KR20080078322A - Power amplifier module - Google Patents

Abstract

A power amplifier module is provided to prevent internal circuits thereof from being damaged by an external signal such as ESC(Electro Static Discharge). A power amplifier module includes a driving amplifying unit(130), a power amplifying unit(150), an output detection unit(170), and an impedance conversion unit(180). The driving amplifying unit adjusts the gain of a signal. The power amplifying unit amplifies the power of the gain-adjusted signal. The output detection unit is coupled to an output stage of the power amplifying unit and divides a part of the amplified signal if the power value of the amplified signal is larger than a predetermined value. The impedance conversion unit is coupled to an input stage of the driving amplifying unit and the output detection unit. The impedance conversion unit isolates an external signal transmitted from the output detection unit. The impedance conversion unit changes the impedance of the input stage of the driving amplifying unit according as the output detection unit is operated.

Description

Power Amplifier Module

1 is a block diagram schematically showing the internal components of a typical power amplifier module.

Figure 2 is a block diagram schematically showing the components of the power amplifier module according to an embodiment of the present invention.

3 is a diagram illustrating a circuit configuration of an output detector of a power amplification module according to an embodiment of the present invention.

4 is a diagram illustrating a circuit configuration of an impedance converter of a power amplification module according to an embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

100: power amplifier module 110: bias circuit

120: input matching unit 130: drive amplifier (DA)

140: intermediate matching unit 150: power amplifier (PA)

160: output matching unit 170: output detection unit

180: impedance conversion unit

The present invention relates to a power amplifier module (PAM).

Currently, mobile communication terminals such as mobile phones, smart phones, personal digital assistants (PDAs), and radio frequency identification (RFID) devices are widely used, and various electronic devices are embedded and operated on the PCB (Printed Circuit Board). It is common to form a communication module integrated in the.

The communication module includes a power amplifier module on the transmitter side to obtain the final RF signal output through the antenna. The power amplifier module amplifies the RF signal input from the transceiver on the mobile communication terminal and sets the amplified signal. Keep it.

In recent years, high efficiency power amplification modules that can control the transmission power to a level such as low power, high power, etc. according to the communication environment are widely used so that the performance of the module is maintained even at the lowest power level of radiated radio waves.

This power control can minimize the source interference problem on the channel, the power consumption is significantly reduced, the battery life can be extended and the performance of the circuit can be stabilized.

However, even in such a conventional power amplifier module, the voltage of the output signal is ideally increased so that the performance of the circuit may be degraded or the circuit may be damaged.

1 is a block diagram schematically illustrating internal components of a general power amplifier module 10.

Referring to FIG. 1, a general power amplifier module 10 includes an input matching circuit 11, a driver amplifier 12, and an inter stage matching circuit 13. And a power amplifier (PA) 14, an output matching circuit 15, and a bias circuit unit 16.

First, the input matching unit 11 compensates for the loss of the input signal from the transceiver (not shown), and the intermediate matching unit 13 matches the impedance of the intermediate connection circuit.

The output matching unit 15 also matches the final amplified output signal.

The driving amplifier 12 adjusts a gain related to the amplitude of power amplification, amplifies the final output signal of the power amplifier 14, and transmits it to the outside (antenna).

The bias circuit unit 16 provides a bias DC voltage to the transistors provided in the driving amplifier 12 and the power amplifier 14.

However, the signal output from the power amplifier 14 may be caused by abnormal power control, generation of oscillation component frequency due to an internal loop circuit, frequency of noise component introduced from an external antenna, and incorrect impedance matching. There is a high probability that an output signal with an abnormal voltage will be amplified.

If this phenomenon occurs, the internal circuit of the power amplification module 10 may not withstand or the circuits related to the external communication module may be damaged. Therefore, the communication quality may deteriorate and the communication module may not function properly. Situations may arise.

An embodiment of the present invention provides a power amplification module so that the voltage of the output signal is stabilized by detecting abnormal power of the output terminal due to abnormally high output, surges drawn from the antenna, and errors in impedance matching and limiting the level of the RF signal. do.

In addition, an embodiment of the present invention provides a power amplification module having a prevention circuit so that an internal circuit is not damaged when an external signal is generated due to an electrostatic discharge (ESD).

Power amplification module according to an embodiment of the present invention includes a drive amplifier for adjusting the gain of the signal; A power amplifier for amplifying the power of the gain-adjusted signal; An output detector connected to an output terminal of the power amplifier and operated when the power value of the amplified signal is greater than or equal to a predetermined value to branch a part of the amplified signal; And an impedance converter connected to an input terminal of the driving amplifier and the output detector, to isolate an external signal transmitted from the output detector, and to change an impedance of the driving amplifier input terminal as the output detector is operated.

Hereinafter, a power amplifier module according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram schematically illustrating components of a power amplification module according to an embodiment of the present invention.

Referring to FIG. 2, the power amplification module 100 according to the embodiment of the present invention includes a bias circuit unit 110, an input matching unit 120, a driver amplifier (DA) 130, and an intermediate portion. The matching unit 140 includes a power amplifier (PA) 150, an output matching unit 160, an output detector 170, and an impedance converter 180.

First, the input matching unit 120 is provided at the input terminal of the driving amplifier 130 and compensates for the loss of the RF signal input from the transceiver. In addition, the intermediate matching unit 140 is provided at an input terminal of the power amplifier 150, and is a circuit for matching impedance between the power amplifier 150 and the driving amplifier 130.

The output matching unit 160 is connected to the output terminal of the power amplifier 150 to perform a function of matching the impedance of the finally amplified signal, according to the ACPR (Adjacent Channel Power Ratio) regulation Amplify the output to the maximum within the linear nature of 150).

The driving amplifier 130 adjusts a gain in amplifying the signal output from the transceiver so that the output does not exceed the allowable level.

Accordingly, it is possible to prevent the amplification signal from being distorted through the driving amplifier 130 and the generation of intermodulation in the bandwidth of the channel signal in which several frequencies are concentrated.

The power amplifier 150 amplifies the power of the gain-adjusted output signal. Unlike the driving amplifier 130, the power amplifier 150 provides a large amount of current to the output terminal and increases power. Therefore, the power amplifier 150 requires a large transistor or a large number of transistors configured in parallel.

The bias circuit unit 110 provides a bias DC voltage to the driving amplifier 130 and the power amplifier 150 to amplify a signal of the transistors included in the driving amplifier 130 and the power amplifier 150. The reference voltage signal Vref, the control signal Vcon, and the like are received from a controller (not shown) to control the amplification operation.

The driving amplifier 130 and the power amplifier 150 differentiate and amplify signals for each band by the reference voltage signal Vref, and the operation is turned on / off by the control signal Vcom.

3 is a diagram illustrating a circuit configuration of the output detector 170 of the power amplification module 100 according to an embodiment of the present invention.

The output detector 170 is connected to the output terminal of the power amplifier 150 and operated when the power value of the amplified signal is greater than or equal to a predetermined value to branch a portion of the amplified signal. For example, an electrostatic discharge (ESD) signal is an output detector. It may be transmitted to the impedance converter 180 through 170.

Referring to FIG. 3, the output detector 170 includes an inductor 171 and a diode 172 connected in parallel. When the power of the output signal passing through the output matching unit 160 is 29 dBm or more, a diode (pin diode) is used. 172 is operated (turn-on) to activate the connection line between the output terminal of the output matching unit 160 and the impedance conversion unit 180.

Therefore, the electrostatic discharge signal may be isolated by the antistatic device included in the impedance converter 180.

In this case, the power of the output signal for operating the diode 172 is adjustable by the capacitance inside the diode 172 and the parallel resonance of the inductor 171.

4 is a diagram illustrating a circuit configuration of the impedance converter 180 of the power amplifier module 100 according to an embodiment of the present invention.

Referring to FIG. 4, the impedance converter 180 includes a resistor 183, a capacitor 184, and a diode array 185. The resistor 183 and the capacitor 184 are driving amplifiers. 130 serves as an impedance conversion circuit 182 for changing the impedance of the input terminal, the diode array 185 serves as an isolation circuit to isolate the electrostatic discharge signal.

The resistor 182 is connected between the driving amplifier 130 and the input matching unit 120, and the output detector 170 is connected between the capacitor 184 and the diode array 185.

As described above, when the output signal passing through the output matching unit 160 reaches an operating voltage of 29 dBm, about 2v to 4v, the output detection unit 170 is turned on and the connection line between the impedance conversion circuit 182 and the output matching unit output terminal By activation, resistor 183 and capacitor 184 function.

Accordingly, a predetermined value of impedance is generated by the resistor 183 and the capacitor 184, which affects the matching of the input matching unit 120.

That is, the impedance of the transmission signal matched by the input matching unit 120 is changed, and the gain value of the driving amplifier 130 is lowered by the change of the input impedance, so that the overall gain value is also changed. Therefore, the power of the output signal is lowered, thereby preventing the risk of high power.

The diode array 185 is a circuit in which a plurality of ESD suppression diodes are arranged. The diode array 185 has characteristics such as fast latch-up operation, low triggering voltage, and isolates / consumes some signals transmitted through the output detector 170.

For example, assuming that 10 diodes having a voltage consumption capacity of about 1.2V form an array, a total of 12V (1.2V × 10) voltages are attenuated.

Therefore, if the output signal amplified to 22V is finally obtained through the power amplifier 150, about 12V is attenuated due to the operation process as described above, and the output signal is about 10V, which does not put a heavy load on the circuit.

Although the present invention has been described above with reference to the embodiments, these are only examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains may have an abnormality within the scope not departing from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not illustrated. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the power amplification module according to an embodiment of the present invention, it is possible to prevent the internal circuit from being damaged due to the influence of an external signal such as an electrostatic discharge signal, and abnormally due to an error of surge and impedance matching introduced from an antenna. The increased output power can be controlled, resulting in stabilization of the output signal and protection of the circuit.

In addition, according to an embodiment of the present invention, since the function of the power amplifier module is stabilized and circuit damage can be prevented, it is possible to extend the product life and maximize the efficiency of power amplification.

Claims (9)

A driving amplifier for adjusting a gain of the signal; A power amplifier for amplifying the power of the gain-adjusted signal; An output detector connected to an output terminal of the power amplifier and operated when the power value of the amplified signal is greater than or equal to a predetermined value to branch a part of the amplified signal; And A power amplification module connected to an input terminal of the driving amplifier and the output detector, to isolate an external signal transmitted from the output detector, and to include an impedance converter configured to change an impedance of the input of the driving amplifier according to the operation of the output detector; . The method of claim 1, An input matching unit connected to the driving amplifier input terminal; An intermediate matching unit connected between the driving amplifier and the power amplifier; A power amplifier module including at least one matching unit of an output matching unit connected to the power amplifier output terminal. The method of claim 1, wherein the output detection unit Power amplification module comprising an inductor and a diode forming a parallel circuit. The method of claim 1, wherein the impedance converter And an isolation circuit and an impedance conversion circuit for isolating the external signal. The method of claim 4, wherein the isolation circuit Power amplification module comprising a diode array. The method of claim 4, wherein the impedance conversion circuit Power amplification module comprising a resistor and a capacitor. The method of claim 4, wherein the output detection unit A power amplification module connected between the isolation circuit and the impedance conversion circuit. The method of claim 1, wherein the impedance conversion unit Power amplification module including an antistatic element. The method of claim 1, wherein the driving amplifier And an amplifying gain value adjusted as the impedance of the input terminal is changed by the impedance changing unit.

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