KR20020069949A - Power amplitude method and apparatus of transmitter in mobile communication system - Google Patents

Abstract

PURPOSE: An apparatus and method for amplifying a power in a transmitter of a mobile communication system is provided to reduce the entire consumption current of a terminal and improve the total call time by dualizing a path when it is necessary for the terminal to output a high power and it is unnecessary for the terminal to output the high power. CONSTITUTION: A power level detecting unit(225) detects a power level of an amplified transmission signal. The first power amplifying unit including the first amplifier(210) and the first isolator(211) amplifies the power of the transmission signal in case that the power level of the transmission signal is more than a reference level. The second power amplifying unit including the second amplifier(215) and the second isolator(216) amplifies the power of the transmission signal in case that the power level of the transmission signal is less than the reference level. A switch unit(209) outputs the transmission signal to the first or second power amplifying unit according to the detected power level. A combining unit(230) outputs the signals inputted from the first power amplifying unit and the second power amplifying unit to a duplexer(213) without mutual interference.

Description

Power amplification apparatus and method of transmitter in mobile communication system {POWER AMPLITUDE METHOD AND APPARATUS OF TRANSMITTER IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to an apparatus and method for power amplifying a transmission signal in a transmitter of a mobile communication system, and more particularly, to an apparatus and method for power amplifier that can reduce power consumption.

FIG. 1 is a block diagram illustrating a configuration of a transmission apparatus of a general mobile communication system. Referring to FIG.

The modulated baseband signal is converted into an intermediate frequency signal by the amplifier 102 and the filter 103, and the intermediate frequency signal is converted into a high frequency signal and transmitted to the base station through the antenna 112. A mixer 105 is used to convert the intermediate frequency into a high frequency signal. The mixer 105 mixes and outputs the radio local oscillation frequency and the intermediate frequency output from the local oscillation frequency generator 104 generating the radio local oscillation frequency. This process is called up converting. On the other hand, unwanted signals are also generated during this upconversion process, and are used by filters (filters 106, 108, and 111) to remove the unnecessary signals. In addition, a power amplifier 109 is used to obtain a prescribed output at the antenna output, an excitation amplifier (driving) and a power amplifier for driving the signal output from the power amplifier 109 An isolation element (Isolator) 110 is provided to protect the power amplifier from the reflected wave input back to the output of 109 and to prevent the power amplifier load impedance change from the impedance change caused by the external environment.

Since the power amplifier of the transmitter having the above configuration requires high power and high linearity during operation, it is a device that consumes a large amount of current even when a relatively low output is required as well as a high output signal.

Therefore, when the output level is relatively high at the antenna, the configuration of FIG. There is a problem.

Accordingly, an object of the present invention is to provide a transmission apparatus and method capable of preventing unnecessary power consumption when transmitting a transmission signal in a mobile communication system.

The present invention to achieve the above object; A power amplifier of a transmitter in a mobile communication system, comprising: a power level detector for detecting a power level of an excitation amplified transmission signal; A first power amplifier, a second power amplifier configured to amplify the power of the transmission signal when the power level of the transmission signal is lower than or equal to the reference level, and the first or second power source according to the detected power level. The switch unit for outputting to the amplifier, and the coupling unit for outputting the signal input from the first power amplifier and the second power amplifier to the duplexer without mutual interference.

The present invention to achieve the above object; In the method of power amplification of a transmitter in a mobile communication system,

A power level process for detecting a power level of the excitation amplified transmission signal,

Determining whether the detected power level is equal to or greater than a predetermined reference level;

Transmitting the transmission signal through a first transmission path when the detected power level is greater than or equal to the reference level, and transmitting the transmission signal through a second transmission path when the detected power level is less than the reference level. It is characterized by.

1 is a diagram showing the configuration of a transmitter of a general mobile communication system.

2 is a diagram illustrating a transmitter and a configuration of a mobile communication system according to an embodiment of the present invention.

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

First, in adding the reference numerals to the components of each drawing, the same components have the same reference numerals as much as possible even if displayed on different drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention provides a level detection unit 225 for detecting a power level of an up-converted and amplified transmission signal, comparing a level of the detected level with a predetermined reference level, and outputting a path selection signal. A first power amplifier which forms a first path serving as a main, a second power amplifier which forms a second path which is newly introduced according to the present invention, and the first power amplifier and the second power Coupling unit 230 for transmitting a transmission signal output from the amplifier to the duplexer 213, and a power supply selection unit 221 for supplying power to the first power amplifier or the second power amplifier in accordance with the path selection signal. Is made of.

The first power amplifier includes a first amplifier 210 that performs power amplification of a typical transmission signal and an isolation device 211 for blocking a signal leaking back through the coupling unit 230. The second power amplifier has a lower power amplification than the first amplifier 210 and blocks a signal leaked from the first power amplifier through the coupling unit 230 and the second amplifier operating at a low operating current. Is composed of an isolation element 216. The coupling unit 230 includes a PIN diode 218 connected in parallel with a second power amplifier, a λ / 4 transmission line connected in series with the PIN diode, or a means for making the electrical length 90 ° accordingly. Λ / 4 transmission line ") and a PIN diode bias circuit activated by a path selection signal.

When the output of the excitation amplifier 207 is above a certain level (high level output), a signal is regularly transmitted through the first power amplifier. At this time, when the logic level of the path selection signal Sps becomes High, the power supply selection unit 221 supplies power to the active element (first amplifier 210) on the main path, that is, the first power amplifier, and the switch unit ( 209 allows a transmission signal to be transmitted toward the first power amplifier.

In this case, the PIN diode 218 has a forward characteristic, so that the impedance of the anode of the diode becomes the ground level, so after the λ / 4 transmission path 220, at the output of the isolation element 211 of the first power amplifier. As the impedance seen toward the second power amplifier becomes infinite, the total impedance at the output of the isolation element 211 of the first power amplifier becomes as shown in FIG. 1.

On the contrary, when the output of the excitation amplifier 207 is below a certain level (output below the intermediate level), when the logic level of the path selection signal Sps becomes LOW, the existing main path is inactivated and the active elements on the negative path and the negative path ( The second amplifier 215 is activated. The active element (second power amplifier 215) on the subpath and the subpath handles lower power than the first power amplifier on the main path, so that it can operate at a lower operating current, thereby improving the overall talk current consumption. have.

At this time, the PIN diode 218 has a reverse characteristic, and the diode becomes an open circuit due to a large reverse impedance. On the other hand, the magnitude of the signal that can be handled in the negative path should be determined within the range that the diode is not turned on by the negative peak of the signal. That is, the high frequency signal of the output of the active element (second power amplifier, 215) on the negative path alternates between the positive and negative maximums. It is decided in the range which is not shown. In order to increase the size of a signal that can be handled in the negative path, it may be achieved by adding a predetermined circuit applying a negative bias to the diode bias circuit 219 of the coupling unit 230 according to the path selection signal Sps. .

On the other hand, when the main path is activated, the output of the isolation element 211 of the main path should be minimized to be fed back through the sub-path. In order to effectively do this, the isolation element 216 is inserted into the sub-path so that The overall isolation is improved, including the isolation of the second amplifier 215 and the isolation of the path selector switch 209.

More specifically, the contribution to the total isolation of the main path through the subpath when the main path is activated is isolated by the combination of the λ / 4 transmission line 220 and the PIN diode 218 and the isolation element 216 on the subpath. ), The isolation of the active element (second power amplifier 215), the isolation of the path selection switch (209). On the other hand, the λ / 4 transmission line 220 is to make the electrical length between the input and output to 90 degrees, the higher the transmission frequency, the longer the path length when implemented in the effect or the actual pattern of the parasitic inductance by the internal package of the PIN diode The electrical length should be less than 90 ° because it must be compensated for.

In other words, the effective path length considering the actual package parasitic inductance of the PIN diode and the actual path from the PIN diode anode to the capacitor 212 should be 90 degrees.

As described above, there is an advantage in that the total talk time can be improved by reducing the current consumption of the entire terminal by dualizing the path when the terminal needs high power and when it does not.

Claims (6)

In the power amplifier of the transmitter in the mobile communication system, A power level detector for detecting a power level of the excitation amplified transmission signal; A first power amplifier configured to amplify the power of the transmission signal when the power level of the transmission signal is greater than or equal to a predetermined reference level; A second power amplifier configured to amplify the power of the transmission signal when the power level of the transmission signal is less than or equal to the reference level; A switch unit for outputting the transmission signal to a first or second power amplifier according to the detected power level; And a coupling unit for outputting a signal input from the first power amplifier and the second power amplifier to a duplexer without mutual interference. The method of claim 1, And a power selection supply unit for supplying power to the first power amplifier if the detected power level is greater than the reference level, and supplying power to the second power amplifier if the power level is smaller than the reference level. . The method of claim 1, wherein the first power amplifier, A first amplifier connected between the switch unit and the coupling unit to amplify a first output signal output from the switch unit; And a first isolating element for blocking a signal input from the second power amplifier through the coupling unit. The method of claim 1, wherein the second power amplifier, A second amplifier connected between the switch unit and the coupling unit to amplify a first output signal output from the switch unit; And a second isolating element for blocking a signal input back through the coupling unit from the first power amplifier. The method of claim 1, wherein the coupling portion, A PIN diode 218 connected in parallel with the first power amplifier and the second power amplifier; Means 220 connected in series with the PIN diode and also connected to the output of the first power amplifying means 210 so as to have an electrical length of 90 °; And the PIN diode biasing means (219) connected to said PIN diode (218) to activate said PIN diode (218). In the method of power amplification of a transmitter in a mobile communication system, A power level process for detecting a power level of the excitation amplified transmission signal, Determining whether the detected power level is equal to or greater than a predetermined reference level; Transmitting the transmission signal through a first transmission path when the detected power level is greater than or equal to the reference level, and transmitting the transmission signal through a second transmission path when the detected power level is less than the reference level. Characterized by the above.