Temperature compensation circuit, power amplifier and radio frequency front-end module

Abstract

The invention discloses a temperature compensation circuit, a power amplifier and a radio frequency front-end module. The temperature compensation circuit comprises a temperature compensation module, a current source module and a control module. The temperature compensation module is used for outputting a first temperature compensation voltage under the condition that the environment temperature is smaller than or equal to a first temperature threshold value; the current source module is connected between the temperature compensation module and the output port and is used for converting the temperature compensation voltage output by the temperature compensation module into control current; the current source module is provided with at least two current adjusting gears, and the control module is connected with the current source module. When the first temperature compensation voltage output by the temperature compensation module is in positive correlation with the environment temperature, and the environment temperature is smaller than or equal to a first temperature threshold value (namely, the low-temperature environment), the control current is reduced accordingly, so that the offset signal of the compensated power amplifier is synchronously reduced, and the offset signal of the power amplifier is synchronously reduced. The working gain of the power amplifier in a low-temperature environment can be reduced, so that the durability of the power amplifier is improved.

Description

Technical Field

[0001] This application relates to the field of radio frequency technology, and more specifically, to a temperature compensation circuit, a power amplifier, and a radio frequency front-end module. Background Technology

[0002] Currently, radio frequency (RF) front-end modules are widely used in wireless communication, the Internet of Things (IoT), smart homes, and other fields. They can process RF signals (e.g., power amplification, filtering, impedance matching, etc.) to complete the tasks of receiving and transmitting RF signals.

[0003] As a core component of the RF front-end module, the power amplifier amplifies the power of RF signals so that the signals can be effectively radiated to the outside world through the antenna. However, under certain extreme conditions, the power amplifier may experience an increase in operating gain, which in turn reduces its ruggedness. Summary of the Invention

[0004] This application provides a temperature compensation circuit, a power amplifier, and a radio frequency front-end module.

[0005] According to a first aspect of this application, an embodiment of this application provides a temperature compensation circuit having an output port for providing a control current to a power amplifier. The control current is used to perform temperature compensation on the bias signal of the power amplifier. The temperature compensation circuit includes a temperature compensation module, a current source module, and a control module. The temperature compensation module outputs a first temperature compensation voltage when the ambient temperature is less than or equal to a first temperature threshold; wherein the first temperature compensation voltage is positively or negatively correlated with the ambient temperature. The current source module is connected between the temperature compensation module and the output port, and is used to convert the temperature compensation voltage output by the temperature compensation module into a control current; wherein the current source module has at least two current adjustment levels. The control module is connected to the current source module; the control module is configured to: control the current source module to be in the first current adjustment level when the ambient temperature is greater than a second temperature threshold; and control the current source module to be in the second current adjustment level when the ambient temperature is less than or equal to the second temperature threshold. The second temperature threshold is less than the first temperature threshold; at the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment level is less than the amplitude of the control current corresponding to the first current adjustment level.

[0006] According to a second aspect of this application, embodiments of this application also provide a power amplifier, which includes a power amplification module, a bias module, and the aforementioned temperature compensation circuit. The bias module is connected to the power amplification module and is used to output a bias signal to the power amplification module. The temperature compensation circuit is connected to the bias module and is used to perform temperature compensation on the bias signal output by the bias module.

[0007] According to a third aspect of this application, embodiments of this application also provide a radio frequency front-end module, which includes the power amplifier described above.

[0008] This application provides a temperature compensation circuit, a power amplifier, and an RF front-end module. The temperature compensation circuit provides a control current to the power amplifier, which is used to compensate for the temperature of the power amplifier's bias signal. The temperature compensation circuit includes a temperature compensation module, a current source module, and a control module.

[0009] On the one hand, when the ambient temperature is less than or equal to the first temperature threshold, the first temperature compensation voltage output by the temperature compensation module is positively or negatively correlated with the ambient temperature. Taking a positive correlation as an example, the control current converted from the first temperature compensation voltage is also positively correlated with the ambient temperature. Therefore, when the ambient temperature is less than or equal to the first temperature threshold (i.e., in a low-temperature environment), the control current will decrease accordingly, so that the bias signal of the compensated power amplifier will decrease synchronously, which can reduce the operating gain of the power amplifier in low-temperature environments and improve the durability of the power amplifier.

[0010] On the other hand, the current source module in this application has at least two current adjustment levels, and the amplitude of the control current output by the current source module is different at each current adjustment level. Therefore, the corresponding current adjustment level can be selected according to the actual operating conditions of the RF front-end module equipped with this temperature compensation circuit, so that the operating gain of the power amplifier can match the operating performance of the RF front-end module. For example, if the RF front-end module has good low-temperature tolerance, a current adjustment level with a larger control current amplitude can be selected to reduce the loss of power amplifier efficiency.

[0011] Furthermore, when the ambient temperature is greater than the second temperature threshold, the current source module is in the first current adjustment setting; when the ambient temperature is less than or equal to the second temperature threshold, the current source module is in the second current adjustment setting. The second temperature threshold is less than the first temperature threshold. Specifically, at the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment setting is less than the amplitude of the control current corresponding to the first current adjustment setting.

[0012] Specifically, when the ambient temperature is above the second temperature threshold but below or equal to the first temperature threshold, the current source module can operate at a current adjustment level with a larger control current amplitude; when the ambient temperature is below or equal to the second temperature threshold, the current source module can operate at a current adjustment level with a smaller control current amplitude. Therefore, if the RF front-end module has good low-temperature tolerance (e.g., can withstand ambient temperatures above the second temperature threshold), it can avoid drastically reducing the control current and sacrificing the power amplifier's efficiency. Once the ambient temperature is below the second temperature threshold, the control current will be further reduced to lower the power amplifier's bias signal and improve its durability. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a structural block diagram of the temperature compensation circuit provided in the embodiments of this application.

[0015] Figure 2 This is a graph showing the relationship between ambient temperature and temperature compensation voltage and control current, as provided in the embodiments of this application.

[0016] Figure 3 yes Figure 1 The diagram shows a schematic of one circuit structure for a temperature compensation circuit.

[0017] Figure 4 yes Figure 1 The diagram shows another circuit structure of the temperature compensation circuit.

[0018] Figure 5 yes Figure 4 The circuit structure diagram of the control module in the temperature compensation circuit shown is shown.

[0019] Figure 6 This is a graph showing the relationship between ambient temperature and control current at different threshold adjustment levels, as provided in the embodiments of this application.

[0020] Figure 7 yes Figure 1 The diagram shows another circuit structure of the temperature compensation circuit.

[0021] Figure 8 This is a graph showing the relationship between ambient temperature and control current under different second current adjustment levels, as provided in the embodiments of this application.

[0022] Figure 9 yes Figure 1 The diagram shows another circuit structure of the temperature compensation circuit.

[0023] Figure 10 This is a schematic diagram of the circuit structure of the power amplifier provided in the embodiments of this application.

[0024] Figure 11 This is a structural block diagram of the radio frequency front-end module provided in the embodiments of this application. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0026] Please see Figure 1 This application provides a temperature compensation circuit 100 that can adjust the bias signal (e.g., bias voltage, bias current) of a power amplifier (PA) based on the ambient temperature to reduce the impact of ambient temperature changes on the performance of the power amplifier. For example, when the power amplifier operates in a low-temperature environment, the temperature compensation circuit 100 can reduce the operating gain of the power amplifier by decreasing the magnitude of the bias signal to ensure that the power amplifier can operate normally in low-temperature environments.

[0027] Specifically, the temperature compensation circuit 100 has an output port 102, which is used to provide a control current to the power amplifier. This control current is used to compensate for the temperature of the power amplifier's bias signal. In other words, the power amplifier can dynamically adjust the bias signal according to changes in the control current to reduce the impact of ambient temperature.

[0028] In this embodiment, the temperature compensation circuit 100 may include a temperature compensation module 20, a current source module 30, and a control module 40. The temperature compensation module 20 is used to output a first temperature compensation voltage when the ambient temperature is less than or equal to a first temperature threshold. The first temperature compensation voltage is positively or negatively correlated with the ambient temperature.

[0029] The "ambient temperature" here can be the temperature of the space where the electronic device equipped with the temperature compensation circuit 100 is located. Specifically, when the ambient temperature is less than or equal to a first temperature threshold, it indicates that the electronic device is in a low-temperature environment. For example, the first temperature threshold can be less than or equal to 10°C, such as -25°C, -10°C, -5°C, 0°C, 5°C, 8°C, 10°C, etc.

[0030] Please see Figure 2 , Figure 2 Part (a) illustrates one possible correspondence between ambient temperature and temperature-compensated voltage. Here, T1 is the first temperature threshold, and the first temperature-compensated voltage can be understood as a segment of the temperature-compensated voltage. Specifically... Figure 2 In part (a), the first temperature compensation voltage is positively correlated with the ambient temperature. Of course, in other possible examples, the first temperature compensation voltage and the ambient temperature may also be negatively correlated, and this embodiment does not specifically limit this.

[0031] A current source module 30 is connected between the temperature compensation module 20 and the output port 102, and it is used to convert the temperature compensation voltage output by the temperature compensation module 20 into a control current. The current source module 30 has at least two current adjustment levels. Specifically, at the same ambient temperature, the amplitude of the control current corresponding to different current adjustment levels is different.

[0032] The control module 40 is connected to the current source module 30. The control module 40 is configured to: control the current source module 30 to be in a first current adjustment position when the ambient temperature is greater than a second temperature threshold; and control the current source module 30 to be in a second current adjustment position when the ambient temperature is less than or equal to the second temperature threshold. The second temperature threshold is less than the first temperature threshold; and at the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment position is less than the amplitude of the control current corresponding to the first current adjustment position.

[0033] Specifically, in Figure 2 Part (b) illustrates a possible correspondence between ambient temperature and control current. Here, T2 is a second temperature threshold. Exemplarily, the second temperature threshold can be less than or equal to 0°C; for example, if the first temperature threshold is 5°C, the second temperature threshold could be -8°C, -5°C, -2°C, 0°C, etc.

[0034] On one hand, when the ambient temperature is less than or equal to the first temperature threshold, the first temperature compensation voltage output by the temperature compensation module 20 is positively or negatively correlated with the ambient temperature. Taking a positive correlation as an example, the control current converted from the first temperature compensation voltage is also positively correlated with the ambient temperature. Therefore, when the ambient temperature is less than or equal to the first temperature threshold (i.e., in a low-temperature environment), the control current will decrease accordingly, so that the bias signal of the compensated power amplifier will decrease synchronously, thereby reducing the operating gain of the power amplifier in low-temperature environments and improving the durability of the power amplifier.

[0035] On the other hand, the current source module 30 in this embodiment has at least two current adjustment levels, and the amplitude of the control current output by the current source module 30 is different at different current adjustment levels. Therefore, the corresponding current adjustment level can be selected according to the actual operating conditions of the RF front-end module equipped with the temperature compensation circuit 100, so that the operating gain of the power amplifier can match the operating performance of the RF front-end module. For example, if the RF front-end module has good low-temperature tolerance, a current adjustment level with a larger control current amplitude can be selected to avoid excessive degradation of the operating gain of the power amplifier.

[0036] Furthermore, when the ambient temperature is greater than the second temperature threshold, the current source module 30 is in the first current adjustment setting; when the ambient temperature is less than or equal to the second temperature threshold, the current source module 30 is in the second current adjustment setting. The second temperature threshold is less than the first temperature threshold. Specifically, at the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment setting is less than the amplitude of the control current corresponding to the first current adjustment setting.

[0037] Specifically, when the ambient temperature is above the second temperature threshold but below or equal to the first temperature threshold, the current source module 30 can operate at a current adjustment level with a larger control current amplitude; when the ambient temperature is below or equal to the second temperature threshold, the current source module 30 can operate at a current adjustment level with a smaller control current amplitude. Therefore, if the RF front-end module has good low-temperature tolerance (e.g., can withstand ambient temperatures above the second temperature threshold), the situation where a significant reduction in control current would sacrifice the power amplifier's efficiency can be avoided. Furthermore, once the ambient temperature is below the second temperature threshold, the control current will be further reduced to lower the power amplifier's bias signal, preventing damage to the power amplifier in low-temperature environments and improving its durability.

[0038] The specific implementation of the temperature compensation circuit 100 is explained below.

[0039] In this embodiment, the temperature compensation module 20 is used to output a temperature compensation voltage related to the ambient temperature. Specifically, when the ambient temperature is less than or equal to a first temperature threshold, the temperature compensation voltage is a first temperature compensation voltage. The first temperature compensation voltage and the ambient temperature are positively or negatively correlated.

[0040] As an example, assuming a positive correlation between the first temperature compensation voltage and the ambient temperature, the temperature compensation module 20 may include a first temperature compensation unit (not shown in the figure). This first temperature compensation unit receives a current signal with a positive temperature coefficient output from a current source and converts it into a temperature compensation voltage, thereby achieving a positive correlation between the output first temperature compensation voltage and the ambient temperature. This embodiment does not limit the specific implementation circuit of the first temperature compensation unit.

[0041] In some possible embodiments, the temperature compensation module 20 is further configured to output a second temperature-compensated voltage when the ambient temperature is greater than or equal to a third temperature threshold. The second temperature-compensated voltage is positively or negatively correlated with the ambient temperature, and the third temperature threshold is greater than the first temperature threshold. Specifically, an ambient temperature greater than or equal to the third temperature threshold indicates that the electronic device is in a high-temperature environment. For example, the third temperature threshold may be greater than or equal to 40°C; for instance, the third temperature threshold may be 40°C, 50°C, 55°C, 58°C, 60°C, etc.

[0042] See again Figure 2 In part (a), T3 is the third temperature threshold, and the second temperature compensation voltage can be understood as another voltage segment within the temperature compensation voltage. Specifically... Figure 2 In part (a), the second temperature compensation voltage is positively correlated with the ambient temperature. Of course, in other possible examples, the second temperature compensation voltage and the ambient temperature may also be negatively correlated, and this embodiment does not specifically limit this.

[0043] Therefore, when the ambient temperature is greater than or equal to the third temperature threshold, the second temperature compensation voltage output by the temperature compensation module 20 is positively or negatively correlated with the ambient temperature. Taking a positive correlation as an example, the control current converted from the second temperature compensation voltage is also positively correlated with the ambient temperature. Therefore, when the ambient temperature is greater than or equal to the third temperature threshold (i.e., a high-temperature environment), the control current will increase accordingly, so that the bias signal of the compensated power amplifier will increase synchronously, which can increase the operating gain of the power amplifier in a high-temperature environment and improve the operating efficiency of the power amplifier.

[0044] As an example, the temperature compensation module 20 may include a second temperature compensation unit (not shown in the figure), which can receive a current signal with a positive temperature coefficient output from a current source and convert it into a second temperature compensation voltage so that the output second temperature compensation voltage is positively correlated with the ambient temperature.

[0045] In some other possible embodiments, the temperature compensation module 20 is further configured to output a third temperature compensation voltage when the ambient temperature is greater than a first temperature threshold and less than a third temperature threshold. The third temperature compensation voltage can be a fixed value. This fixed value can be the maximum value of the first temperature compensation voltage or the minimum value of the second temperature compensation voltage.

[0046] Specifically, when the ambient temperature is greater than a first temperature threshold but less than a third temperature threshold, it indicates that the electronic device is in a normal temperature environment. In this case, the temperature compensation circuit 100 can avoid adjusting the bias signal of the power amplifier to reduce the overall power consumption of the RF front-end module.

[0047] For example, if the control current output by the current source is the default value under the third temperature compensation voltage, then under the action of the first temperature compensation voltage, the control current output by the current source will decrease based on the default value, while under the action of the second temperature compensation voltage, the control current output by the current source will increase based on the default value.

[0048] In this embodiment, the current source module 30 is connected between the temperature compensation module 20 and the output port 102, and is used to convert the temperature compensation voltage output by the temperature compensation module 20 into a control current. The current source module 30 has at least two current adjustment levels. Specifically, at the same ambient temperature, the amplitude of the control current corresponding to different current adjustment levels is different.

[0049] Please see Figure 3 The current source module 30 may include an operational amplifier unit 320, a current mirror unit 340, and an adjustable resistor unit 360. The current mirror unit 340 includes a first current branch S1 and a second current branch S2, with the first terminal of the first current branch S1 and the first terminal of the second current branch S2 configured as the input power supply voltage. For example, the power supply voltage here is... Figure 3 In VBATT, the power supply voltage amplitude can be 3.2V, 3.5V, 4.2V, 5V, etc.

[0050] The inverting input of operational amplifier unit 320 is connected to temperature compensation module 20. The output of operational amplifier unit 320 is connected to the control terminals of the first current branch S1 and the second current branch S2, respectively. The non-inverting input of operational amplifier unit 320 is connected to the second terminal of the first current branch S1, and the second terminal of the second current branch S2 is connected to output port 102. Operational amplifier unit 320 can act as a voltage clamp, allowing the voltage value at the second terminal of the first current branch S1 to change in response to changes in the input voltage (i.e., temperature compensation voltage) at the inverting input of operational amplifier unit 320. Specifically, operational amplifier unit 320 can be an operational amplifier.

[0051] The current mirroring unit 340 is used to mirror the branch current of the first current branch S1. The mirrored current is output to the output port 102 through the second current branch S2. That is, the mirrored current is the control current output by the current source module 30.

[0052] As an example, the first current branch S1 may include a first transistor J1, and the second current branch S2 may include a second transistor J2. Both the first transistor J1 and the second transistor J2 are field-effect transistors (FETs). The first terminal, the second terminal, and the control terminal of the first current branch S1 are the source, drain, and gate of the first transistor J1, respectively. The first terminal, the second terminal, and the control terminal of the second current branch S2 are the source, drain, and gate of the second transistor J2, respectively. Specifically... Figure 3 In the embodiment shown, the first transistor J1 and the second transistor J2 are both P-channel metal-oxide-semiconductor field-effect transistors (PMOS).

[0053] Here, the temperature-compensated voltage is denoted as Tc. The branch current I1 of the first current branch S1 is Tc / R, where R is the equivalent resistance of the adjustable resistor unit 360. The branch current I2 (i.e., the control current) of the second current branch S2 is A*Tc / R, where A is the ratio of the width-to-length ratio of the second transistor J2 to the first transistor J1. For example, when the second transistor J2 and the first transistor J1 are identical, A equals 1; when the width-to-length ratio of the second transistor J2 is greater than that of the first transistor J1, A is greater than 1.

[0054] It is easy to see that, with both A and Tc fixed, the control current can be adjusted by changing the equivalent resistance value of the adjustable resistor unit 360, so that the current source module 30 has at least two current adjustment levels. Specifically, the amplitude of the control current and the equivalent resistance value of the adjustable resistor unit 360 are negatively correlated; that is, the larger the equivalent resistance value of the adjustable resistor unit 360, the smaller the amplitude of the control current.

[0055] exist Figure 3 In the illustrated embodiment, one end of the adjustable resistor unit 360 is connected to the second end of the first current branch S1, and the other end is grounded. The control module 40 is connected to the adjustable resistor unit 360 and is configured to: control the equivalent resistance value of the adjustable resistor unit 360 to a first resistance value when the ambient temperature is greater than a second temperature threshold; and control the equivalent resistance value of the adjustable resistor unit 360 to a second resistance value when the ambient temperature is less than the second temperature threshold. The second resistance value is greater than the first resistance value.

[0056] Specifically, the adjustable resistor unit 360 may include K second resistors R2 and K-1 third switching transistors N3, where K is an integer greater than or equal to 2. Figure 3 In the example shown, K is 5, the five second resistors R2 are R20, R21, R22, R23, and R24, and the four third switches N3 are N31, N32, N33, and N34. Of course, in other possible examples, K can be 2, 3, 4, 6, 8, etc. It's easy to understand that the larger K is, the more current adjustment levels are available.

[0057] exist Figure 3 In the illustrated embodiment, K second resistors R2 are connected in series to form a second resistor string. One end of the second resistor string is connected to the second terminal of the first current branch S1, and the other end is grounded. The first terminals of K-1 third switching transistors N3 are connected one-to-one between adjacent second resistors R2; the second terminals of K-1 third switching transistors N3 are grounded; and the control terminals of K-1 third switching transistors N3 are connected to the control module 40. As an example, the third switching transistor N3 can be a field-effect transistor, where the first terminal, second terminal, and control terminal of the third switching transistor N3 are the drain, source, and gate of the field-effect transistor, respectively. Specifically... Figure 3 In the embodiment shown, the third switch N3 can be an N-channel metal-oxide-semiconductor field-effect transistor (NMOS).

[0058] Therefore, in this embodiment, the control module 40 can adjust the connection state of the K second resistors R2 by controlling the opening and closing states of the K-1 third switching transistors N3, thereby adjusting the equivalent resistance value of the adjustable resistor unit 360. For example, when N31 is in the closed state and N32, N33, and N34 are in the open state, R21, R22, R23, and R24 are not connected, and the equivalent resistance value of the adjustable resistor unit 360 is equal to the resistance value of R20; as another example, when N33 is in the closed state and N31, N32, and N34 are in the open state, R23 and R24 are not connected, and the equivalent resistance value of the adjustable resistor unit 360 is equal to the sum of the resistance values ​​of R20, R21, and R22.

[0059] As one example, the resistance values ​​of the K second resistors R2 can be the same. As another example, the resistance values ​​of the K second resistors R2 can be partially the same. As yet another example, the resistance values ​​of the K second resistors R2 can all be different. For example, the ratio of the resistance values ​​of R20, R21, R22, R23, and R24 can be 4:1:5:10:20, so that the various current adjustment levels of the control current decrease from high to low in a ratio of 10:8:4:2:1. This embodiment does not specifically limit this.

[0060] Specifically, the control process of the control module 40 for the K-1 third switching transistors N3 is described in detail below.

[0061] In this embodiment, the control module 40 is connected to the current source module 30. The control module 40 is configured to: control the current source module 30 to be in a first current adjustment position when the ambient temperature is greater than a second temperature threshold; and control the current source module 30 to be in a second current adjustment position when the ambient temperature is less than or equal to the second temperature threshold. The second temperature threshold is less than the first temperature threshold; and at the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment position is less than the amplitude of the control current corresponding to the first current adjustment position.

[0062] Furthermore, the control module 40 is also configured to adjust the second temperature threshold.

[0063] Therefore, the control module 40 in this embodiment can not only adjust the control current to different current regulation levels, but also adjust the value of the second temperature threshold. For example, when the low-temperature tolerance of the RF front-end module is good, the value of the second temperature threshold can be reduced so that the control current of the RF front-end module will not drop significantly over a relatively long temperature range (T2 to T1), thus avoiding unnecessary sacrifices in the operating efficiency of the power amplifier. Conversely, when the low-temperature tolerance of the RF front-end module is poor, the value of the second temperature threshold can be increased to ensure the normal operation of the RF front-end module and improve the durability of the power amplifier.

[0064] Please see Figure 4 The control module 40 may include a temperature detection unit 410 and a first control unit 420. The first control unit 420 is used to output a first control signal, and the temperature detection unit 410 is used to determine a second temperature threshold based on the first control signal. Specifically, the temperature detection unit 410 is also used to output a temperature detection signal; wherein, when the ambient temperature is greater than the second temperature threshold, the temperature detection signal is a first-level signal; when the ambient temperature is less than or equal to the second temperature threshold, the temperature detection signal is a second-level signal; the second-level signal and the first-level signal are different. For example, the first-level signal may be a high-level signal, and the second-level signal may be a low-level signal.

[0065] Please see Figure 5 The temperature detection unit 410 may include M first resistors R1, M-1 first switching transistors N1, and a voltage comparator 4120, where M is an integer greater than or equal to 2. Figure 5 In the example shown, M is 5, the five first resistors R1 are R10, R11, R12, R13, and R14, and the four first switching transistors N1 are N11, N12, N13, and N14. Of course, in other possible examples, M can be 2, 3, 4, 6, 8, etc. It's easy to understand that the larger M is, the more adjustment levels the second temperature threshold can have.

[0066] Specifically, M first resistors R1 are connected in series to form a first resistor string. One end of the first resistor string is used to input a temperature detection current that is positively or negatively correlated with the ambient temperature, and the other end is grounded. Taking a positive correlation as an example, the temperature detection current here is... Figure 5 The IPTAT current in the temperature detection circuit can be provided by an external temperature detection circuit, or it can be taken from the IPTAT current of the bandgap reference (BG) circuit in the chip where the temperature compensation circuit 100 is located. This embodiment does not limit the specific implementation of the temperature detection circuit. In the following description, the temperature detection current is positively correlated with the ambient temperature as an example.

[0067] The first terminals of M-1 first switching transistors N1 are connected one-to-one between two adjacent first resistors R1; the second terminals of M-1 first switching transistors N1 are connected to form a common terminal, which is connected to the first input terminal of voltage comparator 4120; the control terminal of M-1 first switching transistors N1 is connected to the first control unit 420, and one of the M-1 first switching transistors N1 is turned on according to the code value of the first control signal.

[0068] As an example, all M-1 first switching transistors N1 are field-effect transistors. The first terminal, the second terminal, and the control terminal of the first switching transistor N1 are the source, drain, and gate of the field-effect transistor, respectively.

[0069] Therefore, in this embodiment, the first control unit 420 can switch the voltage sampling point of the first input terminal of the voltage comparator 4120 by controlling the opening and closing states of M-1 first switching transistors N1, thereby adjusting the magnitude of the input voltage of the first input terminal of the voltage comparator 4120. Each connection node between two adjacent first resistors serves as a voltage sampling point. For example, when N11 is closed and N12, N13, and N14 are open, the input voltage of the first input terminal of the voltage comparator 4120 is equal to the voltage at the connection node of R10 and R11, i.e., the product of the sum of the resistance values ​​of R11 to R14 and the temperature detection current IPTAT. Similarly, when N13 is closed and N11, N12, and N14 are open, the input voltage of the first input terminal of the voltage comparator 4120 is equal to the voltage at the connection node of R12 and R13, i.e., the product of the sum of the resistance values ​​of R13 and R14 and the temperature detection current IPTAT.

[0070] As one example, the resistance values ​​of the M first resistors R1 can be the same. As another example, the resistance values ​​of the M first resistors R1 can be partially the same. As yet another example, the resistance values ​​of the M first resistors R1 can all be different; this embodiment does not impose specific limitations on this.

[0071] The second input terminal of voltage comparator 4120 is configured as an input reference voltage, and the output terminal of voltage comparator 4120 is used to output a temperature detection signal based on the relationship between the voltage at the common terminal and the reference voltage. The voltage at the common terminal is the voltage at the voltage sampling point, which is also the voltage at the first terminal of the first switch N1 when it is in the ON state. Figure 5In this circuit, the reference voltage is VBG, and the temperature detection signal is OTP. VBG can be a fixed value. The input voltage of the first input terminal of the voltage comparator 4120 is related to the resistance to ground value and the temperature value of its voltage sampling point. When the input voltage of the first input terminal of the voltage comparator 4120 is equal to VBG, the corresponding temperature value is the second temperature threshold. Therefore, with VBG fixed, the second temperature threshold can be adjusted by switching the voltage sampling point.

[0072] For example, when the voltage at the first terminal of the first switch N1 in the on state is greater than the reference voltage, it indicates that the ambient temperature is greater than the second temperature threshold. At this time, the temperature detection signal is a first level signal. Conversely, when the voltage at the first terminal of the first switch N1 in the on state is less than or equal to the reference voltage, it indicates that the ambient temperature is less than or equal to the second temperature threshold. At this time, the temperature detection signal is a second level signal.

[0073] Therefore, under the same reference voltage VBG, when N11 is closed, the amplitude of the detection current IPTAT is small, i.e., the temperature is low, which can satisfy the condition that "the voltage at the first terminal of the first switch N1 in the conducting state is greater than the reference voltage"; while when N14 is closed, the amplitude of the detection current IPTAT is large, i.e., the temperature is high, in order to satisfy the above condition, thereby realizing the adjustment of the second temperature threshold.

[0074] For the reader's convenience, please refer to Figure 6 This illustrates the possible correlation between ambient temperature and control current at different threshold adjustment levels. Figure 6 Part (a) corresponds to N14 being in a closed state. At this time, the threshold corresponding to the ambient temperature (i.e., the second temperature threshold) is relatively large. Figure 6 Part (b) corresponds to N11 being in a closed state. In this case, the threshold corresponding to the ambient temperature (i.e., the second temperature threshold) is smaller. That is, Figure 6 (b) The second temperature threshold T21 in part (b) is less than Figure 6 (a) The second temperature threshold T20.

[0075] Therefore, in this embodiment, the adjustment of the second temperature threshold can be achieved by controlling the on / off states of M-1 first switching transistors N1. Specifically, the first control signal output by the first control unit 420 has at least two different code values. The temperature detection unit 410 has at least two threshold adjustment levels, and each of the at least two threshold adjustment levels corresponds one-to-one with the at least two code values ​​of the first control signal. The second temperature threshold corresponding to the temperature detection unit 410 is different at each threshold adjustment level.

[0076] As an example, the first control signal can be a signal obtained after decoding the signal received via the MIPI RFFE (Mobile Industry Processor Interface RF Front-end) interface (hereinafter referred to as the first MIPI signal), which can include M-1 bits, each bit having a value of 0 or 1. For example, in... Figure 5 In this configuration, when M equals 5, the first control signal can be a 4-bit signal. For example, when the code value corresponding to the first control signal is 1000, N11 is controlled to be closed, and N12, N13, and N14 are controlled to be open; conversely, when the code value corresponding to the first control signal is 0010, N13 is controlled to be closed, and N11, N12, and N14 are controlled to be open. In other words, each bit in the corresponding code value of the first control signal corresponds one-to-one with the on / off state of each first switch N1. When the bit is 1, the corresponding first switch N1 is controlled to be closed; when the bit is 0, the corresponding first switch N1 is controlled to be open. It is understandable that the first control signal can be the same as or different from the signal received by the MIPI RFFE interface. For example, during decoding, the first MIPI signal received by the MIPI RFFE interface can be directly used as the first control signal, or logical operations can be performed on the first MIPI signal received by the MIPI RFFE interface to obtain the first control signal.

[0077] Therefore, the temperature detection unit 410 in this embodiment has the function of adjusting the second temperature threshold, so that the temperature compensation circuit 100 can be applied to various RF front-end modules with different low-temperature tolerance performance. In other words, the temperature compensation circuit 100 can flexibly adjust the second temperature threshold according to the low-temperature tolerance performance of the applied RF front-end module. This improves working efficiency in low-temperature environments while ensuring durability, thus balancing both efficiency and durability.

[0078] In some possible embodiments, such as Figure 4 As shown, the number of second resistors K in the adjustable resistor unit of the current source module is equal to 2. In this case, the number of third switching transistors N3 is one, and the temperature detection unit 410 can be directly connected to the control terminal of the third switching transistor N3, that is, the output terminal of the voltage comparator 4120 is connected to... Figure 4 The gate of N31 is connected.

[0079] In some other possible embodiments, please refer to Figure 7 The control module 40 may include a temperature detection unit 410 and a logic control unit 430. Of course, Figure 7 The temperature detection unit 410 in the middle can also be connected to the first control unit 420 ( Figure 7 (not shown) are connected to achieve adjustment of the second temperature threshold.

[0080] Specifically, the temperature detection unit 410 is used to output a temperature detection signal. When the ambient temperature is greater than a second temperature threshold, the temperature detection signal is a first-level signal; when the ambient temperature is less than or equal to the second temperature threshold, the temperature detection signal is a second-level signal; the second-level signal and the first-level signal are different. For details on the specific implementation of the temperature detection unit 410, please refer to the relevant description above in the instruction manual, which will not be repeated here.

[0081] The logic control unit 430 is connected to the temperature detection unit 410. The logic control unit 430 is configured to: control the current source module 30 to a first current adjustment level when the temperature detection signal is a first level signal; and control the current source module 30 to a second current adjustment level when the temperature detection signal is a second level signal. Specifically, the logic control unit 430 may include one or more logic gates, such as AND gates, NOT gates, NAND gates, NOR gates, etc., which are not specifically limited in this embodiment.

[0082] In some possible embodiments, the control module 40 is further configured to: control the current source module 30 to be in a first current adjustment position when the power amplifier's supply voltage is less than or equal to a first voltage threshold or the ambient temperature is greater than a second temperature threshold; and control the current source module 30 to be in a second current adjustment position when the power amplifier's supply voltage is greater than the first voltage threshold and the ambient temperature is less than or equal to the second temperature threshold. Specifically, when the power amplifier's supply voltage is greater than the first voltage threshold, it indicates that the power amplifier is in a high-voltage operating state. The first voltage threshold can be 5V, 7V, etc.

[0083] Therefore, in this embodiment, the control module 40 switches the current source module 30 to the second current adjustment level under low temperature and high voltage conditions, thereby reducing the amplitude of the control current and improving the durability of the power amplifier.

[0084] Please refer to it again. Figure 5The temperature detection unit 410 may further include a second switching transistor 4140 and a first voltage detection unit 4160. The first terminal of the second switching transistor 4140 is connected to a common terminal, the second terminal of the second switching transistor 4140 is grounded, and the control terminal of the second switching transistor 4140 is connected to the first voltage detection unit 4160. Specifically, the second switching transistor 4140 is configured to be in a conducting state when the supply voltage is less than or equal to a first voltage threshold, and in a disconnected state when the supply voltage is greater than the first voltage threshold. The supply voltage (Volt Current Condenser, VCC) is the operating voltage of the power amplifier. For example, the supply voltage may be 3V, 3.4V, 4.2V, 5V, etc., and the first voltage threshold may be 5V, 7V, etc. When the supply voltage is less than the first voltage threshold, i.e., the supply voltage is within the normal range, the input voltage at the first input terminal of the voltage comparator 4120 is pulled down to ground by turning on the second switching transistor, which can turn off the temperature detection unit 410 to reduce power consumption. At this time, the current adjustment level of the current source module is the default current adjustment level, such as the highest current adjustment level or the first current adjustment level, to improve the working efficiency of the power amplifier. When the supply voltage is greater than the first voltage threshold, i.e., the power amplifier is operating in a high-voltage environment, the second switching transistor is turned off to enable the temperature detection unit 410, so that the temperature detection unit 410 can output a temperature detection signal. This allows the control module to adjust the current adjustment level of the current source module according to the ambient temperature, improving the durability of the power amplifier.

[0085] As an example, the second switching transistor 4140 can be an NMOS transistor, wherein the first terminal, the second terminal, and the control terminal of the second switching transistor 4140 are the drain, the source, and the gate, respectively. The first voltage detection unit 4160 may include a voltage divider subunit and a comparator subunit (neither shown in the figure). The voltage divider subunit is used to divide the supply voltage, and the comparator subunit is used to compare the divided supply voltage with a preset voltage. When the divided supply voltage is greater than the preset voltage, it indicates that the supply voltage is greater than a first voltage threshold. At this time, the comparator subunit outputs a low-level signal to control the second switching transistor 4140 to be in the off state, thereby ensuring that the temperature detection unit 410 can work smoothly.

[0086] Conversely, when the voltage after voltage division is less than or equal to the preset voltage, it indicates that the supply voltage is less than or equal to the first voltage threshold. In this case, the comparator subunit outputs a high-level signal to control the second switch 4140 to be in the conducting state. At this time, the first input terminal of the voltage comparator 4120 is grounded, and the voltage comparator 4120 outputs a fixed second-level signal. In this situation, the temperature detection unit 410 stops working to reduce the overall power consumption of the temperature compensation circuit 100.

[0087] exist Figure 7 In the illustrated embodiment, the control module 40 may further include an overvoltage detection unit 440, which outputs a voltage detection signal. Specifically, when the supply voltage is less than or equal to a first voltage threshold, the voltage detection signal is a third-level signal; when the supply voltage is greater than the first voltage threshold, the voltage detection signal is a fourth-level signal; the fourth-level signal and the third-level signal are different; the supply voltage is the operating voltage of the power amplifier. For example, the fourth-level signal may be a high-level signal, and the third-level signal may be a low-level signal.

[0088] Specifically, the logic control unit 430 is also connected to the overvoltage detection unit 440. The logic control unit 430 is configured to: control the current source module 30 to be in the first current adjustment range when the temperature detection signal is a first level signal or the voltage detection signal is a third level signal; and control the current source module 30 to be in the second current adjustment range when the temperature detection signal is a second level signal and the voltage detection signal is a fourth level signal. In other words, when the operating voltage of the power amplifier is high and the ambient temperature is low, the control current output by the current source module 30 is at a lower current range, thereby reducing the bias current of the power amplifier, preventing damage to the power amplifier in the adverse environment of low temperature and high pressure, and improving the durability of the power amplifier.

[0089] As an example, the overvoltage detection unit 440 may include a voltage divider subunit and a comparison subunit (neither shown in the figure). The voltage divider subunit is used to divide the supply voltage, and the comparison subunit is used to compare the divided supply voltage with a preset voltage. When the divided supply voltage is greater than the preset voltage, it indicates that the supply voltage is greater than a first voltage threshold, and the comparison subunit outputs a fourth level signal; when the divided supply voltage is less than or equal to the preset voltage, it indicates that the supply voltage is less than or equal to the first voltage threshold, and the comparison subunit outputs a third level signal. Specifically, this embodiment does not limit the circuit structure of the overvoltage detection unit 440.

[0090] As an example, the overvoltage detection unit 440 and in this embodiment Figure 5The first voltage detection unit 4160 can share the same circuit structure to reduce the hardware cost of the temperature compensation circuit 100. Specifically, the control signal output by the first voltage detection unit 4160 can be the inverted voltage detection signal output by the overvoltage detection unit 440. For example, the output port of the overvoltage detection unit 440 can be connected to the logic control unit 430. An inverter can also be provided between the gate of the second switching transistor 4140 and the output port of the overvoltage detection unit 440. The inverter is used to invert the voltage detection signal output by the overvoltage detection unit 440. That is, when the overvoltage detection unit 440 outputs a high-level signal, the gate voltage of the second switching transistor 4140 is low; when the overvoltage detection unit 440 outputs a low-level signal, the gate voltage of the second switching transistor 4140 is high.

[0091] Therefore, if the supply voltage is determined to be less than or equal to the first voltage threshold, there is no need to determine whether the ambient temperature is less than the second temperature threshold. The second switch 4140 can be directly controlled to be in the conducting state to reduce the overall power consumption of the temperature compensation circuit 100.

[0092] It's easy to understand here that when the supply voltage is less than or equal to the first voltage threshold, the power amplifier's gain can be maintained within the normal gain range. In this case, there's no need to reduce the amplitude of the control current to avoid unnecessary sacrifices in the power amplifier's efficiency.

[0093] In some possible embodiments, there are multiple second current adjustment levels. The control module 40 may further include a second control unit 450, which outputs a second control signal. A logic control unit 430 is also connected to the second control unit 450 and is configured to: receive the second control signal; and, when the temperature detection signal is a second level signal, control the current source module 30 to be in the second current adjustment level corresponding to the code value of the second control signal. Specifically, under different second control signals, the logic control unit 430 outputs corresponding logic control signals, and these logic control signals correspond one-to-one with the on / off states of K-1 third switching transistors N3.

[0094] As an example, the logic control signal can be a signal obtained by processing the second control signal, which can include K-1 bits, each bit having a value of 0 or 1. For example, in... Figure 7In this configuration, when K equals 5, the logic control signal can be a 4-bit signal. For example, when the code value corresponding to the logic control signal is 0100, N32 is controlled to be closed, and N31, N33, and N34 are controlled to be open; similarly, when the code value corresponding to the logic control signal is 0010, N33 is controlled to be closed, and N31, N32, and N34 are controlled to be open. In other words, each bit in the corresponding code value of the logic control signal corresponds one-to-one with the on / off state of each third switch N3. When the bit is 1, the corresponding third switch N3 is controlled to be closed; when the bit is 0, the corresponding third switch N3 is controlled to be open.

[0095] Furthermore, when the temperature detection signal is a first-level signal, the logic control signal output by the logic control unit 430 can be a default value, for example, a default value of 1000, to control the current source module 30 to be in the first current adjustment level.

[0096] In one implementation, the second control unit 450 may be a MIPI RFFE interface unit, and the second control signal may be a signal received by the MIPI RFFE interface unit, corresponding to the logic control signal. The second control signal may also be a signal comprising K-1 bits. When the temperature detection signal is a second-level signal, the logic control unit 430 performs logical operations on the temperature detection signal and the second control signal to determine the corresponding logic control signal. Optionally, the logic control signal and the second control signal may be completely identical, have partially identical code values, or all code values ​​may be different. In other possible embodiments, when the temperature detection signal is a second-level signal, the logic control unit 430 performs logical operations on the temperature detection signal, the overvoltage detection signal, and the second control signal to determine the corresponding logic control signal.

[0097] It's easy to understand here that when different third switch transistors N3 are in the closed state, the equivalent resistance value of the adjustable resistor unit 360 is different. Specifically... Figure 7 In the above, when all third switching transistors N3 are open, the equivalent resistance value of the adjustable resistor unit 360 is at its maximum; when N34 is closed, the equivalent resistance value of the adjustable resistor unit 360 is next; and when N31 is closed, the equivalent resistance value of the adjustable resistor unit 360 is at its minimum. Furthermore, when N31 is closed, the current source module 30 can be in a first current adjustment range; when one of N32, N33, and N34 is closed or all third switching transistors N3 are open, the current source module 30 can be in different second current adjustment ranges. For example, as shown... Figure 8As shown, the slope of the control current-ambient temperature curve can be the same at different current adjustment levels. In other examples, the slope of the control current-ambient temperature curve may also be different at different current adjustment levels, and this application does not impose any restrictions on this.

[0098] Please see Figure 8 This illustrates the possible correlation between ambient temperature and control current at different second current adjustment levels. Figure 8 Part (a) in the text corresponds to N32 being in a closed state; in Figure 8 Part (b) in the diagram corresponds to N34 being in a closed state. From Figure 8 It is easy to see that, under the same ambient temperature, and when the ambient temperature is less than the second temperature threshold, the amplitude of the control current corresponding to the closing of N34 is less than the amplitude of the control current corresponding to the closing of N32. It should be further noted that when N31 is closed, the current source module 30 is in the first current adjustment range, which can be considered the default operating range of the current source module 30.

[0099] Therefore, in this embodiment, by controlling the on / off states of K-1 third switching transistors N3, switching between multiple second current adjustment levels can be achieved. For example, when the RF front-end module has good low-temperature tolerance, a second current adjustment level with a larger control current amplitude can be selected under low-temperature and high-pressure conditions; conversely, when the RF front-end module has poor low-temperature tolerance, a second current adjustment level with a smaller control current amplitude can be selected under low-temperature and high-pressure conditions. This allows it to be applied to various RF front-end modules with different low-temperature tolerance performance.

[0100] It should be noted that the first control signal and the second control signal in this embodiment can be determined by the R&D personnel based on the actual test data of the RF front-end module and stored in the temperature compensation circuit 100. This allows the power amplifier equipped with the temperature compensation circuit 100 to have a more reasonable temperature compensation method according to the actual performance of the RF front-end module, so as to improve the working efficiency of the power amplifier in low-temperature environments.

[0101] In some possible embodiments, the control module 40 may include a temperature detection unit 410, an overvoltage detection unit 440, and a logic control unit 430. The temperature detection unit 410 is used to output a temperature detection signal; wherein, when the ambient temperature is greater than a second temperature threshold, the temperature detection signal is a first-level signal; when the ambient temperature is less than or equal to the second temperature threshold, the temperature detection signal is a second-level signal; the second-level signal and the first-level signal are different. The overvoltage detection unit 440 is used to output a voltage detection signal; wherein, when the supply voltage is less than or equal to a first voltage threshold, the voltage detection signal is a third-level signal; when the supply voltage is greater than the first voltage threshold, the voltage detection signal is a fourth-level signal; the fourth-level signal and the third-level signal are different; the supply voltage is the operating voltage of the power amplifier. The logic control unit 430 is connected to the overvoltage detection unit 440 and the temperature detection unit 410 respectively. The logic control unit 430 is configured to: control the current source module 30 to be in the first current adjustment position when the temperature detection signal is a first level signal or the voltage detection signal is a third level signal; and control the current source module 30 to be in the second current adjustment position when the temperature detection signal is a second level signal and the voltage detection signal is a fourth level signal.

[0102] Specifically, the implementation details of the temperature detection unit 410, the overvoltage detection unit 440, and the logic control unit 430 can be found in the relevant descriptions above in the instruction manual, and will not be repeated here.

[0103] It is easy to understand that when the temperature detection signal is at the first level or the voltage detection signal is at the third level, the logic control unit 430 can directly output a logic control signal of 1000 to control the third switch N31 to turn on, thus placing the current source module 30 in the first current adjustment level. When the temperature detection signal is at the second level and the voltage detection signal is at the fourth level, the logic control unit 430 performs logical operations on the temperature detection signal, the voltage detection signal, and the second control signal to determine the corresponding logic control signal, such as 0100, 0010, etc., so that the current source module 30 is placed in the second current adjustment level.

[0104] In some possible embodiments, please refer to Figure 9The temperature compensation circuit 100 may further include a fourth switch 520 and a second voltage detection unit 540. The first terminal of the fourth switch 520 is connected to the output port 102, the second terminal of the fourth switch 520 is grounded, and the control terminal of the fourth switch 520 is connected to the second voltage detection unit 540. Specifically, the fourth switch 520 is configured to be in an off state when the power supply voltage is less than or equal to a second voltage threshold, and in an on state when the power supply voltage is greater than the second voltage threshold. The power supply voltage is the supply voltage of the current source module 30, also known as the VBATT voltage. Specifically, the second voltage threshold can be 6V, 7V, etc., and the amplitude of the power supply voltage VBATT can be 3.2V, 3.5V, 4.2V, 5V, etc.

[0105] As an example, the fourth switch 520 can be an NMOS transistor, wherein the first terminal, the second terminal, and the control terminal of the fourth switch 520 are the drain, the source, and the gate, respectively. The second voltage detection unit 540 may include a voltage divider subunit and a comparator subunit (neither shown in the figure). The voltage divider subunit is used to divide the power supply voltage, and the comparator subunit is used to compare the divided power supply voltage with a preset voltage. When the divided power supply voltage is greater than the preset voltage, it indicates that the power supply voltage is greater than a second voltage threshold. At this time, the comparator subunit outputs a high-level signal to control the fourth switch 520 to be in the conducting state, the output port 102 is grounded, and no more control current is output, thereby turning off the power amplifier and providing overvoltage protection for the power amplifier.

[0106] Conversely, when the power supply voltage after voltage division is less than or equal to the preset voltage, it means that the power supply voltage is less than or equal to the second voltage threshold. At this time, the comparator subunit outputs a low-level signal to control the fourth switch 520 to be in the off state, which can ensure that the control current is smoothly output to the power amplifier through the output port 102.

[0107] This application provides a temperature compensation circuit 100, which has an output port 102. The output port 102 is used to provide a control current to a power amplifier, and the control current is used to perform temperature compensation on the bias signal of the power amplifier.

[0108] In this embodiment, the temperature compensation circuit 100 may include a temperature compensation module 20, a current source module 30, and a control module 40. The temperature compensation module 20 is used to output a first temperature compensation voltage when the ambient temperature is less than or equal to a first temperature threshold. The first temperature compensation voltage is positively or negatively correlated with the ambient temperature.

[0109] A current source module 30 is connected between the temperature compensation module 20 and the output port 102, and it is used to convert the temperature compensation voltage output by the temperature compensation module 20 into a control current. The current source module 30 has at least two current adjustment levels. Specifically, at the same ambient temperature, the amplitude of the control current corresponding to different current adjustment levels is different.

[0110] The control module 40 is connected to the current source module 30. The control module 40 is configured to: control the current source module 30 to be in a first current adjustment position when the ambient temperature is greater than a second temperature threshold; and control the current source module 30 to be in a second current adjustment position when the ambient temperature is less than or equal to the second temperature threshold. The second temperature threshold is less than the first temperature threshold; and at the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment position is less than the amplitude of the control current corresponding to the first current adjustment position.

[0111] On one hand, when the ambient temperature is less than or equal to the first temperature threshold, the first temperature compensation voltage output by the temperature compensation module 20 is positively or negatively correlated with the ambient temperature. Taking a positive correlation as an example, the control current converted from the first temperature compensation voltage is also positively correlated with the ambient temperature. Therefore, when the ambient temperature is less than or equal to the first temperature threshold (i.e., in a low-temperature environment), the control current will decrease accordingly, so that the bias signal of the compensated power amplifier will decrease synchronously, thereby reducing the operating gain of the power amplifier in low-temperature environments and improving the durability of the power amplifier.

[0112] On the other hand, the current source module 30 in this embodiment has at least two current adjustment levels, and the amplitude of the control current output by the current source module 30 is different at different current adjustment levels. Therefore, the corresponding current adjustment level can be selected according to the actual operating conditions of the RF front-end module equipped with the temperature compensation circuit 100, so that the operating gain of the power amplifier can match the operating performance of the RF front-end module. For example, if the RF front-end module has good low-temperature tolerance, a current adjustment level with a larger control current amplitude can be selected to avoid excessive degradation of the operating gain of the power amplifier.

[0113] Furthermore, when the ambient temperature is greater than the second temperature threshold, the current source module 30 is in the first current adjustment setting; when the ambient temperature is less than or equal to the second temperature threshold, the current source module 30 is in the second current adjustment setting. The second temperature threshold is less than the first temperature threshold. Specifically, at the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment setting is less than the amplitude of the control current corresponding to the first current adjustment setting.

[0114] Specifically, when the ambient temperature is above the second temperature threshold but below or equal to the first temperature threshold, the current source module 30 can operate at a current adjustment level with a larger control current amplitude; when the ambient temperature is below or equal to the second temperature threshold, the current source module 30 can operate at a current adjustment level with a smaller control current amplitude. Therefore, if the RF front-end module has good low-temperature tolerance (e.g., can withstand ambient temperatures above the second temperature threshold), the situation where a significant reduction in control current would sacrifice the power amplifier's efficiency can be avoided. Furthermore, once the ambient temperature is below the second temperature threshold, the control current will be further reduced to lower the power amplifier's bias signal and improve its durability.

[0115] Please see Figure 10 This application also provides a power amplifier 600, which amplifies the power of radio frequency signals (i.e., baseband signals) to enable successful transmission of radio frequency signals. The power amplifier 600 may include a power amplification module 610, a bias module 630, and the aforementioned temperature compensation circuit 100. Specifically, the power amplification module 610 may employ a single-ended architecture or a differential architecture; it may also employ a single-stage amplification architecture or a multi-stage amplification architecture.

[0116] The bias module 630 is connected to the power amplifier module 610 and is used to output a bias signal to the power amplifier module 610. The bias signal is used to set the transistors in the power amplifier module 610 at a suitable quiescent operating point to ensure that the power amplifier module 610 has good operating performance (e.g., linearity, gain, and efficiency). Specifically, the bias signal can be a DC voltage signal or a DC current signal; this embodiment does not limit the specific implementation of the power amplifier module 610 and the bias module 630. In one implementation, the bias signal includes a bias current. The bias module 630 generates the bias current based on the control current output by the temperature compensation circuit 100. When the control current is 0, the bias current is also 0. In other words, when the temperature compensation circuit 100 stops outputting the control current, the bias module 630 also stops providing bias to the power amplifier module 610.

[0117] The temperature compensation circuit 100 is connected to the bias module 630 and is used to perform temperature compensation on the bias signal output by the bias module 630 in order to reduce the bias signal of the power amplifier 600 in low temperature environment and avoid damage to the power amplifier 600 in low temperature environment.

[0118] For details regarding the temperature compensation circuit 100, please refer to the relevant description in the instruction manual above; it will not be repeated here.

[0119] Please see Figure 11 This application also provides a radio frequency (RF) front-end module 700, which is a component that integrates two or more discrete devices such as RF switches, low-noise amplifiers, filters, duplexers, and power amplifiers into an independent module, thereby improving integration and hardware performance, and miniaturizing the size. The RF front-end module 700 may include the aforementioned power amplifier 600.

[0120] Furthermore, with the development of 5G technology, the requirements for the performance of radio frequency front-end modules are becoming increasingly stringent. The technical solution of this application can be applied to 5G radio frequency front-end modules to improve the communication performance of 5G communication equipment.

[0121] In this application specification, certain terms are used to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. The specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to"; "generally" means that those skilled in the art can solve the technical problem within a certain margin of error and basically achieve the technical effect.

[0122] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description of this application and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0123] In this application, unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or merely surface contact. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0124] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0125] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A temperature compensation circuit, characterized in that, It has an output port for providing control current to a power amplifier, the control current being used for temperature compensation of the power amplifier's bias signal; the temperature compensation circuit includes: A temperature compensation module is used to output a first temperature compensation voltage when the ambient temperature is less than or equal to a first temperature threshold; wherein the first temperature compensation voltage and the ambient temperature are positively or negatively correlated. A current source module, connected between the temperature compensation module and the output port, is used to convert the temperature compensation voltage output by the temperature compensation module into the control current; wherein, the current source module has at least two current adjustment levels; and A control module is connected to the current source module; the control module is configured to: control the current source module to be in a first current adjustment position when the ambient temperature is greater than a second temperature threshold; and control the current source module to be in a second current adjustment position when the ambient temperature is less than or equal to the second temperature threshold. Wherein, the second temperature threshold is less than the first temperature threshold; and under the same ambient temperature, the amplitude of the control current corresponding to the second current adjustment level is less than the amplitude of the control current corresponding to the first current adjustment level.

2. The temperature compensation circuit according to claim 1, characterized in that, The control module is also configured to adjust the second temperature threshold.

3. The temperature compensation circuit according to claim 2, characterized in that, The control module includes a temperature detection unit and a first control unit. The first control unit is used to output a first control signal, and the temperature detection unit is used to determine the second temperature threshold based on the first control signal.

4. The temperature compensation circuit according to claim 3, characterized in that, The first control signal output by the first control unit has at least two different code values; The temperature detection unit has at least two threshold adjustment levels, and the at least two threshold adjustment levels correspond one-to-one with at least two code values ​​of the first control signal; wherein, the second temperature threshold corresponding to the temperature detection unit is different under different threshold adjustment levels.

5. The temperature compensation circuit according to claim 3, characterized in that, The temperature detection unit includes M first resistors, M-1 first switching transistors, and a voltage comparator, wherein M is greater than or equal to 2; M of the first resistors are connected in series to form a first resistor string. One end of the first resistor string is used to input a temperature detection current that is positively or negatively correlated with the ambient temperature, and the other end is grounded. The first terminals of M-1 first switching transistors are connected one-to-one between two adjacent first resistors; the second terminals of M-1 first switching transistors are connected to form a common terminal, which is connected to the first input terminal of the voltage comparator; the control terminals of M-1 first switching transistors are connected to the first control unit, and one of the M-1 first switching transistors is turned on according to the code value of the first control signal. The second input terminal of the voltage comparator is configured to input a reference voltage, and the output terminal of the voltage comparator is used to output a temperature detection signal based on the relationship between the voltage at the common terminal and the reference voltage.

6. The temperature compensation circuit according to claim 5, characterized in that, The temperature detection unit further includes a second switching transistor, the first end of which is connected to the common terminal, and the second end of which is grounded. The second switch is configured to be in an on state when the supply voltage is less than or equal to a first voltage threshold, and in an off state when the supply voltage is greater than the first voltage threshold; wherein the supply voltage is the operating voltage of the power amplifier.

7. The temperature compensation circuit according to claim 1, characterized in that, The control module includes a temperature detection unit and a logic control unit; The temperature detection unit is used to output a temperature detection signal; wherein, when the ambient temperature is greater than the second temperature threshold, the temperature detection signal is a first level signal; when the ambient temperature is less than or equal to the second temperature threshold, the temperature detection signal is a second level signal; the second level signal and the first level signal are different. The logic control unit is connected to the temperature detection unit, and the logic control unit is configured to: control the current source module to be in a first current adjustment level when the temperature detection signal is a first level signal; and control the current source module to be in a second current adjustment level when the temperature detection signal is a second level signal.

8. The temperature compensation circuit according to claim 7, characterized in that, The control module is configured to control the current source module to be in a first current adjustment position when the power amplifier's supply voltage is less than or equal to a first voltage threshold or the ambient temperature is greater than a second temperature threshold. When the power amplifier's supply voltage is greater than the first voltage threshold and the ambient temperature is less than or equal to the second temperature threshold, the current source module is controlled to be in the second current adjustment position.

9. The temperature compensation circuit according to claim 8, characterized in that, The control module further includes an overvoltage detection unit; the overvoltage detection unit is used to output a voltage detection signal; wherein, when the supply voltage is less than or equal to a first voltage threshold, the voltage detection signal is a third-level signal; when the supply voltage is greater than the first voltage threshold, the voltage detection signal is a fourth-level signal; the fourth-level signal and the third-level signal are different; the supply voltage is the operating voltage of the power amplifier; The logic control unit is also connected to the overvoltage detection unit. The logic control unit is configured to: control the current source module to be in a first current adjustment position when the temperature detection signal is a first level signal or the voltage detection signal is a third level signal; and control the current source module to be in a second current adjustment position when the temperature detection signal is a second level signal and the voltage detection signal is a fourth level signal.

10. The temperature compensation circuit according to claim 7, characterized in that, The number of the second current adjustment levels is multiple; the control module also includes a second control unit, which is used to output a second control signal; The logic control unit is also connected to the second control unit, and the logic control unit is configured to: receive the second control signal; and when the temperature detection signal is a second level signal, control the current source module to be in a second current adjustment position corresponding to the code value of the second control signal.

11. The temperature compensation circuit according to any one of claims 1 to 10, characterized in that, The current source module includes an operational amplifier unit, a current mirror unit, and an adjustable resistor unit. The current mirror unit includes a first current branch and a second current branch. The first end of the first current branch and the first end of the second current branch are configured as input power supply voltage. The inverting input terminal of the operational amplifier unit is connected to the temperature compensation module, the output terminal of the operational amplifier unit is connected to the control terminal of the first current branch and the control terminal of the second current branch respectively, the non-inverting input terminal of the operational amplifier unit is connected to the second terminal of the first current branch, and the second terminal of the second current branch is connected to the output port. One end of the adjustable resistor unit is connected to the second end of the first current branch, and the other end is grounded; the control module is connected to the adjustable resistor unit, and the control module is configured to: control the equivalent resistance value of the adjustable resistor unit to a first resistance value when the ambient temperature is greater than the second temperature threshold; and control the equivalent resistance value of the adjustable resistor unit to a second resistance value when the ambient temperature is less than the second temperature threshold; wherein the second resistance value is greater than the first resistance value.

12. The temperature compensation circuit according to claim 11, characterized in that, The adjustable resistor unit includes K second resistors and K-1 third switching transistors, where K is an integer greater than or equal to 2; K second resistors are connected in series to form a second resistor string. One end of the second resistor string is connected to the second end of the first current branch, and the other end is grounded. The first terminals of K-1 third switching transistors are connected one-to-one between two adjacent second resistors; the second terminals of K-1 third switching transistors are grounded; and the control terminals of K-1 third switching transistors are connected to the control module.

13. The temperature compensation circuit according to claim 11, characterized in that, The first current branch includes a first transistor, and the second current branch includes a second transistor, wherein both the first transistor and the second transistor are field-effect transistors. The first terminal, the second terminal, and the control terminal of the first current branch are the source, drain, and gate of the field-effect transistor, respectively. The first, second, and control terminals of the second current branch are the source, drain, and gate of the field-effect transistor, respectively.

14. The temperature compensation circuit according to any one of claims 1 to 10, characterized in that, The temperature compensation circuit also includes a fourth switching transistor, the first end of which is connected to the output port, and the second end of which is grounded. The fourth switch is configured to be in an off state when the power supply voltage is less than or equal to the second voltage threshold, and in an on state when the power supply voltage is greater than the second voltage threshold; wherein the power supply voltage is the operating voltage of the current source module.

15. The temperature compensation circuit according to any one of claims 1 to 10, characterized in that, The temperature compensation module is further configured to output a second temperature compensation voltage when the ambient temperature is greater than or equal to a third temperature threshold; wherein the second temperature compensation voltage and the ambient temperature are positively or negatively correlated, and the third temperature threshold is greater than the first temperature threshold.

16. The temperature compensation circuit according to any one of claims 1 to 6, characterized in that, The control module includes a temperature detection unit, an overvoltage detection unit, and a logic control unit; The temperature detection unit is used to output a temperature detection signal; wherein, when the ambient temperature is greater than the second temperature threshold, the temperature detection signal is a first level signal; when the ambient temperature is less than or equal to the second temperature threshold, the temperature detection signal is a second level signal; the second level signal and the first level signal are different. The overvoltage detection unit is used to output a voltage detection signal; wherein, when the supply voltage is less than or equal to a first voltage threshold, the voltage detection signal is a third-level signal; when the supply voltage is greater than the first voltage threshold, the voltage detection signal is a fourth-level signal; the fourth-level signal and the third-level signal are different; the supply voltage is the operating voltage of the power amplifier; The logic control unit is connected to the overvoltage detection unit and the temperature detection unit respectively. The logic control unit is configured to: control the current source module to be in a first current adjustment position when the temperature detection signal is a first level signal or the voltage detection signal is a third level signal; and control the current source module to be in a second current adjustment position when the temperature detection signal is a second level signal and the voltage detection signal is a fourth level signal.

17. A power amplifier, characterized in that, include: Power amplifier module; A bias module, connected to the power amplifier module, is used to output a bias signal to the power amplifier module; as well as The temperature compensation circuit according to any one of claims 1 to 16 is connected to the bias module and is used to perform temperature compensation on the bias signal output by the bias module.

18. A radio frequency front-end module, characterized in that, include: The power amplifier as described in claim 17.

Images