CN117240229A

CN117240229A - Bias circuit of power amplifier and power amplifier

Info

Publication number: CN117240229A
Application number: CN202210631414.9A
Authority: CN
Inventors: 谷远辉; 刘鑫海; 孙洪铮
Original assignee: Maxscend Microelectronics Co ltd
Current assignee: Maxscend Microelectronics Co ltd
Priority date: 2022-06-06
Filing date: 2022-06-06
Publication date: 2023-12-15

Abstract

The invention provides a bias circuit of a power amplifier and the power amplifier, wherein the bias circuit of the power amplifier comprises a voltage conversion unit and a feedback unit; the voltage conversion unit is respectively connected with the first power supply and the power amplifier, and the feedback unit is connected with the voltage conversion unit; generating and outputting a feedback signal to the voltage conversion unit according to temperature change information in the power amplifier; the voltage conversion unit converts the power supply voltage output by the first power supply into a feedback bias voltage according to the feedback signal, and outputs the feedback bias voltage to the power amplifier. And generating a feedback signal according to the temperature change information in the power amplifier, converting the power supply voltage according to the feedback signal to obtain a feedback bias voltage, and compensating performance change caused by temperature change in the power amplifier, thereby avoiding affecting the linearity of the power amplifier.

Description

Bias circuit of power amplifier and power amplifier

Technical Field

The present invention relates to the field of radio frequency amplification technologies, and in particular, to a bias circuit of a power amplifier and a power amplifier.

Background

With the development of scientific technology, the development of wireless communication technology is rapid, and the technology is more mature. The power amplifier is a key component of wireless communication and can be used for amplifying RF signals in any wireless communication system conforming to a communication standard, including cellular communication, wireless broadband, and the like.

In practical applications, in order to meet the usage requirements of an ofdm modulated communication system, the power amplifier must have extremely high linearity. The circuit cannot immediately enter a steady state at the moment of starting the radio frequency power amplifier, so that the gain changes along with time. Especially, the non-uniformity of the heating of the transistor inside the radio frequency power amplifier chip is more likely to cause the deterioration of the dynamic error vector magnitude (Dynamic Error Vector Magnitude, DEVM) of the circuit, and the linearity of the power amplifier is affected.

The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present invention and is not intended to represent an admission that the foregoing is prior art.

Disclosure of Invention

The invention mainly aims to provide a bias circuit of a power amplifier and the power amplifier, and aims to solve the technical problem that the linearity of the power amplifier is affected by the fact that the temperature inside an output transistor core of the power amplifier changes along with time when the power amplifier amplifies a modulation signal in the prior art.

In order to achieve the above object, the present invention provides a bias circuit of a power amplifier, the bias circuit of the power amplifier comprising: a voltage conversion unit and a feedback unit;

the voltage conversion unit is respectively connected with the first power supply and the power amplifier, and the feedback unit is connected with the voltage conversion unit;

the feedback unit is used for generating and outputting a feedback signal to the voltage conversion unit according to the temperature change information in the power amplifier;

the voltage conversion unit is used for converting the power supply voltage output by the first power supply into a feedback bias voltage according to the feedback signal and outputting the feedback bias voltage to the power amplifier.

Optionally, the bias circuit of the power amplifier further comprises: a linear adjustment unit;

the linear adjusting unit is respectively connected with the voltage converting unit and the power amplifier;

the voltage conversion unit is further used for outputting the feedback bias voltage to the linear adjustment unit;

and the linear adjusting unit is used for adjusting the radio frequency impedance output by the feedback bias voltage and outputting the adjusted feedback bias voltage to the power amplifier.

Optionally, the voltage conversion unit is further configured to convert a power supply voltage output by the first power supply into an initial bias voltage, and send the initial bias voltage to the linear adjustment unit;

the linear adjusting unit is further used for adjusting the radio frequency impedance of the initial bias voltage output and outputting the adjusted initial bias voltage to the power amplifier.

Optionally, the voltage conversion unit includes: a first resistor, a second resistor, a first transistor, and a second transistor;

the first end of the first resistor is connected with the first power supply, the second end of the first resistor is respectively connected with the control end of the first transistor, the input end of the first transistor and the control end of the second transistor, the output end of the first transistor is grounded through the feedback unit, the first end of the second resistor is connected with the second power supply, the second end of the second resistor is connected with the input end of the second transistor, and the output end of the second transistor is connected with the power amplifier.

Optionally, the feedback unit includes: a third resistor, a fourth resistor, a fifth resistor, a third transistor, and a fourth transistor;

the third transistor is arranged inside an output transistor core of the power amplifier in a layout, a first end of the third resistor is connected with the first power supply and a first end of the first resistor respectively, a second end of the third resistor is connected with an output end of the first transistor and an input end of the third transistor respectively, a control end of the third transistor is connected with a first end of the fourth resistor, a second end of the fourth resistor is connected with an output end of the fourth transistor, a control end of the fourth transistor is connected with a control end of the first transistor, a second end of the first resistor and a control end of the second transistor respectively, an input end of the fourth transistor is connected with a second end of the fifth resistor respectively, a first end of the fifth resistor is connected with the second power supply and the first end of the second resistor respectively, and an output end of the third transistor is grounded.

Optionally, the linear adjustment unit includes: a first capacitor and a sixth resistor;

the first end of the first capacitor is connected with the second end of the first resistor, the control end of the first transistor, the control end of the second transistor and the control end of the fourth transistor, the second end of the first capacitor is grounded, the first end of the sixth resistor is connected with the output end of the second transistor, and the second end of the sixth resistor is connected with the power amplifier.

Optionally, the bias circuit of the power amplifier further comprises: a second capacitor;

the first end of the second capacitor is connected with the first end of the second resistor and the second power supply respectively, and the second end of the second capacitor is grounded.

Optionally, the second transistor is composed of a preset number of sub-transistors;

the control ends of the sub-transistors are connected with each other, the input ends of the sub-transistors are connected with each other, and the output ends of the sub-transistors are connected with each other.

To achieve the above object, the present invention also proposes a power amplifier including: an input matching unit, an amplifying unit, an output matching unit and a bias circuit of the power amplifier;

the input matching unit is respectively connected with the radio frequency input end, the bias circuit of the power amplifier and the amplifying unit, and the input matching unit is connected with the amplifying unit and the radio frequency output end.

Optionally, the amplifying unit includes a third capacitor, a first inductor, and a number of amplifying power tubes;

the first end of the third capacitor is connected with the input matching unit, the second end of the third capacitor is connected with the bias circuit and the control end of each amplifying power tube respectively, the input end of each amplifying power tube is connected with the second end of the first inductor and the output matching unit respectively, the first end of the first inductor is connected with the third power supply, and the output end of each amplifying power tube is grounded.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a first embodiment of a bias circuit of a power amplifier according to the present invention;

fig. 2 is a schematic diagram of a second embodiment of a bias circuit of a power amplifier according to the present invention;

FIG. 3 is a schematic diagram of a second embodiment of a bias circuit of a power amplifier according to the present invention;

FIG. 4 is a schematic diagram of a second embodiment of a bias circuit of a power amplifier according to the present invention;

FIG. 5 is a schematic diagram of a third embodiment of a bias circuit of a power amplifier according to the present invention;

fig. 6 is a schematic circuit diagram of a power amplifier according to the present invention.

Reference numerals illustrate:

reference numerals	Name of the name	Reference numerals	Name of the name
				10	Voltage conversion unit	R1～R6	First to sixth resistors
20	Feedback unit	C1～C3	First to third capacitors
				30	Linear regulating unit	V1～V3	First to third power supplies
Q1～Q4	First to fourth transistors	L1	First inductor
				RFin	Radio frequency input terminal	RFout	Radio frequency output terminal
M1～Mn	Amplifying power tube	GND	Grounded (earth)

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

Furthermore, the description of "first," "second," etc. in this disclosure is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the technical solutions should be considered that the combination does not exist and is not within the scope of protection claimed by the present invention.

Referring to fig. 1, fig. 1 is a schematic diagram of a first embodiment of a bias circuit of a power amplifier according to the present invention. A first embodiment of the biasing circuit of the power amplifier of the present invention is presented based on fig. 1.

In this embodiment, the bias circuit of the power amplifier includes: a voltage conversion unit 10 and a feedback unit 20;

the voltage conversion unit 10 is connected to a first power source and a power amplifier, and the feedback unit 20 is connected to the voltage conversion unit 10.

It should be understood that in this embodiment, the power amplifier is a radio frequency power amplifier, and the radio frequency power amplifier is generally provided with a bias circuit, and a certain bias voltage is provided for an amplifying power tube inside the power amplifier by the bias circuit, so that the power tube works in an amplifying region, thereby realizing power amplification. During operation of the power amplifier, it is necessary for the power amplifier to have extremely high linearity in order to ensure the accuracy of the output result of the power amplifier. Under the condition that the junction temperature of the tube core of the power amplifier changes along with time, the gain of the power tube with the amplifying function changes along with time, namely, along with temperature change, so that the linearity of the power amplifier is directly reduced, for example, the linearity of the power amplifier is affected in the starting process of the power amplifier.

The voltage conversion unit 10 is a unit for converting a power supply voltage supplied from an externally connected power supply into a bias voltage required for a power tube inside the power amplifier. The specific conversion parameters of the voltage conversion unit 10 may be set according to the bias voltage that is required to be output and the received power supply voltage. The voltage conversion unit 10 may be composed of a current mirror and related components. The feedback unit 20 is a unit that feeds back thermal changes in the power amplifier. When the heat of the amplifying power tube in the power amplifier changes, the feedback unit 20 may feed back the thermal change to the voltage conversion unit 10, and adjust the voltage conversion process of the voltage conversion unit 10, so as to compensate the effect of the thermal change on the gain. The feedback unit 20 may directly collect thermal variations within the power amplifier. Of course the feedback unit 20 may collect gain changes or environmental factor changes affecting gain changes by receiving other related structures or units. The first power supply may be used to provide a supply voltage for the voltage conversion unit 10.

In a specific implementation, when the temperature of the power tube in the power amplifier changes, the feedback unit 20 may generate a feedback signal according to the temperature change information in the power amplifier, and output the feedback signal to the voltage conversion unit 10; when receiving the feedback signal, the voltage conversion unit 10 may adjust the power supply voltage conversion process output by the first power supply according to the feedback signal, convert the power supply voltage into a feedback bias voltage for compensating the gain variation, and output the feedback bias voltage to the power amplifier, so as to provide the feedback bias voltage for the amplifying power tube in the power amplifier, and realize real-time control of the gain of the power amplifier, thereby reducing the linearity influence of the temperature variation on the power amplifier.

In this embodiment, there is provided a bias circuit of a power amplifier including a voltage conversion unit and a feedback unit; the voltage conversion unit is respectively connected with the first power supply and the power amplifier, and the feedback unit is connected with the voltage conversion unit; the feedback unit generates and outputs a feedback signal to the voltage conversion unit according to temperature change information in the power amplifier; the voltage conversion unit converts the power supply voltage output by the first power supply into a feedback bias voltage according to the feedback signal, and outputs the feedback bias voltage to the power amplifier. The feedback signal is generated according to the temperature change information in the power amplifier, and the power supply voltage is converted according to the feedback signal to obtain the feedback bias voltage, so that the gain of the power amplifier is controlled in real time, and the influence on the linearity of the power amplifier is avoided.

Referring to fig. 2, fig. 2 is a schematic diagram of a second embodiment of a bias circuit of a power amplifier according to the present invention. The second embodiment of the bias circuit of the power amplifier of the invention is presented based on the first embodiment of the bias circuit of the power amplifier described above.

In this embodiment, the bias circuit of the power amplifier further includes: a linear adjustment unit 30;

wherein the linear adjusting unit 30 is connected to the voltage converting unit 10 and the power amplifier, respectively.

It should be understood that the gain of the amplifying power tube in the power amplifier is greatly affected by the time-varying temperature, and in the case that the gain of the amplifying power tube is changed, the dynamic error vector amplitude of the power amplifier is directly affected. But the linearity of the power amplifier needs to take into account not only the dynamic error vector magnitude but also the effect of the static error vector magnitude of the power amplifier itself. The static error vector magnitude of the power amplifier itself can be adjusted by a linear adjustment unit 30 on the bias circuit.

The linear adjustment unit 30 is a unit that adjusts the radio frequency impedance of the bias voltage input to the power amplifier. The linearity adjustment unit 30 may adjust for linearity variations caused by the static error vector magnitude of the power amplifier die by adjusting the output radio frequency impedance during output bias voltage when the power amplifier causes a gain decrease with increasing input power. The linear adjustment unit 30 may adjust the magnitude of the static error vector of the power amplifier alone in the case that the temperature within the power amplifier is not changed, and the linear adjustment unit 30 may compensate the magnitude of the dynamic error vector and the magnitude of the static error vector of the power amplifier simultaneously with the feedback unit 20 in the case that the temperature is changed.

In a specific implementation, when the time-varying temperature and the input power in the power amplifier affect the linearity of the power amplifier at the same time, the feedback unit 20 may output a feedback signal corresponding to the temperature variation information to the voltage conversion unit 10, and the voltage conversion unit 10 performs voltage conversion according to the feedback signal and outputs the obtained feedback bias voltage to the linear adjustment unit 30; the linear adjustment unit 30 may adjust the rf impedance of the feedback bias voltage output, and output the adjusted feedback bias voltage to the power amplifier. Of course, the linear adjusting unit 30 may also directly adjust the voltage conversion process during the voltage conversion process, so that the voltage converting unit 10 may directly output the adjusted feedback bias voltage.

Further, in the case where the temperature within the power amplifier does not change with time and the input power increases, the voltage conversion unit 10 may directly convert the power supply voltage output from the first power supply into an initial bias voltage and transmit the initial bias voltage to the linear adjustment unit 30; the linear adjustment unit 30 may also adjust the rf impedance of the initial bias voltage output, and output the adjusted initial bias voltage to the power amplifier.

The initial bias voltage is a voltage obtained by directly converting the power supply voltage output by the first power supply by the voltage converting unit 10, and is not regulated by the feedback signal in the conversion process. The radio frequency impedance is the impedance of the bias voltage output of the current bias circuit.

Referring to fig. 3, the voltage conversion unit 10 includes: a first resistor R1, a second resistor R2, a first transistor Q1, and a second transistor Q2;

the first end of the first resistor R1 is connected with the first power supply V1, the second end of the first resistor R1 is connected with the control end of the first transistor Q1, the input end of the first transistor Q1 and the control end of the second transistor Q2, the output end of the first transistor Q1 is grounded through the feedback unit 20, the first end of the second resistor R2 is connected with the second power supply V2, the second end of the second resistor R2 is connected with the input end of the second transistor Q2, and the output end of the second transistor Q2 is connected with the power amplifier.

In this embodiment, the voltage conversion unit 10 may have a structure in which the first resistor R1, the second resistor R2, the first transistor Q1, the second transistor Q2, and the third transistor Q3 connected to the ground together form a current mirror. The structure of the current mirror can output the input current according to a certain proportion to generate bias current. In the case where the output bias current directly outputs the bias current, the bias current may be directly generated by using a current mirror. In fig. 3, the voltage value of the first power supply V1 output to the control terminals of the first transistor Q1 and the second transistor Q2 through the first resistor R1 can directly control the working state of the second transistor Q2, so as to control the magnitude of the current output through the second resistor R2 and the second transistor Q2.

In this embodiment, the feedback unit 20 includes: a third resistor R3, a fourth resistor R4, a fifth resistor R5, a third transistor Q3, and a fourth transistor Q4;

the third transistor Q3 is disposed in the middle of the output transistor die of the power amplifier, a first end of the third resistor R3 is connected to the first power source V1 and a first end of the first resistor R1, a second end of the third resistor R3 is connected to the output end of the first transistor Q1 and an input end of the third transistor Q3, a control end of the third transistor Q3 is connected to a first end of the fourth resistor R4, a second end of the fourth resistor R4 is connected to an output end of the fourth transistor Q4, a control end of the fourth transistor Q4 is connected to a control end of the first transistor Q1, a second end of the first resistor R1 and a control end of the second transistor Q2, an input end of the fourth transistor Q4 is connected to a second end of the fifth resistor R5, and a first end of the fifth resistor R5 is connected to the second power source V2 and the third end of the third resistor R2, respectively.

It will be appreciated that the temperature influence of the transistor will cause a change in the operating state of the transistor and thus influence the current flowing through the transistor. In this embodiment, a transistor in the feedback unit 20 may be directly disposed in the output die stack of the power amplifier, so that the transistor and a power tube for amplifying in the power amplifier are in the same temperature environment, and when the temperature in the power amplifier changes, both the power tube and the transistor in the power amplifier will be affected by the temperature.

The third resistor R3, the fourth resistor R4, and the fifth resistor R5 are all voltage dividing resistors. In order to avoid temperature influence, the third to fifth resistors in the feedback unit 20 and the fourth transistor Q4 and the components in the voltage conversion unit 10 may be disposed inside the output transistor die of the power amplifier and defined by a certain position, for example, the third transistor Q3 needs to be disposed at a temperature change inside the transistor die, and the fourth transistor Q4 may be disposed at a far distance from the temperature change inside the transistor die. In addition, the third to fifth resistors and the fourth transistor Q4 in the feedback unit 20 and the components in the voltage conversion unit 10 may be provided outside the power amplifier output transistor die. The second to fourth transistors are transistors with control ends, and the transistors can be specific elements such as triodes and MOS transistors.

In a specific implementation, since the third transistor Q3 is disposed inside the output die of the power amplifier, when the temperature inside the output die of the power amplifier changes, the operating state of the third transistor Q3 is affected, and at this time, the current passing through the branch where the third transistor Q3 is located changes. Due to the voltage division effect of the third resistor R3, when the current changes in the branch of the third transistor Q3, the voltage division effect of the third resistor R3 changes, so that the voltage at the output end of the first transistor Q1 changes, the voltage between the control end and the output end of the first transistor Q1 remains constant, and at this time, the voltage at the control end of the first transistor Q1 changes. Since the control terminals of the first transistor Q1, the second transistor Q2 and the fourth transistor Q4 are connected together, the voltage at the control terminal of the second transistor Q2 will also change at this time, which is the change of the operating state of the second transistor Q2, so as to compensate the temperature change inside the power tube. For example, when the temperature in the power amplifier increases, the conduction degree of the third transistor Q3 increases, the current flowing through the third resistor R3 increases, the voltage value of the input terminal of the third transistor Q3 decreases, the voltage of the output terminal of the first transistor Q1 decreases, and when the voltage difference between the control terminal and the output terminal of the first transistor Q1 is unchanged, the voltage of the control terminal of the first transistor Q1 decreases with the voltage of the output terminal, that is, the voltage values of the control terminals of the first transistor Q1, the second transistor Q2, and the fourth transistor Q4 decrease. When the voltage value of the control end of the second transistor Q2 is reduced, the output bias current is reduced along with the reduction of the current of the input end of the second transistor Q2, so that the compensation of the temperature change in the power amplifier is realized. In addition, the fourth transistor Q4 is also placed at a suitable position in the transistor die, and when heat is conducted from the output power transistor that generates heat to the third transistor Q3, a certain time interval is required to be conducted to the fourth transistor Q4, so that the change of the conduction degree of the fourth transistor Q4 is caused, and the compensation control over the voltage of the control terminal of the third transistor Q3 with time is realized.

In the present embodiment, the linear adjusting unit 30 includes: a first capacitor C1 and a sixth resistor R6;

the first end of the first capacitor C1 is connected to the second end of the first resistor R1, the control end of the first transistor Q1, the control end of the second transistor Q2, and the control end of the fourth transistor Q4, the second end of the first capacitor C1 is grounded GND, the first end of the sixth resistor R6 is connected to the output end of the second transistor Q2, and the second end of the sixth resistor R6 is connected to the power amplifier.

The first capacitor C1 is a capacitor for adjusting linearization, and the third resistor R3 is a ballast resistor. When the input power is increased, an alternating current loop can be provided through the first capacitor C1, alternating current signals in the bias circuit are directly output to the ground end GND through the first capacitor C1, and the phenomenon that when the input power is excessively increased, the working state of the power tube is changed due to the excessively large amplitude of the input signals, and the gain of the amplifying power tube is influenced is avoided. In addition, the rf impedance in the bias circuit can be adjusted by the sixth resistor R6 to adjust the bias current, thereby adjusting the linearity of the power amplifier.

Referring to fig. 4, in this embodiment, the bias circuit of the power amplifier further includes: a second capacitor C2;

the first end of the second capacitor C2 is connected to the first end of the second resistor R2 and the second power supply, and the second end of the second capacitor C2 is grounded.

It should be understood that the second capacitor C2 is a decoupling capacitor, and noise may exist in the power voltage output by the second power V2, so that the noise in the power voltage may be filtered by the second capacitor C2, and the stability of the power voltage output by the second power V2 is maintained.

Referring to fig. 5, in the present embodiment, the second transistor Q2 is composed of a predetermined number of sub-transistors;

It should be understood that in the process of outputting the bias voltage, there may be a case where the bias voltage to be output is large, and at this time, the second transistor Q2 with a larger size may be replaced, or a certain number of sub-transistors may be connected in parallel. In this embodiment, a certain number of sub-transistors are connected in parallel, so that larger current output, a more convenient layout arrangement mode and thermal effect compensation can be realized. The bias circuit described in this embodiment may be manufactured by GaAs process, and may also be compatible with CMOS, SOI, and other processes.

In this embodiment, the nonlinear effect of the power amplifier itself can be adjusted by providing the linear adjusting unit, so as to improve the linearity of the power amplifier.

Referring to fig. 6, the present invention also provides a power amplifier including: the input matching unit, the amplifying unit, the output matching unit and the bias circuit;

the input matching unit is respectively connected with the radio frequency input end RFin, the bias circuit of the power amplifier and the amplifying unit, and the input matching unit is connected with the amplifying unit and the radio frequency output end RFout.

In fig. 6, the input matching unit may receive a signal to be amplified through the radio frequency input terminal RFin, and after the bias circuit provides the bias voltage for the amplifying unit, the amplifying unit amplifies the signal to be amplified, and after the amplified radio frequency signal is matched through output, the amplified radio frequency signal is sent through the radio frequency output terminal RFout.

In this embodiment, the amplifying unit includes a third capacitor C1, a first inductor L1, and a certain number of amplifying power tubes;

the first end of the third capacitor C1 is connected to the input matching unit, the second end of the third capacitor C3 is connected to the bias circuit and the control end of each amplifying power tube, the input end of each amplifying power tube is connected to the second end of the first inductor and the output matching unit, the first end of the first inductor L1 is connected to the third power supply V3, and the output end of each amplifying power tube is grounded GND.

When the amplifying power tubes M1 to Mn receive the bias voltage, each amplifying power tube is in an amplifying state, the signal to be amplified, which is input by the input matching unit, is amplified by each amplifying power tube, and the amplified radio frequency signal is transmitted. The first inductor L1 is a choke inductor, which can prevent radio frequency components in the signal link from leaking to the ground through the power supply loop. The specific number of power amplifier output transistors may be determined based on the desired output power requirements.

In this embodiment, the specific compensation process of the bias circuit of the power amplifier may refer to the bias circuit of the power amplifier, and will not be described herein.

The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims

1. A bias circuit of a power amplifier, the bias circuit of the power amplifier comprising: a voltage conversion unit and a feedback unit;

2. The bias circuit of the power amplifier of claim 1, wherein the bias circuit of the power amplifier further comprises: a linear adjustment unit;

3. The bias circuit of the power amplifier according to claim 2, wherein the voltage converting unit is further configured to convert a power supply voltage outputted from the first power supply into an initial bias voltage, and send the initial bias voltage to the linear adjusting unit;

4. The bias circuit of the power amplifier of claim 3, wherein said voltage converting unit comprises: a first resistor, a second resistor, a first transistor, and a second transistor;

5. The bias circuit of the power amplifier of claim 4, wherein said feedback unit comprises: a third resistor, a fourth resistor, a fifth resistor, a third transistor, and a fourth transistor;

the third transistor is arranged inside an output transistor core of the power amplifier, a first end of the third resistor is connected with the first power supply and a first end of the first resistor respectively, a second end of the third resistor is connected with an output end of the first transistor and an input end of the third transistor respectively, a control end of the third transistor is connected with a first end of the fourth resistor, a second end of the fourth resistor is connected with an output end of the fourth transistor, a control end of the fourth transistor is connected with a control end of the first transistor, a second end of the first resistor and a control end of the second transistor, an input end of the fourth transistor is connected with a second end of the fifth resistor respectively, and an output end of the third transistor is grounded.

6. The bias circuit of the power amplifier of claim 5, wherein said linear adjusting unit comprises: a first capacitor and a sixth resistor;

7. The bias circuit of the power amplifier of claim 6, wherein the bias circuit of the power amplifier further comprises: a second capacitor;

8. The bias circuit of the power amplifier of claim 4, wherein said second transistor is comprised of a predetermined number of sub-transistors;

9. A power amplifier, the power amplifier comprising: an input matching unit, an amplifying unit, an output matching unit, and a bias circuit of the power amplifier according to any one of claims 1 to 8;

10. The power amplifier of claim 9, wherein the amplifying unit comprises a third capacitor, a first inductance, and a number of amplifying power tubes;