KR200210073Y1 - Bias Voltage Stabilization Circuit in Power Detection Unit - Google Patents

Abstract

The present invention relates to a bias voltage stabilization circuit of a power detector, and in a power detector for detecting power output from a transmission output stage in order to adjust the power output from a transmission output stage of a mobile communication base station, using a conventional power detector circuit, A buffer amplifier for outputting the detected signal to the rectifier from the bias stage of the power uncoupling unit, in which the bias voltage of the power detector unit becomes unstable and unstable when the high-speed RF signal is inputted; A diode connected in series with the buffer amplifier input terminal; A resistor connected to the output of the buffer amplifier; A comparator to which the signal output from the buffer amplifier is fed back and input to the inverting input terminal, and the reference voltage is input to the non-inverting input terminal; A diode connected in parallel to the comparator; A diode connected in parallel to the buffer amplifier input and the output of the comparator; The new circuit consists of capacitors connected in parallel to the output of the comparator, which maintains a constant bias voltage at all times to stabilize the bias voltage and increase precision.

Description

Bias Voltage Stabilization Circuit in Power Detection Unit

1 is a block diagram of a transmission output stage of a conventional mobile communication base station,

2 is a circuit diagram of a conventional power detector;

3 is a circuit diagram of a power detector of the present invention.

* Explanation of symbols for main parts of the drawings

1: driver 2: final amplifier

3: isolator 4: filter

5, 5 ': power detector 6: rectifier

7: Automatic power control unit 8, 8 ': bias stage

9: comparator C1, C2, C3: capacitor

D1, D2, D3: Diode Q1: Buffer Amplifier

R1, R2, R3, R4: Resistance

The present invention relates to a bias voltage stabilization circuit of the power detector, and in the power detector for detecting how much power is output from the transmitter output stage to adjust the power output from the transmitter output stage of the mobile communication base station, It relates to a bias voltage stabilization circuit configured to stabilize.

A configuration of a transmission output terminal of a conventional general mobile communication base station is described in detail with reference to FIG.

The transmission output terminal of the mobile communication base station includes a driver 1 for receiving and outputting a modulated radio frequency (hereinafter referred to as RF) signal; A final amplifier 2 for finally amplifying the modulated RF signal; An isolator (3) for transmitting the RF signal amplified by the final amplifier (2) without attenuation and absorbing a signal flowing back from the output stage; A filter (4) for filtering the RF signal passing through the isolator (3); A power detector 5 for detecting an RF signal transmitted from the final amplifier 2 to the isolator 3 and detecting power of the transmitted RF signal; A rectifier 6 for rectifying the signal detected by the power detector 5; It is comprised by the automatic power control part 7 which adjusts a power automatically by the detected signal.

The operation of the configuration will be described in detail below.

When the driver 1 receives the modulated RF signal and outputs it to the final amplifier 2, the final amplifier 2 finally amplifies the modulated RF signal and outputs the result to the isolator 3, which isolated by the isolator 3. When the signal output from the final amplifier 2 is transmitted to the filter 4 without attenuating, the filter 4 filters the RF signal transmitted from the isolator 3 and outputs the RF signal to the receiver. When the final amplifier 2 detects the RF signal transmitted to the isolator 3 and detects the power of the transmitted RF signal and outputs it to the rectifier 6, the rectifier 6 outputs the signal detected by the power detector 5. After rectifying and outputting to the automatic power control unit 7, the automatic power control unit 7 adjusts the power of the RF signal output by the detected signal and inputs the driver 1 to the output of the RF signal is adjusted. .

When the power detector circuit currently used in the power detector 5 is used, the bias voltage is unstable and the precision is reduced. This will be described in detail with reference to FIG.

2 is a circuit diagram of a conventional power detector 5, comprising a capacitor C1 for detecting power of an RF signal output from a transmission output terminal of a mobile communication base station, and a bias stage 8 for providing a bias voltage. In the bias stage (8) is composed of a diode (D1), resistors (R1, R2), capacitor (C2), the diode (D1) of the bias stage (8) has a low load resistance and high-speed signal, such as mobile communication In this case, since the capacitor C1 needs to be charged / discharged in a short time, a Schottky diode with a fast switching speed is used.As a result, when the high speed signal is input, the forward voltage drop of the diode of the power detector 5 changes, so that the bias voltage Is changed and becomes unstable, and the value actually obtained in the rectifier 6 is obtained with a relative value according to the bias voltage change, resulting in less precision, and changing the relative value to an absolute value. Turn it, and the data converted to a relative value to an absolute value necessary to be additionally added to the circuit, which stores them in memory.

The present invention is to solve the above problems, by newly configuring the circuit of the bias stage in the power detector circuit of the transmission base station of the mobile communication base station, the bias voltage is stabilized by always maintaining a constant bias voltage, the value obtained from the rectifier It becomes an absolute value for the input signal and is characterized by higher precision.

When described in detail with reference to the drawings as follows.

3 is a power detector 5 'circuit of the present invention, comprising a capacitor C1 for detecting power of an RF signal output from a transmission output terminal of a mobile communication base station, and a bias stage 8' for providing a bias voltage. Wherein the bias stage 8 'includes a buffer amplifier Q1 for outputting the detected signal to the rectifier 6; Resistors R3 and R4 connected to the output terminal of the buffer amplifier Q1; A comparator (9) fed back with a signal output from the buffer amplifier (Q1) and input to an inverting input terminal and a reference voltage input to a non-inverting input terminal; A diode D3 connected in parallel with the comparator 9; A diode D1 connected in parallel to the input terminal of the buffer amplifier Q1 and the output terminal of the comparator 9; It consists of a capacitor (C3) connected in parallel to the output terminal of the comparator (9).

The operation of the configuration will be described in detail below.

When the capacitor C1 detects the power of the RF signal output from the transmission output terminal of the mobile communication base station, the buffer amplifier Q1 outputs the detection signal to the rectifier 6, and the signal output from the feedback is fed back to the comparator. When inputted to the inverting input terminal of (9), the comparator 9 compares the signal output from the buffer amplifier Q1 with a reference voltage, and the result of the comparison is fed back to the input side of the buffer amplifier Q1 to provide a buffer amplifier ( Make the bias voltage of Q1) constant.

That is, when the output voltage of the buffer amplifier Q1 is lower than the reference voltage when the high-speed RF signal is input, the diode D1 is turned on (D2 is turned off) and the reference voltage is charged to the capacitor C1. The output voltage of the buffer amplifier Q1 is derived from the reference voltage, and when the high speed RF signal is input, the output voltage of the buffer amplifier Q1 is derived from the reference voltage, and the high speed RF signal is input from the output voltage. When the output voltage of the buffer amplifier Q1 is greater than the reference voltage, the diode D2 is turned on (D1 is turned off) and the output voltage of the buffer amplifier Q1 is derived from the reference voltage charged in the capacitor C1 above. Thus, the buffer amplifier Q1 maintains a constant bias voltage at all times regardless of the input RF signal.

As described above, according to the present invention, since the circuit of the bias stage is newly configured in the power detector circuit of the mobile communication base station transmission output stage as described above, the bias voltage is stabilized by always maintaining a constant bias voltage regardless of the input RF signal. The value obtained from becomes an absolute value for the input signal, increasing the precision.

Claims (1)

A power detector circuit of a transmission output stage of a mobile communication base station, comprising: a capacitor (C1) for detecting power of an RF signal output from a transmission output stage of a mobile communication base station, and a bias stage (8 ') for providing a bias voltage; The bias stage 8 'includes a buffer amplifier Q1 for outputting the detected signal to the rectifier 6; Resistors R3 and R4 connected to the output terminal of the buffer amplifier Q1; A comparator (9) fed back with a signal output from the buffer amplifier (Q1) and input to an inverting input terminal and a reference voltage input to a non-inverting input terminal; A diode D3 connected in parallel with the comparator 9; And a capacitor (C3) connected in parallel to the input terminal of the buffer amplifier (Q1) and the output terminal of the comparator (9).