuration generates an input level control signal in the automatic level control unit by configuring the automatic level control unit and the automatic gain control unit as one circuit, and the automatic gain control unit is configured to adjust the input level. By generating and outputting an output signal for the automatic level control and the automatic gain control, the automatic level and the automatic gain can be simultaneously performed by one circuit.

The present invention having the above-described configuration uses an operational amplifier (OPAMP), a resistor and a capacitor, and the circuit for the control of the automatic level and the automatic gain is formed integrally to form a closed loop of the conventional analog system automatic The circuit configuration is simpler than that of the gain and level control device to facilitate the manufacturing, to significantly reduce the manufacturing cost, and to provide an effect of significantly improving the operation performance.

In addition, the present invention can determine the limits of the gain adjustment and output level of the electronic device, so that the power amplifier can be protected even when a signal having a higher voltage level than the capacity is input to the power amplifier, thereby improving the durability of the equipment. It provides an effect.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

2 is a block diagram of an automatic level and automatic gain control device 100 (hereinafter referred to as "control device 100") for communication and broadcasting equipment according to an embodiment of the present invention.

As shown in FIG. 2, the control device 100 for automatic level and automatic gain control according to an embodiment of the present invention detects a voltage level of an RF transmission target input signal and controls the controller 190 and the delay unit ( An input detector 110 outputting to the automatic level control unit 140 and 120; A delay unit 120 for delaying the voltage level of the input signal detected by the input detection unit 110 to match the voltage level and the phase of the output signal, and outputting the delayed signal to the automatic level control unit 140; An output detector 130 which detects an output signal voltage level of the power amplifier and outputs the voltage to the controller 190 and the automatic level controller 140; It is connected in parallel with the delay unit 120 at the output terminal of the input detector 110 receives the voltage level of the input signal and the output signal voltage level detected by the output detector 130, and then automatically sets the reference level for automatic level control. A controller 190 input to the controller 140 and formed of a substrate on which each component is mounted; The input signal voltage level for adjusting the input signal voltage level so that the input signal has the maximum voltage level of automatic level control by comparing the voltage level of the input signal input from the input detector 110 with the reference level input from the controller 190. An automatic level control unit 140 for generating an adjustment signal and outputting an output signal in which the automatic level control signal is reflected by generating a difference signal between the voltage level adjustment signal of the input signal and the voltage level of the output signal; An automatic gain control reference level output unit 150 for outputting the automatic gain control reference level to the automatic gain control unit; An automatic gain control unit 160 for comparing the output signal of the automatic level control unit 140 with the automatic gain control reference level and outputting the automatic gain control signal to which the automatic level control is performed to the input signal controller 170; An input signal controller 170 for adjusting the RF transmission target input signal; A power amplifier 180 that performs power amplification on the output signal of the input signal controller 170; is configured as an integrated circuit. In this case, the input signal controller 170 includes a variable attenuator.

In the present invention having the above-described configuration, the automatic level control unit 140, the automatic gain control reference level output unit 150 and the automatic gain control unit 160 may be implemented in a circuit as shown in Figs. 2 is a circuit diagram showing the detailed configuration of the automatic level control unit 140 of FIG. 2, and FIG. 4 is a circuit diagram showing the detailed configuration of the automatic gain control unit 160 of FIG.

First, referring to Figure 3 will be described in more detail the automatic level control unit 140 of the present invention.

As shown in FIG. 3, the automatic level control unit 140 inputs the input signal voltage level detected by the input detection unit 110 to the non-inverting terminal through the resistor R41 and outputs the automatic level control output from the control unit 190. A reference level is input to the inverting terminal through the resistor R52 and outputs the difference signal. An anode is connected to the output terminal of the first OP amplifier OP1 and the cathode is connected to the second of the first adder. The diode part 141a which consists of the 1st diode D1 and the 2nd diode D2 connected to the non-inverting terminal of the OP amp OP2 and the anode of the 2nd diode D2 with which the cathode is grounded (refer FIG. 2). A first subtraction unit 141 having a); The output signal of the first subtractor 141 and the automatic level control reference voltage of the controller 190 are input to the inverting terminal through the resistor R38, the voltage level of the input signal is input to the non-inverting terminal through the resistor R34, At the front end of the inverting terminal, one end is connected in parallel with the resistor R34 and the other end is inputted to the non-inverting terminal through a wiring having a resistor R47, and the sum signal is outputted, and the output side includes the resistor R48 as the inverting terminal. A first adder 142 having a second OP amplifier OP2 connected to one side of the resistor R42 so as to be grounded; The first adder 142 output level is input to the inverting terminal through the resistor R35, the voltage level of the output signal of the output detector is configured to be input to the non-inverting terminal through the resistor R39, the inverting terminal is provided with a resistor R49 A third OP amplifier (1) which compares the output level of the first adder 142 and the voltage level of the output signal of the output detector and outputs the difference signal to the non-inverting terminal of the fourth OP amplifier OP4 of the automatic gain control unit 160. And a second subtractor 143 made of OP3).

Next, as shown in FIG. 4, the automatic gain control unit 160 outputs the output signal of the automatic level control unit 140 and the output signal of the automatic gain control reference level output unit 150 through the non-inverting terminal through the resistor R40. And a second adder 161 having a fourth OP amplifier for outputting the output signal reflecting the automatic level control and the automatic gain control and adding the sum signal to improve the stability of the output signal of the second adder 161. Integrator 162 and buffer 163 are sequentially connected to the output terminal of the two adder 161.

The operation of the automatic level control unit 140 and the automatic gain control unit 160 having the above-described configuration will be described below.

First, the automatic level control unit 140 will be described. The automatic level control unit 140 outputs a signal of 0 V when the voltage level of the input signal is in the normal operation state lower than the reference level for the automatic level control. If the voltage level of the signal is higher than or equal to the reference level for automatic level control, the difference signal is output.

In detail, the first subtraction unit 141 of the automatic level control unit 140 has a voltage level smaller than a reference level (maximum input voltage level of automatic level control) of the input signal input to the first OP amplifier OP1. In this case (normal state), the first OP amplifier OP1 outputs a negative voltage signal, and accordingly, the first diode D1 is turned off to turn off the second OP amplifier OP2 of the first adder 142. Make OV input to the reverse terminal. In this case, the second OP amplifier OP2 of the first adder 142 outputs the signal input to the non-inverting terminal to the second subtractor 143 as it is.

However, when the voltage level of the input signal inputted to the first OP amplifier OP1 is greater than the reference level, the first OP amplifier OP1 outputs a positive difference signal to the first adder 142. The first adder 142 adds the difference signal to the voltage level of the input signal and outputs the difference signal to the second subtractor 143.

The second subtractor 143 outputs a signal level of a difference between the voltage level of the output signal and the output level of the first adder 142. In this case, the automatic level control is performed by outputting the output signal of the second subtractor 143. This is the signal that was performed.

That is, when the voltage level of the input signal is higher than the reference level for the automatic level control, the automatic level control unit 140 of FIG. 3 outputs a signal in which the level control is reflected.

Next, the operation of the automatic gain control unit 160 will be described with reference to FIG. 4.

As shown in FIG. 4, the fourth OP amplifier OP4 configured in the second adder 161 of the automatic gain control unit 160 includes the output signal of the automatic level control unit 140 and the automatic gain control reference level output unit 150. The automatic gain control reference level signal is inputted and summed and output. The signal output from the automatic gain control unit 160 is a control signal reflecting the automatic level control and the automatic gain control. The control signal reflecting the automatic level control and the automatic gain control output from the second adder 161 is input to the input signal controller 170 which is a voltage gain adjusting device through the integrator 162 and the buffer 163 to improve stability. .

As described above, the signal in which the auto level and auto gain control is performed is applied to the input signal controller 170 to perform the auto level and auto gain control on the input / output signal from the RF transmitter.

That is, the above-described automatic level and automatic gain control apparatus of the present invention prevents excessive input signal from being input to the amplifier by automatically controlling the input signal level so that the input level has a reference level, and by automatic gain control. The output level can also be controlled to have an appropriate level.

1 is a block diagram of a controller 60 of an RF power amplifier for RF signal transmission of general communication equipment;

2 is a block diagram of an automatic level and automatic gain control apparatus for communication and broadcasting equipment according to an embodiment of the present invention;

3 is a circuit diagram showing a detailed configuration of the automatic level control unit 140 of FIG.

4 is a circuit diagram illustrating a detailed configuration of the automatic gain control unit 160 of FIG. 2.

Description of the main symbols in the drawings

100: automatic level and automatic gain control

110: input detector 120: delay

130: output detector 140: automatic level control unit

150: automatic gain control reference level output unit

160: automatic gain control unit 170: input signal control unit

180: amplification unit 190: control unit

Claims (6)

In the automatic level and automatic gain control device having an input signal control unit, an amplifier for amplifying the output signal of the input signal control unit and a control unit for outputting a reference level signal for automatic level control, An input detector for detecting a voltage level of the input signal; An output detector for detecting a voltage level of the output signal of the amplifier; After generating the difference signal between the input signal voltage level of the input detector and the reference level input from the controller, the difference signal is added to the voltage level of the input signal, and the difference between the summed signal and the voltage level of the output signal. An automatic level control unit for outputting an automatic level control signal as a signal; An automatic gain control unit configured to add the output signal of the automatic level control unit and the automatic gain control reference level to output the automatic gain control signal on which the automatic level control is performed to the input signal controller; and comprises an integrated circuit. And automatic level and gain control device for broadcast equipment. The apparatus of claim 1, wherein the automatic level and automatic gain control device further comprises an automatic gain control reference level output unit for outputting the automatic gain control reference level to the automatic gain control unit. Level and Auto Gain Control. The automatic level for communication and broadcasting equipment according to claim 1, wherein the input detection unit comprises a delay unit which is located in front of the automatic level control unit and delays the detected input signal to have the same phase as the output signal. And automatic gain control device. The method according to claim 1, wherein the automatic level control unit, An input signal voltage level input from the input detection unit is input to a non-inverting terminal, and the automatic level control reference level is input to an inverting terminal and outputs a difference signal to the output terminal of the first OP amplifier. A first subtracter having a diode portion consisting of a first diode and a second diode connected to a non-inverting terminal of a second OP amp of the first adder and an anode of a second diode to which the cathode is grounded; A first adder having a second OP amplifier for outputting the output signal of the first subtractor and the automatic level control reference level of the controller to an inverting terminal and outputting the summed signal; A second subtractor comprising a third OP amplifier receiving the first adder output signal as an inverting terminal and a voltage level of the output signal of the output detecting unit as a non-inverting terminal and outputting a difference signal; Automatic level and automatic gain control device for communication and broadcasting equipment, characterized in that the configuration. The method according to claim 1, wherein the automatic gain control unit, Automatic level for communication and broadcasting equipment comprising a second adder having a fourth OP amplifier for receiving and outputting the output signal of the automatic level control unit and the automatic gain control reference level signal as a non-inverting terminal. And automatic gain control device. The apparatus of claim 5, wherein the automatic gain control unit is configured to sequentially connect an integrator and a buffer to an output terminal of the second adder.

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