Radio-frequency front-end module having voltage standing wave ratio threshold protection, and electronic device and method

Abstract

Disclosed in the present invention are a radio-frequency front-end module having voltage standing wave ratio threshold protection, and an electronic device and a method. The radio-frequency front-end module comprises at least one transmitting path, which comprises an input power measurement circuit, a power amplifier circuit, a matching circuit, a load measurement circuit and a bias control circuit, wherein the input power measurement circuit measures an input radio-frequency signal power of the transmitting path; the load measurement circuit measures load heat loss at an output end; and the bias control circuit selects a corresponding load loss threshold on the basis of a received input power value and by means of an LUT threshold table, compares the load loss threshold with the received load heat loss, and outputs, to a bias circuit unit of the power amplifier circuit, a control signal generated by means of a comparison result, so as to adjust the working state of the power amplifier circuit, thereby achieving a voltage standing wave ratio threshold protection function.

Description

Radio frequency front-end module, electronic device and method with voltage standing wave ratio threshold protection Technical Field

[0001] The present invention relates to a radio frequency front-end module with voltage standing wave ratio threshold protection, an electronic device including the radio frequency front-end module, and a control method for the radio frequency front-end module to implement voltage standing wave ratio threshold protection, belonging to the technical field of radio frequency integrated circuits. Background Art

[0002] In mobile communication devices, according to theoretical RF antenna design, the input and output impedance of the RF front-end module are both 50Ω, resulting in a voltage standing wave ratio (VSWR) of 1:1. However, in actual use, the antenna load can significantly deviate from 50Ω due to environmental factors. For example, load anomalies, temperature fluctuations, and changes in gripping style can lead to load impedance mismatch, increasing the VSWR. RF power amplifier circuit specifications, such as gain, power consumption, and linearity, are typically designed based on the theoretical assumption of a 50Ω impedance. This can cause deviations between the actual and theoretical performance of the power amplifier circuit. When the input power of the power amplifier circuit is high and the load impedance mismatch is severe, the VSWR increases excessively, causing the voltage or current of the power amplifier circuit to increase and approach its limit, potentially burning out the power amplifier circuit components. Therefore, an excessively high VSWR poses a significant threat to the reliability of the power amplifier circuit.

[0003] Summary of the Invention

[0004] The primary technical problem to be solved by the present invention is to provide a radio frequency front-end module with voltage standing wave ratio threshold protection.

[0005] Another technical problem to be solved by the present invention is to provide an electronic device including the radio frequency front-end module.

[0006] Another technical problem to be solved by the present invention is to provide a control method for realizing voltage standing wave ratio threshold protection of a radio frequency front-end module.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present invention, a radio frequency front-end module with voltage standing wave ratio threshold protection is provided, comprising at least one transmitting path, the transmitting path including an input power detection circuit, a power amplifier circuit, a matching circuit, a load detection circuit, and a bias control circuit; wherein,

[0009] The input power detection circuit is used to detect the input RF signal power of the transmission path, the input end of the input power detection circuit is connected to the RF signal input end, the first output end is connected to the input end of the power amplifier circuit, and the second output end is connected to the first input end of the bias control circuit;

[0010] The power amplifier circuit is used to amplify the power of the input radio frequency signal and then output it, and its output end is connected to the input end of the matching circuit;

[0011] The matching circuit is used to achieve impedance matching, and its output end is connected to the input end of the load detection circuit;

[0012] The load detection circuit is used to detect the load heat loss of the output end and output the detection result to the bias control circuit, the first output end is connected to the RF signal output end, and the second output end is connected to the second input end of the bias control circuit;

[0013] The output end of the bias control circuit is connected to the bias end of the power amplifier circuit, and is used to select a corresponding load loss threshold value through a LUT threshold table according to the received input power value, compare it with the received load heat loss, and output a 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.

[0014] Preferably, the load detection circuit includes a loss unit and a thermal sensing unit; wherein,

[0015] The loss unit is connected in series in the radio frequency signal path and is used to generate load heat loss in a working state;

[0016] The thermal sensitive unit is used to generate heat coupling with the loss unit and convert the heat into electrical parameters for output.

[0017] Preferably, the loss unit is implemented by a filter.

[0018] Preferably, 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 interconnected to form a T-type matching network, and the other end of the first inductor is connected to the output end of the matching circuit through the first resistor; the other end of the second inductor is connected to the RF signal output end through the third resistor; and the other end of the first capacitor is connected to the ground potential end through the second resistor.

[0019] Preferably, the thermistor unit is composed of a fourth resistor and a current source; wherein the fourth resistor is a thermistor with a positive temperature coefficient, one end of the fourth resistor is connected to the ground potential end, and the other end is connected to the current source and the bias control circuit as an output end.

[0020] Preferably, the bias control circuit includes 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,

[0021] 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; the output port of the LUT threshold table unit is connected to the second input end of the first comparator through the first D / A converter, and the output end of the first comparator is connected to the bias circuit unit of the power amplifier circuit.

[0022] Preferably, the LUT threshold table unit is used to output a corresponding load loss threshold according to the size of the detected input power; wherein the LUT threshold table includes different input powers and corresponding load losses when the voltage standing wave ratio is 1:1, as well as the set corresponding load loss threshold.

[0023] Preferably, 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, thereby reducing the gain of the power amplifier circuit or shutting down the power amplifier circuit, thereby protecting the power amplifier circuit.

[0024] Preferably, 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, so that the bias current or voltage returns to a normal value, so that the power amplifier circuit returns to a normal working state.

[0025] Preferably, the control signal output by the bias control circuit changes the magnitude of the output bias current or voltage by controlling the bias resistor or power supply in the bias circuit unit;

[0026] When the control signal output by the bias control circuit is at a high level, the bias current or voltage output by the bias circuit is adjusted to decrease, so that the gain of the power amplifier circuit is reduced. At this time, the power amplifier circuit is in a protection state;

[0027] When the control signal output by the bias control circuit is at a low level, the bias current or voltage output by the bias circuit is adjusted to maintain or recover to a normal value. At this time, the power amplifier circuit is in a normal working state.

[0028] According to a second aspect of an embodiment of the present invention, an electronic device is provided, comprising the above-mentioned radio frequency front-end module with voltage standing wave ratio threshold protection.

[0029] According to a third aspect of an embodiment of the present invention, a method for controlling a radio frequency front-end module to implement voltage standing wave ratio threshold protection is provided, comprising the following steps:

[0030] (1) System initialization, generating LUT threshold table;

[0031] (2) Detect the input power of the transmission path and input it into the LUT threshold table processing unit;

[0032] (3) The LUT threshold table processing unit outputs the corresponding load loss threshold according to the input power;

[0033] (4) detecting the load heat loss of the transmission path;

[0034] (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, proceeding to step (6); when the load heat loss is less than the load loss threshold, proceeding to step (7);

[0035] (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 proceeding to step (2);

[0036] (7) Maintain or adjust the bias circuit of the power amplifier circuit, maintain or restore the normal gain of the power amplifier circuit, and then go to step (2).

[0037] Preferably, step (1) includes the following sub-steps:

[0038] (11) When the load impedance is a fixed value, the different input powers of the transmission path and the corresponding load losses are written into the LUT threshold table in sequence;

[0039] (12) Set the load loss thresholds under different input powers and write them into the LUT threshold table respectively.

[0040] Compared with the prior art, the RF front-end module with voltage standing wave ratio threshold protection provided by the embodiment of the present invention adopts a technical solution of dynamically adjusting the gain of the power amplifier circuit by real-time detection of the input power of the RF signal and the load heat loss representing the voltage standing wave ratio. This effectively protects the reliability of the power amplifier circuit under harsh conditions such as large input power and severe load impedance mismatch. At the same time, when the harsh working conditions are alleviated, the power amplifier circuit can smoothly return to normal working state. Therefore, the RF front-end module with voltage standing wave ratio threshold protection provided by the embodiment of the present invention has the beneficial effects of ingenious and reasonable structural design, low design cost, high operating reliability, and excellent circuit performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a structural block diagram of a radio frequency front-end module with voltage standing wave ratio threshold protection provided by an embodiment of the present invention;

[0042] FIG2 is a schematic structural diagram of a load detection circuit according to an embodiment of the present invention;

[0043] FIG3 is a circuit diagram of a load detection circuit in a first solution according to an embodiment of the present invention;

[0044] FIG4 is a circuit diagram of a load detection circuit in a second solution according to an embodiment of the present invention;

[0045] FIG5 is a graph showing the relationship between the heat loss generated by the loss unit and the load voltage standing wave ratio when the input power is -15 dBm in an embodiment of the present invention;

[0046] FIG6 is a graph showing the relationship between the heat loss generated by the loss unit and the load voltage standing wave ratio when the input power is -10 dBm in an embodiment of the present invention;

[0047] FIG7 is a circuit diagram of a bias control circuit according to an embodiment of the present invention;

[0048] FIG8 is a circuit schematic diagram of a bias circuit unit in a power amplifier circuit according to an embodiment of the present invention;

[0049] FIG9 is a flow chart of a control method for implementing voltage standing wave ratio threshold protection in an RF front-end module according to an embodiment of the present invention;

[0050] FIG10 is a schematic diagram of an electronic device using a radio frequency front-end module with voltage standing wave ratio threshold protection provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The technical content of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] As shown in Figure 1, an embodiment of the present invention provides a radio frequency front-end module with voltage standing wave ratio threshold protection, comprising at least one transmit path. The transmit 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 radio frequency 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 radio frequency 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 radio frequency signal output terminal TX_out is connected to the antenna ANT.

[0053] 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.

[0054] The power amplifier circuit 102 is used to amplify the power of the input radio frequency signal and output the amplified signal. The power amplifier circuit includes a power amplifier unit and a bias circuit unit.

[0055] The matching circuit 103 is used to achieve impedance matching and is generally composed of passive networks such as capacitors and inductors.

[0056] The load detection circuit 104 is used to detect the load heat loss at the output end and output the detection result to the bias control circuit 105 .

[0057] The bias control circuit 105 is used to select a corresponding load loss threshold value according to the received input power value through the LUT threshold table, compare it with the received load heat loss, 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.

[0058] As shown in Figure 2, in one embodiment of the present invention, load detection circuit 104 includes a loss element and a thermal sensing element. The loss element is connected in series within the RF signal path, generating varying heat losses at varying input powers and voltage standing wave ratios. The thermal sensing element is physically located close to the loss element, generating thermal coupling with the loss element to detect the heat generated by the loss element and convert it into an electrical parameter output. In this embodiment of the present invention, the specific structure of load detection circuit 104 provides the following two technical solutions.

[0059] The load detection circuit in the first solution is shown in Figure 3. The loss unit is composed of filter D1, which is connected in series in the RF signal path. It produces different heat losses under different input powers and different voltage standing wave ratios. Filter D1 can be a surface acoustic wave filter (SAW) or a bulk acoustic wave filter (BAW). These two filters generally have large heat losses and produce significant temperature increases when the input power and / or voltage standing wave ratio increase.

[0060] The thermal sensing unit consists of a thermistor R and a current source. Thermistor R is a positive temperature coefficient thermistor physically located near filter D1. Through thermal coupling, it can detect thermal changes in filter D1. One end of the thermistor R is connected to ground potential, and the other end, as an output terminal, is connected to the current source and bias control circuit 105.

[0061] When the antenna load impedance changes and deviates from 50Ω, the voltage standing wave ratio increases, and the heat loss generated by filter D1 also changes, causing the surrounding temperature to change accordingly. At this time, the resistance value of thermistor R changes with temperature, generating a voltage signal at the output terminal through the current source, which is output to bias control circuit 105.

[0062] The load detection circuit in the second solution is shown in Figure 4. The loss unit is composed of a first resistor R1, a second resistor R2, a third resistor R3, 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 interconnected to form a T-type matching network that works together with the aforementioned matching circuit 103 to achieve load impedance matching. The other end of the first inductor L1 is connected to the output end 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 end TX_out through the third resistor R3. The other end of the first capacitor C1 is connected to the ground potential end through the second resistor R2. The heat loss 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 is also different.

[0063] The thermal sensing unit consists of a fourth resistor R4 and a current source. The fourth resistor R4 is a positive temperature coefficient thermistor and is physically located near the first resistor R1, the second resistor R2, and the third resistor R3. Through thermal coupling, it can detect thermal changes across the first resistor R1, the second resistor R2, and the third resistor R3. One end of the fourth resistor R4 is connected to ground potential, and the other end, serving as an output terminal, is connected to the current source and the bias control circuit 105.

[0064] When the antenna load impedance changes and deviates from 50Ω, the voltage standing wave ratio (VSWR) increases, and the heat loss generated by the first, second, and third resistors R1, R2, and R3, which are connected in series with the T-matching network, also changes, causing the surrounding temperature to change accordingly. At this time, the resistance value of the fourth resistor R4 changes with temperature, generating a voltage signal at the output terminal of the current source, which is output to the bias control circuit 105.

[0065] Tests show that when the input power is -15dBm, the relationship between the heat loss generated by the first, second, and third resistors R1, R2, and R3 and the load's VSWR is shown in Figure 5. When the input power is -10dBm, the relationship between the heat loss generated by the first, second, and third resistors R1, R2, and R3 and the load's VSWR is shown in Figure 6. In Figures 5 and 6, the abscissa represents the load phase, and the ordinate represents the resistor loss. The three curves, from bottom to top, represent the load VSWRs of 1:1, 5:1, and 10:1, respectively. Figures 5 and 6 show that as the load VSWR increases from 1:1 to 5:1 or 10:1, the heat loss generated by the first, second, and third resistors R1, R2, and R3 increases across all phases. Furthermore, a comparison of Figures 5 and 6 shows that when the input power increases from -15dBm to -10dBm, the resistor heat loss corresponding to each load VSWR increases significantly across all phases.

[0066] It should be noted that, in addition to the above two technical solutions, the loss unit and the thermal sensing unit in the load detection circuit may also adopt other circuit structure technical solutions to detect the heat loss of the output end load.

[0067] As shown in FIG7 , in one embodiment of the present invention, 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 of the input power detection circuit is connected to the first input port of the LUT threshold table unit via the first A / D converter; the second output of the load detection circuit is connected to the second input port of the LUT threshold table unit via the second A / D converter; and the second output of the load detection circuit is also connected to the first input port of the first comparator COMP. The output port of the LUT threshold table unit is connected to the second input port of the first comparator COMP via the first D / A converter, and the output of the first comparator COMP is connected to the bias circuit unit of the power amplifier circuit.

[0068] 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 input power. The load loss threshold is compared with the load heat 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 of the power amplifier circuit and change the working state of the power amplifier circuit.

[0069] The LUT threshold table is the corresponding relationship between the input power and the load loss when the voltage standing wave ratio (VSWR) of the load is 1:1, as well as the corresponding load loss threshold value. The load loss threshold value is the load loss corresponding to the input power and a certain voltage standing wave ratio defined by the protection. The generation of the LUT threshold table needs to be completed when the system is initialized. Specifically, when the load impedance is a fixed value (for example, 50Ω, or other resistance values, such as 25Ω or 75Ω, etc.), the relationship between different input powers and corresponding load losses is written into the system respectively, and the load loss threshold value under different input powers is set. These different load loss threshold values ​​are also written into the system to generate the LUT threshold table. In one embodiment of the present invention, assuming that when the system is initialized, the load impedance is 50Ω and VSWR is 1:1, the output signal of the load detection circuit is input into the LUT threshold table unit through the second A / D converter, as shown by the dotted line in Figure 7. The circuit shown by the dotted line is only used for system initialization. The output signal of the input power detection circuit is input into the LUT threshold table unit through the first A / D converter, and different input powers and 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.

[0070] In actual operation of the RF front-end module, the LUT threshold table unit outputs a corresponding load loss threshold based on the real-time detected input power. When the load impedance is mismatched, the load voltage standing wave ratio increases to a certain value, and the load heat loss detected by the load detection circuit is greater than or equal to the 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, thereby reducing the gain of the power amplifier circuit, or shutting down the power amplifier circuit, thereby protecting the power amplifier circuit. When the load voltage standing wave ratio 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 normal values, allowing the power amplifier circuit to resume normal operation.

[0071] Among them, the circuit structure of the bias circuit unit in the power amplifier circuit is shown in Figure 8, for example. The control signal output by the bias control circuit can be adjusted by adjusting the bias resistor R2 or the power supply Vcc to change the output bias current or voltage, thereby adjusting the gain of the power amplifier circuit.

[0072] When the control signal output by the bias control circuit is at a high level, the bias current or voltage output by the bias circuit is adjusted to decrease, so that the gain of the power amplifier circuit is reduced. At this time, the power amplifier circuit is in a protection state. When the control signal output by the bias control circuit is at a low level, the bias current or voltage output by the bias circuit is maintained or adjusted to maintain or restore to a normal value. At this time, the power amplifier circuit is in a normal working state.

[0073] The RF front-end module with voltage standing wave ratio threshold protection provided by an embodiment of the present invention has a control method for implementing voltage standing wave ratio threshold protection, as shown in FIG9 , which specifically includes the following steps:

[0074] S1: System initialization, generating LUT threshold table.

[0075] Specifically, when the load impedance is a fixed value (eg, 50Ω), the relationship between different input powers of the transmission path and the corresponding load loss, as well as the set load loss thresholds under different input powers, are written into the system to generate a LUT threshold table.

[0076] S2: Detect the input power of the transmission path and input it into the LUT threshold table processing unit.

[0077] S3: The LUT threshold table processing unit outputs a corresponding load loss threshold according to the input power.

[0078] S4: Detect the load heat loss of the transmission path.

[0079] S5: Compare 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, proceed to step S6; when the detected load heat loss is less than the load loss threshold, enter step S7.

[0080] S6: Adjust the bias circuit of the power amplifier circuit, reduce the gain of the power amplifier circuit, or turn off the power amplifier circuit. Then go to step S2.

[0081] S7: Maintain or adjust the bias circuit of the power amplifier circuit to maintain or restore the normal gain of the power amplifier circuit. Then go to step S2.

[0082] From the analysis of the above working principles and workflows, it can be seen that the technical solution provided by the embodiments of the present invention can not only effectively protect the power amplifier circuit under harsh conditions such as large input power and severe load impedance mismatch, but also enable the power amplifier circuit to smoothly return to normal working state when the harsh working conditions are alleviated.

[0083] An embodiment of the present invention further provides an electronic device, which includes the above-mentioned radio frequency front-end module with voltage standing wave ratio threshold protection, and the radio frequency front-end module can be used as an important component of a communication component. The electronic device referred to here refers to a computer device that can be used in a mobile environment and supports multiple communication standards such as GSM, EDGE, CDMA, TD_SCDMA, WCDMA, TDD_LTE, FDD_LTE, NR, etc., including mobile phones, laptops, tablet computers, car computers, etc. In addition, the technical solution provided by the present invention is also applicable to other applications of radio frequency integrated circuits, such as communication base stations, smart connected cars, etc.

[0084] As shown in Figure 10, the electronic device includes at least a processor, a memory and a communication component, and may further include a sensor component, a power component, a multimedia component and an input / output interface according to actual needs. Among them, the memory, communication component, sensor component, power component, multimedia component and input / output interface are all 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, etc., and the processor can be a central processing unit (CPU), a graphics processing unit (GPU), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a digital signal processing (DSP) chip, etc. Other communication components, sensor components, power components, multimedia components, etc. can all be implemented using general components and will not be described in detail here.

[0085] In summary, compared with the prior art, the RF front-end module with voltage standing wave ratio threshold protection provided by the embodiment of the present invention adopts a technical solution of dynamically adjusting the gain of the power amplifier circuit by real-time detection of the input power of the RF signal and the load heat loss representing the voltage standing wave ratio, thereby effectively protecting the reliability of the power amplifier circuit under harsh conditions such as large input power and severe load impedance mismatch. At the same time, when the harsh working conditions are alleviated, the power amplifier circuit can smoothly return to normal working state. Therefore, the RF front-end module with voltage standing wave ratio threshold protection provided by the present invention has the beneficial effects of ingenious and reasonable structural design, low design cost, high working reliability, and excellent circuit performance.

[0086] It should be noted that the above embodiments are only examples, and the technical solutions of the various embodiments can be combined and are all within the protection scope of the present invention.

[0087] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0088] The above describes in detail the RF front-end module, electronic device, and method with voltage standing wave ratio threshold protection provided by the present invention. For those skilled in the art, any obvious modification made to the present invention without departing from the essence of the present invention will constitute an infringement of the present invention's patent rights and will result in corresponding legal liability.

Claims

1. A radio frequency front-end module with voltage standing wave ratio threshold protection, characterized in that The invention comprises at least one transmitting path, wherein 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 is used to detect the input RF signal power of the transmission path, the input end of the input power detection circuit is connected to the RF signal input end, the first output end is connected to the input end of the power amplifier circuit, and the second output end is connected to the first input end of the bias control circuit; The power amplifier circuit is used to amplify the power of the input radio frequency signal and then output it, and its output end is connected to the input end of the matching circuit; The matching circuit is used to achieve impedance matching, and its output end is connected to the input end of the load detection circuit; The load detection circuit is used to detect the load heat loss of the output end and output the detection result to the bias control circuit, the first output end is connected to the RF signal output end, and the second output end is connected to the second input end of the bias control circuit; The output end of the bias control circuit is connected to the bias end of the power amplifier circuit, and is used to select a corresponding load loss threshold value through a LUT threshold table according to the received input power value to compare with the received load heat loss, and output a 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 radio frequency front-end module with voltage standing wave ratio threshold protection according to claim 1, characterized in that: The load detection circuit includes a loss unit and a thermal sensing unit; wherein, The loss unit is connected in series in the radio frequency signal path and is used to generate load heat loss in the working state; The thermal sensitive unit is used to generate heat coupling with the loss unit and convert the heat into electrical parameter output.

3. The RF front-end module with voltage standing wave ratio threshold protection according to claim 2, characterized in that: The loss unit is implemented by a filter.

4. The RF front-end module with voltage standing wave ratio threshold protection according to claim 2, characterized in that: 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 interconnected to form a T-type matching network, the other end of the first inductor is connected to the output end of the matching circuit through the first resistor; the other end of the second inductor is connected to the RF signal output end through the third resistor; the other end of the first capacitor is connected to the ground potential end through the second resistor.

5. The radio frequency front-end module with voltage standing wave ratio threshold protection according to claim 2, characterized in that: The thermistor unit is composed of a fourth resistor and a current source; wherein the fourth resistor is a thermistor with a positive temperature coefficient, one end of the fourth resistor is connected to the ground potential end, and the other end is connected to the current source and the bias control circuit as an output end.

6. The radio frequency front-end module with voltage standing wave ratio threshold protection according to claim 1, characterized in that: The bias control circuit includes 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 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; the output port of the LUT threshold table unit is connected to the second input end of the first comparator through the first D / A converter, and the output end of the first comparator is connected to the bias circuit unit of the power amplifier circuit.

7. The radio frequency front-end module with voltage standing wave ratio threshold protection according to claim 6, characterized in that: The LUT threshold table unit is used to output a corresponding load loss threshold according to the size of the detected input power; wherein the LUT threshold table includes different input powers and corresponding load losses when the voltage standing wave ratio is 1:1, as well as the set corresponding load loss threshold.

8. The radio frequency front-end module with voltage standing wave ratio threshold protection according to claim 6, characterized in that: When the load heat loss detected by the load detection circuit is greater than or equal to the load loss threshold When the value is set, the first comparator outputs a high-level control signal to control the bias circuit unit of the power amplifier circuit to reduce the output bias current or voltage, so that the gain of the power amplifier circuit is reduced or the power amplifier circuit is shut down to protect the power amplifier circuit.

9. The radio frequency front-end module with voltage standing wave ratio threshold protection according to claim 6, characterized in that: 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, so that the bias current or voltage returns to a normal value, so that the power amplifier circuit returns to a normal working state.

10. The radio frequency front-end module with voltage standing wave ratio threshold protection according to claim 8 or 9, characterized in that: The control signal output by the bias control circuit changes the magnitude of the output bias current or voltage by controlling the bias resistor or power supply in the bias circuit unit; When the control signal output by the bias control circuit is at a high level, the bias current or voltage output by the bias circuit is adjusted to decrease, so that the gain of the power amplifier circuit is reduced. At this time, the power amplifier circuit is in a protection state; When the control signal output by the bias control circuit is at a low level, the bias current or voltage output by the bias circuit is adjusted to maintain or restore to a normal value. At this time, the power amplifier circuit is in a normal working state.

11. An electronic device, characterized in that A radio frequency front-end module with voltage standing wave ratio threshold protection comprising any one of claims 1 to 10.

12. A control method for realizing voltage standing wave ratio threshold protection of a radio frequency front-end module, characterized in that The steps include: (1) System initialization, generating LUT threshold table; (2) Detecting the input power of the transmission path and inputting it into 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) Compare 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, proceed to step (6); when the load heat loss is less than the load loss threshold, When the loss threshold is reached, input step (7); (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 proceeding to step (2); (7) Maintain or adjust the bias circuit of the power amplifier circuit, maintain or restore the normal gain of the power amplifier circuit, and then go to step (2).

13. The control method for realizing voltage standing wave ratio threshold protection of the radio frequency front-end module according to claim 12, characterized in that The step (1) comprises the following sub-steps: (11) When the load impedance is a fixed value, the different input powers of the transmission path and the corresponding load losses are sequentially written into the LUT threshold table; (12) Set the load loss thresholds under different input powers and write them into the LUT threshold table respectively.

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