Radio frequency front end module with vswr threshold protection, electronic device and method

Abstract

The application discloses a radio frequency front end module with voltage standing wave ratio threshold protection, electronic equipment and a method. The radio frequency front end module comprises at least one transmitting path, the transmitting path comprises an input power detection circuit, a power amplifier circuit, a matching circuit, a load detection circuit and a bias control circuit; wherein the input power detection circuit detects the input radio frequency signal power of the transmitting path; the load detection circuit detects the load heat loss of the output end; the bias control circuit selects the corresponding load loss threshold through the LUT threshold table according to the received input power value, compares the received load heat loss, and outputs the control signal generated by the comparison result to the bias circuit unit of the power amplifier circuit, adjusts the working state of the power amplifier circuit, and realizes the voltage standing wave ratio threshold protection function.

Description

TECHNICAL FIELD

[0001] The present application relates to a radio frequency front-end module with VSWR (Voltage Standing Wave Ratio) threshold protection, and also relates to an electronic device comprising the radio frequency front-end module, and further relates to a control method for implementing VSWR threshold protection by the radio frequency front-end module, and belongs to the technical field of radio frequency integrated circuits. BACKGROUND

[0002] In a mobile communication device, according to the theoretical design of a radio frequency antenna, the input and output impedances of a radio frequency front-end module are both 50Ω, i.e., the voltage standing wave ratio (VSWR) is 1:1. However, in actual applications, the antenna load will change significantly with changes in surrounding environmental factors and deviate from 50Ω, for example, changes in factors such as load abnormalities, temperature changes, and holding methods, which will all cause load impedance mismatch and increase the voltage standing wave ratio. The various indicators of a radio frequency power amplifier circuit, such as gain, power consumption, and linearity, are usually designed based on the assumption that the impedance is 50Ω, which causes a deviation between the actual working performance and the theoretical performance of the power amplifier circuit. In the case of high input power of the power amplifier circuit, when there is a serious mismatch in the load impedance, the voltage standing wave ratio increases too much, and the voltage or current of the power amplifier circuit will increase and approach the limit, so that the phenomenon of burning out the components of the power amplifier circuit will occur. Therefore, an excessively high voltage standing wave ratio poses a fatal threat to the reliability of the working performance of the power amplifier circuit.

[0003] In the prior art, a method for solving the above problem is to reduce the gain of the power amplifier circuit or directly turn off the power amplifier circuit when the voltage standing wave ratio increases too much, so as to protect the power amplifier circuit from burning out components due to an increase in the voltage standing wave ratio. However, this method has two disadvantages, one is that when the input power of the power amplifier circuit is low, even if the voltage standing wave ratio increases too much, the power amplifier circuit will not be burned out, at which time the power amplifier circuit should remain in normal operation; the other is that it cannot guarantee the safety of the power amplifier circuit when switching from the protection state to the normal working state.

[0004] In the Chinese utility model with patent No. ZL 201822139086.2, a power amplification circuit with mismatch protection function is disclosed. The power amplification circuit includes an input matching unit, an output matching unit, and a power amplifier circuit die connected between the input matching unit and the output matching unit. A zener diode is electrically connected between the power amplifier circuit die and the GND. The zener diode is used for mismatch protection when the power amplifier circuit die is loaded mismatch. The technical scheme introduces a zener diode between the power amplifier circuit and the GND. When the load is mismatched, the zener diode can stabilize the drain voltage of the power amplifier circuit within a safe range, and can protect the power amplification circuit from mismatch, thereby improving the open circuit robustness of the power amplifier circuit. SUMMARY

[0005] The primary technical problem to be solved by the present application is to provide a radio frequency front-end module with voltage standing wave ratio threshold protection.

[0006] Another technical problem to be solved by the present application is to provide an electronic device comprising the radio frequency front-end module.

[0007] Still another technical problem to be solved by the present application is to provide a control method for implementing voltage standing wave ratio threshold protection in a radio frequency front-end module.

[0008] To achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0009] According to a first aspect of an embodiment of the present application, a radio frequency front-end module with voltage standing wave ratio threshold protection is provided, comprising at least one transmission path, the transmission path comprising an input power detection circuit, a power amplifier circuit, a matching circuit, a load detection circuit and a bias control circuit; wherein,

[0010] The input power detection circuit is used to detect the input radio frequency signal power of the transmission path, and its input end is connected with the radio frequency signal input end, the first output end is connected with the input end of the power amplifier circuit, and the second output end is connected with the first input end of the bias control circuit;

[0011] The power amplifier circuit is used to amplify the input radio frequency signal and output, and its output end is connected with the input end of the matching circuit;

[0012] The matching circuit is used to realize impedance matching, and its output end is connected with the input end of the load detection circuit;

[0013] The load detection circuit is used to detect the load heat loss of the output end, and outputs the detection result to the bias control circuit. The first output end is connected with the radio frequency signal output end, and the second output end is connected with the second input end of the bias control circuit;

[0014] The output end of the bias control circuit is connected with the bias end of the power amplifier circuit, for selecting corresponding load loss threshold value through LUT threshold table according to the received input power value, comparing the received load thermal loss with the comparison result, and outputting the control signal generated by the comparison result to the bias circuit unit of the power amplifier circuit to adjust the working state of the power amplifier circuit.

[0015] Preferably, the load detection circuit comprises a loss unit and a thermal sensitive unit; wherein,

[0016] The loss unit is connected in series in the radio frequency signal path, and is used for generating load thermal loss in the working state.

[0017] The thermal sensitive unit is used for generating thermal coupling effect with the loss unit, and converting the heat into an electrical parameter output.

[0018] Preferably, the loss unit is realized by a filter.

[0019] Preferably, the loss unit is composed of a first resistance, a second resistance, a third resistance, a first inductance, a second inductance and a first capacitance; wherein, one end of the first inductance, the second inductance and the first capacitance are connected to each other to form a T-type matching network, the other end of the first inductance is connected with the output end of the matching circuit through the first resistance; the other end of the second inductance is connected with the radio frequency signal output end through the third resistance; the other end of the first capacitance is connected with the ground potential end through the second resistance.

[0020] Preferably, the thermal sensitive unit is composed of a fourth resistance and a current source; wherein, the fourth resistance is a positive temperature coefficient thermistor, one end of the fourth resistance is connected with the ground potential end, and the other end is connected with the current source and the bias control circuit as an output end.

[0021] Preferably, the bias control circuit comprises a LUT threshold table unit, a first comparator, a first A / D converter, a second A / D converter and a first D / A converter; wherein,

[0022] The second output end of the input power detection circuit is connected with the first input port of the LUT threshold table unit through the first A / D converter; the second output end of the load detection circuit is connected with the second input port of the LUT threshold table unit through the second A / D converter; at the same time, the second output end of the load detection circuit is also connected with the first input end of the first comparator; the output port of the LUT threshold table unit is connected with the second input end of the first comparator through the first D / A converter, and the output end of the first comparator is connected with the bias circuit unit of the power amplifier circuit.

[0023] Preferably, the LUT threshold table unit is configured to output a corresponding load loss threshold according to the size of the detected input power; the LUT threshold table comprises different input powers, corresponding load losses when the voltage standing wave ratio is 1:1, and corresponding load loss thresholds set.

[0024] Preferably, when the load loss detected by the load detection circuit is greater than or equal to the load loss threshold, the first comparator outputs a high-level control signal to control the bias circuit unit of the power amplifier circuit, so as to reduce the output bias current or voltage, reduce the gain of the power amplifier circuit, or turn off the power amplifier circuit, thereby protecting the power amplifier circuit.

[0025] Preferably, when the load loss detected by the load detection circuit is less than the load loss threshold, the first comparator outputs a low-level control signal to control the bias circuit unit of the power amplifier circuit, so as to restore the bias current or voltage to a normal value, thereby restoring the power amplifier circuit to a normal working state.

[0026] Preferably, the control signal output by the bias control circuit is configured to control the bias resistor in the bias circuit unit or the power supply, so as to change the size of the output bias current or voltage.

[0027] When the control signal output by the bias control circuit is high, the bias current or voltage output by the bias circuit is adjusted to be reduced, so that the gain of the power amplifier circuit is reduced, and the power amplifier circuit is in a protection state.

[0028] When the control signal output by the bias control circuit is low, the bias current or voltage output by the bias circuit is adjusted to be kept or restored to a normal value, and the power amplifier circuit is in a normal working state.

[0029] According to a second aspect of the embodiment of the present application, an electronic device is provided, which comprises the above-mentioned radio frequency front-end module with voltage standing wave ratio threshold protection.

[0030] According to a third aspect of the embodiment of the present application, a control method for implementing voltage standing wave ratio threshold protection by a radio frequency front-end module is provided, which comprises the following steps:

[0031] (1) System initialization, generating a LUT threshold table;

[0032] (2) Detecting the input power of the transmission path and inputting it to the LUT threshold table processing unit;

[0033] (3) The LUT threshold table processing unit outputs a corresponding load loss threshold according to the input power;

[0034] (4) detecting the load heat loss of the transmitting path;

[0035] (5) comparing the detected load heat loss with a load loss threshold value; when the load heat loss is greater than or equal to the load loss threshold value, going to step (6); when the load heat loss is less than the load loss threshold value, going to step (7);

[0036] (6) adjusting the bias circuit of the power amplifier circuit, reducing the gain of the power amplifier circuit or shutting down the power amplifier circuit, and then going to step (2);

[0037] (7) keeping or adjusting the bias circuit of the power amplifier circuit, keeping or restoring the normal gain of the power amplifier circuit, and then going to step (2).

[0038] Preferably, step (1) comprises the following sub-steps:

[0039] (11) when the load impedance is a fixed value, sequentially writing the different input powers of the transmitting path and the corresponding load losses into the LUT threshold table;

[0040] (12) setting the load loss threshold values under different input powers and writing them into the LUT threshold table respectively.

[0041] Compared with the prior art, the radio frequency front-end module with voltage standing wave ratio threshold protection provided by the embodiment of the present application realizes the reliability of effectively protecting the power amplifier circuit from working under the severe condition of large input power and serious load impedance mismatch, and the power amplifier circuit can smoothly return to the normal working state when the severe working condition is relieved, by adopting the technical scheme of real-time detecting the input power of the radio frequency signal and the load heat loss representing the voltage standing wave ratio, and dynamically adjusting the gain of the power amplifier circuit. Therefore, the radio frequency front-end module with voltage standing wave ratio threshold protection provided by the embodiment of the present application has the beneficial effects of ingenious and reasonable structure design, low design cost, high working reliability, excellent circuit performance and the like. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The structure block diagram of the radio frequency front-end module with voltage standing wave ratio threshold protection provided by the embodiment of the present application is shown in the figure;

[0043] Figure 2 The structure schematic diagram of the load detection circuit in the embodiment of the present application is shown in the figure;

[0044] Figure 3 The circuit principle diagram of the load detection circuit in the first scheme in the embodiment of the present application is shown in the figure;

[0045] Figure 4 The circuit principle diagram of the load detection circuit in the second scheme in the embodiment of the present application is shown in the figure;

[0046] Figure 5 This is a graph showing the relationship between heat loss generated by the loss unit and the load voltage standing wave ratio when the input power is -15dBm, as described in an embodiment of the present invention.

[0047] Figure 6 In this embodiment of the invention, when the input power is -10dBm, the curve showing the relationship between the heat loss generated by the loss unit and the load voltage standing wave ratio is shown.

[0048] Figure 7 This is a circuit diagram of the bias control circuit in an embodiment of the present invention;

[0049] Figure 8 This is a circuit diagram of the bias circuit unit in the power amplifier circuit in an embodiment of the present invention;

[0050] Figure 9 This is a flowchart illustrating the control method for implementing voltage standing wave ratio threshold protection in the radio frequency front-end module, as described in this embodiment of the invention.

[0051] Figure 10 This is a schematic diagram of an electronic device employing an RF front-end module with voltage standing wave ratio threshold protection provided in an embodiment of the present invention. Detailed Implementation

[0052] The technical content of the present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0053] like Figure 1 As shown in the figure, an embodiment of the present invention provides an RF front-end module with voltage standing wave ratio (VSWR) threshold protection, including at least one transmission path. The transmission path includes an input power detection circuit 101, a power amplifier circuit 102, a matching circuit 103, a load detection circuit 104, and a bias control circuit 105. The RF signal input terminal TX_in is connected to the input terminal of the input power detection circuit 101; the first output terminal of the input power detection circuit 101 is connected to the input terminal of the power amplifier circuit 102; the second output terminal of the input power detection circuit 101 is connected to the first input terminal of the bias control circuit 105; the output terminal of the power amplifier circuit 102 is connected to the input terminal of the matching circuit 103; the output terminal of the matching circuit 103 is connected to the input terminal of the load detection circuit 104; the first output terminal of the load detection circuit 104 is connected to the RF signal output terminal TX_out; the second output terminal of the load detection circuit 104 is connected to the second input terminal of the bias control circuit 105; and the output terminal of the bias control circuit 105 is connected to the bias terminal of the power amplifier circuit 102. The RF signal output terminal TX_out is connected to the antenna ANT.

[0054] The input power detection circuit 101 is used to detect the input radio frequency signal power of the transmission path and output the detection result to the bias control circuit 105. The input power detection circuit can be implemented using a directional coupler and a detector.

[0055] The power amplifier circuit 102 is used to amplify the power of the input radio frequency signal before outputting it. The power amplifier circuit includes a power amplification unit and a bias circuit unit.

[0056] The matching circuit 103 is used to achieve impedance matching and is generally composed of passive networks such as capacitors and inductors.

[0057] The load detection circuit 104 is used to detect the load heat loss at the output terminal and output the detection result to the bias control circuit 105.

[0058] The bias control circuit 105 is used to select the corresponding load loss threshold and compare it with the received load heat loss according to the received input power value through the LUT threshold table, and output the control signal generated by the comparison result to the bias circuit unit of the power amplifier circuit 102 to adjust the working state of the power amplifier circuit.

[0059] like Figure 2 As shown, in one embodiment of the present invention, the load detection circuit 104 includes a loss unit and a thermistor unit. The loss unit is connected in series in the radio frequency signal path, and it generates different heat losses under different input power and different voltage standing wave ratios. The thermistor unit is physically located close to the loss unit, and it generates thermal coupling with the loss unit, thereby detecting the heat generated by the loss unit and converting the heat into electrical parameter output. In the embodiments of the present invention, the specific structure of the load detection circuit 104 provides the following two technical solutions.

[0060] The load detection circuit in the first scheme is as follows: Figure 3 As shown, the loss unit consists of filter D1, which is connected in series in the RF signal path. Filter D1 generates different heat losses under different input power and different voltage standing wave ratios (VSWR). Filter D1 can be a surface acoustic wave (SAW) filter or a bulk acoustic wave (BAW) filter. Both of these filters typically have significant heat losses, resulting in a noticeable temperature increase when the input power and / or VSWR increases.

[0061] The heat-sensitive unit is composed of a heat-sensitive resistor R and a current source. The heat-sensitive resistor R is a positive temperature coefficient heat-sensitive resistor, which is arranged close to the filter D1 in physical position and can detect the heat change on the filter D1 through heat coupling. One end of the heat-sensitive resistor R is connected to the ground potential terminal, and the other end is connected to the current source and the bias control circuit 105 as an output terminal.

[0062] When the antenna load impedance deviates from 50Ω, the voltage standing wave ratio increases, the heat loss generated on the filter D1 changes, and the temperature around the filter D1 changes. At this time, the resistance value of the heat-sensitive resistor R changes with the temperature, and a voltage signal is generated on the output terminal through the current source and output to the bias control circuit 105.

[0063] The load detection circuit in the second scheme is shown in Figure 4 The loss unit is composed of a first resistor R1, a second resistor R2, a third resistor R3, and a first inductor L1, a second inductor L2, and a first capacitor C1. One end of the first inductor L1, the second inductor L2, and the first capacitor C1 are connected to each other to form a T-type matching network, which is used together with the matching circuit 103 to realize load impedance matching. The other end of the first inductor L1 is connected to the output terminal of the matching circuit 103 through the first resistor R1. The other end of the second inductor L2 is connected to the RF signal output terminal TX_out through the third resistor R3. The other end of the first capacitor C1 is connected to the ground potential terminal through the second resistor R2. The heat losses generated by the first resistor R1, the second resistor R2, and the third resistor R3 under different input powers and different voltage standing wave ratios are also different.

[0064] The heat-sensitive unit is composed of a fourth resistor R4 and a current source. The fourth resistor R4 is a positive temperature coefficient heat-sensitive resistor, which is arranged close to the first resistor R1, the second resistor R2, and the third resistor R3 in physical position and can detect the heat change on the first resistor R1, the second resistor R2, and the third resistor R3 through heat coupling. One end of the fourth resistor R4 is connected to the ground potential terminal, and the other end is connected to the current source and the bias control circuit 105 as an output terminal.

[0065] When the antenna load impedance deviates from 50Ω, the voltage standing wave ratio increases, and the heat losses generated on the first resistor R1, the second resistor R2, and the third resistor R3 connected in series with the T-type matching network also change, causing the temperature around them to change. At this time, the resistance value of the fourth resistor R4 changes with the temperature, and a voltage signal is generated on the output terminal through the current source and output to the bias control circuit 105.

[0066] Through testing, when the input power is -15dBm, the relationship between the heat loss generated by the first resistor R1, the second resistor R2, and the third resistor R3 and the voltage standing wave ratio of the load is as shown in Figure 5As shown in the figure; when the input power is -10dBm, the relationship between the thermal loss generated by the first resistor R1, the second resistor R2 and the third resistor R3 and the load voltage standing wave ratio is as shown in the figure Figure 6 As shown in the figure Figure 5 And Figure 6 In the figure, the abscissa is the load phase, and the ordinate is the resistance loss. The three curves in the figure from bottom to top are the cases when the load voltage standing wave ratio is 1:1, 5:1 and 10:1 respectively. As can be seen from the figure Figure 5 And Figure 6 As can be seen from the figure, when the load voltage standing wave ratio increases from 1:1 to 5:1 or 10:1, the thermal loss generated by the first resistor R1, the second resistor R2 and the third resistor R3 increases in the full phase. At the same time, Figure 5 And Figure 6 As can be seen from the comparison between

[0067] It should be noted that the loss unit and the thermal sensitive unit in the load detection circuit can also use other circuit structure technical solutions to realize the detection of the thermal loss of the output end load in addition to the above two technical solutions.

[0068] As shown in the figure Figure 7 In an embodiment of the present application, the bias control circuit 105 includes a LUT threshold table unit, a first comparator COMP, a first A / D converter, a second A / D converter and a first D / A converter. The second output end of the input power detection circuit is connected to the first input port of the LUT threshold table unit through the first A / D converter; the second output end of the load detection circuit is connected to the second input port of the LUT threshold table unit through the second A / D converter; at the same time, the second output end of the load detection circuit is also connected to the first input end of the first comparator COMP; the output port of the LUT threshold table unit is connected to the second input end of the first comparator COMP through the first D / A converter, and the output end of the first comparator COMP is connected to the bias circuit unit of the power amplifier circuit.

[0069] The LUT threshold table unit is a processing unit of the control system, which is used to output a corresponding load loss threshold according to the size of the input input power. The load loss threshold is compared with the load thermal loss detected by the load detection circuit through the comparator COMP, and the control signal generated after the comparison is output to the bias circuit unit of the power amplifier circuit to control the gain size of the power amplifier circuit and change the working state of the power amplifier circuit.

[0070] The LUT threshold table represents the relationship between input power and load loss when the load voltage standing wave ratio (VSWR) is 1:1, along with the corresponding load loss threshold. This load loss threshold represents the load loss corresponding to a specific VSWR defined by the protection at that input power. The generation of the LUT threshold table needs to be completed during system initialization. Specifically, the relationship between different input powers and corresponding load losses when the load impedance is fixed (e.g., 50Ω, or other resistance values ​​such as 25Ω or 75Ω) is written into the system, and load loss thresholds are set for different input powers. These different load loss thresholds are also written into the system to generate the LUT threshold table. In one embodiment of the invention, assuming that during system initialization, the load impedance is 50Ω and VSWR is 1:1, the output signal of the load detection circuit is input to the LUT threshold table unit through a second A / D converter, such as... Figure 7 As shown by the dashed line, this line is only used for system initialization. The output signal of the input power detection circuit is input to the LUT threshold table unit through the first A / D converter. Different input powers and their corresponding load losses are written into the LUT threshold table. At the same time, the load loss threshold corresponding to each set input power is also written into the table to establish the LUT threshold table.

[0071] In practical operation, the LUT threshold unit of the RF front-end module outputs a corresponding load loss threshold based on the real-time detected input power. When load impedance mismatch or the load voltage standing wave ratio (VSWR) rises to a certain value, and the load heat loss detected by the load detection circuit is greater than or equal to this load loss threshold, the first comparator COMP outputs a high-level control signal to control the bias circuit unit of the power amplifier circuit, reducing the output bias current or voltage. This reduces the gain of the power amplifier circuit or shuts it down, thereby protecting the power amplifier circuit. When the load VSWR decreases and the load heat loss detected by the load detection circuit is less than the load loss threshold, the first comparator COMP outputs a low-level control signal to control the bias circuit unit of the power amplifier circuit, restoring the bias current or voltage to its normal value, allowing the power amplifier circuit to return to normal operation.

[0072] The circuit structure of the bias circuit unit in the power amplifier circuit is as follows: Figure 8 As shown, the control signal output by the bias control circuit can be adjusted by changing the magnitude of the output bias current or voltage by adjusting the bias resistor R2 or the power supply Vcc, thereby adjusting the gain of the power amplifier circuit.

[0073] When the control signal output by the bias control circuit is at high level, the bias current or voltage output by the bias circuit is adjusted to be reduced, so that the gain of the power amplifier circuit is reduced, at this time, the power amplifier circuit is in the protection state; when the control signal output by the bias control circuit is at low level, the bias current or voltage output by the bias circuit is kept or adjusted to be kept or restored to the normal value, at this time, the power amplifier circuit is in the normal working state.

[0074] The working flow of the control method for the voltage standing wave ratio threshold protection of the radio frequency front end module is shown in the figure, and specifically includes the following steps: Figure 9

[0075] S1: system initialization, generating a LUT threshold table.

[0076] Specifically, when the load impedance is a fixed value (for example, 50Ω), the relationship between different input powers of the transmission path and the corresponding load loss, and the load loss threshold under different input powers are written into the system respectively, and a LUT threshold table is generated.

[0077] S2: detecting the input power of the transmission path and inputting the LUT threshold table processing unit.

[0078] S3: the LUT threshold table processing unit outputs the corresponding load loss threshold according to the input power.

[0079] S4: detecting the load heat loss of the transmission path.

[0080] S5: comparing the detected load heat loss with the load loss threshold; when the detected load heat loss is greater than or equal to the load loss threshold, step S6 is entered; when the detected load heat loss is less than the load loss threshold, step S7 is input.

[0081] S6: adjusting the bias circuit of the power amplifier circuit, reducing the gain of the power amplifier circuit or shutting down the power amplifier circuit. Then step S2 is entered.

[0082] S7: keeping or adjusting the bias circuit of the power amplifier circuit, keeping or restoring the normal gain of the power amplifier circuit. Then step S2 is entered.

[0083] From the analysis of the working principle and working flow, it can be seen that the technical scheme provided by the embodiment of the present application can effectively protect the power amplifier circuit under the severe condition of large input power and serious load impedance mismatch, and can also smoothly restore the power amplifier circuit to the normal working state when the severe working condition is relieved.

[0084] ​The electronic device refers to a computer device that can be used in a mobile environment, supports multiple communication standards such as GSM, EDGE, CDMA, TD_SCDMA, WCDMA, TDD_LTE, FDD_LTE, NR, and the like, and includes a mobile phone, a notebook computer, a tablet computer, a vehicle-mounted computer, and the like. In addition, the technical solutions provided by the present application are also applicable to other occasions of radio frequency integrated circuit application, such as a communication base station, a smart connected vehicle, and the like.

[0085] As shown in Figure 10 The electronic device at least includes a processor, a memory, and a communication component, and can further include a sensor component, a power supply component, a multimedia component, and an input / output interface according to actual needs. The memory, the communication component, the sensor component, the power supply component, the multimedia component, and the input / output interface are connected to the processor. The memory can be a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, and the like. The processor can be a central processing unit (CPU), a graphics processing unit (GPU), a field programmable logic gate array (FPGA), an application specific integrated circuit (ASIC), a digital signal processing (DSP) chip, and the like. Other communication components, sensor components, power supply components, multimedia components, and the like can be realized by general-purpose components, and will not be described in detail here.

[0086] In summary, compared with the prior art, the radio frequency front-end module with voltage standing wave ratio threshold protection provided by the embodiments of the present application realizes the reliability of effectively protecting the power amplifier circuit in operation under severe conditions of large input power and serious load impedance mismatch, while the power amplifier circuit can smoothly recover to a normal working state when the severe working condition is alleviated. Therefore, the radio frequency front-end module with voltage standing wave ratio threshold protection provided by the present application has the beneficial effects of ingenious and reasonable structure design, low design cost, high working reliability, excellent circuit performance, and the like.

[0087] It should be noted that the above-mentioned multiple embodiments are only examples, and the technical solutions of each embodiment can be combined, all within the protection scope of the present application.

[0088] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Thus, features defined with "first", "second" can include one or more of such features explicitly or implicitly. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise expressly and specifically defined.

[0089] The radio frequency front-end module, the electronic device and the method provided by the present application are described in detail above. Any obvious modification made by those skilled in the art without departing from the essential content of the present application will constitute an infringement of the patent right of the present application and will bear the corresponding legal responsibility.

Claims

1. A radio frequency front end module with voltage standing wave ratio threshold protection, characterized by The transmitting path comprises an input power detection circuit, a power amplifier circuit, a matching circuit, a load detection circuit and a bias control circuit. The input power detection circuit is used for detecting the input RF signal power of the transmitting path, and its input end is connected with the RF signal input end, the first output end is connected with the input end of the power amplifier circuit, and the second output end is connected with the first input end of the bias control circuit. The power amplifier circuit is used for amplifying the input RF signal and outputting, and its output end is connected with the input end of the matching circuit. The matching circuit is used for realizing impedance matching, and its output end is connected with the input end of the load detection circuit. The load detection circuit is used for detecting the load heat loss of the output end and outputting the detection result to the bias control circuit, and the first output end is connected with the RF signal output end, and the second output end is connected with the second input end of the bias control circuit. The output end of the bias control circuit is connected with the bias end of the power amplifier circuit, and is used for comparing the received load heat loss with the corresponding load loss threshold value selected from the LUT threshold table according to the received input power value, and outputting the control signal generated by the comparison result to the bias circuit unit of the power amplifier circuit to adjust the working state of the power amplifier circuit.

2. The RF front-end module with VSWR threshold protection according to claim 1, wherein: The load detection circuit comprises a loss unit and a thermosensitive unit; wherein, The loss unit is connected in series in the RF signal path and is used for generating the load heat loss in the working state; The thermosensitive unit is used for coupling with the loss unit to generate heat and converting the heat into an electrical parameter output.

3. The RF front-end module with VSWR threshold protection according to claim 2, wherein: The loss unit is realized by a filter.

4. The RF front-end module with VSWR threshold protection according to claim 2, wherein: The loss unit is composed of a first resistor, a second resistor, a third resistor, a first inductor, a second inductor and a first capacitor; wherein, one end of the first inductor, the second inductor and the first capacitor are connected to each other to form a T-type matching network, the other end of the first inductor is connected with the output end of the matching circuit through the first resistor; the other end of the second inductor is connected with the RF signal output end through the third resistor; and the other end of the first capacitor is connected with the ground potential end through the second resistor.

5. The RF front-end module with VSWR threshold protection according to claim 2, wherein: The thermosensitive unit is composed of a fourth resistor and a current source; wherein, the fourth resistor is a positive temperature coefficient thermistor, one end of the fourth resistor is connected with the ground potential end, and the other end is connected with the current source and the bias control circuit as an output end.

6. The RF front-end module with VSWR threshold protection according to claim 1, wherein: The bias control circuit comprises a LUT threshold table unit, a first comparator, a first A / D converter, a second A / D converter and a first D / A converter; wherein, The second output end of the input power detection circuit is connected with the first input port of the LUT threshold table unit through the first A / D converter; the second output end of the load detection circuit is connected with the second input port of the LUT threshold table unit through the second A / D converter; meanwhile, the second output end of the load detection circuit is also connected with the first input end of the first comparator; the output port of the LUT threshold table unit is connected with the second input end of the first comparator through the first D / A converter, and the output end of the first comparator is connected with the bias circuit unit of the power amplifier circuit.

7. The RF front-end module with VSWR threshold protection of claim 6, wherein: The LUT threshold table unit is used for outputting corresponding load loss threshold according to the size of the detected input power; wherein, the LUT threshold table comprises different input powers and corresponding load losses when the VSWR is 1:1, and corresponding load loss thresholds set.

8. The RF front-end module with VSWR threshold protection of claim 6, wherein: When the load heat loss detected by the load detection circuit is greater than or equal to the load loss threshold, the first comparator outputs a high-level control signal to control the bias circuit unit of the power amplifier circuit, reduce the output bias current or voltage, so that the gain of the power amplifier circuit is reduced or the power amplifier circuit is turned off, and the protection of the power amplifier circuit is realized.

9. The RF front-end module with VSWR threshold protection of claim 6, wherein: When the load heat loss detected by the load detection circuit is less than the load loss threshold, the first comparator outputs a low-level control signal to control the bias circuit unit of the power amplifier circuit, and the bias current or voltage returns to the normal value, so that the power amplifier circuit returns to the normal working state.

10. The RF front-end module with VSWR threshold protection of claim 8 or 9, wherein: The control signal output by the bias control circuit adopts the mode of controlling the bias resistance in the bias circuit unit or the power supply, to change the size of the output bias current or voltage; When the control signal output by the bias control circuit is high level, the bias current or voltage output by the bias circuit is adjusted to be reduced, so that the gain of the power amplifier circuit is reduced, and at this time, the power amplifier circuit is in the protection state; When the control signal output by the bias control circuit is low level, the bias current or voltage output by the bias circuit is adjusted to be kept or returned to the normal value, and at this time, the power amplifier circuit is in the normal working state.

11. An electronic device, characterized in that... The RF front-end module with VSWR threshold protection of any one of claims 1-10.

12. A control method for a radio frequency front end module implementing voltage standing wave ratio threshold protection, the method comprising: receiving a signal from a power amplifier; determining a voltage standing wave ratio of the signal; and adjusting a gain of the power amplifier based on the voltage standing wave ratio. The method comprises the following steps: (1) system initialization, generating a LUT threshold table; (2) detecting the input power of the transmitting path and inputting it to the LUT threshold table processing unit; (3) The LUT threshold table processing unit outputs the corresponding load loss threshold according to the input power; (4) Detecting the load heat loss of the transmission path; (5) Comparing the detected load heat loss with the load loss threshold; when the load heat loss is greater than or equal to the load loss threshold, step (6) is entered; when the load heat loss is less than the load loss threshold, step (7) is entered; (6) Adjusting the bias circuit of the power amplifier circuit, reducing the gain of the power amplifier circuit or turning off the power amplifier circuit, and then entering step (2); (7) Keeping or adjusting the bias circuit of the power amplifier circuit, keeping or restoring the normal gain of the power amplifier circuit, and then entering step (2).

13. The control method of claim 12 wherein the RF front end module implements voltage standing wave ratio threshold protection. The step (1) includes the following sub-steps: (11) When the load impedance is a fixed value, sequentially write the different input powers of the transmission path and the corresponding load losses into the LUT threshold table; (12) Set the load loss threshold under different input powers and write them into the LUT threshold table respectively.

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