Radio frequency module, electronic equipment and load traction method
By designing the series structure of the E-modulation impedance traction circuit and the gain module in the RF module, the problem of increasing the directional index of the coupler caused by load traction is solved, and the effect of reducing costs and improving linearity and power consumption efficiency is achieved.
Patent Information
- Application Number
- CN202510590445.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2025-06-27
AI Technical Summary
Load traction leads to an increase in the directional indicator requirements for the coupler, and even leads to an increase in cost or unachievable problem in the implementation of RF module solutions.
A radio frequency module is designed, including a radio frequency transceiver chip and a power amplifier module. The power amplifier module is composed of a first gain module, an electrostatic impedance traction circuit, a second gain module and a coupler module connected in series. The impedance adjustment is performed according to the target electrostatic parameters through the electrostatic impedance traction circuit to realize load traction.
Through this method, the requirements for the directional index of the coupler are reduced, the implementation cost of the RF module is reduced, and the overall linearity and power consumption efficiency of the RF module are improved.
Smart Images
Figure CN120223115A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of communication technologies, and particularly relates to a radio frequency module, an electronic device, and a load pull method. Background Art
[0002] With the continuous pursuit of the air interface performance of terminal devices, the differences in the indicators pursued by the transmitting end at different data throughput rates are becoming increasingly obvious, and the corresponding adaptation requirements for the differences in load pull positions are also higher.
[0003] For example, in a low-speed scenario such as Modulation and Coding Scheme (MCS) 0, signal penetration is more emphasized, and the load pull position will pursue the position with the highest gain and output power; while in a high-speed scenario such as MCS 9, users hope to stay in the high-speed state more persistently, so pursuing a highly linear position with good Error Vector Magnitude (EVM) will be the preferred option.
[0004] Since the data throughput rate of the transmitting end is dynamically changing, it is necessary to dynamically adapt to the load pull that is optimal for the corresponding rate.
[0005] In related technologies, load pull adjustment is usually performed at the output port of the transmitting end near the antenna. Since power detection (PDET) and antenna load position identification need to be performed at this position simultaneously, the impedance change at the output end will increase the power difference contrast between the incident power and the reflected power at the output end of the power amplifier, and it is easier to have a situation where a large incident power and a small reflected power coexist. This poses more stringent index requirements for the directivity of the coupler, which will lead to an increase in the implementation cost of the radio frequency module solution or even make it impossible to implement. Summary of the Invention
[0006] The purpose of the embodiments of this application is to provide a radio frequency module, an electronic device, and a load pull method, which can solve the problem that load pull causes more stringent index requirements for the directivity of the coupler, and even leads to an increase in the implementation cost of the radio frequency module solution or even make it impossible to implement.
[0007] In a first aspect, the embodiments of this application provide a radio frequency module, which includes: a radio frequency transceiver chip and a power amplification module;
[0008] The power amplification module includes a first gain module, an electrically tunable impedance traction circuit, a second gain module, and a coupler module connected in series in sequence;
[0009] The first end of the radio frequency transceiver chip is electrically connected to the input end of the first gain module, the second end of the radio frequency transceiver chip is electrically connected to the control end of the electrically tunable impedance pulling circuit, and the third end of the radio frequency transceiver chip is electrically connected to the coupler module;
[0010] Wherein, the radio frequency transceiver chip determines a target electrically tunable parameter according to the difference between the current Γin and the target Γin of the second gain module, and sends the target electrically tunable parameter to the electrically tunable impedance pulling circuit. The electrically tunable impedance pulling circuit adjusts the impedance according to the target electrically tunable parameter, and the second gain module outputs a target Γload under the action of the target Γin output by the electrically tunable impedance pulling circuit;
[0011] Γin is the equivalent reflection coefficient loaded at the input end of the second gain module, and Γload is the equivalent reflection coefficient loaded at the output end of the second gain module.
[0012] In a second aspect, an embodiment of the present application provides an electronic device, which includes an antenna and the radio frequency module as described in the first aspect. The antenna is electrically connected to the coupler module in the radio frequency module.
[0013] In a third aspect, an embodiment of the present application provides a load pulling method, which is applied to the radio frequency module as described in the first aspect. The method includes:
[0014] Obtain the current Γin of the second gain module;
[0015] Obtain the target Γin;
[0016] Determine a target electrically tunable parameter according to the difference between the current Γin and the target Γin of the second gain module;
[0017] Control the electrically tunable impedance pulling circuit to adjust the impedance according to the target electrically tunable parameter, and adjust the Γload of the second gain module to the target Γload corresponding to the target Γin;
[0018] Wherein, Γin is the equivalent reflection coefficient loaded at the input end of the second gain module, and Γload is the equivalent reflection coefficient loaded at the output end of the second gain module.
[0019] In an embodiment of the present application, the radio frequency module includes: a radio frequency transceiver chip and a power amplifier module; the power amplifier module includes a first gain module, an electrically tunable impedance pulling circuit, a second gain module, and a coupler module connected in series in sequence; a first end of the radio frequency transceiver chip is electrically connected to an input end of the first gain module, a second end of the radio frequency transceiver chip is electrically connected to a control end of the electrically tunable impedance pulling circuit, and a third end of the radio frequency transceiver chip is electrically connected to the coupler module; wherein, the radio frequency transceiver chip determines a target electrical tuning parameter according to the difference between the current Γin and the target Γin of the second gain module, and sends the target electrical tuning parameter to the electrically tunable impedance pulling circuit, and the electrically tunable impedance pulling circuit adjusts the impedance according to the target electrical tuning parameter, and the second gain module outputs a target Γload under the action of the target Γin output by the electrically tunable impedance pulling circuit; Γin is the equivalent reflection coefficient loaded at the input end of the second gain module, and Γload is the equivalent reflection coefficient loaded at the output end of the second gain module. By setting two gain modules and connecting the electrically tunable impedance pulling circuit in series between the two gain modules, on the one hand, the second gain module between the electrically tunable impedance pulling circuit and the coupler module can achieve a better balance in adjusting the loadpull amplitude and the sensitivity of the system PDET / antenna load identification, reducing the index requirement for the coupler directivity required for PDET / antenna load identification; on the other hand, a first gain module can be added at the input end of the electrically tunable impedance pulling circuit, so that even if the electrically tunable impedance pulling circuit introduces insertion loss, the overall linearity of the power amplifier module can be improved based on the first gain module, which helps to reduce the overall power consumption of the radio frequency module. Description of the Drawings
[0020] Figure 1 is a schematic structural diagram of a radio frequency module provided in some embodiments of the present application;
[0021] Figure 2 is a schematic structural diagram of an electrically tunable impedance pulling circuit in some embodiments of the present application;
[0022] Figure 3 is a schematic diagram of the working process of a radio frequency module provided in some embodiments of the present application;
[0023] Figure 4 is a flowchart of a load pulling method provided in some embodiments of the present application. Detailed Embodiments
[0024] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.
[0025] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same category, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.
[0026] Next, in conjunction with the accompanying drawings, the radio frequency module, electronic device, and load pulling method provided by the embodiments of the present application will be described in detail through specific embodiments and their application scenarios.
[0027] Refer to Figure 1 , the radio frequency module provided by the embodiments of the present application includes: a radio frequency transceiver chip 1 and a power amplifier module 2;
[0028] The power amplifier module 2 includes a first gain module 21, an electrically tunable impedance pulling circuit 22, a second gain module 23, and a coupler module 24 connected in series in sequence;
[0029] The first end of the radio frequency transceiver chip 1 is electrically connected to the input end of the first gain module 21, the second end of the radio frequency transceiver chip 1 is electrically connected to the control end of the electrically tunable impedance pulling circuit 22, and the third end of the radio frequency transceiver chip 1 is electrically connected to the coupler module 24;
[0030] Among them, the radio frequency transceiver chip 1 determines the target electrically tunable parameter according to the difference between the current Γin and the target Γin of the second gain module 23, and sends the target electrically tunable parameter to the electrically tunable impedance pulling circuit 22. The electrically tunable impedance pulling circuit 22 adjusts the impedance according to the target electrically tunable parameter. Under the action of the target Γin output by the electrically tunable impedance pulling circuit 22, the second gain module 23 outputs the target Γload;
[0031] Γin is the equivalent reflection coefficient loaded at the input end of the second gain module 23, and Γload is the equivalent reflection coefficient loaded at the output end of the second gain module 23.
[0032] In some embodiments, the first end of the radio frequency transceiver chip 1 may be the radio frequency signal output end of the radio frequency transceiver chip 1, the second end of the radio frequency transceiver chip 1 may be the control signal output end of the radio frequency transceiver chip 1, and the third end of the radio frequency transceiver chip 1 may be the detection signal receiving end of the radio frequency transceiver chip 1.
[0033] In some embodiments, the first gain module 21 and the second gain module 23 may be power amplifiers or other circuits with gain functions. For the sake of convenience of description, in the embodiments of the present application, the first gain module 21 and the second gain module 23 are both taken as power amplifiers as an example for illustration.
[0034] It should be noted that the functions of the first gain module 21 and the second gain module 23 in the power amplification module 2 are not the same.
[0035] Among them, the second gain module 23 participates in load pulling, that is, adjusts the Γin of the second gain module 23 according to the output impedance of the electrically tunable impedance pulling circuit 22, and then changes the Γload of the second gain module 23 to achieve the load pulling function.
[0036] The first gain module 21 does not participate in load pulling, but uses the first gain module 21 to meet the cascade budget of at least one of the gain, linearity, and bottom noise of the power amplification module 2.
[0037] In some embodiments, the gain of the first gain module 21 is positively correlated with the overall gain of the power amplification module 2;
[0038] The bottom noise of the first gain module 21 dominates the overall bottom noise of the power amplification module 2, and / or the first gain module 21 is used to improve the overall linearity of the power amplification module 2.
[0039] In some embodiments, the gain of the first gain module 21 being positively correlated with the overall gain of the power amplification module 2 may indicate that the first gain module 21 meets the cascade budget of the overall gain of the power amplification module 2, that is, the gain of the first gain module 21 needs to consider the influence of the subsequent electrically tunable impedance pulling circuit 22 and the second gain module 23, so that the overall gain of the power amplification module 2 meets the requirements.
[0040] For example: Suppose the required overall gain of the power amplification module 2 is 100 dB, the gain index of the second gain module 23 is 10 dB, and the power loss of the electrically tunable impedance pulling circuit 22 is 5 dB. Then the gain index of the first gain module 21 can be 100 - 10 + 5 = 95 dB. In the embodiments of the present application, the first gain module 21 is arranged in the front stage of the electrically tunable impedance pulling circuit 22.
[0041] In this way, the first gain module 21 and the second gain module 23 can be used to adjust the gain distribution of the entire power amplifier module 2, reduce the power entering the electrical tuning impedance traction circuit 22 without changing the insertion loss of the electrical tuning impedance traction circuit 22, and reduce the power loss of the electrical tuning impedance traction circuit 22. This power loss can be compensated by the second gain module 23, so as to maintain the constant power output of the overall power amplifier module 2. In this way, the overall linearity of the power amplifier module 2 is improved, which helps to reduce the overall power consumption of the radio frequency module.
[0042] In addition, the subsequent electrical tuning impedance traction circuit 22 and the second gain module 23 are used for post-processing the output signal of the first gain module 21, so that the overall bottom noise of the power amplifier module 2 is dominated by the bottom noise of the first gain module 21.
[0043] In this way, when realizing the cascaded budget of the overall gain, bottom noise and linearity of the power amplifier module 2 through the first gain module 21, the second gain module 23 can focus more on load traction, and can improve the load traction effect of the electrical tuning impedance traction circuit 22 and the second gain module 23.
[0044] In some embodiments, the input end of the coupler module 24 is electrically connected to the output end of the second gain module 23, and the output end of the coupler module 24 is used to connect to the antenna load. The radio frequency transceiver chip 1 can realize PDET and antenna load identification through the coupler module 24.
[0045] It should be noted that the input Γin of the second gain module 23 and the output Γload of the second gain module 23 are in a corresponding relationship. In this way, the current Γin of the second gain module 23 can be calculated according to the current Γload of the second gain module 23. The output Γload of the second gain module 23 can be measured based on the coupler module 24, that is, the coupler module 24 is located on the output end side of the second gain module 23. In this way, the radio frequency transceiver chip 1 obtains the Γload of the output end of the second gain module 23 fed back by the coupler module 24, and then calculates the corresponding Γin based on Γload, which is the current Γin of the second gain module 23.
[0046] For example: The Γin and Γload of the second gain module 23 can be converted based on the S parameters of the second gain module 23:
[0047] Γin = (S11 + S12 · S22 · Γload) / (1 - S22 · Γload)
[0048] Wherein, Γin is the equivalent reflection coefficient loaded at the input end of the second gain module 23; Γload is the equivalent reflection coefficient loaded at the output end of the second gain module 23; S11 is the reflection coefficient inherent to the input end of the second gain module 23; S21 is the forward transmission coefficient of the second gain module 23, i.e., the amplification gain; S12 is the reverse transmission coefficient of the second gain module 23, i.e., the isolation; S22 is the reflection coefficient inherent to the output end of the second gain module 23.
[0049] In some embodiments, the S parameters of the second gain module 23, namely S11, S21, S12, and S22, can be obtained through actual measurement of different DC biases (DC BIAS) of the power amplification module 2. For example: the DC bias of the power amplification module 2 can be adjusted, and an S parameter table can be generated based on the measured S parameters of the second gain module 23, and the S parameter table can be stored in the register inherent to the radio frequency transceiver chip 1 or the power amplification module 2.
[0050] It should be noted that Γin of the second gain module 23 can be adjusted by the electrically tunable impedance pulling circuit 22 located in the front stage of the second gain module 23. The specific value of Γin is adjusted by the characteristics of the electrically tunable impedance pulling circuit 22 itself. For example, the value of Γin is adjusted by changing the impedance characteristics of the electrically tunable impedance pulling circuit 22. The value of Γin has nothing to do with the circuits located in the rear stage of the electrically tunable impedance pulling circuit 22, namely the second gain module 23 and the coupler module 24. Therefore, it is not necessary to confirm the change of Γin based on the feedback of the coupler module 24; these four S parameters from S11 to S22 are the inherent parameters of the second gain module 23 and can be measured in advance. Therefore, Γload at the output end of the second gain module 23 can be calculated one-to-one through calculation based on Γin and the S parameters of the second gain module 23.
[0051] In some embodiments, the value of the target Γin can be calculated based on the value of the target Γload, wherein the target Γload can be pre-stored in the register inherent to the radio frequency transceiver chip 1 or the power amplification module 2. For example: the target Γin is calculated according to the target Γload set by the user in advance, or a first correspondence relationship between the MCS level and the occupied bandwidth (OBW) and Γin is pre-stored in the register inherent to the radio frequency transceiver chip 1 or the power amplification module 2. For example, it is measured or calculated according to the bandwidth characteristics of the second gain module 23 at the factory stage and stored in the register inherent to the radio frequency transceiver chip 1 or the power amplification module 2 in the form of a third table. In this way, during the process of load pulling control, the third table can be looked up according to the MCS level and OBW actually used in the radio frequency transceiver chip 1 during actual operation, and the Γin corresponding to the MCS level and OBW in the third table is the target Γin.
[0052] In this way, during actual load pulling, it is only necessary to first compare the current Γin corresponding to Γload fed back by the coupler module 24 with the target Γin required by the system. Then, by controlling the tuning parameters of the electronically tunable impedance pulling circuit 22, the Γin of the second gain module 23 can be adjusted to the target Γin, and thus the Γload of the second gain module 23 can be adjusted to the target Γload required by the system.
[0053] In some embodiments, the second gain module 23 may include an amplifier with poor isolation. In this way, adjusting the input impedance of the second gain module 23 can indirectly adjust its output impedance due to the poor isolation, making Γin correspond to Γload. Here, poor isolation can be understood as the isolation of the second gain module 23 being less than the isolation of the power amplifier in the related art, or the isolation of the second gain module 23 being less than the isolation of the first gain module 21. For example, if the isolation of the first gain module 21 is 20 dB higher than the gain value, the isolation of the second gain module 23 can be only 5 - 10 dB higher than the gain.
[0054] Of course, in addition to the power amplifier with low isolation, the second gain module 23 can also be other circuits or devices in which the input impedance is linearly related to the output impedance, which is not specifically limited herein.
[0055] In the embodiment of the present application, by providing two gain modules in the power amplification module 2 and connecting the electronically tunable impedance pulling circuit 22 in series between the two gain modules, on the one hand, using the second gain module 23 between the electronically tunable impedance pulling circuit 22 and the coupler module 24 can achieve a better balance in adjusting the loadpull amplitude and the sensitivity of the system to PDET / antenna load identification, reduce the index requirements for the coupler directivity required for PDET / antenna load identification, reduce the cost of the coupler module 24, and enable the RF module solution to meet the performance requirements of the RF function; on the other hand, a first gain module 21 can be added at the input end of the electronically tunable impedance pulling circuit 22, so that even if the electronically tunable impedance pulling circuit 22 introduces insertion loss, the overall linearity of the power amplification module 2 can be improved based on the first gain module 21, which helps to reduce the overall power consumption of the RF module.
[0056] As an optional embodiment, the electronically tunable impedance pulling circuit 22 adopts a varactor architecture.
[0057] It should be noted that the electronically tunable impedance pulling circuit 22 of the varactor architecture has the advantage of low cost. At the same time, due to the manufacturing process limitations of the electronically tunable impedance pulling circuit, the quality factor (Q value) of the varactor is relatively low, resulting in a large power loss in the electronically tunable impedance pulling circuit 22. Based on the embodiments of the present application, a first gain module 21 is provided at the front stage of the electronically tunable impedance pulling circuit 22, and the first gain module 21 and the second gain module 23 can be used to adjust the gain distribution of the entire power amplification module 2, reducing the power entering the electronically tunable impedance pulling circuit 22 without changing the insertion loss of the electronically tunable impedance pulling circuit 22, reducing the power loss of the electronically tunable impedance pulling circuit 22. This power loss can be compensated by the second gain module 23, thereby maintaining the constant power output of the overall power amplification module 2. In this way, the overall linearity of the power amplification module 2 is improved, which helps to reduce the overall power consumption of the RF module.
[0058] It is worth noting that in the related art, the electronically tunable impedance pulling circuit is arranged at the output end of the power amplification module. Due to the manufacturing process limitations of the electronically tunable impedance pulling circuit, when using the electronically tunable impedance pulling circuit of the varactor architecture, the power loss increases due to the low quality factor (Q value) of the varactor. In this regard, in the related art, the power loss is reduced by using the electronically tunable impedance pulling circuit of the Micro-Electro-Mechanical System (MEMS) architecture. However, the manufacturing cost of MEMS is high and it is difficult to integrate it onto a single chip wafer. It can be seen that in the related art, if the electronically tunable impedance pulling circuit of the varactor architecture is arranged at the output end of the power amplification module, the linearity of the power amplification module will deteriorate due to the increased insertion loss of the varactor; if the electronically tunable impedance pulling circuit of the MEMS architecture is arranged at the output end of the power amplification module, the cost of the RF module will be too high.
[0059] In this embodiment, on the premise of improving the overall linearity of the power amplification module 2 and reducing the overall power consumption of the RF module, the cost of the RF module can also be reduced.
[0060] Of course, the electronically tunable impedance pulling circuit 22 in the embodiments of the present application can be implemented using MEMS or other architectures, which is not specifically limited herein.
[0061] As an alternative embodiment, as Figure 2 shown, the electronically tunable impedance pulling circuit 22 includes a first adjustable capacitor Cse, a first inductor Lse, a second adjustable capacitor Csh, and a second inductor Lsh;
[0062] The first end of the first adjustable capacitor Cse is electrically connected to the output end of the first gain module 21. The second end of the first adjustable capacitor Cse is electrically connected to the first end of the first inductor Lse. The second end of the first inductor Lse is electrically connected to the input end of the second gain module 23 and the first end of the second adjustable capacitor Csh. The second end of the second adjustable capacitor Csh is grounded through the second inductor Lsh.
[0063] Wherein, the inductance value of the first inductor Lse is used to cancel out the first capacitance value. The first capacitance value is greater than the minimum capacitance value of the first adjustable capacitor Cse and less than the maximum capacitance value of the first adjustable capacitor Cse. The inductance value of the second inductor Lsh is used to cancel out the second capacitance value. The second capacitance value is greater than the minimum capacitance value of the second adjustable capacitor Csh and less than the maximum capacitance value of the second adjustable capacitor Csh.
[0064] In this embodiment, the electrically tunable impedance pulling circuit 22 adopts a varactor architecture, including a parallel branch and a series branch. Among them, the series branch means that the first adjustable capacitor Cse and the first inductor Lse are connected in series between the output end of the first gain module 21 and the input end of the second gain module 23. The parallel branch means that the second adjustable capacitor Csh and the second inductor Lsh connect the series branch in parallel to the ground.
[0065] It should be noted that the inductance value of the first inductor Lse is used to cancel out the first capacitance value. The first capacitance value is greater than the minimum capacitance value of the first adjustable capacitor Cse and less than the maximum capacitance value of the first adjustable capacitor Cse, which can be expressed as: within the operating frequency band of the RF module, the inductance value of the first inductor Lse can cancel out the minimum capacitance value of the first adjustable capacitor Cse, but cannot cancel out the maximum capacitance value of the first adjustable capacitor Cse. In this way, the impedance of the series branch can cover capacitive impedance and inductive impedance by adjusting the capacitance value of the first adjustable capacitor Cse. Similarly, the inductance value of the second inductor Lsh is used to cancel out the second capacitance value. The second capacitance value is greater than the minimum capacitance value of the second adjustable capacitor Csh and less than the maximum capacitance value of the second adjustable capacitor Csh, which can be expressed as: within the operating frequency band of the RF module, the inductance value of the second inductor Lsh can cancel out the minimum capacitance value of the second adjustable capacitor Csh, but cannot cancel out the maximum capacitance value of the second adjustable capacitor Csh. In this way, the impedance of the parallel branch can cover capacitive impedance and inductive impedance by adjusting the capacitance value of the second adjustable capacitor Csh.
[0066] In this embodiment, the electrically tunable impedance pulling circuit 22 can cover the entire range of the Smith chart.
[0067] In some embodiments, the control terminals of the electronically tunable impedance pulling circuit 22 include the control terminal of the first tunable capacitor Cse and the control terminal of the second tunable capacitor Csh. At this time, the RF transceiver chip 1 includes two second terminals, one of which is used to provide the first control voltage Vse to the control terminal of the first tunable capacitor Cse, and the other is used to provide the second control voltage Vsh to the control terminal of the second tunable capacitor Csh. In this way, the RF transceiver chip 1 can adjust the impedance of the series branch by adjusting the value of the first control voltage Vse, and can adjust the impedance of the parallel branch by adjusting the value of the second control voltage Vsh. In this embodiment, the target electronically tunable parameters sent by the RF transceiver chip 1 to the electronically tunable impedance pulling circuit 22 include the above-mentioned first control voltage Vse and second control voltage Vsh.
[0068] In some embodiments, the correspondence between the electronically tunable parameters and Γin can be pre-stored. For example: at the factory stage, measure Γin at the output terminal of the electronically tunable impedance pulling circuit 22 under each combination of the first control voltage Vse and the second control voltage Vsh, and associate and store the measured Γin with the electronically tunable parameters when this Γin is measured. Among them, the electronically tunable parameters include the combination of the first control voltage Vse and the second control voltage Vsh.
[0069] In this way, after the RF transceiver chip 1 obtains the target Γin, it can find the target electronically tunable parameters corresponding to the target Γin based on this correspondence.
[0070] Of course, the RF transceiver chip 1 can store the parameters of the electronically tunable impedance pulling circuit 22, so that after obtaining the target Γin, it can calculate the target electronically tunable parameters that can make the output terminal of the electronically tunable impedance pulling circuit 22 be the target Γin according to the parameters of the electronically tunable impedance pulling circuit 22.
[0071] For the convenience of description, in the following embodiments, it is taken as an example that the first table is pre-stored in the register owned by the RF transceiver chip 1 or the power amplification module 2, and the first table includes the correspondence between Γin and the electronically tunable parameters. Among them, the electronically tunable parameters include the combination of the first control voltage Vse and the second control voltage Vsh.
[0072] In some embodiments, the first table may further include the characteristic impedance of the output terminal of the first gain module 21. At this time, the correspondence between Γin and the electronically tunable parameters is related to the characteristic impedance of the output terminal of the first gain module 21 and the impedance characteristics of the electronically tunable impedance pulling circuit 22.
[0073] In still other embodiments, the characteristic impedance adapted by the first gain module 21 to the electronically tunable impedance pulling circuit 22 is 50Ω.
[0074] In this embodiment, the characteristic impedance of the output terminal of the first gain module 21 is fixed at 50 Ω. At this time, the correspondence between Γin and the tuning parameter is only related to the impedance characteristic of the tuning impedance pulling circuit 22, and is not related to the characteristic impedance of the output terminal of the first gain module 21, which can simplify the correspondence between Γin and the tuning parameter, or reduce the amount of data in the first table.
[0075] As an optional embodiment, the difference between the isolation of the first gain module 21 and the gain value of the first gain module 21 is the first difference;
[0076] The difference between the isolation of the second gain module 23 and the gain value of the second gain module 23 is the second difference;
[0077] Wherein, the first difference is greater than the second difference.
[0078] In some embodiments, the first gain module 21 may be a power amplifier with a normal active isolation index, and the second gain module 23 may be a power amplifier with a low active isolation index.
[0079] In some embodiments, the low active isolation index of the second gain module 23, i.e., S12, can be achieved by at least one of methods such as die selection, die size design, and bias design.
[0080] Due to the low active isolation of the second gain module 23, by adjusting Γin input by the tuning impedance pulling circuit 22 to the second gain module 23, the Γload output by the second gain module 23 can be effectively changed. It should be noted that although the low active isolation of the second gain module 23 is low, there is still a certain low active isolation, that is, |S12| is not equal to 1. In this way, the reflected power caused by changing Γin of the tuning impedance pulling circuit 22 is difficult to leak through the second gain module 23 and couple with the reflected power of the antenna load. In this way, adjusting the impedance of the tuning impedance pulling circuit 22 is not easily affected by the traction change of the external antenna load and does not show reciprocating non-linear changes, and one-step adjustment of load pulling control can be achieved, thereby ensuring the immediacy of impedance adjustment.
[0081] For the convenience of understanding the working principle of the radio frequency module provided in the embodiments of the present application, the working process of the radio frequency module as shown in Figure 1 is taken as an example for illustration. As shown in Figure 3 , the radio frequency transceiver chip 1 in the radio frequency module can perform the following load pulling control process:
[0082] Step 301, perform PDET and antenna load position recognition from the feedback path of the coupler module 24 to detect the current Γloa of the second gain module 23.
[0083] Step 302: Retrieve the S-parameter table of the second gain module 23 according to the current DC bias.
[0084] In this step, the S-parameter table can be pre-stored in the register of the radio frequency transceiver chip 1 or the power amplifier module 2 itself.
[0085] Step 303: Calculate the current Γin of the second gain module 23 according to the current Γload and the S-parameters of the second gain module 23.
[0086] Step 304: Obtain the target Γin.
[0087] In this step, the target Γin set by the user can be obtained, or the radio frequency transceiver chip 1 can find the target Γin corresponding to the MCS and OBW of the current transmission signal from the third table.
[0088] Step 305: Determine whether the current Γin is consistent with the target Γin.
[0089] If the judgment result in step 305 is "yes", end the load-pull control; otherwise, execute step 306 and step 307.
[0090] Step 306: Retrieve the first table.
[0091] Among them, the corresponding relationship between Γin and the electrical tuning parameters is pre-stored in the first table.
[0092] Step 307: Determine the target electrical tuning parameter according to the difference between the current Γin and the target Γin, and control the electrical tuning impedance pulling circuit 22 to perform impedance adjustment according to the target electrical tuning parameter.
[0093] In this step, after the electrical tuning impedance pulling circuit 22 performs impedance adjustment according to the target electrical tuning parameter, the Γin at the output end of the electrical tuning impedance pulling circuit 22 can be adjusted to the target Γin, and the second gain module 23 outputs the target Γload corresponding to this target Γin, finally realizing the load-pull control function.
[0094] Through the above load-pull control process, on the premise of using the second gain module 23 with low isolation, the electrical tuning impedance pulling circuit 22 is introduced at the input end of the second gain module 23. On the one hand, the requirement for the directivity index of the subsequent coupler module 24 can be significantly reduced. On the other hand, the immediacy and accuracy of adjusting loadpull can be realized according to the data throughput rate and working bandwidth of the transmitting end of the radio frequency transceiver chip 1. At the same time, the high-loss electrical tuning impedance pulling circuit is moved to the input end of the second gain module 23, which helps to optimize the overall power amplifier linearity of the radio frequency module, reduce the power consumption of the radio frequency module, and enable the radio frequency module to balance high performance and low cost.
[0095] The embodiments of the present application further provide an electronic device. As Figure 1 shown, the electronic device includes an antenna 10 and any one of the radio frequency modules in the foregoing embodiments of the present application. The antenna 10 is electrically connected to a coupler module 24 in the radio frequency module.
[0096] In some embodiments, the electronic device in the embodiments of the present application may be a terminal or other devices other than terminals. Exemplarily, the electronic device may be a mobile phone, a tablet computer, a laptop computer, a handheld computer, a vehicle-mounted electronic device, a Mobile Internet Device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA), etc. It may also be a server, a Network Attached Storage (NAS), a personal computer (PC), a television (TV), a teller machine, or a self-service machine, etc. The embodiments of the present application do not make specific limitations.
[0097] In the embodiments of the present application, by providing the radio frequency module of the embodiments of the present application on the electronic device, the linearity of the power amplification process in the antenna module can be optimized by using the radio frequency module, the power consumption of the antenna module can be reduced, so that the antenna module can take into account both antenna performance and low cost.
[0098] The embodiments of the present application further provide a load pulling method. The load pulling method can be applied to the radio frequency module in the foregoing embodiments of the present application. As Figure 4 shown, the load pulling method includes the following steps:
[0099] Step 401: Obtain the current Γin of the second gain module;
[0100] Step 402: Obtain the target Γin;
[0101] Step 403: Determine the target electrical tuning parameter according to the difference between the current Γin of the second gain module and the target Γin;
[0102] Step 404: Control the electrical tuning impedance pulling circuit to perform impedance adjustment according to the target electrical tuning parameter, and adjust the Γload of the second gain module to the target Γload corresponding to the target Γin;
[0103] Wherein, Γin is the equivalent reflection coefficient loaded at the input end of the second gain module, and Γload is the equivalent reflection coefficient loaded at the output end of the second gain module.
[0104] It should be noted that the current Γin, target Γin, target electrical tuning parameter, and target Γload of the second gain module in this embodiment have the same meaning and the same function as those of the second gain module in the foregoing radio frequency module embodiment of the present application, and are obtained or calculated by the same method. To avoid repetition, they will not be elaborated here.
[0105] The load pulling method of the embodiment of the present application can implement each process in the load pulling control of the radio frequency transceiver chip 1 in the foregoing radio frequency module embodiment of the present application, and can achieve the same beneficial effects as those of the foregoing radio frequency module embodiment of the present application. To avoid repetition, they will not be elaborated here.
[0106] In some embodiments, obtaining the current Γin of the second gain module includes:
[0107] Obtaining the current Γload of the second gain module through a coupler module;
[0108] Obtaining the S parameters of the second gain module according to the DC bias;
[0109] Determining the current Γin of the second gain module according to the current Γload of the second gain module and the S parameters.
[0110] Wherein, the S parameters include S11, S12, S21, and S22. S11 is the reflection coefficient inherent at the input end of the second gain module 23; S21 is the forward transmission coefficient of the second gain module 23, that is, the amplification gain; S12 is the reverse transmission coefficient of the second gain module 23, that is, the isolation degree; S22 is the reflection coefficient inherent at the output end of the second gain module 23.
[0111] In this embodiment, the output Γload of the second gain module 23 can be measured through a coupler module. The S parameters can be determined by a look-up table method. For example: a table of S parameters of the second gain module 23 is pre-stored in a register inherent to the radio frequency transceiver chip 1 or the power amplifier module 2. By looking up the table of S parameters, the S parameters corresponding to the current DC bias of the power amplifier module 2 can be determined, which are the current S parameters of the second gain module; then, through conversion according to the current Γload and the S parameters, the current Γin of the second gain module can be obtained.
[0112] In some embodiments, obtaining the target Γin includes any one of the following:
[0113] Obtain the target Γin set by the user;
[0114] According to the first correspondence relationship between the modulation and coding strategy (MCS) level, the operating bandwidth (OBW), and Γin, determine that the Γin corresponding to the MCS level and OBW used by the radio frequency transceiver chip is the target Γin.
[0115] In some embodiments, the first correspondence relationship can be stored in the register owned by the radio frequency transceiver chip 1 or the power amplifier module 2 in the form of the third table in the foregoing embodiments of the present application.
[0116] In this embodiment, the target Γin can be user-defined or the Γin corresponding to the MCS level and OBW actually used by the radio frequency transceiver chip when transmitting signals, which can improve the flexibility of determining the target Γin.
[0117] In some embodiments, determining the target electrical tuning parameter according to the difference between the current Γin of the second gain module and the target Γin includes:
[0118] Obtain the second correspondence relationship between the Γin of the second gain module and the electrical tuning parameter of the electrical tuning impedance pulling circuit;
[0119] According to the second correspondence relationship, determine the electrical tuning parameter corresponding to the target Γin as the target electrical tuning parameter.
[0120] In some embodiments, the second correspondence relationship can be stored in the register owned by the radio frequency transceiver chip 1 or the power amplifier module 2 in the form of the first table in the foregoing embodiments of the present application.
[0121] In this embodiment, the electrical tuning parameter corresponding to the target Γin can be directly determined as the target electrical tuning parameter based on the second correspondence relationship, which simplifies the complexity of determining the target electrical tuning parameter.
[0122] It should be noted that in this text, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising such element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.
[0123] Through the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as a Read-Only Memory (ROM), Random Access Memory (RAM), magnetic disk, optical disc), and includes several instructions to enable a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present application.
[0124] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Those of ordinary skill in the art, under the inspiration of the present application and without departing from the spirit and scope protected by the claims of the present application, can still make many forms, all of which fall within the protection scope of the present application.
Claims
1. A radio frequency module, characterized in that: include: RF transceiver chip and power amplifier module; The power amplification module comprises a first gain module, an electrically adjustable impedance pulling circuit, a second gain module and a coupler module connected in series in sequence; The first end of the RF transceiver chip is electrically connected to the input end of the first gain module, the second end of the RF transceiver chip is electrically connected to the control end of the electrically adjustable impedance pulling circuit, and the third end of the RF transceiver chip is electrically connected to the coupler module; The RF transceiver chip determines the target electrical adjustment parameter according to the difference between the current Γin of the second gain module and the target Γin, and sends the target electrical adjustment parameter to the electrical adjustment impedance traction circuit. The electrical adjustment impedance traction circuit performs impedance adjustment according to the target electrical adjustment parameter. The second gain module outputs the target Γload under the action of the target Γin output by the electrical adjustment impedance traction circuit. Γin is the equivalent reflection coefficient loaded at the input end of the second gain module, and Γload is the equivalent reflection coefficient loaded at the output end of the second gain module.
2. The radio frequency module according to claim 1, characterized in that: The electrically adjustable impedance pulling circuit adopts a varactor architecture.
3. The radio frequency module according to claim 2, characterized in that: The electrically adjustable impedance pulling circuit comprises a first adjustable capacitor, a first inductor, a second adjustable capacitor and a second inductor; The first end of the first adjustable capacitor is electrically connected to the output end of the first gain module, the second end of the first adjustable capacitor is electrically connected to the first end of the first inductor, the second end of the first inductor is electrically connected to the input end of the second gain module and the first end of the second adjustable capacitor, and the second end of the second adjustable capacitor is grounded through the second inductor; The inductance value of the first inductor is used to offset the first capacitance value, the first capacitance value is greater than the minimum capacitance value of the first adjustable capacitor, and the first capacitance value is less than the maximum capacitance value of the first adjustable capacitor; the inductance value of the second inductor is used to offset the second capacitance value, the second capacitance value is greater than the minimum capacitance value of the second adjustable capacitor, and the second capacitance value is less than the maximum capacitance value of the second adjustable capacitor.
4. The radio frequency module according to any one of claims 1 to 3, characterized in that: The gain of the first gain module is positively correlated with the overall gain of the power amplifier module; The bottom noise of the first gain module dominates the overall bottom noise of the power amplifier module, and / or the first gain module is used to improve the overall linearity of the power amplifier module.
5. The radio frequency module according to any one of claims 1 to 3, characterized in that: The difference between the isolation of the first gain module and the gain value of the first gain module is a first difference; The difference between the isolation of the second gain module and the gain value of the second gain module is a second difference; The first difference is greater than the second difference.
6. An electronic device, characterized in that: It comprises an antenna and a radio frequency module as described in any one of claims 1 to 5, wherein the antenna is electrically connected to a coupler module in the radio frequency module.
7. A load pulling method, characterized in that: Applied to the radio frequency module according to any one of claims 1 to 5, the method comprising: Get the current Γin of the second gain module; Get the target Γin; Determining a target electrical adjustment parameter according to a difference between a current Γin of the second gain module and the target Γin; Controlling the electrically adjustable impedance pulling circuit to adjust impedance according to the target electrically adjustable parameter, and adjusting the Γload of the second gain module to a target Γload corresponding to the target Γin; Wherein, Γin is the equivalent reflection coefficient loaded at the input end of the second gain module, and Γload is the equivalent reflection coefficient loaded at the output end of the second gain module.
8. The method according to claim 7, characterized in that The obtaining of the current Γin of the second gain module comprises: Acquire the current Γ load of the second gain module through the coupler module; Acquire an S parameter of the second gain module according to a DC bias; The current Γin of the second gain module is determined according to the current Γload of the second gain module and the S parameter.
9. The method according to claim 7, characterized in that: The acquisition target Γin includes any of the following: Get the target Γin set by the user; According to the first corresponding relationship between the modulation and coding strategy MCS level and the working bandwidth OBW and Γin, the Γin corresponding to the MCS level and OBW used by the radio frequency transceiver chip is determined as the target Γin.
10. The method according to claim 7, characterized in that The step of determining a target electrical adjustment parameter according to a difference between the current Γin of the second gain module and the target Γin includes: Acquire a second corresponding relationship between Γin of the second gain module and an electrical adjustment parameter of the electrical adjustment impedance pulling circuit; According to the second corresponding relationship, the electrical adjustment parameter corresponding to the target Γin is determined as the target electrical adjustment parameter.