CN100547910C - Efficient power amplifier with multiple power modes - Google Patents

Abstract

The present invention relates to a power amplifying device installed in a wireless communication terminal, in particular to a high-efficiency power amplifying device that can effectively amplify power according to various output power levels without using a bypass switch circuit. The high-efficiency power amplifying device according to the present invention makes it possible to amplify various levels of power without using a bypass switch circuit, so that problems in prior art multi-mode power amplifying devices, such as those caused by the use of a bypass switch circuit, can be solved The power loss of the power amplifier, the increase of the size of the power amplification device, the deterioration of price competition, etc. Also, the high-efficiency power amplifying device according to the present invention reduces the DC power consumption in the low power mode, so that the power addition efficiency characteristics of the power amplifying device can be improved.

Description

Efficient power amplifier with multiple power modes

technical field

The invention relates to a power amplifier in a mobile handset. More particularly, the present invention relates to a multi-power mode power amplifier having high efficiency, which is suitable for amplifying power corresponding to various output power levels without using a bypass switch circuit.

Background technique

Recently, as mobile handsets used for wireless communication services have become smaller and lighter, much research has been conducted on extending the talk time of mobile handsets using small-sized batteries. In conventional mobile handsets, radio frequency (RF) power amplifiers consume a large portion of the power consumed by the overall system of the mobile handset. Therefore, the inefficiency of the RF power amplifier reduces the efficiency of the overall system, thereby reducing talk time.

For this reason, most research in this field focuses on improving the efficiency of RF power amplifiers. Multi-power mode power amplifiers are one of the devices recently introduced as a result of such research to improve the efficiency of RF power amplifiers.

A multi-power mode power amplifier is configured to operate its own power stage corresponding to the desired situation, and to operate in several operating modes corresponding to output power levels. Typically, a bypass switch circuit is used for this operation of a multi-power mode power amplifier.

If low output power is required, then the power transfer is routed to bypass the power stage. Conversely, if high output power is required, the power transfer is routed through the power stages in order to provide high output power. Using a conventional multi-power mode power amplifier that selectively performs mode conversion according to a desired output power level, DC (direct current) power consumption can be reduced when transmitting a signal of low output power.

However, in order to operate a multi-power mode power amplifier, more than one power stage should be switched among multiple power stages connected in series, and more than one bypass switch circuit and complex logic control circuit for controlling the bypass switch circuit are required for switching operations.

The power loss caused by the switching operation of the bypass switch circuit reduces the output power, which reduces the efficiency of the multi-power mode power amplifier. In addition, there is another problem in that adjacent channel power ratio (ACPR) deteriorates. In addition, the size of the entire system becomes larger due to the bypass switch circuit and an additional complex logic control circuit for controlling the bypass switch circuit. Therefore, considering the trend of small-sized mobile handsets, the prior art multi-power mode power amplifier is considered to be backward, and the enlarged size of the whole system is disadvantageous in price competition.

A multi-power mode power amplifier using a bypass switch circuit in the prior art will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a prior art multi-power mode power amplifier using a bypass switch circuit. The multi-power mode power amplifier shown in FIG. 1 is configured using 3 bypass switch circuits.

If the power amplifier operates in high power mode, both the first switch 31 and the second switch 32 are closed and the third switch 33 is opened, so that the output of the driver 10 including the impedance matching unit is input into the power stage 22 . Conversely, if the power amplifier is operating in a low power mode, both the first switch 31 and the second switch 32 are open and the third switch is closed, so that the output of the driver 10 including the impedance matching unit bypasses the power stage 22 .

Since the multi-power mode power amplifier shown in FIG. 1 uses 3 bypass switch circuits, the degree of freedom in the configuration of the multi-power mode power amplifier increases. But at the same time, it has disadvantages of an increase in size of the entire system and an increase in power loss of the entire system due to power loss of the bypass switch circuit. Especially the power loss of the second switch 32 connected to the output terminal of the power stage seriously affects the operating efficiency and linearity in the high power mode, so a bypass switch circuit with large power capacity and good loss characteristics should be used instead of a bypass switch circuit. The necessity of a one-way switching circuit entails high cost.

Figure 2 shows a prior art multi-power mode power amplifier using an additional bypass switch circuit. The multi-power mode power amplifier as shown in FIG. 2 is configured not to use a series switch but to use a shunt switch.

In the high power mode, the shunt switch of the second bypass switch circuit 49 is grounded, and operates together with the third impedance converter 48 as an impedance matching unit. The first impedance converter 47 converts the load of the output stage including the second bypass switch circuit 49 and the third impedance converter 48 into an optimum impedance Zopt that maximizes the output of the power stage 45 . The switches of the first bypass switch circuit 44 are connected to the input 43 of the power stage.

In low power mode, the second bypass switch circuit 49 is connected to the output of the second impedance converter, and the first impedance converter 47 passes the power to be turned off together with the second impedance converter 46 and the third impedance converter 48. The output impedance of stage 45 is converted to an impedance of j50 ohms to form an impedance matching unit. The switch of the first bypass switch circuit 44 is connected to the input terminal of the second impedance converter 46 to form a bypass. The first bypass switch circuit 44 may be configured using two diode switches, while the second bypass switch circuit 49 may be configured using one shunt diode switch.

Since the power amplifier as shown in FIG. 2 should use at least 3 switches, the performance is deteriorated due to the loss of the switch itself, and the price competition is deteriorated due to the increase in size of the power amplifier.

Figure 3a shows a prior art multi-power mode power amplifier using a bypass switch circuit connected to the output of a λ/4 bypass transmission line. The multi-power mode power amplifier as shown in FIG. 3 a includes a carrier amplifier 51 and has bypassing realized by a bypass switch circuit configured by using a λ/4 bypass transmission line 52 and a shunt switch 53 .

In the high power mode, the bypass switch 53 of the bypass switch circuit is grounded, and the bypass switch circuit including the bypass switch 53 operates as an open stub by being connected to the λ/4 bypass transmission line 52.

In the low power mode, the shunt switch 53 of the bypass switch circuit is connected to the output terminal of the carrier amplifier 51 and operates as a bypass together with the λ/4 bypass transmission line 52 .

Figure 3b shows a prior art multi-power mode power amplifier using a bypass switch circuit connected to the input of a λ/4 bypass transmission line.

The difference between the multi-power mode power amplifier shown in FIG. 3b and the multi-power mode power amplifier shown in FIG. 3a is only the sequence of the λ/4 bypass transmission line and the bypass switch circuit.

Since the multi-power mode power amplifier shown in FIGS. 3a and 3b includes only one bypass switch circuit, it has the advantage that the size of the whole system is small. But at the same time, the disadvantage is that the bandwidth is limited due to the use of the λ/4 bypass transmission line.

Figure 4 shows a prior art multi-power mode power amplifier using an additional bypass switch circuit.

Q3 (65) is a carrier amplifier, and Q2 (62) is an operational amplifier. The series switch 66 comprises two diodes connected in parallel, the anodes of which are connected to the Vcc of the carrier amplifier.

In high power mode, Q1 (68) is off and series switch 66 is open. Therefore, the output of Q2 (62) is input into Q3 (65), and the first impedance matching unit 63 is an impedance matching unit that converts the input impedance into 15 ohm impedance.

In low power mode, the base bias of Q3 (65) is turned off and Q1 (68) is turned on, causing switch 66 to close. The second impedance matching unit 64 is an impedance matching unit that converts the load impedance into 25 ohm impedance. The second impedance matching unit 64 has an impedance smaller than the input impedance of Q3 (65) when the switch 66 is closed, and has an impedance larger than the input impedance of Q3 (65) when the switch 66 is open. Therefore, the second impedance matching unit 64 operates as a bypass.

Contents of the invention

An object of the present invention is to solve at least the above-mentioned problems of prior art multi-power mode power amplifiers using bypass switch circuits, and to provide a multi-power mode power amplifier with high efficiency by making the path for bypassing the power stage and the path for passing through the power stage are joined at the optimal point and an optimal impedance transformer is implemented on the path for bypassing the power stage, this multi-power mode power amplifier can amplify multiple level of power.

A high-efficiency multi-power mode power amplifier is provided, including: a driver, used to amplify input power; a first impedance matching unit, connected in series with the driver; a second impedance matching unit connected in series with the first impedance matching unit; power stage, which is connected in series with the second impedance matching unit; the applied voltage control circuit, which is connected in parallel with the power stage, is used to control the voltage applied to the power stage corresponding to the first power mode and the second power mode, so that in the first power mode turning off the power stage and turning on the power stage in a second power mode, wherein in the second power mode, the power stage is configured to receive the power amplified by the driver through the first impedance matching unit and the second impedance matching unit, amplify again power and output the power amplified again; the impedance converter is used to receive the power amplified by the driver through the first impedance matching unit in the first power mode; the third impedance matching unit is connected in series with the power stage and used in the second In the power mode, the power amplified by the power stage is received; and the fourth impedance matching unit is used to transmit the power transmitted from the third impedance matching unit or the impedance converter to the output stage.

Preferably, the impedance converter is connected in parallel with the second impedance matching unit, the power stage and the third impedance matching unit, and in the first power mode, the impedance converter receives the power amplified by the driver through the first impedance matching unit and uses the power output to the fourth impedance matching unit. In addition, the impedance converter has a structure of a bandpass filter.

Preferably, the third impedance matching unit prevents power delivered through the impedance transformer from leaking to the power stage.

Preferably, the fourth impedance matching unit receives power from the impedance converter in the first power mode, and the fourth impedance matching unit receives power from the third impedance matching unit in the second power mode.

Preferably, the path through which power is transferred to the fourth impedance matching unit through the first impedance matching unit is by combining the impedance observed from the first impedance matching unit towards the power stage with the impedance observed from the first impedance matching unit towards the impedance transformer The impedance is determined by comparison.

Preferably, in the second power mode, the impedance observed from the first impedance matching unit towards the impedance converter together with the first impedance matching unit forms an inter-stage matching unit between the driver and the power stage.

Another high-efficiency multi-power mode power amplifier is provided, including: a driver for variably amplifying the gain of an input signal using a variable gain amplifier; a power stage for passing through a first impedance matching unit connected in series with the driver and with the The second impedance matching unit connected in series with the first impedance matching unit receives the power amplified by the driver, re-amplifies the power and outputs the re-amplified power; the external voltage control unit, which is connected in parallel with the power stage, is used to control the power corresponding to the first power mode and The applied voltage of the second power mode; the impedance converter is used to receive the power amplified by the driver through the first impedance matching unit according to the operation of the applied voltage control circuit; the third impedance matching unit is connected in series with the power stage for controlling the circuit according to the applied voltage. The operation of the power control circuit receives the power amplified by the power stage; and a fourth impedance matching unit, which is connected in series with the third impedance matching unit and connected in series with the impedance converter, is used to match the impedance from the third impedance according to the operation of the applied voltage control circuit. The power delivered by the unit or impedance transformer is delivered to the output stage.

Preferably, in the second power mode, the power stage is connected in series with the second impedance matching unit, and the power stage receives the power amplified by the driver through the second impedance matching unit and amplifies the power again.

Preferably, the applied voltage control circuit controls the driver so that a gain input into the driver is amplified differently according to the first power mode and the second power mode. The applied voltage control circuit adjusts the voltage applied to the power stage to turn off the power stage in the first power mode and turn on the power stage in the second power mode.

Preferably, the impedance converter is connected in parallel with the second impedance matching unit, the power stage and the third impedance matching unit. In the first power mode, the impedance converter receives the power amplified by the driver through the first impedance matching unit and outputs the power to the fourth impedance matching unit. The impedance transformer has a structure of a bandpass filter.

Preferably, the third impedance matching unit prevents power delivered through the impedance transformer from leaking to the power stage.

Preferably, the fourth impedance matching unit receives power from the impedance converter in the first power mode, and the fourth impedance matching unit receives power from the third impedance matching unit.

Preferably, the path through which the power is transmitted to the fourth impedance matching unit through the first impedance matching unit is by combining the impedance observed from the first impedance matching unit towards the power stage with the impedance viewed from the first impedance matching unit towards the impedance transformer determined by comparing the impedances obtained.

Preferably, in the second power mode, the impedance observed from the first impedance matching unit towards the impedance converter together with the first impedance matching unit forms an inter-stage matching unit between the driver and the power stage.

Brief description of the drawings

Figure 1 shows a prior art multi-power mode power amplifier using a bypass switch circuit;

Figure 2 shows a prior art multi-power mode power amplifier using other bypass switch circuits;

Figure 3a shows a prior art multi-power mode power amplifier using a bypass switch circuit connected to the output of a λ/4 bypass transmission line;

Figure 3b shows a prior art multi-power mode power amplifier using a bypass switch circuit connected to the input of the λ/4 bypass transmission line;

Figure 4 shows a prior art multi-power mode power amplifier using an additional bypass switch circuit;

Figure 5 shows a high-efficiency multi-power mode power amplifier according to a preferred embodiment of the present invention, which adopts a power mode conversion structure without a bypass switch circuit;

Fig. 6 shows in detail the high-efficiency multi-power mode power amplifier shown in Fig. 5, for explaining the power mode conversion structure without bypass switch circuit;

The graph of Figure 7a shows the gain characteristics corresponding to the high power mode and the low power mode of the multi-power mode power amplifier according to a preferred embodiment of the present invention;

The graph of Figure 7b shows the power added efficiency (PAE) characteristics corresponding to the high power mode and the low power mode of the multi-power mode power amplifier according to a preferred embodiment of the present invention;

FIG. 8 shows a high-efficiency multi-power mode power amplifier according to another preferred embodiment of the present invention, which adopts a power mode conversion structure without a bypass switch circuit;

BEST MODE FOR CARRYING OUT THE INVENTION

A detailed description of the high-efficiency multi-power mode power amplifier according to the preferred embodiment of the present invention will be given below with reference to the accompanying drawings. Hereinafter, the first power mode is called a low power mode and the second power mode is called a high power mode.

FIG. 5 shows a high-efficiency multi-power-mode power amplifier using a power-mode conversion architecture without a bypass switch circuit according to a preferred embodiment of the present invention.

The high-efficiency multi-power mode power amplifier as shown in Figure 5 includes: a driver 100 for amplifying the input power; a power stage 120 for passing through the first impedance matching unit 130 connected in series with the driver and connected in series with the first impedance matching unit 130 The second impedance matching unit 140 receives the power amplified by the driver 100, and re-amplifies the power and outputs the re-amplified power; the external voltage control circuit 90, which is connected in parallel with the power stage 120, is used to communicate with the low power mode and the high power mode Correspondingly control the applied voltage; the impedance converter 170 is used to receive the power amplified by the driver 100 through the first impedance matching unit 130 according to the operation of the applied voltage control circuit 90, and transmit the power to the fourth impedance matching unit 160; Three impedance matching units 150, which are connected in series with the power stage 120, for transmitting the power amplified by the power stage 120 to the fourth power matching unit 160; and the fourth impedance matching unit 160, which are connected in series with the third impedance matching unit 150 and It is connected in series with the impedance converter 170 for transferring the power delivered from the third impedance matching unit 150 or the impedance converter 170 to the output stage 78 according to the operation of the applied voltage control circuit 90 .

The applied voltage control circuit 90 adjusts the voltage applied to the power stage 120 using an external control signal input corresponding to a low power mode and a high power mode. In the low power mode, since the output power is not obtained through the power stage 120 but through the optimal first impedance matching unit 130 and the optimal impedance converter 170, the external voltage control circuit 90 adjusts the voltage applied to the power stage 120 to turn off the transistors of the power stage 120 .

On the contrary, since the output power is obtained through the first impedance matching unit 130 , the second impedance matching unit 140 and the power stage 120 , the applied voltage control circuit 90 applies a voltage suitable for transistor operation of the power stage 120 .

The driver 100 in the low power mode amplifies the input power and transmits the amplified power to the impedance converter 170 through the optimal first impedance matching unit 130 . Conversely, the driver 100 in the high power mode amplifies the input power and delivers the amplified power to the power stage 120 through the optimal first impedance matching unit 130 and the optimal second impedance matching unit 140 .

The power stage 120 in the low power mode is turned off by the applied voltage control circuit 90 , and the power stage 120 in the high power mode amplifies the signal amplified by the driver 100 and input to the power stage 120 .

The first impedance matching unit 130 is an optimum circuit for optimum operation corresponding to the low power mode and the high power mode. The first impedance matching unit 130 selectively transmits the input power amplified by the driver 100 to the impedance converter 170 or the power stage 120 corresponding to an operation mode.

The second impedance matching unit 140 is an optimum circuit for optimum operation corresponding to the low power mode and the high power mode. The second impedance matching unit 140 transmits the power amplified by the driver 100 and transmitted through the first impedance matching unit 130 to the impedance converter 170 in the low power mode and to the power stage 120 in the high power mode.

The impedance converter 170 is an impedance conversion circuit that appropriately converts impedance in accordance with the low power mode and the high power mode. In low power mode, the impedance transformer 170 forms a path around the power stage 120 so that the output of the driver 100 is passed to the output stage 78 of the power amplifier.

FIG. 6 shows in detail the high-efficiency multi-power-mode power amplifier shown in FIG. 5 for illustrating a power-mode conversion structure without a bypass switch circuit.

The output power of the driver 100 passes through the first impedance matching unit 130 to the junction 72 for separating the paths corresponding to the power modes.

In the low power mode, the power stage 120 is turned off by the voltage applied by the applied voltage control circuit 90, and the input impedance Z _INT-H of the power stage 120 observed from the perspective of the first impedance matching unit 130 is compared from the first impedance matching The input impedance Z _INT-L of the path bypassing the power stage 120 seen from the perspective of the unit 130 is much larger. Accordingly, the power amplified by driver 100 and delivered to junction 72 is optimized such that the amount of power input into impedance converter 170 is much greater than the amount of power input into power stage 120 . The output power is delivered by the third impedance matching unit 150 and the fourth impedance matching unit 160 to the output stage 78 with minimized power leakage to the power stage.

In the high power mode, the power stage 120 is turned on by the voltage applied by the applied voltage control circuit 90, and the input impedance Z _INT-H of the power stage 120 observed from the perspective of the first impedance matching unit 130 is compared from the first impedance matching The input impedance Z _INT-L of the path bypassing the power stage 120 seen from the perspective of the unit 130 is small. Thus, most of the power amplified by the driver 100 and delivered to the junction 72 is amplified by the power stage 120 and transformed by the optimal third impedance matching unit 150 and the optimal fourth impedance matching unit 160 with minimized leakage to impedance The power from the amplifier 170 is delivered to the output stage 78 of the power amplifier.

In the high power mode, the input impedance ZINT-L of the path bypassing the power stage 120 observed from the perspective of the first impedance matching unit 130 together with the first impedance matching unit 130 forms an interstage between the driver 100 and the power stage 120 The matching unit, so that the output power of the driver 100 is well transmitted to the power stage 120 .

Fig. 7a is a graph showing gain characteristics corresponding to high power mode and low power mode of a multi-power mode power amplifier according to a preferred embodiment of the present invention.

In the low power mode, the power stage 120 is turned off by the applied voltage control circuit 90 so that the output of the driver 100 is not amplified by the power stage 120 and the output of the driver 100 is transmitted to the output stage 78 through the impedance converter 170 . Therefore, it is impossible to obtain a gain characteristic when amplified by the power stage 120 . However, this eliminates the DC power consumed by the power stage 120, resulting in excellent PAE characteristics.

Conversely, in the high power mode, the output of the driver 100 is amplified by the power stage 120 and reaches the output stage 78, such that the gain characteristic when amplified by the power stage 120 is increased to that of operation in the low power mode, and the PAE The characteristics depend on the power stage 120 which typically has a high output power level.

Therefore, as shown in Fig. 7a, the gain characteristic in the low power mode is relatively low and the gain characteristic in the high power mode is relatively high.

Fig. 7b is a graph showing power addition efficiency characteristics corresponding to high power mode and low power mode of a multi-power mode power amplifier according to a preferred embodiment of the present invention.

As shown in Fig. 7a, the PAE characteristics in low power mode are excellent because the DC power consumed by the power stage 120 can be eliminated. In the high power mode, the output of the power stage 120 is transmitted to the output stage 78 through the third impedance matching unit 150 and the fourth impedance matching unit 160, and the third impedance matching unit 150, the fourth impedance matching unit 160 and the impedance converter 170 No switches are used, thus allowing the output of the power stage 120 to pass without loss to the output stage 78, thus enabling excellent PAE characteristics in high power mode.

FIG. 8 shows a high-efficiency multi-power-mode power amplifier employing a power-mode conversion architecture without a bypass switch circuit according to another preferred embodiment of the present invention.

According to another preferred embodiment of the present invention, a high-efficiency multi-power mode power amplifier adopting a power mode conversion structure without a bypass switch circuit includes: a driver 210 for variably amplifying the gain of an input signal using a variable gain amplifier The power stage 220 is used to receive the power amplified by the driver 210 through the first impedance matching unit 230 connected in series with the driver 210 and the second impedance matching unit 240 connected in series with the first impedance matching unit 230, amplify the power again and output the amplified again The power of the applied voltage control unit 190, which is connected in parallel with the power stage 220, is used to control the applied voltage corresponding to the low power mode and the high power mode; the impedance converter 270 is used to pass the first The impedance matching unit 230 receives the power amplified by the driver 210; the third impedance matching unit 250, which is connected in series with the power stage 220, is used to receive the power amplified by the power stage 220 according to the operation of the external power control circuit; and the fourth impedance matching unit 260, which is connected in series with the third impedance matching unit 250 and in series with the impedance transformer 270, for transferring the power delivered from the third impedance matching unit 250 or the impedance transformer 270 to the output stage 178 according to the operation of the applied voltage control circuit.

The applied voltage control circuit 190 controls the driver so that the signal gain input into the driver is differently amplified according to the low power mode and the high power mode. The applied voltage control circuit adjusts the voltage applied to the power stage 220 using an external control signal input corresponding to a low power mode and a high power mode. Because the output power is obtained not through the power stage 220 but through the optimal first impedance matching unit 230 and the optimal impedance converter 270 in the low power mode, the external voltage control circuit adjusts the voltage applied to the power stage 220 To turn off the transistors of the power stage 220 .

On the contrary, since the output power is obtained through the first impedance matching unit 230 , the second impedance matching unit 240 and the power stage 220 , the applied voltage control circuit 190 applies a voltage suitable for transistor operation of the power stage 220 .

The variable gain amplifier variably amplifies the gain of a signal input through the input terminal 180 of the power amplifier according to the operation of the applied voltage control circuit 190, and supplies the amplified gain to the first impedance matching unit 230, the power stage 220, and the impedance converter 270. The variable gain amplifier functions not only as a driver but also as a linear circuit, so that the efficiency and linearity of the circuit are optimized. In addition, the discontinuous gain characteristics of the power amplifier shown in FIG. 7a can be adjusted accordingly according to the application.

The power stage 220 in the low power mode is turned off by the applied voltage control circuit 190 , and the power stage 220 in the high power mode amplifies the signal amplified by the driver 210 and input into the power stage 220 .

The first impedance matching unit 230 is an optimum circuit for optimum operation corresponding to the low power mode and the high power mode. The first impedance matching unit 230 selectively transmits the input power amplified by the driver 210 to the impedance transformer 270 or the power stage 220 corresponding to an operation mode.

The second impedance matching unit 240 is an optimal circuit for optimal operation corresponding to the low power mode and the high power mode. The second impedance matching unit 240 transmits the power amplified by the variable gain amplifier and transmitted through the first impedance matching unit 230 to the impedance transformer 270 in the low power mode and to the power stage 220 in the high power mode.

The impedance converter 270 is an impedance conversion circuit that appropriately converts impedance in accordance with the low power mode and the high power mode. In low power mode, the impedance transformer 270 forms a path around the power stage 220 so that the output of the driver 210 is passed to the output stage 178 of the power amplifier.

The multi-power mode power amplifier according to the present invention is not limited to these preferred embodiments but can be realized by various modifications by those skilled in the art without departing from the scope and spirit of the invention disclosed by the appended claims.

Industrial applicability

According to the multi-power mode power amplifier of the present invention, power of various levels can be amplified without using the bypass switch circuit, thereby making the multi-power mode power amplifier in the prior art caused by the use of the bypass switch circuit Problems of loss, increase in power amplifier size, deterioration of price competition, etc. can be solved. In addition, the multi-power mode power amplifier according to the present invention reduces the DC power consumption that actually affects the battery life in the low power mode, so that the PAE performance of the power amplifier can be improved, and the power amplifier equipped with the multi-power mode power amplifier according to the present invention can be improved. Amplifiers can extend the talk time of mobile handheld devices.

In addition, the present invention using a variable gain amplifier as a driver minimizes the loss of the multi-power mode power amplifier in the prior art in the high power mode, so that the PAE characteristics in the high power mode can be improved, and high power can be solved. Bad linearity problem in mode. In addition, an improvement in the speech quality of a mobile handset equipped with a multi-power mode power amplifier according to the present invention and a reduction in the size of a hand-held device equipped with a multi-power mode power amplifier according to the invention can be achieved.

Claims (8)

1. many power modes of high efficiency power amplifier comprises:

Driver is used for amplifying input power;

First impedance matching unit, it is connected with described driver;

Second impedance matching unit, it is connected with described first impedance matching unit;

Power stage, it is connected with described second impedance matching unit;

The applied voltage control circuit, it is in parallel with described power stage, and be configured to be applied to the voltage of described power stage corresponding to first power mode and second power mode control, so that described power stage is closed described power stage is opened, wherein under described second power mode, described power stage is configured to receive the power that is amplified by described driver by described first impedance matching unit and described second impedance matching unit, amplifies the power that described power and output are amplified once more once more;

Impedance transformer, it is configured to receive the power that is amplified by described driver by described first impedance matching unit under described first power mode;

The 3rd impedance matching unit, it is connected with described power stage, and is configured to receive under described second power mode power that is amplified by described power stage; And

The 4th impedance matching unit, it is configured to the power from described the 3rd impedance matching unit or the transmission of described impedance transformer is sent to output stage.

2. many power modes power amplifier as claimed in claim 1, wherein, the Power leakage that described the 3rd impedance matching unit prevents to transmit by described impedance transformer is to described power stage.

3. many power modes power amplifier as claimed in claim 1, wherein, described the 4th impedance matching unit receives the power that comes from described impedance transformer under described first power mode, receive the power that comes from described the 3rd impedance matching unit under described second power mode.

4. many power modes power amplifier as claimed in claim 1, wherein, the power path that is transmitted to described the 4th impedance matching unit through described first impedance matching unit will be by determining with comparing towards the observed impedance of described impedance transformer from described first impedance matching unit towards the observed impedance of described power stage from described first impedance matching unit.

5. many power modes power amplifier as claimed in claim 4, wherein, under described second power mode, form interstage matched unit between described driver and the described power stage towards the observed impedance of described impedance transformer with described first impedance matching unit from described first impedance matching unit.

6. many power modes power amplifier as claimed in claim 1, wherein, described driver is to be configured to the variable gain amplifier of the gain of amplification input signal changeably.

7. many power modes power amplifier as claimed in claim 6, wherein, described applied voltage control circuit control described driver so that the gain that is input to the signal in the described driver corresponding to described first power mode and described second power mode and differently amplified.

8. as any described many power modes power amplifier in the claim 1 to 7, wherein, described first power mode is a low-power mode, and described second power mode is a high-power mode.

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