Radio frequency front-end module with impedance mismatch protection, electronic device, and method

Abstract

Disclosed in the present invention are a radio frequency front-end module with impedance mismatch protection, an electronic device, and a method. The radio frequency front-end module comprises at least one transmit channel, and the transmit channel comprises an input power measurement circuit, a power amplifier circuit, a matching circuit, a load measurement circuit, and a gain control circuit, wherein the input power measurement circuit measures the power of an input radio frequency signal of the transmit channel; the load measurement circuit measures output forward transmission power and reverse transmission power in an output radio frequency signal and calculates a difference; and the gain control circuit compares an input power value and the difference between the output forward transmission power and reverse transmission power with a set first threshold value and a set second threshold value respectively, and outputs a control signal generated on the basis of the comparison result to the power amplifier circuit, so as to adjust the working state of the power amplifier circuit. Thus, impedance mismatch protection is achieved.

Description

RF front-end module, electronic device and method with impedance mismatch protection Technical Field

[0001] The present invention relates to a radio frequency front-end module with impedance mismatch protection, an electronic device including the radio frequency front-end module, and a control method for implementing impedance mismatch protection in the radio frequency front-end module, belonging to the technical field of radio frequency integrated circuits. Background Art

[0002] In mobile communication devices, the theoretical design of RF antennas dictates that the input and output impedance of the RF front-end module are both 50Ω. However, in practice, 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, resulting in RF signal reflections and an increased Voltage Standing Wave Ratio (VSWR). Power amplifier 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. When the power amplifier's input power is high and a severe load impedance mismatch occurs, the voltage or current of the power amplifier increases and approaches its limit, potentially damaging the power amplifier's components. Therefore, load impedance mismatch poses a significant threat to the reliability of the power amplifier.

[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 impedance mismatch 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 implementing impedance mismatch protection in 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 impedance mismatch protection is provided, comprising at least one transmission path, the transmission path including an input power detection circuit, a power amplifier circuit, a matching circuit, a load detection circuit, and a gain 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 gain 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 forward transmission power and reverse transmission power of the output radio frequency signal, and calculate the difference between the forward transmission power and the reverse transmission power as an output signal, the first output end is connected to the radio frequency signal output end, and the second output end is connected to the second input end of the gain control circuit;

[0013] The output end of the gain control circuit is connected to the control end of the power amplifier circuit, and is used to compare the received input power value with a first threshold, compare the difference between the output forward transmission power and the reverse transmission power with a second threshold, and output a control signal generated by the comparison result to the power amplifier circuit to adjust the working state of the power amplifier circuit.

[0014] Preferably, the load detection circuit includes a first directional coupler, a second directional coupler and a power difference unit; wherein,

[0015] The first directional coupler and the second directional coupler are connected in reverse series in the radio frequency signal path; the output end of the first directional coupler is connected to the first input end of the power difference unit, the output end of the second directional coupler is connected to the second input end of the power difference unit, and the output end of the power difference unit is connected to the second input end of the gain control circuit.

[0016] Preferably, the first directional coupler is connected in a forward direction to detect the power of the radio frequency signal transmitted in the forward direction on the signal path;

[0017] The second directional coupler is connected in reverse order to detect the power of the reversely transmitted reflected signal generated by the impedance mismatch on the signal path.

[0018] Preferably, when the load impedance is mismatched, the difference between the forward transmission power and the reverse transmission power detected by the first directional coupler and the second directional coupler varies inversely with the voltage standing wave ratio.

[0019] Preferably, the gain control circuit includes a first comparator, a second comparator and a first AND gate; wherein,

[0020] The first input end of the first comparator is connected to the output end of the input power detection circuit, the second input end of the first comparator is connected to the first threshold end, and the output end of the first comparator is connected to the first input end of the first AND gate; the first input end of the second comparator is connected to the output end of the load detection circuit, the second input end of the second comparator is connected to the second threshold end, and the output end of the second comparator is connected to the second input end of the first AND gate; the output end of the first AND gate is connected to the control end of the attenuator unit in the power amplifier circuit.

[0021] Preferably, when the detected input power is greater than or equal to a first threshold, and the difference between the forward transmission power and the reverse transmission power of the output signal is less than or equal to a second threshold, the first AND gate outputs a high-level control signal to control the attenuator unit in the power amplifier circuit to start, so that the input RF signal of the transmitting path enters the power amplifier unit only after at least one attenuation. At this time, the power amplifier circuit is in a protection working state.

[0022] Preferably, when the detected input power is less than a first threshold, and / or the difference between the forward transmission power and the reverse transmission power of the output signal is greater than a second threshold, the first AND gate outputs a low-level control signal to control the attenuator unit in the power amplifier circuit to be turned off, and the input RF signal of the transmission path directly enters the power amplifier unit. At this time, the power amplifier circuit is in normal working state.

[0023] Preferably, the output end of the gain control circuit is connected to the adjustable bias circuit unit in the power amplifier circuit; the control signal output by the gain control circuit controls the adjustable bias circuit in the power amplifier circuit, and the gain of the power amplifier circuit is adjusted by adjusting the magnitude of the bias voltage or current output by the bias circuit, thereby achieving impedance mismatch protection.

[0024] Preferably, the control signal output by the gain control circuit changes the magnitude of the output bias current or voltage by controlling the bias resistor or power supply in the adjustable bias circuit unit;

[0025] When the control signal output by the gain control circuit is at a high level, the bias current or voltage output by the adjustable 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;

[0026] When the control signal output by the gain control circuit is at a low level, the bias current or voltage output by the adjustable 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.

[0027] 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 impedance mismatch protection.

[0028] According to a third aspect of an embodiment of the present invention, a control method for implementing impedance mismatch protection in a radio frequency front-end module is provided, comprising the following steps:

[0029] (1) Setting a first threshold and a second threshold;

[0030] (2) Detecting the input power of the radio frequency signal in the transmission path;

[0031] (3) detecting the forward transmission power and the reverse transmission power of the RF signal at the output end, and calculating the difference between the forward transmission power and the reverse transmission power;

[0032] (4) comparing the detected input power with a first threshold;

[0033] (5) comparing the detected difference between the forward transmission power and the reverse transmission power at the output end with a second threshold;

[0034] (6) When the detected input power is greater than or equal to the first threshold, and the difference between the forward transmission power and the reverse transmission power at the output end is less than or equal to the second threshold, proceed to step (7); otherwise, proceed to step (8);

[0035] (7) Starting the attenuator in the power amplifier circuit, the input RF signal enters the power amplifier unit through the attenuator; then proceeding to step (2);

[0036] (8) Turn off the attenuator in the power amplifier circuit, and input the RF signal directly into the power amplifier unit; then go to step (2).

[0037] Preferably, step (7) adopts the following sub-steps:

[0038] Reduce the bias current or voltage in the power amplifier circuit to reduce the gain of the power amplifier circuit; then go to step (2).

[0039] Preferably, step (8) adopts the following sub-steps:

[0040] Maintain or restore the bias current or voltage of the power amplifier circuit for normal operation, so that the power amplifier circuit maintains or restores the gain of normal operation; then proceed to step (2).

[0041] Compared with the prior art, the RF front-end module with impedance mismatch protection provided by the embodiments of the present invention adopts a technical solution that dynamically adjusts the gain of the power amplifier circuit by real-time detection of the input power of the RF signal and the difference between the forward and reverse output powers representing the voltage standing wave ratio. This effectively protects the reliability of the power amplifier circuit under harsh conditions such as high input power and severe load impedance mismatch. At the same time, the power amplifier circuit can smoothly return to normal operating conditions when the harsh operating conditions are alleviated. Therefore, the RF front-end module with impedance mismatch protection provided by the embodiments 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

[0042] FIG1 is a structural block diagram of a radio frequency front-end module with impedance mismatch protection provided by an embodiment of the present invention;

[0043] FIG2 is a circuit diagram of a radio frequency front-end module with impedance mismatch protection in one embodiment of the present invention;

[0044] FIG3 is a graph showing the difference between forward transmission power and reverse transmission power under different VSWRs in an embodiment of the present invention;

[0045] FIG4 is a circuit schematic diagram of a radio frequency front-end module with impedance mismatch protection in another embodiment of the present invention;

[0046] FIG5 is a circuit structure diagram of an adjustable bias circuit unit in another embodiment of the present invention;

[0047] FIG6 is a flowchart of a control method for implementing impedance mismatch protection in a radio frequency front-end module according to an embodiment of the present invention;

[0048] FIG7 is a schematic diagram of an electronic device using a radio frequency front-end module with impedance mismatch protection provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The technical content of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] As shown in FIG1 , an embodiment of the present invention provides a radio frequency front-end module with impedance mismatch protection, including at least one transmit path, comprising an input power detection circuit 101, a power amplifier circuit 102, a matching circuit 103, a load detection circuit 104, and a gain 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 gain 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 gain control circuit 105, and the output terminal of the gain control circuit 105 is connected to the control terminal of the power amplifier circuit 102. The radio frequency signal output terminal TX_out is connected to the antenna ANT.

[0051] 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 gain control circuit 105. The input power detection circuit can be implemented by using a directional coupler.

[0052] The power amplifier circuit 102 is used to amplify the power of the input radio frequency signal and then output it. The power amplifier circuit generally includes a power amplifier unit and a bias circuit unit, and may also include an attenuator unit according to specific needs.

[0053] The matching circuit 103 is used to achieve impedance matching and is generally composed of passive components such as capacitors and inductors.

[0054] The load detection circuit 104 is used to detect the forward transmission power and the reverse transmission power of the output radio frequency signal, and output the difference between the forward transmission power and the reverse transmission power to the gain control circuit 105 .

[0055] The gain control circuit 105 is used to compare the received input power value, the difference between the output forward transmission power and the reverse transmission power with the set first threshold and second threshold respectively, and output the control signal generated by the comparison result to the power amplifier circuit 102 to adjust the working state of the power amplifier circuit.

[0056] As shown in FIG2 , in one embodiment of the present invention, the load detection circuit 104 includes a first directional coupler DC1, a second directional coupler DC2, and a power differential unit. The first directional coupler DC1 and the second directional coupler DC2 are connected in reverse series in the RF signal path. The coupled output of the first directional coupler DC1 is connected to the first input of the power differential unit, the coupled output of the second directional coupler DC2 is connected to the second input of the power differential unit, and the output of the power differential unit is connected to the second input of the gain control circuit 105.

[0057] The first directional coupler, DC1, is connected in the forward direction and detects the power of the RF signal transmitted in the forward direction of the signal path. The second directional coupler, DC2, is connected in the reverse direction and detects the power of the reflected signal transmitted in the reverse direction due to impedance mismatch in the signal path. When the load impedance is 50Ω (other impedance values ​​are acceptable), the difference between the forward and reverse transmission powers detected by the first and second directional couplers, DC1 and DC2, is equal to the isolation of the directional couplers themselves. When the load impedance mismatch exists, the difference between the forward and reverse transmission powers detected by the first and second directional couplers, DC1 and DC2, decreases.

[0058] As shown in Figure 3, the voltage standing wave ratio (VSWR) varies depending on the degree of load impedance mismatch, and the difference between the forward and reverse transmission powers detected by the first directional coupler DC1 and the second directional coupler DC2 also differs. In Figure 3, the horizontal axis represents phase, and the vertical axis represents the difference between the forward and reverse transmission powers. When the VSWR is 3:1, the difference between the forward and reverse transmission powers is 6.2dB at all phases; when the VSWR is 6:1, the difference between the forward and reverse transmission powers is 3dB at all phases; and when the VSWR is 12:1, the difference between the forward and reverse transmission powers is 1.5dB at all phases.

[0059] That is, the difference between the forward transmission power and the reverse transmission power detected by the first directional coupler DC1 and the second directional coupler DC2 becomes smaller (i.e., changes in the opposite direction) as the voltage standing wave ratio increases, and a larger voltage standing wave ratio indicates a more serious load impedance mismatch.

[0060] The circuit structure of the power difference unit may be formed by electronic components or by electronic components plus algorithm processing.

[0061] As shown in FIG2 , in one embodiment of the present invention, the gain control circuit 105 includes a first comparator COM1, a second comparator COM2, and a first AND gate AND. The first input of the first comparator COM1 is connected to the output of the input power detection circuit, the second input of the first comparator COM1 is connected to a first threshold value set by the system, and the output of the first comparator COM1 is connected to the first input of the first AND gate AND. The first input of the second comparator COM2 is connected to the output of the load detection circuit, the second input of the second comparator COM2 is connected to a second threshold value set by the system, and the output of the second comparator COM2 is connected to the second input of the first AND gate AND. The output of the first AND gate AND is connected to the control terminal of the attenuator unit in the power amplifier circuit.

[0062] The first comparator COM1 is used to compare the RF signal input power detected by the input power detection circuit with a first threshold value set by the system. This first threshold is a set input power value. When the detected input power value is greater than or equal to the first threshold, the first comparator COM1 outputs a high level; otherwise, it outputs a low level. The second comparator COM2 is used to compare the difference between the forward and reverse transmission powers of the RF signal detected by the load detection circuit with a second threshold value set by the system. This second threshold is the difference between the forward and reverse transmission powers at a set voltage standing wave ratio when the load impedance is mismatched. When the difference between the forward and reverse transmission powers of the RF signal detected by the load detection circuit is less than or equal to the second threshold, the second comparator COM2 outputs a high level; otherwise, it outputs a low level. The output signals of the first comparator COM1 and the second comparator COM2 pass through a first AND gate and output a control signal to control the attenuator unit in the power amplifier circuit.

[0063] When the detected input power is greater than or equal to a first threshold, and the difference between the forward transmission power and the reverse transmission power of the output signal is less than or equal to a second threshold, the first AND gate AND outputs a high-level control signal to control the attenuator unit in the power amplifier circuit to start, so that the input RF signal of the transmission path enters the power amplifier unit after at least one attenuation.

[0064] When the detected input power is less than a first threshold, and / or the difference between the forward transmission power and the reverse transmission power of the output signal is greater than a second threshold, the first AND gate AND outputs a low-level control signal to control the attenuator unit in the power amplifier circuit to be turned off, and the input RF signal of the transmission path directly enters the power amplifier unit.

[0065] That is, when the input power is less than the first threshold, the attenuator unit in the power amplifier circuit will not activate, regardless of the voltage standing wave ratio (VSWR) representing the degree of load impedance mismatch. At this point, the power amplifier circuit remains in normal operation. On the other hand, when the difference between the forward and reverse transmission powers of the output signal is greater than the second threshold, the attenuator unit in the power amplifier circuit will not activate, regardless of the input power. At this point, the power amplifier circuit remains in normal operation. Only when the detected input power is greater than or equal to the first threshold, and the difference between the forward and reverse transmission powers of the output signal is less than or equal to the second threshold, will the attenuator unit in the power amplifier circuit activate. At this point, the power amplifier circuit enters a protective operating state, thereby preventing the power amplifier circuit from burning out.

[0066] When the power amplifier circuit is in the protection working state, if the input power decreases to less than the first threshold value, the first comparator COM1 outputs a low level, the first AND gate AND outputs a low-level control signal, the attenuator unit in the power amplifier circuit is turned off, and the power amplifier circuit returns to a normal working state and maintains a normal gain size; if the difference between the forward transmission power and the reverse transmission power of the output signal increases to greater than the second threshold value, the second comparator COM2 outputs a low level, the first AND gate AND outputs a low-level control signal, the attenuator unit in the power amplifier circuit is turned off, and the power amplifier circuit returns to a normal working state and maintains a normal gain size.

[0067] From the analysis of the above working principles, 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.

[0068] The attenuator unit in the power amplifier circuit is connected in series to the input end of the power amplifier unit in the signal path, and can be implemented by an array circuit composed of switches, resistors and capacitors.

[0069] As shown in Figure 4, in another embodiment of the present invention, a radio frequency front-end module with impedance mismatch protection includes at least one transmit path. This transmit path includes an input power detection circuit, a power amplifier circuit 102, a matching circuit, a load detection circuit 104, and a gain control circuit 105. The structures of the load detection circuit 104, the gain control circuit 105, the input power detection circuit, and the matching circuit are the same as those in the above embodiment, except that the output of the gain control circuit 105 is connected to the adjustable bias circuit unit in the power amplifier circuit 102.

[0070] In this embodiment, the control signal output by the gain control circuit 105 controls the adjustable bias circuit in the power amplifier circuit 102. By adjusting the bias voltage or current output by the bias circuit, the gain of the power amplifier circuit is adjusted. This effectively protects the power amplifier circuit under adverse conditions such as high input power and severe load impedance mismatch, and allows the power amplifier circuit to smoothly return to normal operation when the adverse operating conditions are alleviated. The remaining specific operating processes of the technical solution provided in this embodiment are the same as those in the above-described embodiment and are therefore not further described.

[0071] Among them, the circuit structure of the adjustable bias circuit unit in the power amplifier circuit 102 is shown in Figure 5, for example. The control signal output by the gain control circuit 105 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 gain control circuit 105 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 gain control circuit 105 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 impedance mismatch protection provided by an embodiment of the present invention has a control method for impedance mismatch protection, as shown in FIG6 , which specifically includes the following steps:

[0074] S1: setting a predetermined input power value of the input end as a first threshold, and setting a predetermined difference between the forward transmission power and the reverse transmission power of the output end as a second threshold.

[0075] S2: Detect the input power of the RF signal in the transmission path.

[0076] S3: Detecting the forward transmission power and the reverse transmission power of the RF signal at the output end, and calculating the difference between the forward transmission power and the reverse transmission power.

[0077] S4: Compare the detected input power with a first threshold.

[0078] S5: Compare the detected difference between the forward transmission power and the reverse transmission power of the output end with a second threshold.

[0079] S6: When the detected input power is greater than or equal to the first threshold, and the difference between the forward transmission power and the reverse transmission power at the output end is less than or equal to the second threshold, proceed to step S7; otherwise, proceed to step S8.

[0080] S7: Start the attenuator in the power amplifier circuit, and the input radio frequency signal enters the power amplifier unit through the attenuator; then go to step S2.

[0081] S8: Turn off the attenuator unit in the power amplifier circuit, and the input radio frequency signal directly enters the power amplifier unit; then go to step S2.

[0082] In the above workflow, steps S2 and S3 are performed simultaneously, and steps S4 and S5 are also performed simultaneously. In addition, steps S7 and S8 can also adopt the following technical solutions:

[0083] S71: Reduce the bias current or voltage in the power amplifier circuit to reduce the gain of the power amplifier circuit; then go to step S2.

[0084] S81: Maintain or restore the bias current or voltage of the power amplifier circuit for normal operation, so that the power amplifier circuit maintains or restores the gain of normal operation; then go to step S2.

[0085] Based on the above-mentioned RF front-end module with impedance mismatch protection, an embodiment of the present invention further provides an electronic device, which includes the above-mentioned RF front-end module with impedance mismatch protection, and the RF front-end module can be used as an important component of a communication component. The electronic device mentioned 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 RF integrated circuits, such as communication base stations, smart connected cars, etc.

[0086] As shown in FIG7 , the electronic device includes at least a processor, a memory, and a communication component, and may further include a sensor component, a power supply component, a multimedia component, and an input / output interface, etc., according to actual needs. Among them, the memory, communication component, sensor component, power supply 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 supply components, multimedia components, etc. can all be implemented using general-purpose components and will not be described in detail here.

[0087] In summary, compared with the prior art, the RF front-end module with impedance mismatch 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 difference between the forward and reverse output powers 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 a normal working state. Therefore, the RF front-end module with impedance mismatch 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.

[0088] 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.

[0089] 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.

[0090] The above describes in detail the RF front-end module, electronic device, and method with impedance mismatch protection provided by the present invention. For those skilled in the art, any obvious modifications made thereto without departing from the essence of the present invention will constitute an infringement of the patent rights of the present invention and will result in corresponding legal liability.

Claims

1. A radio frequency front-end module with impedance mismatch protection, characterized in that It includes at least one transmission path, which includes an input power detection circuit, a power amplifier circuit, a matching circuit, a load detection circuit and a gain 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 which 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 gain 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 forward transmission power and the reverse transmission power of the output radio frequency signal, and calculate the difference between the forward transmission power and the reverse transmission power as the output signal, the first output end of the load detection circuit is connected to the radio frequency signal output end, and the second output end of the load detection circuit is connected to the second input end of the gain control circuit; The output end of the gain control circuit is connected to the control end of the power amplifier circuit, and is used to compare the received input power value with the first threshold, compare the difference between the output forward transmission power and the reverse transmission power with the second threshold, and output the control signal generated by the comparison result to the power amplifier circuit to adjust the working state of the power amplifier circuit.

2. The RF front-end module with impedance mismatch protection according to claim 1, characterized in that: The load detection circuit includes a first directional coupler, a second directional coupler and a power difference unit; wherein, The first directional coupler and the second directional coupler are connected in reverse series in the radio frequency signal path; the output end of the first directional coupler is connected to the first input end of the power differential unit, the output end of the second directional coupler is connected to the second input end of the power differential unit, and the output end of the power differential unit is connected to the second input end of the gain control circuit.

3. The RF front-end module with impedance mismatch protection according to claim 2, characterized in that: The first directional coupler is connected in the forward direction and is used to detect the power of the radio frequency signal transmitted in the forward direction on the signal path; The second directional coupler is reversely connected and is used to detect the power of the reversely transmitted reflected signal generated by the impedance mismatch on the signal path.

4. The RF front-end module with impedance mismatch protection according to claim 2, characterized in that: When the load impedance is mismatched, the difference between the forward transmission power and the reverse transmission power detected by the first directional coupler and the second directional coupler varies inversely with the voltage standing wave ratio.

5. The RF front-end module with impedance mismatch protection according to claim 1, characterized in that: The gain control circuit includes a first comparator, a second comparator and a first AND gate; wherein, The first input end of the first comparator is connected to the output end of the input power detection circuit, the second input end of the first comparator is connected to the first threshold end, and the output end of the first comparator is connected to the first input end of the first AND gate; the first input end of the second comparator is connected to the output end of the load detection circuit, the second input end of the second comparator is connected to the second threshold end, and the output end of the second comparator is connected to the second input end of the first AND gate; the output end of the first AND gate is connected to the control end of the attenuator unit in the power amplifier circuit.

6. The RF front-end module with impedance mismatch protection according to claim 5, characterized in that: When the detected input power is greater than or equal to a first threshold, and the difference between the forward transmission power and the reverse transmission power of the output signal is less than or equal to a second threshold, the first AND gate outputs a high-level control signal to control the attenuator unit in the power amplifier circuit to start, so that the input RF signal of the transmission path enters the power amplifier unit only after at least one attenuation. At this time, the power amplifier circuit is in a protection working state.

7. The RF front-end module with impedance mismatch protection according to claim 5, characterized in that: When the detected input power is less than the first threshold, and / or the difference between the forward transmission power and the reverse transmission power of the output signal is greater than the second threshold, the first AND gate outputs a low level The control signal controls the attenuator unit in the power amplifier circuit to be closed, and the input RF signal of the transmission path directly enters the power amplifier unit. At this time, the power amplifier circuit is in a normal working state.

8. The RF front-end module with impedance mismatch protection according to claim 5, characterized in that: The output end of the gain control circuit is connected to the adjustable bias circuit unit in the power amplifier circuit; the control signal output by the gain control circuit controls the adjustable bias circuit in the power amplifier circuit, and the gain of the power amplifier circuit is adjusted by adjusting the magnitude of the bias voltage or current output by the bias circuit to achieve impedance mismatch protection.

9. The RF front-end module with impedance mismatch protection according to claim 8, characterized in that: The control signal output by the gain control circuit changes the magnitude of the output bias current or voltage by controlling the bias resistor or power supply in the adjustable bias circuit unit; When the control signal output by the gain control circuit is at a high level, the bias current or voltage output by the adjustable 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 gain control circuit is at a low level, the bias current or voltage output by the adjustable 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.

10. An electronic device, characterized in that A radio frequency front-end module with impedance mismatch protection comprising any one of claims 1 to 9.

11. A control method for realizing impedance mismatch protection of a radio frequency front-end module, characterized in that The steps include: (1) setting a first threshold and a second threshold; (2) Detecting the input power of the RF signal in the transmission path; (3) detecting the forward transmission power and the reverse transmission power of the RF signal at the output end, and calculating the difference between the forward transmission power and the reverse transmission power; (4) comparing the detected input power with a first threshold; (5) comparing the detected difference between the forward transmission power and the reverse transmission power at the output end with a second threshold; (6) When the detected input power is greater than or equal to the first threshold, and the difference between the forward transmission power and the reverse transmission power at the output end is less than or equal to the second threshold, proceed to step (7); otherwise, proceed to step (8); (7) starting the attenuator in the power amplifier circuit, and the input RF signal enters the power amplifier unit through the attenuator; then proceeding to step (2); (8) Turn off the attenuator in the power amplifier circuit, and the input RF signal directly enters the power amplifier unit; then go to step (2).

12. The control method for implementing impedance mismatch protection of the RF front-end module according to claim 11, characterized in that Step (7) includes the following sub-steps: Reduce the bias current or voltage in the power amplifier circuit to reduce the gain of the power amplifier circuit; then go to step (2).

13. The control method for implementing impedance mismatch protection of the RF front-end module according to claim 11, characterized in that Step (8) includes the following sub-steps: Maintain or restore the bias current or voltage of the power amplifier circuit for normal operation, so that the power amplifier circuit maintains or restores the gain of normal operation; then proceed to step (2).

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