KR200291223Y1 - A control circuit of output level for base site transmitter - Google Patents

Abstract

The present invention relates to a circuit for automatically controlling the transmitter output level of the base station equipment, and more particularly, to simplify the configuration of the control circuit by applying the superposition theory, the circuit for controlling the output level of the base station transmitter; A comparison unit for inputting a control value and an input level value to an inverting terminal, inputting an output level value and a reference value to a non-inverting terminal, and amplifying a difference between signals input to each terminal at a predetermined ratio set in an opamp; An integrating unit for inputting and integrating a signal output from the comparing unit as an inverting terminal; Characterized in that the control unit for inputting the signal output from the integrator and automatically control the output level of the base station transmitter, simplifying the circuit configuration, miniaturization, low cost, easy maintenance, industrial use effect and trouble reduction The reliability of the control circuit is increased.

Description

Output level control circuit of base station transmitter {A CONTROL CIRCUIT OF OUTPUT LEVEL FOR BASE SITE TRANSMITTER}

The present invention relates to a circuit for automatically controlling the transmitter output level of the base station equipment, and more particularly, to simplify the configuration of the control circuit by applying the super position theory (SUPER POSITION THEORY).

The base station system of the mobile communication up-converts the intermediate frequency (IF) signal applied from the control station to the corresponding high frequency (RF) signal and transmits the radio by wirelessly transmitting the radio signal from the mobile terminal. It receives a high frequency signal to be transmitted and down-converts (DOWN-CONVERTING) to convert to an intermediate frequency signal to output to the control station.

The up-and-down conversion function as described above is called an up / down converter, and in particular, since the output level of the signal transmitted wirelessly from the base station transmitter must be constant, the output level control circuit plays a very important function.

The mobile communication system uses a technology that allows a plurality of subscribers to receive a mobile communication service using limited frequency resources. For example, a code division multiple access (CDMA) technique is used. At the same time, the level of the signal received from the plurality of mobile terminals must be the same at the base station, and the level output from the base station must also be kept in a controlled state.

In order to maintain the level output from the transmitter in a controlled state in the CDMA mobile communication base station system as described above, the output level and the input level are detected and used, Control the output level of the base station transmitter to be constant.

Hereinafter, a transmitter output level control circuit of a base station equipment according to the prior art will be described with reference to the accompanying drawings.

1 is a block diagram of a base station transmitter output level control circuit according to the prior art.

Referring to FIG. 1, the transmitter output level control circuit of the base station equipment according to the prior art detects the output level value of the high frequency signal output from the base station transmitter (TRANSMITTER) to the inverting terminal (-). Inputs a control value to control the level output from the base station transmitter to a non-inverting terminal (+), compares the value input to each terminal, and amplifies the difference value at a predetermined ratio. A first comparator 10 to output;

Detects the input level value of the intermediate frequency (IF) signal applied to the base station and inputs it to the inverting terminal, and inputs a reference value for controlling the output level of the base station transmitter as the non-inverting terminal, A second comparator 20 which compares the input value and amplifies the difference value at a predetermined predetermined ratio and outputs the difference;

The value of the output signal of the first comparator 10 is input to the inverting terminal (-), the value of the output signal of the second comparator 20 is input to the non-inverting terminal (+), and each terminal A third comparator 30 for amplifying and outputting a difference value at a predetermined ratio;

An integrator 40 for inputting and integrating the value of the signal output from the third comparator 30 as an inverting terminal, and

The controller 50 is configured to input a signal output from the integrator 40 to automatically control the gain of the output level of the base station transmitter (AGC: AUTO GAIN CONTROL).

Hereinafter, a base station transmitter output level control circuit according to the related art having the above configuration will be described in detail with reference to FIG.

In the code division multiple access (CDMA) mobile communication base station system, the output level of the transmitter must be kept constant. The output level control circuit performs the above functions.

The control circuit detects a high frequency (RF) output level of the transmitter, inputs a corresponding value to the inverting terminal (-) of the first comparator 10, and controls to artificially control the output level of the transmitter to a desired value. The value is input to the non-inverting terminal (+) of the first comparator 10.

The first comparator inputs a value input to each terminal to the OP amplifier through each load resistor, detects a difference value between the values input to the respective terminals, and amplifies a predetermined ratio to output the point A.

In addition, the second comparator 20 inputs an input level value of an intermediate frequency (IF) signal applied to the base station to the inverting terminal (-), and inputs a reference value for controlling the output level of the base station transmitter to the non-inverting terminal (+). The signal input to each terminal is input to the OP amplifier through the load resistance, thereby amplifying the difference value of the value applied to each terminal at a predetermined ratio and outputting it to the B point.

The signal output to the points A and B causes a difference between the minimum values.

The signal output from the output point A of the first comparator 10 is input to the inverting terminal (-) of the third comparator 30, and is output from the output point B of the second comparator 20. The signal is input to the non-inverting terminal (+) of the third comparator 30, and the third comparator 30 amplifies at a predetermined rate by inputting a signal input to each terminal to the OP amplifier through a load resistor. By outputting to the C point, C = B-A.

The signal output to the output point (C) of the third comparator 30 is input to the integrator 40, the integrator 40 is input to the inverting terminal (-) of the OP amplifier through the load resistance Integrate and print.

The signal output from the integrator 40 is input to the controller 50 for automatically controlling the output level or the gain of the transmitter, and under the control of the controller 50, the base station transmitter output level is controlled and output.

The base station transmitter output level control circuit of the prior art as described above has a problem that a large number of comparators are used and the circuit configuration is complicated by inputting control conditions using the first to third comparators 10, 20, and 30.

The object of the present invention is to apply a super position theory, and to provide a circuit that simplifies the configuration and reduces the size by using less comparator of the transmitter output level control circuit.

The present invention devised to achieve the above object, in the circuit for controlling the output level of the base station transmitter; A comparison unit for inputting a control value and an input level value to an inverting terminal, inputting an output level value and a reference value to a non-inverting terminal, and amplifying a difference between signals input to each terminal at a predetermined ratio set in an opamp; An integrating unit for inputting and integrating a signal output from the comparing unit as an inverting terminal; And a control unit for inputting a signal output from the integrating unit and automatically controlling the output level of the base station transmitter.

1 is a block diagram of a base station transmitter output level control circuit according to the prior art,

2 is a block diagram of an output level control circuit of a base station transmitter according to the present invention.

** Explanation of symbols on the main parts of the drawing **

10: first comparator 20: second comparator

30: third comparator 40: integrator

50,120 control unit 100: comparison unit

110: integral part

Hereinafter, an output level control circuit of a base station transmitter according to the present invention will be described with reference to the accompanying drawings.

Attached to explain the present invention, Figure 2 is a block diagram of the output level control circuit of the base station transmitter according to the present invention.

2, the transmitter output level control circuit of the mobile communication base station system according to the present invention,

By setting the output power level of the transmitter to a predetermined required level value, a control value of DC and an input level of DC of a signal input as an intermediate frequency signal are determined by a super position theory. The output power level of the high frequency signal output from the transmitter is input to the inverting terminal (-) of the through and the output value of the direct current and the reference value for controlling the output power level of the transmitter are superimposed. According to the position theory (SUPER POSITION THEORY), one non-inverting terminal (+) is input through each load resistor, and the difference between the signals input to the inverting terminal (-) and the non-inverting terminal (+), respectively, A comparator 100 for amplifying and outputting at an amplification ratio of a predetermined ratio set in the OP) amp;

The signal output from the comparator 100 is input to the inverting terminal (-) of the OP amp through the load resistance, and the non-inverting terminal (+) of the OP amp is grounded through the resistor. And an integrator 110 for outputting an integrated signal by connecting a capacitor C between the inverting terminal and the output terminal.

The controller 120 is configured to input a signal output from the integrator 110 and to automatically control the output level or the output gain of the base station transmitter according to the input signal.

Hereinafter, the output level control circuit of the base station transmitter according to the present invention having the above configuration will be described in detail with reference to FIG. 2.

The comparing unit 100 and the integrating unit 110 are functional units configured by applying an op amp having an inverting input terminal (-) and a non-inverting input terminal (+), respectively.

A resistance is connected between the input terminal and the output terminal of the op amp, and the theoretical amplification factor is set by a ratio between the resistance value of the resistor and the resistance value of the load resistor connected to the input terminal. The comparator 100 amplifies the difference between the input signals.

The integrating unit 110 integrates and outputs a signal input by connecting a condenser between the input terminal and the output terminal of the op amp.

The control unit 120 adjusts the gain GAIN of the transmitter (not shown) according to the value of the input control signal to automatically set the output level or output power of the transmitter.

SUPER POSITION THEORY is a theory that uses the linearity of the op amp, and when there are a plurality of inputs, the respective input signals are amplified and output without being summed.

The function of the configuration and theory by the ordered combination of the functional units as described above, the base station transmitter output level control circuit according to the present invention is a control value (-) (A ') of the inverting terminal (-') of the comparator 100 TX_RF_GAIN) and the input level value TX_IF_LVL are input by the superposition theory through the respective load resistors.

The control value TX_RF_GAIN is a DC signal value directly controlled by a user so that the output level of the base station transmitter becomes a predetermined level, and the input level value TX_IF_LVL is a level input as an intermediate medium (IF) signal. It is a DC signal value.

The control value TX_RF_GAIN and the input level value TX_IF_LVL are input to the inverting terminal (-) (A ') of the op amp through respective load resistors, and the resistance value of the input resistance and the op amp input terminal The amplification factor of the opamp is set by the ratio of the resistance value of the resistor connected between the output terminals, so that the amplification factor is set in the linear amplification characteristic range of the opamp so that the super position theory is applied.

As the non-inverting terminal (+) (B ') of the comparison unit 100, the output level value TP5 and the reference value REF are inputted to the op amp by the superposition theory through the respective load resistors. do.

The output level value TP5 is a direct current signal value indicating a level of output power by a high frequency (RF) signal output from a base station transmitter, and the reference value REF is a reference value for determining the output level of the transmitter and the inversion. This value is adjusted so that the signal difference between the terminal (-) (A ') and the non-inverting terminal (+) (B') is minimized.

The op amp has a relatively large amplification factor or gain GAIN, and amplifies a difference value of a DC signal input to the inverting terminal (-) (A ') and the non-inverting terminal (+) (B'). It is preferable that the magnitude | size of a difference value is comparatively small, and a reference value performs the above function.

When the signal output to the output terminal C 'of the comparator 100 is calculated by the signals input to the respective input terminals A' and B ', C' = B '-A' = reference value REF + Output level value (TP5)-[Control value (TX_RF_GAIN) + Input level value (TX_IF_LVL)] = [Reference value (REF)-Input level value (TX_IF_LVL)]-[Control value (TX_RF_GAIN)-Output level value (TP5) ] = B-A = C, it is confirmed that the same result can be obtained.

That is, it can be seen that the same characteristics as the result of using the three comparators 10, 20, and 30 in the prior art and the result of using one comparator 100 in the present invention.

It is important that the op amp constituting the comparator 100 has an amplification effect in a linear characteristic region, and a plurality of signals input to each terminal of the op amp are influenced by signals amplified and output. This is because the superposition theory is applied, which does not give the result.

The control unit AGC 120 output from the integrating unit 110 by the change of the control value TX_RF_GAIN is the control unit AGC output from the integrating unit 110 by the change of the input level value TX_IF_LVL. (120) Does not affect control value change.

That is, when the control value TX_RF_GAIN increases, the output value of the integrator 110 increases. When the input level value TX_IF_LVL increases, the output value of the integrator 110 increases, and when the output level value TP5 increases. When the output value of the integrator 110 decreases and the reference value REF increases, the output value of the integrator 110 decreases.

Therefore, the base station transmitter output level control circuit according to the present invention is miniaturized by a simple configuration using a single comparator 100, low in cost, easy to maintain, and low in occurrence of failures. There is an advantage to do the same.

The present invention of the above configuration has the industrial use effect of simplifying the circuit configuration, miniaturization, low cost, and easy maintenance by processing a plurality of input signals using one comparison unit.

In addition, since there are fewer components, there is an effect that the failure occurrence factor is reduced and the reliability of the control circuit is increased.

Claims (3)

In the circuit for controlling the output level of the base station transmitter, A comparison unit for inputting the control value and the input level value to the inverting terminal, the output level value and the reference value to the non-inverting terminal, and amplifying the difference between the signals input to each terminal at a predetermined ratio set in the opamp; An integrating unit for inputting and integrating a signal output from the comparing unit into an inverting terminal, And a control unit configured to input a signal output from the integrating unit and automatically control an output level of the base station transmitter. According to claim 1, The control value is a DC signal for controlling the output level of the base station transmitter to the required level, The input level value is a DC signal as the magnitude of the input intermediate frequency signal, The output level value is a DC signal as the magnitude of the high frequency signal output from the base station transmitter, The reference value is a reference value for controlling the output of the base station transmitter, and at the same time to minimize the size difference between the signal input to the inverting terminal and the non-inverting terminal of the comparator, characterized in that the output level control circuit of the base station transmitter. The method of claim 1, wherein the comparison unit, Input each signal through the load resistance, An output level control circuit of a base station transmitter, characterized in that the op amp has a predetermined ratio of amplification rate.