Radio frequency circuit capable of temperature compensation, control method, control module and radio frequency chip

Abstract

The embodiment of the invention provides a radio frequency circuit capable of temperature compensation, a control method, a control module and a radio frequency chip, and the radio frequency circuit comprises a radio frequency link which comprises an amplifier and at least one attenuator; the temperature acquisition module is used for acquiring the current temperature to obtain quantized temperature information; the register module is used for searching and outputting a corresponding target control signal based on the temperature information; the register module stores a corresponding relation between the target control signal and the temperature information; the at least one voltage generation module is used for performing digital-to-analog conversion on the target control signal to generate a first voltage; the attenuator is used for adjusting the gain of the attenuator according to the first voltage; wherein the target control signal controls the trend of the gain of the attenuator along with the temperature change, and the trend is opposite to the trend of the gain of the amplifier along with the temperature change. According to the embodiment of the invention, the gain stability of the radio frequency link at different temperatures can be ensured.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular, to a temperature-compensable radio frequency circuit, a control method, a control module, and a radio frequency chip. Background Art

[0002] Millimeter-wave phased array chips, radio frequency chips, etc. based on Complementary Metal Oxide Semiconductor (CMOS) technology all require amplifier modules to provide a certain gain to suppress signal transmission loss. However, the gain of these amplifier modules fluctuates at different temperature points. For example, the transistor characteristics of the amplifier and the quality factor (Q value) of the matching circuit are affected by temperature, resulting in gain changes.

[0003] The characteristic that the gain of the amplifier changes with temperature is transmitted to the entire radio frequency link, affecting the gain performance and causing the chip link gain to change with temperature. In actual applications, the chip usually requires a stable gain, that is, the gain does not change with temperature. Summary of the Invention

[0004] Embodiments of the present disclosure provide a temperature-compensable radio frequency circuit, a control method, a control module, and a radio frequency chip, which can compensate for the change in the gain of the amplifier with temperature.

[0005] In a first aspect, embodiments of the present disclosure provide a temperature-compensable radio frequency circuit, including: A radio frequency link for receiving and / or transmitting radio frequency signals; the radio frequency link includes an amplifier and at least one attenuator, and the attenuator is used to attenuate the radio frequency signals; A temperature acquisition module for acquiring the current temperature to obtain quantified temperature information; A register module for receiving the temperature information and, based on the temperature information, searching for and outputting a corresponding target control signal; wherein, the corresponding relationship between the target control signal and the temperature information is stored in the register module; At least one voltage generation module is connected to the register module for receiving the target control signal and performing digital-to-analog conversion on the target control signal to generate a first voltage; a first control end of the attenuator is connected to the voltage generation module for receiving the first voltage and adjusting the gain of the attenuator according to the first voltage; Wherein, the trend of the target control signal controlling the gain of the attenuator to change with temperature is opposite to the trend of the gain of the amplifier to change with temperature.

[0006] Second aspect, embodiments of the present disclosure provide a control method, which is applied to the radio frequency circuit in the first aspect. The method includes: Obtain the temperature information at each preset temperature; Output an initial control signal, where the initial control signal is used to control the voltage value of the first voltage generated by the voltage generation module; Obtain the gain of the radio frequency link under the initial control signal; Traverse different initial control signals. When the difference between the gain and the preset gain is the smallest, determine the initial control signal as the target control signal corresponding to the current temperature information. The preset gain is the expected gain of the radio frequency link; Traverse all the preset temperatures, obtain the corresponding relationship between each temperature information and the target control signal, and store it in the register module.

[0007] Third aspect, embodiments of the present disclosure provide a control module for executing the control method in the second aspect.

[0008] Fourth aspect, embodiments of the present disclosure provide a radio frequency chip, which includes the radio frequency circuit in the first aspect.

[0009] The beneficial effects of the embodiments of the present disclosure are as follows: The radio frequency circuit includes a radio frequency link, a temperature acquisition module, a register module, and a voltage generation module; the radio frequency link includes an amplifier and at least one attenuator, and the gain of the amplifier changes with temperature; The temperature acquisition module acquires the current temperature to obtain quantified temperature information; since the register module stores the corresponding relationship between the target control signal and the temperature information, and the temperature information is dynamically generated according to the current temperature, the corresponding relationship is used to make the attenuator have different gains (such as attenuation amounts) at different temperatures. When the current temperature is different, the target control signal changes accordingly; The voltage generation module performs digital-to-analog conversion according to the target control signal to generate a first voltage. When the current temperature is different, the first voltage changes accordingly; The attenuator adjusts the gain (such as attenuation amount) of the attenuator according to the first voltage. Since the first voltage is obtained by digital-to-analog conversion of the target control signal, the gain of the attenuator can be dynamically adjusted with the change of temperature; and the trend of the gain of the attenuator changing with temperature is opposite to the trend of the gain of the amplifier changing with temperature. The gain (such as attenuation amount) of the attenuator changes dynamically, which can automatically compensate for the change of the gain of the amplifier with temperature, thereby improving the reliability and stability of the entire radio frequency circuit.

[0010] In addition, the register module pre-stores the corresponding relationship between the target control signal and the temperature information, and the pre-stored target control signal can be directly output by looking up the table, with a short response time.

[0011] The register module includes: a readable and writable register, a non-volatile memory, and a selector. The readable and writable register is used to store an initial control signal, and the initial control signal is used to calibrate a target control signal. Therefore, the target control signal can be pre-calibrated through the readable and writable register to obtain the corresponding relationship between the target control signal and the temperature information. The corresponding relationship obtained through pre-calibration can be stored in the non-volatile memory. Through pre-calibration, the attenuation amount of the attenuator at each temperature for each chip can be accurately obtained; and when the circuit is working, the attenuation amount can be quickly and accurately adjusted according to the current temperature.

[0012] The radio frequency circuit includes a plurality of voltage generation modules and a plurality of attenuators; in each storage unit corresponding to the temperature information, a plurality of sub-control signals corresponding to the plurality of voltage generation modules are stored. That is to say, by performing a search for the target control signal in the non-volatile memory once, all the sub-control signals corresponding to the plurality of voltage generation modules can be obtained, and accurate compensation for the entire radio frequency link can be quickly achieved.

[0013] Attenuators are included in both the receiving link, the transmitting link, and the common branch. The accuracy of the attenuator in the receiving link or the transmitting link is greater than the accuracy of the attenuator in the common branch. The low accuracy of the attenuator in the common branch can be used for coarse adjustment to expand the adjustment range of the attenuation amount; the high accuracy of the attenuator in the receiving link or the transmitting link can be used for fine adjustment to increase the adjustment accuracy. Description of the Drawings

[0014] Figure 1 Exemplary structural schematic diagram of a radio frequency transmission system provided by an embodiment of the present disclosure; Figure 2 Exemplary simplified structural schematic diagram of a radio frequency transmission system provided by an embodiment of the present disclosure; Figure 3 Structural schematic diagram of different types of attenuators provided by an embodiment of the present disclosure; Figure 4 Schematic diagram of the change trend of the gain of an attenuator with the first voltage provided by an embodiment of the present disclosure; Figure 5 Structural schematic of a temperature acquisition module provided by an embodiment of the present disclosure Figure 1 ; Figure 6 Structural schematic of a temperature acquisition module provided by an embodiment of the present disclosure Figure 2 ; Figure 7 Structural schematic of a non-volatile memory provided by an embodiment of the present disclosure Figure 1 ; Figure 8 Structural schematic of a non-volatile memory provided by an embodiment of the present disclosure Figure 2 ; Figure 9 A structural schematic diagram of a register module provided by an embodiment of the present disclosure; Figure 10 A structural schematic diagram of a voltage generation module provided by an embodiment of the present disclosure; Figure 11 A structural schematic diagram of a voltage clamping circuit provided by an embodiment of the present disclosure; Figure 12 An equivalent circuit structural schematic diagram of a voltage clamping circuit provided by an embodiment of the present disclosure; Figure 13 A schematic diagram showing the correspondence between a first voltage and a second voltage at different temperatures provided by an embodiment of the present disclosure; Figure 14 A schematic diagram showing the variation of the gain of a radio frequency chip with temperature in the case where temperature adjustment is not performed using an attenuator provided by an embodiment of the present disclosure; Figure 15 A schematic diagram showing the variation of the gain of a radio frequency chip with temperature in the case where temperature adjustment is performed using an attenuator provided by an embodiment of the present disclosure. Detailed implementation manners

[0015] Next, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present disclosure. It can be understood that the specific embodiments described herein are only used to explain the relevant disclosure, rather than limiting the disclosure. Additionally, it should be noted that for the sake of description, only parts related to the relevant disclosure are shown in the drawings.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this disclosure belongs. The terms used herein are only for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure.

[0017] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments. However, it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0018] It should be noted that the terms "first / second / third" related to the embodiments of the present disclosure are only used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first / second / third" can be interchanged with a specific order or sequence when permitted, so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0019] See Figure 1 and Figure 2 , wherein,Figure 1 Exemplary structural schematic diagram of the radio frequency transmission system provided by the embodiments of the present disclosure Figure 2 Exemplary simplified structural schematic diagram of the radio frequency transmission system provided by the embodiments of the present disclosure. The radio frequency transmission system includes a temperature-compensable radio frequency circuit 10 (abbreviated as radio frequency circuit 10).

[0020] As Figure 1 Or Figure 2 As shown, the radio frequency circuit 10 provided by the embodiments of the present disclosure includes: a radio frequency link 101, a temperature acquisition module 102, a register module 103, and at least one voltage generation module 104. Among them: The radio frequency link 101 is used to receive and / or transmit radio frequency signals; the radio frequency link 101 includes an amplifier AMP and at least one attenuator VVA. The amplifier AMP is used to amplify radio frequency signals, and the gain of the amplifier AMP changes with temperature. The attenuator VVA is used to attenuate radio frequency signals. The gain (attenuation amount) of the attenuator VVA changes with temperature, and the trend of the gain of the attenuator VVA changing with temperature is opposite to the trend of the gain of the amplifier AMP changing with temperature, so as to compensate for the change in the gain of the amplifier AMP with temperature and make the overall gain of the radio frequency link 101 remain consistent with temperature changes.

[0021] It should be noted that, as Figure 1 shown, the radio frequency link 101 generally includes a common branch 1011, a transmit link 1012, and a receive link 1013. Among them, the common branch 1011 is used for both the transmission and reception of radio frequency signals, the transmit link 1012 is only used for the transmission of radio frequency signals, and the receive link 1013 is only used for the reception of radio frequency signals. The attenuator VVA is a voltage variable attenuator (abbreviated as VVA), which is a device that can adjust the attenuation amount of a signal by applying different voltages.

[0022] The common branch 1011 may include a first attenuator VVA1, a digital step attenuator DSA (Digital Step Attenuator), a phase shifter PS (Phase Shifter), and a first switch SW1 connected in sequence. The first switch SW1 may be a single-pole double-throw switch, which switches to connect to the receive link 1013 when receiving radio frequency signals; and switches to connect to the transmit link 1012 when transmitting radio frequency signals.

[0023] Among them, the voltage controlling the variable attenuator VVA is an analog quantity, indicating that the attenuation amount of the variable attenuator VVA can vary continuously. The control voltage of the digital step attenuator DSA is a digital quantity, and its attenuation amount can only be a specified value. For example, the conventional attenuation amounts are 0.5 / 1 / 1.5 dB, etc. Therefore, the attenuation amount of the digital step attenuator DSA changes discontinuously. Thus, compared with the digital step attenuator DSA, the variable attenuator VVA can achieve more flexible and better compensation, enabling the overall gain of the radio frequency link 101 to maintain better consistency with temperature changes.

[0024] The transmitting link 1012 may include a second variable attenuator VVA2 and two amplifiers AMP (denoted as the first amplifier AMP1 and the second amplifier AMP2 respectively). Among them, the input end of the first amplifier AMP1 is connected to the first switch SW1, and the second variable attenuator VVA2 is connected between the output end of the first amplifier AMP1 and the input end of the second amplifier AMP2.

[0025] The receiving link 1013 may include a third variable attenuator VVA3 and two amplifiers (denoted as the third amplifier AMP3 and the fourth amplifier AMP4 respectively). The output end of the fourth amplifier AMP4 is connected to the first switch SW1, and the third variable attenuator VVA3 is connected between the output end of the third amplifier AMP3 and the input end of the fourth amplifier AMP4.

[0026] The output end of the second amplifier AMP2 and the input end of the third amplifier AMP3 are both connected to the second switch SW2. The second switch SW2 can also be a single-pole double-throw switch. In the case of receiving a radio frequency signal, it is switched to be connected to the receiving link 1013, specifically to the input end of the third amplifier AMP3 in the receiving link 1013; in the case of transmitting a radio frequency signal, it is switched to be connected to the transmitting link 1012, specifically to the output end of the second amplifier AMP2 in the transmitting link 1012.

[0027] It should be noted that generally, the radio frequency link 101 includes active modules (such as: amplifier AMP) and passive modules (such as: phase shifter PS / digital step attenuator DSA / variable attenuator VVA, etc.). In this embodiment, the active devices and passive devices are arranged alternately (the cascading method is "active module - passive module - active module - passive module"), which can optimize performances such as gain, filtering, and impedance matching while maintaining signal integrity, achieve control of noise and distortion, improvement of circuit stability, and balance of overall performance. In some embodiments, in Figure 1 Among them, the digital step attenuator DSA in the common branch 1011 can exchange positions with the phase shifter PS or the first variable attenuator VVA1 because they are all passive modules in essence. The digital step attenuator DSA located in the common branch 1011 can be shared for both transmission and reception, thus saving area.

[0028] It should also be noted that the amplifiers in the transmission link 1012 usually need to have high power output and high efficiency to ensure that the signal can be transmitted over a long distance without distortion. Therefore, the first amplifier AMP1 and the second amplifier AMP2 in the transmission link 1012 can specifically be power amplifiers (PA). The amplifiers in the receiving link 1013 are usually used to amplify the received weak signals and need to have high gain and high anti-interference ability to ensure that useful signals can be accurately extracted and amplified from a complex electromagnetic environment. Therefore, the third amplifier AMP3 and the fourth amplifier AMP4 in the receiving link 1013 can specifically be low noise amplifiers (LNA).

[0029] It should also be noted that Figure 1 The specific component structures of the shown common branch 1011, transmission link 1012, and receiving link 1013 are only one example. In other examples, the common branch 1011, transmission link 1012, receiving link 1013, and their internal component structures are all optional. For example, the common branch 1011 can also include one or more amplifiers AMP. One or both of the transmission link 1012 and the receiving link 1013 can also include an amplifier AMP. The radio frequency link 101 can also only include the common branch 1011 or only include the receiving link 1013 and the transmission link 1012, or it can also be any other feasible structure. Structures such as the digital step attenuator DSA and phase shifter PS in Figure 1 may not be included in the circuit, and no specific limitation is made thereto.

[0030] In the embodiments of the present disclosure, it is possible that the common branch 1011, transmission link 1012, and receiving link 1013 all include attenuators VVA. For example Figure 1 as shown, the common branch 1011 includes a first attenuator VVA1, the transmission link 1012 includes a second attenuator VVA2, and the receiving link 1013 includes a third attenuator VVA3. It is also possible that only one or two of the common branch 1011, transmission link 1012, and receiving link 1013 include attenuators VVA, which can be specifically designed in combination with the requirements of the actual link accuracy, gain, etc., and no specific limitation is made thereto. For example Figure 2 as shown, the radio frequency link 101 can only include the first attenuator VVA1. It can be understood that Figure 2 this is a simplified structural schematic diagram, not indicating that there is only one device, i.e., the first attenuator VVA1, in the entire radio frequency link 101. The radio frequency link 101 can also include devices such as amplifiers and phase shifters.

[0031] In an embodiment of the present disclosure, the attenuator VVA is a voltage-controlled attenuator with variable gain, and its gain can be regulated by a first voltage VC received at its first control terminal to meet the required gain change. Specifically, the first voltage VC is an analog voltage related to temperature. Therefore, the radio frequency circuit 10 may further include a temperature acquisition module 102 for acquiring temperature and a voltage generation module 104 for generating the first voltage VC according to the temperature.

[0032] The temperature acquisition module 102, which can also be referred to as a temperature quantization module, is used to acquire the current temperature, specifically the temperature of the radio frequency chip, and quantize the temperature into a digital level, denoted as the quantized temperature information (hereinafter referred to as temperature information) for use by other modules.

[0033] The register module 103 stores the correspondence between the target control signal and the temperature information. The register module 103 is configured to receive the temperature information and, based on the temperature information, search for and output the corresponding target control signal. The voltage generation module 104 is configured to receive the target control signal and perform digital-to-analog conversion on the target control signal to generate the first voltage VC. The target control signal is a digital signal stored in the register module 103 and is pre-corresponded to the current temperature information to achieve temperature compensation control of the overall gain of the radio frequency link 101.

[0034] It should be noted that the register module 103 can be connected to the temperature acquisition module 102, so that the temperature acquisition module 102 can directly send the temperature information to the register module 103, or as Figure 1 shown, the radio frequency transmission system further includes a control module 20. The control module 20 is respectively connected to the temperature acquisition module 102 and the register module 103. The temperature acquisition module 102 sends the temperature information to the control module 20, and the control module 20 sends the temperature information to the register module 103. There is no specific limitation on this.

[0035] Among them, the control module 20 and the radio frequency circuit 10 can both be integrated in a radio frequency chip, or the radio frequency circuit 10 is integrated in the radio frequency chip, and the control module 20 is an off-chip device independent of the radio frequency chip. There is no specific limitation on this either.

[0036] As Figure 1 shown, the radio frequency link 101 includes three attenuators VVA whose gains are controlled by the target control signal, and there are also three corresponding voltage generation modules 104, which are respectively denoted as: the first voltage generation module 104-1 corresponding to the first attenuator VVA1, the second voltage generation module 104-2 corresponding to the second attenuator VVA2, and the third voltage generation module 104-3 corresponding to the third attenuator VVA3. Each voltage generation module 104 is connected to the register module 103 to receive the target control signal sent by the register module 103.

[0037] It should also be noted that there is also the following situation: The RF link 101 includes multiple attenuators VVA, but only a part of them are controlled for gain by the target control signal. For example, for Figure 1 the three attenuators VVA in, if only the second attenuator VVA2 and the third attenuator VVA3 are controlled for gain by the target control signal, only two voltage generation modules 104 corresponding to these two attenuators VVA are required.

[0038] It should also be noted that in the embodiments of the present disclosure, in the case where multiple attenuators VVA need to be controlled for gain by the target control signal, a first voltage VC needs to be generated for each attenuator VVA, and each first voltage VC is converted by the corresponding voltage generation module 104 based on the target control signal. Therefore, the target control signal may include at least one sub-control signal, and each sub-control signal corresponds to an attenuator VVA, that is, corresponds to a voltage generation module 104.

[0039] For example, corresponding to Figure 1 the three voltage generation modules 104 shown, the target control signal includes three sub-control signals: a first sub-control signal corresponding to the first voltage generation module 104-1, a second sub-control signal corresponding to the second voltage generation module 104-2, and a third sub-control signal corresponding to the third voltage generation module 104-3, to respectively control the corresponding voltage generation module 104 to generate the corresponding first voltage VC, and further adjust the gain of the corresponding attenuator VVA.

[0040] Taking Figure 1 as an example, when performing temperature compensation (i.e., temperature warming) on the RF link 10, the temperature acquisition module 102 acquires the current temperature of the chip and quantifies it into temperature information and sends it to the register module 103 or the control module 20; the register module 103 obtains the temperature information from the temperature acquisition module 102 or the control module 20, and outputs a target control signal corresponding to the temperature information based on the temperature information, that is, a target control signal corresponding to the current temperature. Among them, the register module 103 stores the corresponding relationship between the target control signal and the temperature information, that is, the target control signal when the overall gain of the RF link 101 is maintained stable or basically stable (i.e., allowing a certain error range) at different temperatures is predetermined, and when performing temperature warming, the target control signal corresponding to the current temperature information can be directly found.

[0041] The target control signal is used to control three voltage generation modules 104 to generate corresponding first voltages VC. The register module 103 sends a first sub-control signal to the first voltage generation module 104-1. The first voltage generation module 104-1 performs digital-to-analog conversion on the first sub-control signal to generate a first voltage VC1 that acts on the first control end of the first attenuator VVA1, thereby realizing the adjustment of the gain (such as attenuation amount) of the first attenuator VVA1. At the same time, the register module 103 sends a second sub-control signal to the second voltage generation module 104-2. The second voltage generation module 104-2 performs digital-to-analog conversion on the second sub-control signal to generate a first voltage VC2 that acts on the first control end of the second attenuator VVA2, thereby realizing the gain adjustment of the second attenuator VVA2. At the same time, the register module 103 sends a third sub-control signal to the third voltage generation module 104-3. The third voltage generation module 104-3 performs digital-to-analog conversion on the third sub-control signal to generate a first voltage VC3 that acts on the first control end of the third attenuator VVA3, thereby realizing the gain adjustment of the third attenuator VVA3.

[0042] In the embodiments of the present disclosure, the register module 103 is responsible for information interaction with the control module 20 (or called the control and signal processing module). The control module 20 can write a control signal (the target control signal or the initial control signal for determining the target control signal, both are digital signals) to the register module 103. The register module 103 can also read back the control signal from the control module 20 to determine whether the written control signal is correct. After determining that it is correct, the register module 103 writes the control signal to the voltage generation module 104, and the voltage generation module 104 outputs a first voltage VC. The first voltage is an analog signal to adjust the performance of the radio frequency chip.

[0043] For another example Figure 2 As shown, the radio frequency circuit 101 only includes a first attenuator VVA1 or only the first attenuator VVA1 needs to have its gain controlled by the target control signal. The voltage generation module 104 is one, that is, the first voltage generation module 104-1 corresponding to the first attenuator VVA1. In other embodiments, it is also possible to set corresponding voltage generation modules 104 for one or two of the three attenuators VVA, and no specific limitation is made in this regard.

[0044] For Figure 2 For the circuit shown, the target control signal output by the register module 103 is the first sub-control signal. The register module 103 sends the target control signal to the only first voltage generation module 104-1. The first voltage generation module 104-1 performs digital-to-analog conversion to generate a first voltage VC1 that acts on the first control end of the first attenuator VVA1, thereby realizing the gain adjustment of the first attenuator VVA1, that is, realizing the gain adjustment of the entire radio frequency link 101.

[0045] It should also be noted that the trend of the target control signal controlling the gain of the attenuator VVA with temperature change is opposite to the trend of the gain of the amplifier AMP with temperature change. In this way, at each temperature information, through the regulation of the corresponding target control signal, the change direction of the gain of the attenuator VVA is opposite to the change direction of the gain of the amplifier AMP, so that the total gain of the two can be maintained stable. Even when the temperature changes, the overall gain of the link is stable and will not be unstable due to temperature change, thus ensuring that the RF circuit has good performance at different temperatures.

[0046] For example, if the gain of the amplifier AMP decreases with temperature change, it will cause the gain of the entire RF link 101 to decrease. Therefore, the gain of the attenuator VVA is increased to offset the decrease in the gain of the amplifier AMP, ensuring that the gain does not fluctuate with temperature and remains stable.

[0047] It should also be noted that the trend of the target control signal controlling the gain of each attenuator VVA with temperature change can be opposite to the trend of the gain of the amplifier AMP in its affiliated link with temperature change, so as to achieve precise compensation for the affiliated link. Usually, the trends of the gains of each amplifier AMP with temperature change are the same.

[0048] It should also be noted that the attenuator VVA in the embodiments of the present disclosure can specifically be a voltage-controlled attenuator such as a π-type attenuator, a bridge-T attenuator, or a T-type attenuator. Exemplarily, as Figure 3 shown, the π-type attenuator is composed of a switching transistor M1, two switching transistors M2, a resistor R1 connected in parallel with the switching transistor M1, and resistors R2 respectively connected in series with the two switching transistors M2. When the π-type attenuator is in the reference state, the switching transistor M1 is in the on state, equivalent to an on-resistance, and the two switching transistors M2 are both in the off state, equivalent to an off-capacitance, so that the input signal Rfin is not attenuated and the output signal Rfout is obtained. When the π-type attenuator is in the attenuation state, the switching transistor M1 is in the off state, equivalent to an off-capacitance, and the two switching transistors M2 are both in the on state, equivalent to an on-resistance, so as to achieve the attenuation of the input signal Rfin and obtain the output signal Rfout.

[0049] The bridge-T attenuator consists of a switching transistor M1, a switching transistor M2, a resistor R1 connected in parallel with the switching transistor M1, two resistors Z0 connected in series and in parallel with the switching transistor M1, and a resistor R2 connected in series with the switching transistor M2 and connected to the two resistors Z0. When the bridge-T attenuator is in the reference state, the switching transistor M1 is in the on state, equivalent to an on-resistance, and the switching transistor M2 is in the off state, equivalent to an off-capacitance, so as not to attenuate the input signal Rfin and obtain the output signal Rfout. When the bridge-T attenuator is in the attenuation state, the switching transistor M1 is in the off state, equivalent to an off-capacitance, and the switching transistor M2 is in the on state, equivalent to an on-resistance, so as to achieve the attenuation of the input signal Rfin and obtain the output signal Rfout.

[0050] The T-type attenuator consists of a switching transistor M1, a switching transistor M2, two resistors R1 connected in series and in parallel with the switching transistor M1, and a resistor R2 connected in series with the switching transistor M2 and connected to the two resistors R1. When the T-type attenuator is in the reference state, the switching transistor M1 is in the on state, equivalent to an on-resistance, and the switching transistor M2 is in the off state, equivalent to an off-capacitance, so as not to attenuate the input signal Rfin and output an output signal Rfout with almost no loss. When the T-type attenuator is in the attenuation state, the switching transistor M1 is in the off state, equivalent to an off-capacitance, and the switching transistor M2 is in the on state, equivalent to an on-resistance, so as to achieve the attenuation of the input signal Rfin and obtain the output signal Rfout.

[0051] In the three attenuators of the examples, the branch where the switching transistor M1 is located can be understood as the transmission main path, which is connected between the signal input end and the signal output end; the branch where the switching transistor M2 is located can be understood as the attenuation branch, which is connected between the signal input end and the ground, and / or is connected between the signal output end and the ground. Among them, the input signal Rfin is input at the signal input end, and the output signal Rfout is output at the signal output end. In the transmission main path, the number of switching transistors M1 can be one as shown in Figure 3 or multiple in series; in the attenuation branch, the number of switching transistors M2 can be one as shown in Figure 3 or multiple in series; no specific limitation is made thereto.

[0052] In the embodiments of the present disclosure, the control terminal (i.e., the gate) of the switching transistor M2 in the attenuation branch serves as the first control terminal of the attenuator VVA, and the control terminal of the switching transistor M1 in the transmission trunk serves as the second control terminal of the attenuator VVA. It can be understood that in a π-type attenuator, there are two first control terminals. The first control terminal of the attenuator VVA is connected to the voltage generation module 104 for receiving a first voltage VC and adjusting the gain of the attenuator VVA according to the first voltage VC. The variation trend of the gain of the attenuator VVA with the first voltage VC can be referred to Figure 4 as shown. As the first voltage VC increases, the insertion loss of the attenuator VVA increases and the gain decreases. In this way, by controlling the voltage value of the first voltage VC at different temperatures, the gain adjustment of the attenuator VVA is achieved.

[0053] It should also be noted that as described above, when the attenuator VVA operates in the reference state and the attenuation state respectively, one of the switching transistor M1 and the switching transistor M2 is turned on and the other is turned off. Therefore, the control terminals (the second control terminal) of the switching transistor M1 and the control terminal (the first control terminal) of the switching transistor M2 receive a pair of signals with opposite logic states. In the embodiments of the present disclosure, as Figure 1 or Figure 2 shown, the voltage clamping circuit 105 can be used to perform clamping according to the first voltage VC to generate a second voltage VP that is negatively correlated with the first voltage VC and acts on the second control terminal of the attenuator VVA. Each attenuator VVA whose gain is controlled by a target control signal corresponds to a voltage clamping circuit 105, and each voltage clamping circuit 105 is respectively connected between the corresponding voltage generation module 104 and the corresponding attenuator VVA.

[0054] Combined with Figure 1 shown, for three attenuators VVA whose gains are controlled by target control signals, the radio frequency circuit 10 includes three voltage clamping circuits 105: The first voltage clamping circuit 105-1 corresponding to the first attenuator VVA1, whose input terminal is connected to the output terminal of the first voltage generation module 104-1, and whose output terminal is connected to the second control terminal of the first attenuator VVA1; is used to receive the first voltage VC1 and generate a second voltage VP1 that is negatively correlated with the first voltage VC1; The second voltage clamping circuit 105-2 corresponding to the second attenuator VVA2, whose input terminal is connected to the output terminal of the second voltage generation module 104-2, and whose output terminal is connected to the second control terminal of the second attenuator VVA2; is used to receive the first voltage VC2 and generate a second voltage VP2 that is negatively correlated with the first voltage VC2; The third voltage clamping circuit 105-3 corresponding to the third attenuator VVA3 has its input terminal connected to the output terminal of the third voltage generation module 104-3, and its output terminal connected to the second control terminal of the third attenuator VVA3. It is used to receive the first voltage VC3 and generate a second voltage VP3 that is negatively correlated with the first voltage VC3.

[0055] For example Figure 2 As shown, corresponding to a first attenuator VVA1, the radio frequency circuit 10 includes a first voltage clamping circuit 105-1.

[0056] It should also be noted that each second voltage VP has an inverse relationship with the corresponding first voltage VC. Using the voltage clamping circuit 105, the second voltage VP can be generated based on the first voltage VC, thereby realizing the gain control of the attenuator VVA.

[0057] In this way, in order to make the gain of the radio frequency link 101 stable and not change with temperature, the embodiment of the present disclosure integrates an attenuator VVA in the radio frequency link 101. The attenuator VVA is controlled by the first voltage VC, and its insertion loss increases with the increase of the first voltage VC. In practical applications, different insertion losses at different temperature points are obtained by setting different first voltages VC at different temperature points, thereby adjusting the gain of the radio frequency link 101. Since the change direction of the gain of the attenuator VVA with temperature is opposite to the change direction of the gain of the amplifier AMP with temperature, the gain of the radio frequency link 10 is ensured to be stable at different temperatures and does not change with temperature.

[0058] Next, the component structures and working modes of each module in the radio frequency circuit 10 will be described in detail by way of example.

[0059] In some embodiments, as Figure 5 shown, the temperature acquisition module 102 includes: A bandgap reference circuit 1021 for generating a reference voltage VTC that is positively correlated with temperature; An analog-to-digital conversion circuit ADC for performing analog-to-digital conversion on the reference voltage to generate quantized temperature information.

[0060] It should be noted that the bandgap reference circuit 1021, that is, the Bandgap circuit, can generate a positive temperature curve voltage (i.e., the reference voltage VTC), and its voltage value increases with the increase of temperature. The reference voltage VTC is an analog voltage, which is subjected to analog-to-digital conversion by the analog-to-digital conversion circuit ADC to obtain a digital signal, that is, quantized temperature information. In other examples, the bandgap reference circuit 1021 can also generate a reference voltage VTC that is negatively correlated with temperature and can also be used to represent temperature, and no specific limitation is made thereto.

[0061] Among them, the number of bits output by the analog-to-digital conversion circuit ADC determines the number of temperature compensation levels. For example, if the analog-to-digital conversion circuit ADC outputs an 8-bit (bit) digital signal, it can represent 256 different temperatures, and thus temperature compensation can be achieved under 256 different temperature information levels.

[0062] Based on Figure 5 as shown in Figure 6 Figure, the temperature acquisition module 102 may further include: a first operational amplifier OPA1, whose non-inverting input terminal (+) is connected to the output terminal of the bandgap reference circuit 1021; its output terminal is connected to its inverting input terminal (-) and grounded through a resistor RT.

[0063] Among them, the first operational amplifier OPA1 is connected end to end as a voltage follower, and its gain is constantly 1, which can achieve "lossless transmission" of the signal, thus ensuring the signal quality. In this way, after the first operational amplifier OPA1 enhances the reference voltage VTC, an enhanced reference voltage VTC1 can be obtained, and then the analog-to-digital converter ADC performs analog-to-digital conversion to obtain the quantized temperature information.

[0064] Furthermore, as shown in Figure 6 Figure, the temperature acquisition module 102 may further include: a decoder 1022, whose input terminal is connected to the output terminal of the analog-to-digital converter ADC, and is used to decode the temperature information to obtain the decoded temperature information. Among them, a decoder (Decoder) is a digital logic circuit, and its function is to convert the binary-coded input into a specific output signal. It can recognize 2 n different input combinations of n-bit binary coding and output through multiple output terminals. Each output terminal outputs a high level (valid signal) under a certain specific input combination and outputs a low level under other input combinations.

[0065] For example, if the temperature information output by the analog-to-digital converter ADC is 8-bit temperature information, the decoder 1022 can be an 8-to-256 decoder, which decodes the 8-bit temperature information into 256-bit temperature information: T<1>~T<256>, which can represent 256 temperatures.

[0066] That is to say, the temperature acquisition module 102 generates a reference voltage VTC through the bandgap reference circuit 1021, and inputs it to an 8-bit analog-to-digital converter ADC through a voltage follower composed of the first operational amplifier OPA1. The analog-to-digital converter ADC converts the analog voltage signal into a digital signal, and then outputs the decoded outputs of T<1> to T<256> through an 8-to-256 decoder. This path is mainly used to quantify the temperature value into a digital level. For example, the VTC voltage at -50°C is 500mV, the output of the ADC is 00000000, and the output of the decoder is T<1> = "1". That is, -50°C corresponds to the high-level enable of T<1>. The temperature acquisition module 102 feeds back the obtained digital levels T<1> to T<256> to the control module 20 or the register module 103.

[0067] In this way, the decoder 1022 converts a multi-bit digital signal (such as 8-bit) into a digital signal with only single-bit validity (for example, only 1 bit is valid among 256 bits), so that the control module 20 can easily identify and process it, simplifying the processing logic of the control module 20.

[0068] In some embodiments, the register module 103 includes a non-volatile memory 1031, such as Figure 7 or Figure 8 As shown, the non-volatile memory 1031 includes: Multiple non-volatile cells Fuse for storing target control signals corresponding to multiple temperature information; A signal processing module 1032 for outputting the target control signal stored in the non-volatile cell Fuse corresponding to the temperature information based on the temperature information and the corresponding relationship.

[0069] It should be noted that the non-volatile memory 1031 is a register with fixed and immutable stored data. The non-volatile cells Fuse store fixed data, which will no longer change after the data is written. Specifically, the non-volatile cell can be a one-time programmable (OTP) memory, such as an electronic fuse (Efuse), which can be specifically composed of several fuses. Therefore, in the drawings, the non-volatile cell is represented by Fuse.

[0070] The signal processing module 1032 realizes the accurate selection of the target control signal in the following way: Each non-volatile storage unit (non-volatile cell Fuse) is assigned a unique address (such as 256 non-volatile cells Fuse corresponding to addresses 1 to 256), and forms a one-to-one mapping relationship with the 256-channel temperature coding signals (T<1> to T<256>) output by the decoder 1022 (for example, address k corresponds to temperature signal T <k>). When the system detects specific temperature information (such as T <k>When the decoder 1022 activates the corresponding k-th output, the signal processing module 1032 captures this signal through its 256 input ports (hard-wired directly to the output end of the decoder 1022), locates the non-volatile cell Fuse at address k, reads the pre-stored control parameters (such as voltage, current or switch commands) from it, and finally outputs the target control signal. This design realizes fast response and high reliability through the direct mapping of address-temperature signals and the physical direct connection mechanism.

[0071] It should also be noted that, as described above, corresponding to multiple attenuators VVA for temperature compensation, the radio frequency circuit 10 includes multiple voltage generation modules 104, which are respectively connected to multiple attenuators VVA, and the target control signal includes multiple sub-control signals corresponding to multiple attenuators VVA. Taking 3 as an example, as Figure 7 shown, the three sub-control signals corresponding to the same temperature information are stored in the same non-volatile cell Fuse, that is, one temperature information corresponds to one non-volatile cell Fuse, in which multiple sub-control signals corresponding to multiple voltage generation modules 104 are stored.

[0072] Taking 256 temperature information as an example, as Figure 7 shown, it corresponds to 256 non-volatile cells Fuse: Fuse1~Fuse256. Taking the non-volatile cell Fuse corresponding to temperature information 1 as an example, in the Figure 7 example shown, the target control signal 1 stored in the corresponding non-volatile cell Fuse1 includes three sub-control signals: the first sub-control signal 1 corresponding to the first attenuator VVA1, the second sub-control signal 1 corresponding to the second attenuator VVA2, and the third sub-control signal 1 corresponding to the third attenuator VVA3. In the Figure 8 example shown, it corresponds to 3 non-volatile cells: the non-volatile cell Fuse-1 is used to store the first sub-control signal 1; the non-volatile cell Fuse-2 is used to store the second sub-control signal 1; the non-volatile cell Fuse-3 is used to store the third sub-control signal 1.

[0073] Assuming that the sub-control signal is a 4-bit digital signal, the target control signal is a 12-bit digital signal. For example, it is 000011110010 in sequence, where the first 4 bits "0000" are the first sub-control signal, the middle 4 bits "1111" are the second sub-control signal, and the last 4 bits "0010" are the third sub-control signal. In the Figure 7 Among them, these 12-bit digital signals are stored in the same non-volatile cell Fuse. Each of these 12-bit digital signals is connected to a data transmission line. The data transmission lines corresponding to the first 4 bits are connected to the first voltage generation module 104-1, so that the first sub-control signal can be transmitted to the first voltage generation module 104-1; the data transmission lines corresponding to the middle 4 bits are connected to the second voltage generation module 104-2, so that the second sub-control signal can be transmitted to the second voltage generation module 104-2; the data transmission lines corresponding to the last 4 bits are connected to the third voltage generation module 104-3, so that the third sub-control signal can be transmitted to the third voltage generation module 104-3.

[0074] Taking the temperature information 1 as an example, during temperature compensation: For Figure 7 , the signal processing module 1032 receives the temperature information 1, searches for and determines the corresponding non-volatile cell Fuse1, and sends the field of the first sub-control signal 1 in the target control signal 1 to the first voltage generation module 104-1, sends the field of the second sub-control signal 1 in the target control signal 1 to the second voltage generation module 104-2, and sends the field of the third sub-control signal 1 in the target control signal 1 to the third voltage generation module 104-3.

[0075] In Figure 8 In the example shown, the three sub-control signals corresponding to the same temperature information are stored in three non-volatile cells Fuse, that is, one sub-control signal corresponds to one storage cell Fuse. Taking 256 temperature information as an example, in Figure 8 correspond to 256×3 non-volatile cells Fuse: Fuse1-1~Fuse256-3. Assuming that the sub-control signal is a 4-bit digital signal and the target control signal is a 12-bit digital signal, in Figure 8 In the example shown, these 12-bit digital signals are respectively stored in three non-volatile cells Fuse. It can still be the connection method where one 1-bit digital signal corresponds to one data transmission line connected to the corresponding voltage generation module 104, which will not be elaborated here.

[0076] Taking the temperature information 1 as an example, during temperature compensation: For Figure 8 , the signal processing module 1032 receives the temperature information 1, searches for and determines the corresponding non-volatile cells Fuse1-1, non-volatile cell Fuse1-2, and non-volatile cell Fuse1-3, and sends the first sub-control signal 1 stored in the non-volatile cell Fuse1-1 to the first voltage generation module 104-1, sends the second sub-control signal 1 stored in the non-volatile cell Fuse1-2 to the second voltage generation module 104-2, and sends the third sub-control signal 1 stored in the non-volatile cell Fuse1-3 to the third voltage generation module 104-3.

[0077] Furthermore, the present disclosure embodiment also provides a method for obtaining the correspondence between the target control signal and the temperature information. This obtaining process can be executed by the control module 20. The control module 20 can obtain the correspondence between the target control signal and the temperature information based on the gain of the radio frequency link 101 under the initial control signal.

[0078] It should be noted that the initial control signal is used to obtain this temperature relationship. The initial control signal is a preset and original control signal that has not been determined as the target control signal. The value range of the initial control signal is determined by the adjustment range of the attenuator VVA. In some embodiments, when the initial control signal takes the maximum value, the gain of the attenuator VVA is the largest; when the initial control signal takes the minimum value, the gain of the attenuator VVA is the smallest. Or, when the initial control signal takes the maximum value, the gain of the attenuator VVA is the smallest; when the initial control signal takes the minimum value, the gain of the attenuator VVA is the largest. Taking Figure 2 the case where there is only one first attenuator VVA1 as an example, simply speaking, at a certain preset temperature, the control module 20 sends different initial control signals to the first voltage generation module 104-1 respectively. Based on the initial control signal, the first voltage generation module 104-1 generates the first voltage VC1, the first voltage clamping circuit 105-1 generates the second voltage VP1, the first attenuator VVA1 operates based on the first voltage VC1 and the second voltage VP1. The control module 20 connects the input end and the output end of the radio frequency link 101, so that the power of the input radio frequency signal and the output radio frequency signal can be obtained, and then the gain of the radio frequency link 101 at this preset temperature can be obtained. By traversing each initial control signal, the gain of the radio frequency link 101 under each initial control signal can be obtained, and the initial control signal with the gain closest to the preset gain is determined as the target control signal corresponding to this temperature information. The preset gain is the expected gain of the radio frequency link 101. In this way, the control module 20 obtains the gain of the radio frequency link 101 and, based on the gain, obtains the correspondence between the target control signal and the temperature information.

[0079] It should also be noted that generally, the accuracy of the third attenuator VVA3 in the receiving link 1013 or the second attenuator VVA2 in the transmitting link 1012 is higher than that of the first attenuator VVA1 in the common branch 1011. That is, during the temperature compensation process, the first attenuator VVA1 in the common branch 1011 is usually used for coarse gain adjustment, while the third attenuator VVA3 in the receiving link 1013 and the second attenuator VVA2 in the transmitting link 1012 are used for fine gain adjustment. In this way, the first attenuator VVA1 in the common branch 1011 has a low accuracy and can be used for coarse adjustment to expand the adjustment range of the attenuation amount; the attenuators VVA in the receiving link 1013 or the transmitting link 1012 have a high accuracy and can be used for fine adjustment to increase the adjustment accuracy.

[0080] In the case where the correspondence between multiple sub-control signals and temperature information needs to be confirmed, the initial control information also includes multiple sub-initial signals. One way is to send an initial control signal containing all the multiple sub-initial signals each time during traversal. In this way, after one round of traversal, the target control signal can be determined. However, in the case where the number of bits of the target control signal is large, there are multiple combination methods, which may take a long time.

[0081] Another way is to traverse each attenuator VVA separately. For example, at a certain preset temperature, first only traverse the first sub-initial signal to determine the first sub-control signal; then traverse the second sub-initial signal to determine the second sub-control signal, and then traverse the third sub-initial signal to determine the third sub-control signal. Finally, the three sub-control signals form the complete target control signal. In the second way, in the case where some sub-control signals have been determined, when traversing the remaining sub-initial signals, the determined sub-control signals can be used for gain control of the corresponding attenuator VVA during the traversal process to ensure that the final effect is the combined effect of all sub-control signals. In this way, although separate traversals are required, the number of bits of each sub-initial signal is small, and the overall traversal time can be saved.

[0082] Exemplarily, coarse adjustment means that the gain adjustment of each gear of the attenuator VVA is relatively large. Fine adjustment means that the gain adjustment of each gear of the attenuator VVA is relatively small. For example, for coarse adjustment, the gain is adjusted by 0.5 dB per gear, and for fine adjustment, the gain is adjusted by 0.1 dB per gear; the gears correspond to different values of the sub-control signals. For example, a set of sub-control signals output by coarse adjustment is: 0101, 1010, 1101, corresponding to gains of 0.5 dB, 1 dB, 1.5 dB; a set of sub-control signals output by fine adjustment is: 0001, 0010, 0011, corresponding to gains of 0.1 dB, 0.2 dB, 0.3 dB.

[0083] Regardless of the method, the gain adjustment of each attenuator VVA is independent and has no connection with each other, and they will not affect each other. As described above, the RF link 10 of the RF chip includes a receive link and a transmit link. Each link includes different amplifiers, so the gains required for the receive and transmit links are different at high and low temperatures. Therefore, the gain of the first attenuator VVA1 in the common branch 1011 (corresponding to the first voltage VC1) can be adjusted first for preliminary coarse adjustment; then the gain of the third attenuator VVA3 in the receive link 1013 (corresponding to the third voltage VC3) and the gain of the second attenuator VVA2 in the transmit link 1012 (corresponding to the second voltage VC2) can be adjusted for further fine adjustment.

[0084] It should also be noted that the control module 20 can send an initial control signal to the voltage generation module 104 through the register module 103. Specifically, as Figure 9 shown, in some embodiments, the register module 103 further includes: A readable and writable register 1033, connected to the control module 20, for storing the initial control signal output by the control module 20, and the initial control signal is used to establish the correspondence between the temperature information and the target control signal; A selector MUX, the first input terminal (0) of the selector MUX is connected to the output terminal of the non-volatile memory 1031, the second input terminal (1) of the selector MUX is connected to the output terminal of the readable and writable register 1033, the control terminal of the selector MUX receives a selection control signal, and the output terminal of the selector MUX is connected to the voltage generation module 104. The selector MUX is used to selectively output the target control signal stored in the non-volatile memory 1031 or the initial control signal stored in the readable and writable register 1033 to the voltage generation module 104 according to the selection control signal.

[0085] It should be noted that, as an example, in Figure 9 , when the selection control signal is logic 0 (low level), it indicates that the current is in the normal working stage of the RF circuit 10, and the target control signal stored in the non-volatile memory 1031 is output. When the selection control signal is logic 1 (high level), it indicates that the current is in the stage of determining the correspondence between the target control signal and the temperature information, and the initial control signal stored in the readable and writable register 1033 is output. Or it can be the opposite, or other control methods, which are not specifically limited here, only taking Figure 9 shown as an example.

[0086] It should also be noted that the writable register 1033 means that the value in the register can be written repeatedly and read repeatedly. The non-volatile memory 1031 (also called Efuse register, Fuse register, fuse register) is the collection of all bits of Efuse. The default value inside is all 0. After programming, some of them become 1. After programming, the non-volatile memory 1031 becomes a read-only register and can only read data.

[0087] It should also be noted that in the case of corresponding to multiple voltage generation modules 104, multiple selectors MUX can be correspondingly set to respectively send corresponding sub-control signals or sub-initial signals to the corresponding voltage generation modules 104. Among them, the control signal selected and output by the selector MUX can be fed back to the control module 20 at the same time to judge the source of the control signal and whether the control signal is correct.

[0088] In the embodiments of the present disclosure, a specific control method for the control module 20 to obtain the correspondence between the target control signal and the temperature information is also provided, which may include: At each preset temperature, the control module 20 obtains temperature information; wherein, the temperature information is collected by the temperature acquisition module 102 and sent to the control module 20; The control module 20 outputs an initial control signal, and the initial control signal is transmitted to the voltage generation module 104. The initial control signal is used to control the voltage value of the first voltage VC generated by the voltage generation module 104; Under the initial control signal, the control module 20 obtains the gain of the radio frequency link 101; Traverse different initial control signals. When the difference between the obtained gain and the preset gain is the smallest, the initial control signal is determined as the target control signal corresponding to the current temperature information; Traverse all preset temperatures, obtain the correspondence between each temperature information and the target control signal, and store it in the register module 103, specifically stored in the non-volatile memory 1031.

[0089] This control method can be executed by the control module 20, and the control module 20 can be implemented by software or hardware. In some embodiments, the control module 20 includes a processor and a memory; the processor is used to execute the instructions stored in the memory so that the control module 20 executes this control method. It should be noted that the control module 20 can be a digital circuit and can also be composed of logic circuits, and no specific limitation is made thereto.

[0090] It should be noted that Figure 2 and Figure 9 For example, the control module 20 is further configured to output a selection control signal in the first state to the selector MUX when obtaining the correspondence between the target control signal and the temperature information, and select to output the initial control signal stored in the readable and writable register 1033 to the first voltage generation module 104-1. Here, the first state may be logic 1, and correspondingly, logic 0 may be denoted as the second state, but it is not specifically limited.

[0091] In the embodiment of the present disclosure, the control module 20 writes the initial control signal into the readable and writable register 1033, and then the selector MUX selects the control signal source as the readable and writable register 1033, so that the initial control signal in the readable and writable register 1033 can be directly given to the voltage generation module 104. The working process is as follows: First, use the readable and writable register 1033 to traverse the initial control signal of a certain radio frequency chip at a fixed temperature, and feedback it to the control module 20 to record the determined target control signal. That is, the target control signal is: at a certain temperature, the initial control signal input to the voltage generation module 104 to achieve the expected insertion loss of the attenuator VVA, and the expected insertion loss can make the gain of the radio frequency link closest to the preset gain at the current temperature. After all temperatures are traversed, the target control signal is burned into the non-volatile memory 1031 (or a target control signal or sub-control signal can also be determined and burned), and the selector MUX is used to select the output from the non-volatile memory 1031.

[0092] In this way, the correspondence between each temperature information and the target control signal is stored in the non-volatile memory 1031. For example, through Efuse burning, the Efuse is blown, causing the Efuse circuit structure to change physically, and this change can be equivalent to permanently changing the value of the Efuse.

[0093] During temperature compensation, the control module 20 sends a selection control signal in the second state to the selector MUX, so as to select the target control signal in the non-volatile memory 1031 and output it to the voltage generation module 104. The voltage generation module 104 performs digital-to-analog conversion to convert the digital signal (target control signal) into an analog voltage (the first voltage VC).

[0094] Thus, the voltage generation module 104 can be a digital-to-analog converter for performing analog-to-digital conversion. Exemplarily, as Figure 10 shown, the voltage generation module 104 includes a plurality of resistors and a plurality of switches, and the target control signal includes multiple-bit control data; in Figure 10 Among them, it is assumed that the voltage generation module 104 includes 100 resistors, namely: R<1> to R<100>, and their corresponding sub-control signals include 99-bit control data: namely V<1> to V<99>, and the corresponding 99 switches are respectively M1<1> to M<99>. A plurality of resistors are connected in series, and the first end of each switch is connected to the connection node of two adjacent resistors; the control end of each switch receives one bit of control data; the second ends of all switches are connected together for outputting a first voltage VC. Here, taking the switch as an NMOS transistor as an example, in other examples, the switch can also be a PMOS transistor or other numerically controlled switches; each resistor can be a fixed resistor or a MOS transistor resistor, etc., and no specific limitations are made thereto. A plurality of series-connected resistors form a resistor string. The resistors are connected between the power supply and the ground terminal. Here, a low dropout linear regulator (LDO) can be used to provide a stable power supply.

[0095] Among them, at a certain temperature point, only one of V<1> to V<99> is enabled to turn on the corresponding switch and output a determined first voltage VC. Assuming that the sub-control signal is a 7-bit digital signal, the correspondence between the 7-bit digital signal and the enabling of V<1> to V<99> can be, for example: for example, 0000001 corresponds to the enabling of V<1>, and the rest of the control data are not enabled; 0000011 corresponds to the enabling of V<3>, and the rest of the control data are not enabled; 0010000 corresponds to the enabling of V<16>, and the rest of the control data are not enabled.

[0096] Figure 10 The shown voltage generation module 104 is also called a ladder resistor voltage division module. Through ladder resistor voltage division, it can be seen that when V<1> = "1", the switch M<1> is turned on, and the output, for example, 0.025V is sent to the voltage follower composed of the second operational amplifier OPA2. At this time, the first voltage VC connected is also 0.025V.

[0097] By connecting the bit positions from the register module 103 to V<1> to V<99>, the first voltage VC required at different temperature points can be obtained. Combining the foregoing Figure 6 example, at a certain temperature point, only one of T<1> to T<256> is T <x>Enable. After the enable bit is fed back to the control module 20, the current temperature point can be recognized. Then, according to the first voltage VC required for the current temperature point, the control module 20 makes the control register module output a string of bits (i.e., the control signal), corresponding to a certain V among V<1>~V<99> <x>Enable it to obtain the required first voltage VC. Table 1 exemplarily shows a schematic mapping table of T<1>~<256> and V<1>~<99>.

[0098] Table 1

[0099] Furthermore, as Figure 10 shown, after each voltage generation module 104, a second operational amplifier OPA2 can also be connected; wherein, the non-inverting input terminal (+) of the second operational amplifier OPA2 is connected to the output terminal of the voltage generation module 104, the output terminal of the second operational amplifier OPA2 is connected to the inverting input terminal (-) of the second operational amplifier OPA2, and is grounded through a resistor RC, and the output terminal of the second operational amplifier OPA2 outputs an enhanced first voltage VC.

[0100] In this way, the second operational amplifier OPA2 is connected end to end as a voltage follower, which has a driving effect, and its output voltage has a certain driving ability to the outside and has a good ability to resist load changes.

[0101] In addition to sending the generated first voltage VC to the first control terminal of the corresponding attenuator VVA, the voltage generation module 104 also sends the first voltage VC to the voltage clamping circuit 105 for clamping to generate a second voltage VP. For the voltage clamping circuit 105, in some embodiments, as Figure 11 shown, the voltage clamping circuit 105 includes a mirror attenuator MVVA and four fixed resistors: resistor RL1, resistor RL2, resistor RH1, resistor RH2, and a third operational amplifier OPA3. The first ends of resistor RH1 and resistor RH2 are both connected to the power supply voltage VDD; the second end of resistor RH1 is connected to the output terminal OUT of the mirror attenuator MVVA and the non-inverting input terminal (+) of the third operational amplifier OPA3; the second end of resistor RH2 is connected to the first end of resistor RL2 and the inverting input terminal (-) of the third operational amplifier OPA3; the first end of resistor RL1 is connected to the input terminal IN of the mirror attenuator MVVA; the second ends of resistor RL1 and resistor RL2 are both grounded; the output terminal of the third operational amplifier OPA3 is connected to the second control terminal of the mirror attenuator MVVA for outputting the second voltage VP; the first control terminal of the mirror attenuator MVVA receives the first voltage VC, and the first voltage VC is provided by the connected voltage generation module 104.

[0102] It should be noted that the mirror attenuator MVVA has the same composition structure as the aforementioned attenuator VVA, and will not be elaborated here. The operational amplifier (OPA) has the characteristics of virtual short and virtual open: virtual short means that the voltage difference between the non-inverting input terminal and the inverting input terminal of the operational amplifier is very small and can be considered equal. Since there is no actual physical connection, it is called virtual short (to distinguish it from the physical connection of short circuit); since the operational amplifier is a high-impedance device, it can be considered that the current values flowing into the operational amplifier from the two input terminals are 0, that is, the currents at the non-inverting input terminal and the inverting input terminal are both 0. Intuitively, it feels like the two ports are disconnected, so it is called virtual open.

[0103] The mirror attenuator MVVA can simulate the working state of the attenuator VVA. The working principle of the voltage clamping circuit 105 is as follows: The first voltage VC is an analog signal provided by the voltage generation module 104. For the balanced mirror attenuator MVVA, when the voltage value of the first voltage VC changes, the impedance of the switching transistor M2 in the attenuation branch changes. As a result, the mismatch of the mirror attenuator MVVA causes the equivalent impedance between point X and ground to no longer be a fixed value, and then a voltage difference exists between point X and point Y. Under the action of the third operational amplifier OPA3, this voltage difference will adjust the voltage value of the second voltage VP. At the same time, the second voltage VP will synchronously adjust the working parameters of the mirror attenuator MVVA, so that the port standing wave of the mirror attenuator MVVA develops in the direction of reducing the voltage difference between point X and point Y until after achieving good matching, there is no voltage difference between point X and point Y, meeting the virtual short and virtual open characteristics of the operational amplifier. At this time, a dynamic correspondence relationship is established between the first voltage VC and the second voltage VP.

[0104] Taking the mirror attenuator MVVA as a π-type attenuator as an example, the equivalent circuit schematic diagram of the voltage clamping circuit 105 is as Figure 12 , the equivalent model of the mirror attenuator VVA can be simplified into three equivalent resistors: the resistor R11 corresponding to the transmission trunk line, and the two resistors R12 corresponding to the two attenuation branches. Among them, the first voltage VC controls the resistor R12, and the second voltage VP is used to control the resistor R11. Generally, the larger the first voltage VC (the smaller the resistor R12), the smaller the second voltage VP (the larger the resistor R11), which correspondingly means that the attenuation amount of the mirror attenuator MVVA is larger.

[0105] For example, when the first voltage VC = 2.5V, the resistor R12 is close to 50Ω, and the resistor R11 is close to 100kΩ. At this time, the voltages at the non-inverting input terminal and the inverting input terminal of the third operational amplifier OPA3 are equal. After passing through the third operational amplifier OPA3, the output second voltage VP is 0V. The second voltage VP feedback-clamps the resistance value of the resistor R11, making its resistance close to 100kΩ and maintaining a stable state.

[0106] For example, when the first voltage VC = 0V, the resistance R12 is close to 100 kΩ, and the resistance R11 is close to 3 - 4 Ω. At this time, the voltages at the non-inverting input terminal and the inverting input terminal of the third operational amplifier OPA3 are approximately equal. After passing through the third operational amplifier OPA3, the output second voltage VP is 2.5V. The feedback of the second voltage VP clamps the resistance value of the resistance R11, keeping its resistance at 3 - 4 Ω to maintain a stable state.

[0107] In this way, the second voltage VP is clamped by the first voltage VC through the third operational amplifier OPA3, that is, a second voltage VP can be obtained from a first voltage VC. At different temperatures, the corresponding relationship between the first voltage VC and the clamped second voltage VP can be referred to Figure 13 as shown.

[0108] Since the insertion loss required by the attenuator VVA is related to temperature, and the first voltage VC can be used to control the insertion loss of the attenuator VVA, in the embodiments of the present disclosure, only a first voltage VC that changes with temperature needs to be designed, and the second voltage VP can be automatically feedback - locked through the voltage clamping circuit 105, so as to obtain the expected insertion loss at different temperatures to compensate for the gain of the circuit.

[0109] In the embodiments of the present disclosure, a control method for a radio frequency circuit 10 is further provided, including: At each preset temperature, obtain temperature information; Output an initial control signal, where the initial control signal is used to control the voltage value of the first voltage generated by the voltage generation module 104; Under the initial control signal, obtain the gain of the radio frequency link 101; Traverse different initial control signals. When the difference between the gain and the preset gain is the smallest, determine the initial control signal as the target control signal corresponding to the current temperature information, where the preset gain is the expected gain of the radio frequency link 101; Traverse all preset temperatures, obtain the corresponding relationship between each temperature information and the target control signal, and store it in the register module 103.

[0110] This control method can be executed by the control module 20. The following combines Figure 2 、 Figure 6 、 Figure 9 、 Figure 10 in the specific circuits as examples to elaborate on the control method in detail.

[0111] Step 1: At each preset temperature, obtain temperature information; In some embodiments, before acquiring temperature information, the selector MUX selects to connect the output terminal of the readable and writable register 1033 to the first voltage generation module 104-1, so as to output an initial control signal to the first voltage generation module 104-1 to the third voltage generation module 104-3; Figure 6 The temperature acquisition module 102 shown is located inside the RF chip. The bandgap reference circuit 1021 therein can generate a reference voltage VTC that increases with the increase of temperature. Then, the reference voltage VTC is converted into a digital signal through the analog-to-digital converter ADC, so as to quantify the temperature of the RF chip into a digital signal. Only one of the temperature information T<1>~T<256> obtained by decoding by the decoder 1022 is enabled (for example, high-level enabling). The control module 20 can identify the chip temperature according to the temperature information. For example, when T<1> is enabled, the temperature inside the RF chip is -50°C.

[0112] Step 2, output an initial control signal, and the initial control signal is used to control the voltage value of the first voltage generated by the voltage generation module 104; After the control module 20 acquires the temperature information, it gives Figure 9 The initial control signal is written into the readable and writable register 1033 in the register module 103 shown. On the one hand, this initial control signal is transmitted by the selector MUX to the voltage generation module 104, and on the other hand, it can also be fed back to the control module 20.

[0113] The initial control signal is converted into an analog signal (i.e., the first voltage VC) after passing through the voltage generation module 104 and is transmitted to the voltage clamping circuit 105. The voltage clamping circuit 105 outputs a second voltage VP. The first voltage VC and the second voltage VP control the gain of the attenuator VVA, directly changing the gain performance of the RF link 101.

[0114] The control module 20 also respectively obtains the power or voltage of the RF input signal and the RF output signal. According to the ratio of the power or voltage of the RF input signal and the RF output signal, the gain of the RF link 101 can be obtained.

[0115] Step 3, traverse different initial control signals. When the difference between the gain and the preset gain is the smallest, the initial control signal is determined as the target control signal corresponding to the current temperature information, and the preset gain is the expected gain of the RF link 101; At each temperature, the control module 20 records the link gain under each initial control signal respectively, so as to determine the gain with the smallest difference from the preset gain as the optimal gain, and the initial control signal under the optimal gain is the target control signal. At this time, the gain at this temperature point is calibrated.

[0116] Specifically, such as Figure 6 and Figure 10 As shown, assume there are 256 different preset temperatures ( Figure 6 only one of T<1> to T<256> in Figure 9 is enabled, corresponding to a specific temperature) and 99 initial control signals ( Figure 9 only one of V<1> to V<99> in Figure 9 is enabled, the corresponding switch is turned on, corresponding to a specific voltage). Taking preset temperature 1 as an example, the control module 20 obtains the temperature information corresponding to preset temperature 1 from the temperature acquisition module 102. Assume that T<1> is enabled, and the remaining T <x>None of them are enabled. Write the initial control signal 1 to the readable and writable register 1033. Assume that V<1> is enabled. The initial control signal 1 is transmitted to the voltage generation module 104 to generate the first voltage VC to adjust the gain of the attenuator VVA. The control module 20 determines the gain of the RF link 101. Then write the initial control signal 2 to the readable and writable register 1033. Assume that V<2> is enabled. The initial control signal 2 is transmitted to the voltage generation module 104 to generate the first voltage VC to adjust the gain of the attenuator VVA. The control module 20 determines the gain of the RF link 101;...; Finally, write the initial control signal 99 to the readable and writable register 1033. Assume that V<99> is enabled. The initial control signal 99 is transmitted to the voltage generation module 104 to generate the first voltage VC to adjust the gain of the attenuator VVA. The control module 20 determines the gain of the RF link 101. The gain among the 99 gains that is closest to the preset gain is the optimal gain, and the corresponding initial control signal is the target control signal.

[0117] It should be noted that the above takes the traversal order of the initial control signal 1, the initial control signal 2,..., the initial control signal 99 as an example, but it is not limited to this, and the traversal can be carried out in any order.

[0118] Step 4: Traverse all preset temperatures, obtain the corresponding relationship between each temperature information and the target control signal, and store it in the register module 103.

[0119] Place the RF chip at different preset temperatures in sequence to traverse all preset temperatures. Repeat Steps 1 to 3 at each preset temperature until the target control signals for all temperature points are confirmed.

[0120] Burn the target control signals of all temperature points in the non-volatile memory 1031, and select the output from the non-volatile memory 1031 through the selector MUX.

[0121] The process of determining the corresponding relationship can be carried out in advance and does not need to be adjusted in real time when the RF link 101 is working, which can save time.

[0122] When the RF link 101 is working, the RF link 101 receives or transmits RF signals. The temperature acquisition module 102 can still sense the temperature of the RF chip and can quantify the temperature into a digital level. The signal processing module 1032 in the non-volatile memory 1031 looks up the target control signal corresponding to the temperature of the digital level, and the selector MUX outputs the target control signal to the voltage generation module 104 to control the generation of the first voltage VC to adjust the attenuation amount of the attenuator VVA, so as to automatically and accurately compensate the gain of the RF chip, achieving the ideal effect that the gain of the link does not change with temperature.

[0123] Figure 14 And Figure 15 respectively show the variation of the gain of the RF chip (i.e., the gain of the RF link) with temperature when the attenuator is not used for temperature adjustment and when the attenuator is used for adjustment. It can be seen that when the attenuator is not used for adjustment, the gain decreases with the decrease of temperature, while after the adjustment by the attenuator, the gain remains stable at different temperatures.

[0124] In an embodiment of the present disclosure, a control module is further provided for executing the above control method.

[0125] In an embodiment of the present disclosure, an RF chip is further provided. The RF chip includes any one of the above RF circuits 10. In addition to the RF circuit 10, the RF chip may further include devices such as a filter and a phase discriminator.

[0126] The above are only the preferred embodiments of the present disclosure and are not used to limit the protection scope of the present disclosure.

[0127] It should be noted that in the present disclosure, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0128] The serial numbers of the above embodiments of the present disclosure are only for description and do not represent the advantages or disadvantages of the embodiments.

[0129] The methods disclosed in several method embodiments provided by the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments.

[0130] The features disclosed in several product embodiments provided by the present disclosure can be arbitrarily combined without conflict to obtain new product embodiments.

[0131] The features disclosed in several method or device embodiments provided by the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0132] The above are only the specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present disclosure, and all should be covered by the protection scope of the present disclosure.< / x> < / x> < / x> < / k> < / k>

Claims

1. A temperature-compensated radio frequency circuit, characterized in that: include: A radio frequency link, for receiving and / or transmitting radio frequency signals; The radio frequency link comprises an amplifier and at least one attenuator, wherein the attenuator is used to attenuate the radio frequency signal; Temperature acquisition module, used to collect current temperature and obtain quantitative temperature information; A register module, used to receive the temperature information, and based on the temperature information, search and output a corresponding target control signal; wherein the register module stores a corresponding relationship between the target control signal and the temperature information; at least one voltage generating module, connected to the register module, for receiving the target control signal, and performing digital-to-analog conversion on the target control signal to generate a first voltage; the first control terminal of the attenuator is connected to the voltage generating module, for receiving the first voltage, and adjusting the gain of the attenuator according to the first voltage; The target control signal controls the trend of the gain of the attenuator changing with temperature, which is opposite to the trend of the gain of the amplifier changing with temperature.

2. The radio frequency circuit according to claim 1, characterized in that: The register module includes a non-volatile memory, and the non-volatile memory includes: A plurality of non-volatile units, used for storing the target control signals corresponding to the plurality of temperature information; A signal processing module is used to output the target control signal stored in the non-volatile unit corresponding to the temperature information based on the temperature information and the corresponding relationship.

3. The radio frequency circuit according to claim 2, characterized in that: The radio frequency link comprises a transmitting link, a receiving link and a common branch, and at least two of the transmitting link, the receiving link and the common branch comprise the attenuator; The radio frequency circuit includes a plurality of the voltage generating modules, each of which is connected to a plurality of the attenuators, and the target control signal includes a plurality of sub-control signals corresponding to the plurality of the attenuators; In the non-volatile unit corresponding to each of the temperature information, a plurality of sub-control signals corresponding to a plurality of the voltage generating modules are stored; Alternatively, each piece of the temperature information corresponds to a plurality of the non-volatile units, and the non-volatile unit stores a corresponding sub-control signal.

4. The radio frequency circuit according to claim 2, characterized in that: The register module also includes: A readable and writable register connected to the control module and used to store an initial control signal output by the control module, wherein the initial control signal is used to establish a corresponding relationship between the temperature information and the target control signal; A selector, wherein a first input end of the selector is connected to an output end of the non-volatile memory, a second input end of the selector is connected to an output end of the readable and writable register, a control end of the selector receives a selection control signal, an output end of the selector is connected to the voltage generating module, and the selector is used to selectively output the target control signal stored in the non-volatile memory or the initial control signal stored in the readable and writable register to the voltage generating module according to the selection control signal.

5. The radio frequency circuit according to claim 4, characterized in that: The control module is also included, and the control module is connected to the input end and the output end of the radio frequency link to obtain the gain of the radio frequency link; The control module is configured to obtain a corresponding relationship between the target control signal and the temperature information based on the gain of the radio frequency link under the initial control signal.

6. The radio frequency circuit according to claim 5, characterized in that: The control module obtains the corresponding relationship between the target control signal and the temperature information, including: At each preset temperature, obtaining the temperature information; Outputting an initial control signal, wherein the initial control signal is used to control the voltage value of the first voltage generated by the voltage generating module; Under the initial control signal, obtaining a gain of the radio frequency link; Traversing different initial control signals, when the difference between the gain and the preset gain is the smallest, determining the initial control signal as the target control signal corresponding to the current temperature information, and the preset gain is the gain expected by the radio frequency link; All the preset temperatures are traversed to obtain the corresponding relationship between each temperature information and the target control signal, and store the corresponding relationship in the non-volatile memory.

7. The radio frequency circuit according to claim 6, characterized in that: The control module is further configured to, when acquiring the corresponding relationship between the target control signal and the temperature information, output the selection control signal of the first state to the selector to select the output end of the readable and writable register to be connected to the voltage generating module.

8. The radio frequency circuit according to any one of claims 1 to 7, characterized in that: The radio frequency circuit further comprises at least one voltage clamping circuit, wherein the voltage clamping circuit is connected between the corresponding voltage generating module and the corresponding attenuator; The voltage clamp circuit is configured to receive the corresponding first voltage and generate a second voltage negatively correlated with the first voltage; The attenuator includes an attenuation branch and a transmission trunk; the attenuation branch includes the first control end, and the first control end receives the first voltage; the transmission trunk includes a second control end, and the second control end is connected to the output end of the voltage clamping circuit to receive the second voltage.

9. The radio frequency circuit according to any one of claims 4 to 7, characterized in that: The register module is also connected to the control module or the temperature acquisition module, and the control module or the temperature acquisition module sends the temperature information to the register module.

10. The radio frequency circuit according to any one of claims 1 to 7, characterized in that: The temperature acquisition module comprises: a bandgap reference circuit for generating a temperature-dependent reference voltage; The analog-to-digital conversion circuit is used to perform analog-to-digital conversion on the reference voltage to generate the quantized temperature information.

11. The radio frequency circuit according to any one of claims 1 to 7, characterized in that: The voltage generating module is a digital-to-analog converter.

12. The radio frequency circuit according to any one of claims 1 to 7, characterized in that: The voltage generation module includes a plurality of resistors and a plurality of switches, and the target control signal includes a plurality of bits of control data; The multiple resistors are connected in series, and the first end of the switch is connected to a connection node of two adjacent resistors; The control end of the switch receives the corresponding control data; The second ends of all the switches are connected together to output the first voltage.

13. The radio frequency circuit according to any one of claims 1 to 7, characterized in that: The radio frequency link includes a receiving link, a transmitting link and a common branch. The receiving link, the transmitting link and the common branch all contain the attenuator. The accuracy of the attenuator in the receiving link or the transmitting link is greater than the accuracy of the attenuator in the common branch.

14. A method for controlling a radio frequency circuit, characterized in that: Applied to the radio frequency circuit according to any one of claims 1 to 13, the method comprising: At each preset temperature, obtaining the temperature information; Outputting an initial control signal, wherein the initial control signal is used to control the voltage value of the first voltage generated by the voltage generating module; Under the initial control signal, obtaining a gain of the radio frequency link; Traversing different initial control signals, when the difference between the gain and the preset gain is the smallest, determining the initial control signal as the target control signal corresponding to the current temperature information, and the preset gain is the gain expected by the radio frequency link; All the preset temperatures are traversed to obtain the corresponding relationship between each temperature information and the target control signal, and store the corresponding relationship in the register module.

15. A control module, characterized in that: The control module is used to execute the control method as claimed in claim 14.

16. A radio frequency chip, characterized in that: The method comprises the radio frequency circuit as claimed in any one of claims 1 to 13.

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