KR100377586B1 - the circuit of power amplifier in used mobile communication termainal - Google Patents

Abstract

The present invention relates to a power amplifier circuit for a mobile communication terminal,

When the external input signal is low power because a predetermined current flows between the drain terminal and the source terminal of the high electron-mobility transistor transistor that amplifies the power of the externally input signal. By amplifying by using the unique current value of the high electron transfer transistor of the amplifying circuit

The power used in the amplification circuit can be reduced, thereby increasing the efficiency of the power used in the terminal, thereby increasing the battery life of the terminal.

Description

The circuit of power amplifier in used mobile communication termainal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power amplification circuit used in a mobile communication terminal. In particular, a high-powered transistor having a constant current flowing in a drain and a source is used to output a signal from a low power state to a low output of an external input signal. It relates to a power amplification circuit for a mobile communication terminal capable of amplifying.

As the mobile communication market gradually expands, the corresponding technology is also gradually developing, and the mobile communication terminal is also required to have small size, light weight, and excellent performance. In particular, technical efforts have been made to increase total battery life in limited battery sizes in mobile communication terminals. Accordingly, technologies for increasing the efficiency of power used in a mobile communication terminal are also gradually developed.

1 is a circuit diagram showing a configuration of an amplification circuit for a mobile communication terminal according to the prior art, an amplifier 2 for amplifying the power of the signal through the input terminal 1, the input terminal 1 and the amplifier 2 Outputs an amplified signal, a bias unit 3 configured to be coupled with resistors R1 and R2 for applying current, a power supply unit 4 for supplying power for operating the amplifier 2, It is composed of an output stage (5).

Referring to the operation characteristics of the conventional mobile communication terminal amplifying device configured as described above, the signal input from the outside is amplified by the first resistor (R1) and the second resistor (R2) in the bias unit 3 according to the signal level A bias is applied to the unit 2, and the power of the signal is amplified by the amplifying unit 2 by the power supplied from the power supply unit 4 and output from the output terminal 5.

However, in the conventional power amplifier circuit for mobile communication terminals, even when the power level of the external input signal is low power, the power consumption is increased because power is consumed in the same way as the power level of the external input signal and power in the bias unit or the power supply unit. There is a problem that the efficiency of the power falls.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and an object thereof is defined between a drain and a source stage in order to amplify a signal to a high output or a low output according to the power level of an external input signal. Using a field effect transistor through which current flows, the signal is amplified with low power while the external signal is low power, and a certain current flows when the voltage is applied to the gate terminal at 0V. The present invention provides a power amplification circuit for a mobile communication terminal capable of designing a circuit.

1 is a circuit diagram of a power amplifier circuit for a mobile communication terminal according to the prior art;

2 is a circuit diagram of a power amplifier circuit for a mobile communication terminal according to a first embodiment of the present invention;

3 is a circuit diagram of a power amplifier circuit for a mobile communication terminal according to a second embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

11 input 12: high electron transfer transistor (HEMT)

13 bias part 14 power supply part

15 switch 16 power detection unit

17: output stage

According to a feature of the power amplifier circuit for a mobile communication terminal according to the present invention for solving the above problems, a predetermined current flows between a drain terminal and a source terminal while amplifying the power of an externally input signal. A high electron transfer transistor, a bias unit for applying a bias voltage to a gate terminal of the high electron transfer transistor, a power supply unit connected to a drain terminal of the high electron transfer transistor to supply power, and When the input signal level is a high power, it is composed of a power interrupter for supplying power to the high electron transfer transistor by switching the power supply.

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

FIG. 2 is a circuit diagram illustrating a configuration of a power amplifier circuit for a mobile communication terminal according to a first embodiment of the present invention. The input terminal 11 to which a signal is input from the outside, and a high-voltage shift transistor for amplifying the power of the signal ( High Electron-Mobility Transistor (HEMT) 12, a bias unit 13 for applying a bias to the gate terminal of the high electron transfer transistor (HEMT) 12, and a power supply unit for supplying power for operating the transistor 12 14, a switch 15 for intermitting the power supplied from the power supply unit 14 to the transistor 12, and a power for detecting a power level of an external input signal and transmitting a control signal to the switch 15 The detector 16 and an output terminal 17 for outputting the amplified signal, the power detector 16 is composed of a coupler for sensing the power level of the external input signal.

The high electron transfer transistor 12 is manufactured to have a unique current value between a drain and a source for amplifying a low power signal input from the outside.

The bias unit 13 includes a bias power supply Vb and resistors R1 and R2 which serve as a bias voltage distribution according to a bias external signal.

FIG. 2 is a circuit diagram illustrating a power amplification circuit of a mobile communication terminal according to a second embodiment of the present invention, and a description of a configuration overlapping with the first embodiment will be omitted.

In the second embodiment, a variable power source in which a power supply unit for supplying bias power from the bias unit 13 of the first embodiment is electrically connected to the power detection unit 16 to change the bias according to the power level of an external input signal. It consists of 13a.

Referring to Figures 2 and 3 the operation of the mobile communication terminal according to the present invention configured as described above is as follows.

First, when a signal is input from the outside, the power detector 16 detects the level of the external signal and transmits a driving signal to the switch 15 when the signal level is high power. The switch is operated by a driving signal and is induced through an inductor L to supply operating power to the drain of the high electron transfer transistor HEMT 12. The external signal is applied to the gate of the high electron transfer transistor 12 through the bias, the signal is amplified in the transistor 12 and output from the output terminal 17.

When the level of the external signal is low power in the power detector 16, the switch 15 is maintained in the OFF state to cut off the power supplied to the drain of the high electron transfer transistor 12. Accordingly, the low power signal input from the outside is processed by a unique current value of the high electron transfer transistor 12 and output to the output terminal 17.

In the second embodiment of FIG. 3, the power supply of the bias unit 13 is varied according to the level of the external signal detected by the power detector 16 so that a high voltage is applied when the output is high and a low voltage is applied when the output is low. Increase the power efficiency of the power amplifier circuit.

For example, in general, when the external input signal is input in a state of high power, the bias unit power is applied to 3V from the variable power source 13a to operate in the full power mode to process the signal normally.

When the external input signal is input in the state of low power, 0V, that is, the bias power is kept in the cutoff state and is applied to the transistor 12 only with the power of the external input signal. It operates in a power saving power mode in which signals are processed.

As described above, the power amplification circuit of the mobile communication terminal needs to maintain the standby mode of the low output state for a long time. Therefore, when a low power signal is input from the outside, the power amplifier circuit determines the unique current value of the high-electron transistor. It can prevent unnecessary power consumption.

The power amplification circuit for a mobile communication terminal of the present invention configured as described above processes a signal by a unique current value when a low power state of an external signal is input by using a high-electron transistor having a constant current value at a drain end and a source end. by doing,

By reducing the power used in the amplification circuit it is possible to increase the efficiency of the power used in the terminal, thereby increasing the use time of the battery of the terminal.

Claims (4)

A high electron transfer transistor configured to amplify the power of a signal input from the outside and to flow a predetermined current between a drain terminal and a source terminal; A bias unit for applying a bias voltage to a gate terminal of the high electron transfer transistor; A power supply unit connected to the drain terminal of the high electron transfer transistor to supply power; The power amplifier circuit for mobile communication terminal comprising a power interrupter for supplying power to the high-voltage moving transistor by switching the power supply when the signal level input from the outside is high power. delete The method of claim 1, And a power detector configured to detect a level of an external input signal, and a switching unit to control a power supply according to a control signal transmitted from the power detector. The method of claim 3, wherein And the bias unit applies a bias in accordance with the level of the external input signal detected by the power detection unit.