Power amplifier and radio frequency chip

Abstract

The application is suitable for the field of radio frequency technology, and particularly relates to a power amplifier and a radio frequency chip. The power amplifier comprises a voltage conversion circuit, a bias control circuit and an amplification circuit. An input end of the voltage conversion circuit is used for receiving an external control voltage, and an output end of the voltage conversion circuit is connected to an input end of the bias control circuit. The voltage conversion circuit is used for converting the external control voltage into an output voltage and outputting the output voltage to the bias control circuit. The external control voltage and the output voltage have one of a linear relationship, a logarithmic relationship, an integral relationship and an exponential relationship. Compared with the prior art, the application converts the external control voltage into the output voltage with multiple mathematical relationships, and combines multiple-gear bias proportion adjustment to realize more flexible and more accurate power control of the power amplifier in different working modes, and improve the performance of the power amplifier.

Description

Technical Field

[0001] This invention relates to the field of radio frequency technology, and in particular to a power amplifier and a radio frequency chip. Background Technology

[0002] With the rapid development of modern portable communication systems, their application scenarios are becoming increasingly diverse, encompassing various types such as voice calls, high-speed data transmission, high-definition video streaming, and IoT communication. Different application scenarios place varying demands on the performance indicators of power amplifiers, specifically in multiple dimensions such as output power, noise figure, linearity, and power consumption. Therefore, power amplifiers need to be able to operate in multiple modes and achieve flexible and precise power control.

[0003] like Figure 1 As shown, Figure 1 This is a circuit diagram of a power amplifier in related technologies. The power control of power amplifiers in related technologies generally adopts a scheme of direct drive by ramp control voltage (Vramp): the ramp control voltage is directly input to the bias control circuit, and different output linear voltages Vbias (Vbias=Vramp(1+∑R5i / R4), i=1,2…n) are generated by changing the off state of the resistor switching switches S51~S5n; then the linear bias voltage is input to the bias circuit of the power amplifier, and the output power is adjusted by changing the static operating point of the power amplifier.

[0004] However, the aforementioned power amplifier has the following technical defects: since the bias control circuit can only generate a single linear bias voltage curve based on the input ramp control voltage, the power regulation method is limited and it cannot generate bias voltages with multiple characteristics such as nonlinear, integral, and exponential. This makes it difficult to meet the differentiated requirements of power amplifiers for multi-dimensional performance under the diverse working modes of modern communication systems, thus limiting the performance optimization space and application scenario expansion of power amplifiers.

[0005] Therefore, there is an urgent need for a new power amplifier and RF chip to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a power amplifier and an RF chip, which aims to convert an external control voltage into an output voltage with various mathematical relationships, and combine it with multi-level bias ratio adjustment to achieve more flexible and precise power control of the power amplifier in different operating modes.

[0007] In a first aspect, the present invention provides a power amplifier, the power amplifier including a voltage conversion circuit, a bias control circuit, and an amplification circuit.

[0008] The input terminal of the voltage conversion circuit is used to connect to an external control voltage, and the output terminal of the voltage conversion circuit is connected to the input terminal of the bias control circuit. The voltage conversion circuit is used to convert the external control voltage into an output voltage and output the output voltage to the bias control circuit. The external control voltage and the output voltage have any one of the following relationships: linear, logarithmic, integral, and exponential.

[0009] The output terminal of the bias control circuit is connected to the first input terminal of the amplifier circuit; the bias control circuit is used to generate a bias voltage according to the received output voltage and output the bias voltage to the amplifier circuit.

[0010] The second input terminal of the amplifier circuit is used to receive radio frequency signals, and the output terminal of the amplifier circuit is used to connect to an external antenna terminal; the amplifier circuit is used to amplify the power of the radio frequency signals.

[0011] Preferably, the voltage conversion circuit includes a first mode adjustment unit, a second mode adjustment unit, a first operational amplifier, and a first resistor.

[0012] The input terminal of the first mode adjustment unit serves as the input terminal of the voltage conversion circuit. The output terminal of the first mode adjustment unit is connected to the negative input terminal of the first operational amplifier and the input terminal of the second mode adjustment unit, respectively. The output terminal of the second mode adjustment unit is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier serves as the output terminal of the voltage conversion circuit. The first mode adjustment unit and the second mode adjustment unit cooperate with each other to adjust the relationship between the external control voltage and the output voltage to any one of linear, logarithmic, integral, and exponential relationships.

[0013] The positive input terminal of the first operational amplifier is connected to the first terminal of the first resistor, and the second terminal of the first resistor is grounded.

[0014] Preferably, the first mode adjustment unit includes a first switch, a second switch, a second resistor, and a first diode.

[0015] The common terminal of the first switch serves as the input terminal of the first mode adjustment unit. The normally open terminal of the first switch is connected to the first terminal of the second resistor. The second terminal of the second resistor serves as the output terminal of the first mode adjustment unit. The common terminal of the second switch is connected to the common terminal of the first switch. The normally open terminal of the second switch is connected to the positive terminal of the first diode. The negative terminal of the first diode is connected to the second terminal of the second resistor.

[0016] Preferably, the second mode adjustment unit includes a third switch, a fourth switch, a fifth switch, a third resistor, a second diode, and a first capacitor.

[0017] The common terminal of the third switch is connected to the common terminals of the fourth switch and the fifth switch, respectively, and serves as the input terminal of the second mode adjustment unit. The normally open terminal of the third switch is connected to the first terminal of the first capacitor. The normally open terminal of the fourth switch is connected to the positive terminal of the second diode. The normally open terminal of the fifth switch is connected to the first terminal of the third resistor. The second terminal of the first capacitor, the negative terminal of the second diode, and the second terminal of the third resistor are connected to each other and serve as the output terminal of the second mode adjustment unit.

[0018] Preferably, the bias control circuit includes a second operational amplifier, a first MOSFET, a fourth resistor, n fifth resistors, and n sixth switches; wherein n is a positive integer greater than or equal to 1.

[0019] The negative input terminal of the second operational amplifier serves as the input terminal of the bias control circuit. The positive input terminal of the second operational amplifier is connected to the first terminal of the fourth resistor, the second terminal of the fourth resistor is grounded, the output terminal of the second operational amplifier is connected to the gate of the first MOS transistor, and the source of the first MOS transistor is used to connect to an external power supply voltage.

[0020] The n fifth resistors are connected in series, with the first end of the first fifth resistor connected to the drain of the first MOS transistor, and the second end of the nth fifth resistor connected to the first end of the fourth resistor.

[0021] The common terminal of each of the n sixth switches is connected to the first terminal of each of the n fifth resistors, and the normally open terminals of the n sixth switches are interconnected and serve as the output terminal of the bias control circuit.

[0022] Preferably, the power amplifier further includes an output matching circuit.

[0023] The input terminal of the output matching circuit is connected to the output terminal of the amplifier circuit, and the output terminal of the output matching circuit is used to connect to the external antenna terminal; the output matching circuit is used to adjust the impedance matching between the amplifier circuit and the external antenna terminal.

[0024] In a second aspect, the present invention also provides a radio frequency chip, the radio frequency chip comprising a power amplifier as described in any of the above embodiments.

[0025] Compared to existing technologies, this invention uses a voltage conversion circuit to regulate the external control voltage, converting a single external control voltage into four different output voltages: linear, logarithmic, integral, and exponential. Combined with the resistor branch switching function of the bias control circuit, it can generate a greater number of bias voltage curves with richer characteristics. This allows for precise matching of the power amplifier's varying output power requirements in different application scenarios, while simultaneously optimizing key performance indicators such as noise figure, linearity, and power consumption. This results in more diverse power control and improved power amplifier performance. Furthermore, the voltage conversion circuit consists only of conventional RF integrated circuit components such as switches, resistors, diodes, capacitors, and operational amplifiers, eliminating the need for complex circuit topology design and special semiconductor processes. It is seamlessly compatible with the bias control circuits of existing power amplifier modules, resulting in a simple and easy-to-implement power amplifier structure that effectively reduces chip design complexity. Attached Figure Description

[0026] The present invention will now be described in detail with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and more readily understood through the detailed description following the accompanying drawings. In the drawings: Figure 1 This is a circuit diagram of a power amplifier based on related technologies; Figure 2 This is a circuit diagram of a power amplifier provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] Example 1 Please refer to Figure 2 The present invention provides a power amplifier 100, which includes a voltage conversion circuit 1, a bias control circuit 2, and an amplification circuit 3.

[0029] The input terminal of the voltage conversion circuit 1 is connected to an external control voltage Vramp, and the output terminal of the voltage conversion circuit 1 is connected to the input terminal of the bias control circuit 2. The voltage conversion circuit 1 is used to convert the external control voltage Vramp into an output voltage Vout and output the output voltage Vout to the bias control circuit 2. The external control voltage Vramp and the output voltage Vout have any one of the following relationships: linear, logarithmic, integral, and exponential.

[0030] The output terminal of the bias control circuit 2 is connected to the first input terminal of the amplifier circuit 3; the bias control circuit 2 is used to generate a bias voltage Vbias according to the received output voltage Vout, and output the bias voltage Vbias to the amplifier circuit 3.

[0031] The second input terminal of the amplifier circuit 3 is used to receive radio frequency signals, and the output terminal of the amplifier circuit 3 is used to connect to an external antenna terminal ANT; the amplifier circuit 3 is used to amplify the power of the radio frequency signals.

[0032] In this embodiment of the invention, the voltage conversion circuit 1 includes a first mode adjustment unit 11, a second mode adjustment unit 12, a first operational amplifier OP1, and a first resistor R1.

[0033] The input terminal of the first mode adjustment unit 11 serves as the input terminal of the voltage conversion circuit 1. The output terminal of the first mode adjustment unit 11 is connected to the negative input terminal of the first operational amplifier OP1 and the input terminal of the second mode adjustment unit 12, respectively. The output terminal of the second mode adjustment unit 12 is connected to the output terminal of the first operational amplifier OP1, and the output terminal of the first operational amplifier OP1 serves as the output terminal of the voltage conversion circuit 1. The first mode adjustment unit 11 and the second mode adjustment unit 12 cooperate with each other to adjust the relationship between the external control voltage Vramp and the output voltage Vout to any one of the following: linear relationship, logarithmic relationship, integral relationship, and exponential relationship.

[0034] The positive input terminal of the first operational amplifier OP1 is connected to the first terminal of the first resistor R1, and the second terminal of the first resistor R1 is grounded.

[0035] In this embodiment of the invention, the first mode adjustment unit 11 includes a first switch S1, a second switch S2, a second resistor R2, and a first diode D1.

[0036] The common terminal of the first switch S1 serves as the input terminal of the first mode adjustment unit 11. The normally open terminal of the first switch S1 is connected to the first terminal of the second resistor R2. The second terminal of the second resistor R2 serves as the output terminal of the first mode adjustment unit 11. The common terminal of the second switch S2 is connected to the common terminal of the first switch S1. The normally open terminal of the second switch S2 is connected to the positive terminal of the first diode D1. The negative terminal of the first diode D1 is connected to the second terminal of the second resistor R2.

[0037] In this embodiment of the invention, the second mode adjustment unit 12 includes a third switch S3, a fourth switch S4, a fifth switch S5, a third resistor R3, a second diode D2, and a first capacitor C1.

[0038] The common terminal of the third switch S3 is connected to the common terminal of the fourth switch S4 and the common terminal of the fifth switch S5, and serves as the input terminal of the second mode adjustment unit 12. The normally open terminal of the third switch S3 is connected to the first terminal of the first capacitor C1. The normally open terminal of the fourth switch S4 is connected to the positive terminal of the second diode D2. The normally open terminal of the fifth switch S5 is connected to the first terminal of the third resistor R3. The second terminal of the first capacitor C1, the negative terminal of the second diode D2, and the second terminal of the third resistor R3 are connected to each other and serve as the output terminal of the second mode adjustment unit 12.

[0039] In this embodiment of the invention, the bias control circuit 2 includes a second operational amplifier OP2, a first MOS transistor M1, a fourth resistor R4, n fifth resistors R5, and n sixth switches S6; where n is a positive integer greater than or equal to 1.

[0040] The negative input terminal of the second operational amplifier OP2 serves as the input terminal of the bias control circuit 2. The positive input terminal of the second operational amplifier OP2 is connected to the first terminal of the fourth resistor R4, and the second terminal of the fourth resistor R4 is grounded. The output terminal of the second operational amplifier OP2 is connected to the gate of the first MOS transistor M1, and the source of the first MOS transistor M1 is used to connect to the external power supply voltage VBAT.

[0041] n fifth resistors R5 are connected in series, with the first end of the first fifth resistor R5 connected to the drain of the first MOS transistor M1, and the second end of the nth fifth resistor R5 connected to the first end of the fourth resistor R4. The common terminal of each of the n sixth switches S6 is connected to the first terminal of each of the n fifth resistors R5. The normally open terminals of the n sixth switches S6 are interconnected and serve as the output terminal of the bias control circuit 2.

[0042] In this embodiment of the invention, the power amplifier 100 further includes an output matching circuit 4.

[0043] The input terminal of the output matching circuit 4 is connected to the output terminal of the amplifier circuit 3, and the output terminal of the output matching circuit 4 is used to connect to the external antenna terminal ANT; the output matching circuit 4 is used to adjust the impedance matching between the amplifier circuit 3 and the external antenna terminal ANT.

[0044] Specifically, the external control voltage Vramp, through the voltage conversion circuit 1 proposed in this invention, combines the on and off states of the switches in the first mode adjustment unit 11 and the second mode adjustment unit 12 in various ways to achieve the conversion of the output voltage Vout of different mode curves. The output voltage Vout then passes through the bias control circuit 2, so that the bias voltage Vbias and the output voltage Vout satisfy: Vbias=Vout(1+∑R5i / R4), i=1,2…n, thereby realizing the generation of diversified bias voltage Vbias by the controller modulation, and realizing more diversified control of the output power in different modes.

[0045] When the power amplifier 100 is in linear conversion mode, the external control voltage Vramp is linearly related to the output voltage Vout. At this time, the first switch S1 and the fifth switch S5 are closed, and the second switch S2, the third switch S3, and the fourth switch S4 are open, thus implementing the linear conversion function of the external control voltage Vramp. The external control voltage Vramp and the output voltage Vout satisfy the following conditions: Vout = -Vramp•R3 / R2; When the power amplifier 100 is in logarithmic conversion mode, the external control voltage Vramp and the output voltage Vout are logarithmically related. At this time, the first switch S1 and the fourth switch S4 are closed, and the second switch S2, the third switch S3, and the fifth switch S5 are open, thus implementing the logarithmic conversion function of the external control voltage Vramp. The external control voltage Vramp and the output voltage Vout satisfy the following conditions: Vout = -VT•ln(Vramp / Is / R2); Where Is is the diode reverse saturation current and VT is the temperature voltage equivalent; When the power amplifier 100 is in integral conversion mode, the external control voltage Vramp and the output voltage Vout are integrally related. At this time, the first switch S1 and the third switch S3 are closed, and the second switch S2, the fourth switch S4 and the fifth switch S5 are open, thus implementing the external control voltage integral conversion function. The external control voltage Vramp and the output voltage Vout satisfy the following conditions: Vout=-1 / (R2•C1)• ; When the power amplifier 100 is in exponential conversion mode, the external control voltage Vramp and the output voltage Vout are exponentially related. At this time, the second switch S2 and the fifth switch S5 are closed, and the first switch S1, the third switch S3, and the fourth switch S4 are open, thus implementing the exponential conversion function of the external control voltage Vramp. The external control voltage Vramp and the output voltage Vout satisfy the following conditions: Vout=-R3•Is•e^(Vramp / VT).

[0046] Compared to existing technologies, this invention regulates the external control voltage through a voltage conversion circuit, converting a single external control voltage into four different output voltages: linear, logarithmic, integral, and exponential. Combined with the resistor branch switching function of the bias control circuit, it can generate a greater number of bias voltage curves with richer characteristics. This allows for precise matching of the differentiated output power requirements of power amplifiers in various application scenarios, while simultaneously optimizing key performance indicators such as noise figure, linearity, and power consumption, achieving more diversified power control. Furthermore, the voltage conversion circuit consists only of conventional RF integrated circuit components such as switches, resistors, diodes, capacitors, and operational amplifiers, eliminating the need for complex circuit topology design and special semiconductor processes. It is seamlessly compatible with the bias control circuits of existing power amplifier modules, resulting in a simple and easy-to-implement power amplifier structure, effectively reducing chip design complexity.

[0047] Example 2 This invention also provides a radio frequency (RF) chip, which includes the power amplifier 100 as described in the above embodiments and can achieve the same technical effect. Please refer to the description in the above embodiments, which will not be repeated here.

[0048] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0049] The embodiments of the present invention have been described above with reference to the accompanying drawings. The disclosed embodiments are merely preferred embodiments of the present invention. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many equivalent changes in form under the guidance of the present invention without departing from the spirit and scope of the claims. All such changes are within the protection scope of the present invention.

Claims

1. A power amplifier, characterized in that, The power amplifier includes a voltage conversion circuit, a bias control circuit, and an amplification circuit. The input terminal of the voltage conversion circuit is used to connect to an external control voltage, and the output terminal of the voltage conversion circuit is connected to the input terminal of the bias control circuit; the voltage conversion circuit is used to convert the external control voltage into an output voltage and output the output voltage to the bias control circuit; wherein, the external control voltage and the output voltage have any one of the following relationships: linear, logarithmic, integral, and exponential; The output terminal of the bias control circuit is connected to the first input terminal of the amplifier circuit; the bias control circuit is used to generate a bias voltage according to the received output voltage and output the bias voltage to the amplifier circuit. The second input terminal of the amplifier circuit is used to receive radio frequency signals, and the output terminal of the amplifier circuit is used to connect to an external antenna terminal; the amplifier circuit is used to amplify the power of the radio frequency signals. The voltage conversion circuit includes a first mode adjustment unit, a second mode adjustment unit, a first operational amplifier, and a first resistor; The input terminal of the first mode adjustment unit serves as the input terminal of the voltage conversion circuit. The output terminal of the first mode adjustment unit is connected to the negative input terminal of the first operational amplifier and the input terminal of the second mode adjustment unit, respectively. The output terminal of the second mode adjustment unit is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier serves as the output terminal of the voltage conversion circuit. The first mode adjustment unit and the second mode adjustment unit cooperate with each other to adjust the relationship between the external control voltage and the output voltage to any one of linear, logarithmic, integral, and exponential relationships. The positive input terminal of the first operational amplifier is connected to the first terminal of the first resistor, and the second terminal of the first resistor is grounded.

2. The power amplifier as described in claim 1, characterized in that, The first mode adjustment unit includes a first switch, a second switch, a second resistor, and a first diode; The common terminal of the first switch serves as the input terminal of the first mode adjustment unit. The normally open terminal of the first switch is connected to the first terminal of the second resistor, and the second terminal of the second resistor serves as the output terminal of the first mode adjustment unit. The common terminal of the second switch is connected to the common terminal of the first switch. The normally open terminal of the second switch is connected to the anode of the first diode, and the cathode of the first diode is connected to the second terminal of the second resistor.

3. The power amplifier as described in claim 1, characterized in that, The second mode adjustment unit includes a third switch, a fourth switch, a fifth switch, a third resistor, a second diode, and a first capacitor; The common terminal of the third switch is connected to the common terminals of the fourth switch and the fifth switch, respectively, and serves as the input terminal of the second mode adjustment unit. The normally open terminal of the third switch is connected to the first terminal of the first capacitor. The normally open terminal of the fourth switch is connected to the positive terminal of the second diode. The normally open terminal of the fifth switch is connected to the first terminal of the third resistor. The second terminal of the first capacitor, the negative terminal of the second diode, and the second terminal of the third resistor are connected to each other and serve as the output terminal of the second mode adjustment unit.

4. The power amplifier as described in claim 1, characterized in that, The bias control circuit includes a second operational amplifier, a first MOSFET, a fourth resistor, n fifth resistors, and n sixth switches; where n is a positive integer greater than or equal to 1. The negative input terminal of the second operational amplifier serves as the input terminal of the bias control circuit. The positive input terminal of the second operational amplifier is connected to the first terminal of the fourth resistor, the second terminal of the fourth resistor is grounded, the output terminal of the second operational amplifier is connected to the gate of the first MOS transistor, and the source of the first MOS transistor is used to connect to the external power supply voltage. The n fifth resistors are connected in series, with the first end of the first fifth resistor connected to the drain of the first MOS transistor, and the second end of the nth fifth resistor connected to the first end of the fourth resistor. The common terminal of each of the n sixth switches is connected to the first terminal of each of the n fifth resistors, and the normally open terminals of the n sixth switches are interconnected and serve as the output terminal of the bias control circuit.

5. The power amplifier as described in claim 1, characterized in that, The power amplifier also includes an output matching circuit; The input terminal of the output matching circuit is connected to the output terminal of the amplifier circuit, and the output terminal of the output matching circuit is used to connect to the external antenna terminal; the output matching circuit is used to adjust the impedance matching between the amplifier circuit and the external antenna terminal.

6. A radio frequency chip, characterized in that, The radio frequency chip includes a power amplifier as described in any one of claims 1-5.

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