Low noise amplifiers, RF front-end modules and electronic devices

Abstract

The present application is applicable to the field of communication technology, and provides a low noise amplifier, a radio frequency front-end module, and an electronic device. By setting an input protection module between the input terminal and the ground terminal of the low noise amplifier, the input protection module can not only filter out non-target radio frequency signals whose frequencies are in the non-working frequency band of the low noise amplifier received by the input terminal of the radio frequency low amplifier, and prevent the non-target radio frequency signals from entering the amplification module of the low noise amplifier, but also discharge the high-power radio frequency signals whose power is greater than or equal to the preset power threshold received by the input terminal of the low noise amplifier to the ground through the ground terminal, and prevent the high-power radio frequency signals from damaging the low noise amplifier, so that the low noise amplifier has both out-of-band attenuation function and input power protection function.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a low noise amplifier, a radio frequency front-end module and an electronic device. Background Art

[0002] A low noise amplifier is an amplifier with a very low noise coefficient. A low noise amplifier can be used in a radio frequency receiving link. For example, it can be connected between the receiving antenna and the radio frequency transceiver of the radio frequency receiving link to amplify the weak radio frequency signal received by the receiving antenna, so as to facilitate the radio frequency transceiver to perform subsequent processing on the radio frequency signal received by the receiving antenna.

[0003] In specific applications, in order to ensure that the low noise amplifier has good amplification performance, the low noise amplifier is usually required to have a certain out-of-band attenuation function to suppress the RF signal in the non-working frequency band of the low noise amplifier. At the same time, in order to reduce the risk of damage to the low noise amplifier, the low noise amplifier is also required to have a good input power protection function. However, the low noise amplifiers in the related art do not have both out-of-band attenuation function and input power protection function. Summary of the invention

[0004] The embodiments of the present application provide a low noise amplifier, a radio frequency front-end module and an electronic device, which can enable the low noise amplifier to have both an out-of-band attenuation function and an input power protection function.

[0005] In the first aspect, the embodiment of the present application provides a low noise amplifier, including an input protection module, an input matching module, an amplification module and an output matching module. Among them, the input protection module is connected between the input terminal and the ground terminal of the low noise amplifier, and is used to filter out non-target RF signals whose frequencies are in the non-working frequency band of the low noise amplifier received at the input terminal, and is used to discharge the high-power RF signals whose power is greater than or equal to the preset power threshold received at the input terminal to the ground through the ground terminal; the input matching module is connected between the input terminal and the input matching terminal of the amplification module, and is used to transmit the RF signal to be amplified received at the input terminal to the amplification module; the amplification module is used to amplify the RF signal to be amplified, obtain the amplified RF signal, and transmit the amplified RF signal to the output matching module; the output matching module is connected to the output matching terminal of the amplification module, the power supply terminal of the low noise amplifier and the output terminal of the low noise amplifier, and is used to output the amplified RF signal.

[0006] The operating frequency band of the low noise amplifier may refer to a specific frequency range in the spectrum in which the low noise amplifier can effectively amplify the signal. The operating frequency band of the low noise amplifier may vary depending on the actual usage scenario.

[0007] The frequency is in the non-working frequency band of the low noise amplifier, that is, the frequency is not within the working frequency band of the low noise amplifier, that is, the non-target RF signal may include a RF signal with a frequency less than the lower limit of the working frequency band of the low noise amplifier and / or a RF signal with a frequency greater than the upper limit of the working frequency band of the low noise amplifier.

[0008] The preset power threshold is related to the degree of protection of the low noise amplifier. The lower the preset power threshold, the higher the degree of protection of the low noise amplifier, and the less likely the low noise amplifier is to be damaged.

[0009] According to the low-noise amplifier provided in the embodiment of the present application, an input protection module is arranged between the input end and the ground end of the low-noise amplifier. The input protection module can not only filter out non-target RF signals whose frequencies are in the non-working frequency band of the low-noise amplifier and are received at the input end of the RF low-noise amplifier, thereby preventing the non-target RF signals from entering the amplification module of the low-noise amplifier, but also discharge the high-power RF signals whose powers are greater than or equal to a preset power threshold received at the input end of the low-noise amplifier to the ground through the ground end, thereby preventing the high-power RF signals from damaging the low-noise amplifier, thereby enabling the low-noise amplifier to have both out-of-band attenuation function and input power protection function.

[0010] In an optional implementation of the first aspect, the input protection module includes a first suppression protection unit; the first suppression protection unit is connected between the input terminal and the ground terminal of the low noise amplifier; the first suppression protection unit is used to filter out non-target RF signals received at the input terminal whose frequency is less than the lower limit value of the working frequency band, and is used to discharge the high-power RF signal received at the input terminal whose power is greater than or equal to a preset power threshold to the ground through the ground terminal.

[0011] According to the low-noise amplifier provided in the embodiment of the present application, by setting a first suppression protection unit in the input protection module, it is possible to suppress non-target RF signals with a frequency lower than the lower limit of the working frequency band of the low-noise amplifier from entering the amplification module while preventing high-power RF signals with a power greater than or equal to a preset power threshold from causing damage to the low-noise amplifier; in addition, by discharging the high-power RF signal to the ground through the ground terminal, an electrostatic protection function can also be achieved.

[0012] In an optional implementation of the first aspect, the first suppression protection unit includes a first inductor, a first variable capacitor and a power protection subunit; the first end of the first inductor is connected to the input end, the second end of the first inductor is connected to the first end of the power protection subunit and the first end of the first variable capacitor, and the second end of the power protection subunit and the second end of the first variable capacitor are both connected to the ground end; the power protection subunit includes a working state and a non-working state; when there is no high-power RF signal input at the input end, the power protection subunit is in a non-working state and electrically presents as a parasitic capacitor; the parasitic capacitor, the first variable capacitor and the first inductor constitute an LC series resonant circuit with an adjustable resonant frequency; the LC series resonant circuit is used to filter out non-target RF signals having a frequency equal to the resonant frequency of the LC series resonant circuit; the resonant frequency of the LC series resonant circuit is configured to be less than the lower limit of the working frequency band; when there is a high-power RF signal input at the input end, the power protection subunit is in a working state and is used to discharge the high-power RF signal to the ground through the ground end.

[0013] Optionally, the capacitive reactance value of the first variable capacitor can be adjusted according to the frequency of the non-target RF signal to be filtered out. By adjusting the capacitive reactance value of the first variable capacitor, the resonant frequency of the LC series resonant circuit can be adjusted, thereby filtering out non-target RF signals of different frequencies.

[0014] In an optional implementation of the first aspect, the first variable capacitor is also connected to a controller; the controller is used to determine the target capacitive reactance value of the first variable capacitor corresponding to the non-target RF signal to be filtered out based on the correspondence between the frequencies of the pre-stored plurality of first signals to be suppressed and the capacitive reactance value of the first variable capacitor, and adjust the capacitive reactance value of the first variable capacitor to the target capacitive reactance value; the frequency of the first signal to be suppressed is less than the lower limit value of the operating frequency band. The LC series resonant circuit can be configured to filter out non-target RF signals whose frequencies are less than the lower limit value of the operating frequency band of the low noise amplifier.

[0015] According to the low-noise amplifier provided by the embodiment of the present application, by setting a first inductor, a first variable capacitor and a power protection subunit in the first suppression protection unit, and connecting the first inductor and the first variable capacitor in series, and connecting the power protection subunit and the first variable capacitor in parallel, when the power protection subunit is in a non-working state, the power protection subunit, the first variable capacitor and the first inductor constitute an LC series resonant circuit with an adjustable resonant frequency, and the resonant frequency of the LC series resonant circuit can be adjusted by adjusting the capacitive reactance value of the first variable capacitor, thereby filtering out non-target RF signals with a frequency equal to the resonant frequency of the LC series resonant circuit; at the same time, when a high-power RF signal with a power greater than a preset power threshold is input to the input end of the low-noise amplifier, the power protection subunit can be put into a working state, and since the resistance to ground of the power protection subunit is 0 when it is in a working state, the high-power RF signal can be discharged to the ground through the ground terminal, thereby preventing the high-power RF signal from damaging the low-noise amplifier.

[0016] In addition, since the power protection subunit can be connected in parallel with the first variable capacitor to form a new variable capacitor in a non-working state, the adjustable range of the capacitive reactance value of the variable capacitor can be widened, thereby widening the adjustable range of the resonant frequency of the LC series resonant circuit, so that the LC series resonant circuit can filter out more non-target radio frequency signals of different frequencies, thereby enhancing the out-of-band attenuation function of the low-noise amplifier. At the same time, the LC series resonant circuit presents an inductive reactance characteristic within the working frequency band of the low-noise amplifier, and can also achieve the best matching of the noise and gain of the low-noise amplifier.

[0017] In an optional implementation of the first aspect, the power protection subunit includes at least one first diode and at least one second diode; the at least one first diode is used to constitute a forward power protection path of the power protection subunit, and the forward power protection path is used to discharge a high-power RF signal with a voltage higher than the ground voltage to the ground through the ground terminal; the at least one second diode is used to constitute a negative power protection path of the power protection subunit, and the negative power protection path is used to discharge a high-power RF signal with a voltage lower than the ground voltage to the ground through the ground terminal.

[0018] Optionally, when the power protection subunit includes a first diode and a second diode, the positive electrode of the first diode can be commonly connected to the negative electrode of the second diode and used as the first end of the power protection subunit, and the negative electrode of the first diode can be commonly connected to the positive electrode of the second diode and used as the second end of the power protection subunit. In this case, the preset power threshold can include a first power threshold and a second power threshold. The first power threshold can be the product of the conduction voltage of the first diode and the input current of the low-noise amplifier; the second power threshold can be the product of the conduction voltage of the second diode and the input current of the low-noise amplifier. The power protection subunit can discharge a high-power non-target RF signal with a power greater than the first power threshold and a voltage greater than the ground voltage to the ground; or can discharge a high-power non-target RF signal with a power greater than the second power threshold and a voltage less than the ground to the ground.

[0019] Optionally, when the power protection subunit includes a plurality of first diodes and a second diode, the positive electrode of the first first diode can be commonly connected to the negative electrode of the second diode and used as the first end of the power protection subunit, the negative electrode of the last first diode can be commonly connected to the positive electrode of the second diode and used as the second end of the power protection subunit, and the positive electrode of the i-th first diode can be connected to the negative electrode of the (i - 1)-th first diode. Wherein, 1 < i ≤ n, and n is the number of first diodes. In this case, the preset power threshold can include a third power threshold and a second power threshold. The third power threshold can be the product of the sum of the conduction voltages of the plurality of first diodes and the input current of the low-noise amplifier. The power protection subunit can discharge a high-power non-target RF signal with a power greater than the third power threshold and a voltage greater than the ground voltage to the ground; or can discharge a high-power non-target RF signal with a power greater than the second power threshold and a voltage less than the ground to the ground.

[0020] Optionally, when the power protection subunit includes a first diode and a plurality of second diodes, the positive electrode of the first diode can be commonly connected to the negative electrode of the first second diode and used as the first end of the power protection subunit, the negative electrode of the first diode can be commonly connected to the positive electrode of the last second diode and used as the second end of the power protection subunit, and the negative electrode of the j-th second diode can be connected to the positive electrode of the (j - 1)-th second diode. 1 < j ≤ m, and m is the number of second diodes. In this case, the preset power threshold can include a first power threshold and a fourth power threshold. The fourth power threshold can be the product of the sum of the conduction voltages of the plurality of second diodes and the input current of the low-noise amplifier. The power protection subunit can discharge a high-power non-target RF signal with a power greater than the first power threshold and a voltage greater than the ground voltage to the ground; or can discharge a high-power non-target RF signal with a power greater than the fourth power threshold and a voltage less than the ground to the ground.

[0021] Optionally, when the power protection subunit includes a plurality of first diodes and a plurality of second diodes, the positive electrode of the first first diode can be commonly connected to the negative electrode of the first second diode and used as the first end of the power protection subunit, the negative electrode of the last first diode can be commonly connected to the positive electrode of the last second diode and used as the second end of the power protection subunit, the positive electrode of the i-th first diode can be connected to the negative electrode of the (i - 1)-th first diode, and the negative electrode of the j-th second diode can be connected to the positive electrode of the (j - 1)-th second diode. Wherein, 1 < j ≤ m, m is the number of second diodes; 1 < j ≤ m, m is the number of second diodes. In this case, the preset power threshold can include a third power threshold and a fourth power threshold. The power protection subunit can discharge a high-power non-target radio frequency signal with a power greater than the third power threshold and a voltage greater than the ground terminal voltage to the ground; or can discharge a high-power non-target radio frequency signal with a power greater than the fourth power threshold and a voltage less than the ground terminal to the ground.

[0022] In this way, when a high-power radio frequency signal with a power greater than the preset power threshold is input to the input end of the low-noise amplifier, each first diode and / or each second diode in the power protection subunit can be in a conducting state, so that the power protection subunit enters a working state, achieving the purpose of discharging the high-power radio frequency signal to the ground through the grounding terminal.

[0023] According to the low-noise amplifier provided by the embodiment of the present application, by setting a forward power protection path and a negative power protection path, it is possible to simultaneously filter out high-power radio frequency signals with a voltage greater than the ground terminal voltage and high-power radio frequency signals with a voltage less than the ground terminal voltage, which is beneficial to achieving comprehensive protection of the low-noise amplifier.

[0024] In an optional implementation manner of the first aspect, the input matching module includes a second inductor, and the second inductor is connected between the input end of the low-noise amplifier and the input matching end of the amplification module; the second inductor is used to match the input impedance of the low-noise amplifier with the output impedance of the pre-stage circuit; the pre-stage circuit refers to the circuit located before the input end of the low-noise amplifier in the signal transmission direction.

[0025] According to the low-noise amplifier provided by the embodiment of the present application, by setting a second inductor in the input matching module, it is possible to match the input impedance of the low-noise amplifier with the output impedance of the pre-stage circuit, which is beneficial to reducing the reflection of the radio frequency signal at the input end of the low-noise amplifier and enabling the radio frequency signal to be more effectively transmitted from the pre-stage circuit to the amplification module.

[0026] In an optional implementation manner of the first aspect, the first inductor and the second inductor are coupled.

[0027] According to the low noise amplifier provided in the embodiment of the present application, the area of ​​the low noise amplifier can be reduced by coupling the first inductor and the second inductor.

[0028] In an optional implementation of the first aspect, the amplification module includes a first transistor, a second transistor and a third inductor; the gate of the first transistor serves as an input matching end of the amplification module, the source of the first transistor is connected to the ground end through the third inductor, the drain of the first transistor is connected to the source of the second transistor, and the drain of the second transistor serves as an output matching end of the amplification module.

[0029] In an optional implementation of the first aspect, the input protection module also includes a second suppression unit, which is connected to the ground terminal and is coupled with the third inductor; the second suppression unit is used to suppress non-target RF signals whose frequencies are greater than an upper limit value of the operating frequency band.

[0030] According to the low-noise amplifier provided in the embodiment of the present application, by setting the first suppression protection unit and the second suppression unit in the input protection module, not only the non-target radio frequency signals with a frequency less than the lower limit value of the working frequency band of the low-noise amplifier can be filtered out, but also the non-target radio frequency signals with a frequency greater than the upper limit value of the working frequency band of the low-noise amplifier can be filtered out, thereby preventing radio frequency signals in the non-working frequency band of the low-noise amplifier from entering the amplification module, and at the same time preventing high-power radio frequency signals from causing damage to the low-noise amplifier, so that the low-noise amplifier has both out-of-band attenuation function and input power protection function.

[0031] In an optional implementation of the first aspect, the second suppression unit includes a second variable capacitor and a fourth inductor; the first end of the second variable capacitor is connected to the first end of the fourth inductor, the second end of the second variable capacitor and the second end of the fourth inductor are both connected to the ground end, and the fourth inductor is coupled with the third inductor; the second variable capacitor and the fourth inductor constitute an LC parallel resonant circuit with an adjustable resonant frequency, and the LC parallel resonant circuit is used to suppress non-target radio frequency signals having a frequency equal to the resonant frequency of the LC parallel resonant circuit; the resonant frequency of the LC parallel resonant circuit is greater than the upper limit value of the working frequency band.

[0032] Optionally, the capacitive reactance value of the second variable capacitor can be adjusted according to the frequency of the non-target RF signal to be filtered out. By adjusting the capacitive reactance value of the second variable capacitor, the resonant frequency of the LC parallel resonant circuit can be adjusted, thereby achieving the suppression of non-target RF signals of different frequencies. The LC parallel resonant circuit can be configured to suppress non-target RF signals whose frequencies are greater than the upper limit of the operating frequency band of the low noise amplifier.

[0033] In order to adjust the capacitive reactance value of the second variable capacitor, the second variable capacitor can also be connected to the controller. The controller can be used to adjust the capacitive reactance value of the second variable capacitor. The controller can store the corresponding relationship between the frequency of multiple second signals to be suppressed and the capacitive reactance value of the second variable capacitor. The capacitive reactance value of the second variable capacitor corresponding to the frequency of each pre-stored second signal to be suppressed can make the resonant frequency of the LC parallel resonant circuit equal to the frequency of the second signal to be suppressed, so that the LC parallel resonant circuit can suppress the second signal to be suppressed. Among them, the frequencies of multiple second signals to be suppressed can be greater than the upper limit of the working frequency band of the low noise amplifier. Based on this, when it is necessary to suppress non-target RF signals whose frequencies are greater than the upper limit of the working frequency band of the low noise amplifier, the controller can determine the target capacitive reactance value of the second variable capacitor corresponding to the non-target RF signal to be suppressed based on the corresponding relationship between the frequencies of multiple pre-stored second signals to be suppressed and the capacitive reactance value of the second variable capacitor, and adjust the actual capacitive reactance value of the second variable capacitor to the target capacitive reactance value, so that the LC parallel resonant circuit can suppress the non-target RF signal.

[0034] According to the low-noise amplifier provided in the embodiment of the present application, by configuring the second suppression unit as an LC parallel resonance circuit coupled to the third inductor and grounded, and configuring the resonant frequency of the LC parallel resonance to be greater than the upper limit value of the operating frequency band of the low-noise amplifier, it is possible to suppress non-target RF signals greater than the upper limit value of the operating frequency band of the low-noise amplifier.

[0035] In a second aspect, an embodiment of the present application provides a radio frequency front-end module, including a radio frequency receiving link; the radio frequency receiving link includes a low noise amplifier as described in any one of the first aspects above, the input end of the low noise amplifier is used to connect to an antenna, and the output end of the low noise amplifier is used to connect to a radio frequency receiver.

[0036] In a third aspect, an embodiment of the present application provides a mobile communication module, which includes a radio frequency transceiver and a radio frequency front-end module as described in the second aspect above, and the radio frequency front-end module can be connected between the antenna and the radio frequency transceiver.

[0037] In a fourth aspect, an embodiment of the present application provides a wireless communication module, which includes a radio frequency transceiver and a radio frequency front-end module as described in the second aspect above, and the radio frequency front-end module can be connected between an antenna and the radio frequency transceiver.

[0038] In a fifth aspect, an embodiment of the present application provides an electronic device, comprising a processor and a mobile communication module and / or a wireless communication module as described in the third aspect or the fourth aspect above, wherein the processor is connected to the mobile communication module and / or the wireless communication module.

[0039] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of an application scenario of a radio frequency front-end module;

[0041] Figure 2 A schematic diagram of the structure of a low noise amplifier provided in an embodiment of the present application;

[0042] Figure 3 A schematic diagram of the structure of a low noise amplifier provided in another embodiment of the present application;

[0043] Figure 4 A schematic diagram of a circuit principle of a low noise amplifier provided in an embodiment of the present application;

[0044] Figure 5 A schematic diagram of a circuit principle of a low noise amplifier provided in another embodiment of the present application;

[0045] Figure 6 A schematic diagram of a circuit principle of a low noise amplifier provided in yet another embodiment of the present application;

[0046] Figure 7 A schematic diagram of the structure of a low noise amplifier provided in an embodiment of the present application;

[0047] Figure 8 A schematic diagram of a circuit principle of a low noise amplifier provided in yet another embodiment of the present application;

[0048] Fig. 9 A schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of the present application;

[0049] Fig.10 A schematic diagram of the structure of a mobile communication module or a wireless communication module provided in an embodiment of the present application;

[0050] Fig.11 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] It should be noted that the terms used in the implementation methods of the embodiments of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more than two, "at least one" and "one or more" mean one, two or more than two.

[0052] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, it is defined that the "first" and "second" features may explicitly or implicitly include one or more of the features.

[0053] References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0054] To facilitate understanding, the relevant concepts involved in the embodiments of the present application are first explained.

[0055] 1. Radio frequency front-end (RFFE) module

[0056] RFFE modules are essential communication components for mobile phones, tablets and other electronic devices to achieve wireless communication functions. Figure 1 , is a schematic diagram of an application scenario of the RFFE module. Figure 1As shown, the RFFE module 11 can be arranged in the wireless communication module and / or the mobile communication module of the electronic device, and specifically can be arranged between the RF transceiver 12 of the wireless communication module and / or the mobile communication module and the antenna 13 of the electronic device. The RFFE module 11 can be used to process the RF signal to be transmitted from the RF transceiver 12 during the process of the electronic device transmitting the wireless signal; or, the RFFE module 11 can be used to process the RF signal received by the antenna 13 during the process of the electronic device receiving the wireless signal.

[0057] Exemplarily, the RFFE module 11 may include an RF transmission link 111 and an RF reception link 112. The antenna 13 of the electronic device may include a transmission antenna 131 and a reception antenna 132. The RF transmission link 111 may be used to perform power amplification and filtering processing on the RF signal to be transmitted from the RF transceiver 12 during the process of the electronic device transmitting a wireless signal, and transmit the processed RF signal to be transmitted through the transmission antenna 131. The RF reception link 112 may be used to perform filtering processing and low-noise amplification processing on the RF signal received by the reception antenna 132 during the process of the electronic device receiving a wireless signal, and transmit the processed RF signal to the RF transceiver 12.

[0058] Specifically, the RF transmission link 111 may include a RF power amplifier (PA) 1111 , a first filter 1112 , and a first antenna switch 1113 , which are sequentially connected between the RF transceiver 12 and the transmitting antenna 131 .

[0059] The RF power amplifier 1111 can be used to perform power amplification processing on the RF signal to be transmitted from the RF transceiver 12 during the process of the electronic device transmitting the wireless signal. The power amplification processing refers to amplifying the power of the RF signal.

[0060] The first filter 1112 can be used to filter the radio frequency signal to be transmitted after power amplification processing to ensure that only the radio frequency signal within the target transmission frequency band can be transmitted.

[0061] The first antenna switch 1113 may be used to implement switching of the transmitting antennas 131 of different frequency bands. The transmitting antennas 131 of different frequency bands may refer to antennas used to transmit radio frequency signals of different frequency bands.

[0062] The RF receiving chain 112 may include a second antenna switch 1121 , a second filter 1122 , and a RF low noise amplifier (LNA) 1123 , which are sequentially connected between the receiving antenna 132 and the RF transceiver 12 .

[0063] The second antenna switch 1121 may be used to switch between receiving antennas 132 of different frequency bands. The receiving antennas 132 of different frequency bands may refer to antennas used to receive radio frequency signals of different frequency bands.

[0064] The second filter 1122 can be used to filter the RF signal received by the receiving antenna 132 to ensure that only the RF signal within the target receiving frequency band can be received by the RF transceiver 12, and at the same time reduce the impact of the out-of-band radiation generated by the signal transmission link on the signal reception link.

[0065] Since the voltage level of the RF signal received by the receiving antenna 132 is usually low (i.e., the RF signal is relatively weak), the RF low noise amplifier 1123 can be used to perform low noise amplification processing on the weak RF signal received by the receiving antenna 132, and transmit the RF signal after the low noise amplification processing to the RF transceiver 12. Among them, the low noise amplification processing refers to a signal amplification process that minimizes the noise generated by the RF low noise amplifier 1123 itself while amplifying the voltage of the weak RF signal received by the receiving antenna 132.

[0066] 2. RF Low Noise Amplifier

[0067] A low noise amplifier is an amplifier with a very low noise figure. A radio frequency low noise amplifier is a low noise amplifier used to process radio frequency signals. Figure 1 The RF low noise amplifier 1123 can be used in the RF receiving link 112 of the electronic device to perform voltage amplification processing on the weak RF signal received by the receiving antenna 132, so as to facilitate the RF transceiver 12 of the electronic device to perform subsequent processing on the RF signal received by the receiving antenna 132.

[0068] In a specific application, in order to ensure that the RF receiving link 112 can normally receive wireless signals, the low noise amplifier 1123 is usually required to have characteristics such as high gain, low noise and high linearity within its operating frequency band.

[0069] The operating frequency band may refer to a specific frequency range in the spectrum in which the RF low noise amplifier 1123 can effectively amplify signals. For example, assuming that the operating frequency band of the RF low noise amplifier 1123 is 2.35 gigahertz (GHz) to 2.45 GHz, it means that the RF low noise amplifier 1123 can effectively amplify RF signals with a frequency range of 2.35 GHz to 2.45 GHz.

[0070] The high gain characteristic means that the RF low noise amplifier 1123 can effectively perform voltage amplification processing on the input RF signal to facilitate the RF transceiver 12 to perform other processing on the RF signal. The low noise characteristic means that the RF low noise amplifier 1123 can control the noise introduced by itself at a low level while providing high gain, so as to ensure that the signal-to-noise ratio of the wireless communication system is within an acceptable range. The high linearity characteristic means that the RF low noise amplifier 1123 can process RF signals of different amplitudes without distortion, especially when processing RF signals with higher power, it can maintain a low distortion level.

[0071] In addition, since there is usually spatial coupling between the transmitting antenna 131 and the receiving antenna 132 of the electronic device, that is, the transmitting antenna 131 and the receiving antenna 132 usually influence or interact with each other, the receiving antenna 132 may receive the RF signal leaked from the transmitting antenna 131, and the leaked RF signal will be transmitted to the RF low noise amplifier 1123 via the receiving antenna 132, the second antenna switch 1121 and the second filter 1122.

[0072] When the RF signal leaked from the transmitting antenna 131 is transmitted to the RF low noise amplifier 1123, on the one hand, it may cause the RF low noise amplifier 1123 to enter a compression state (in the compression state, the gain of the RF low noise amplifier 1123 is no longer kept constant, but exhibits a characteristic of a nonlinear relationship with the power of the input signal), thereby deteriorating the performance of the RF low noise amplifier 1123; on the other hand, when the power of the RF signal leaked from the transmitting antenna 131 is large, the RF signal with large power may damage the RF low noise amplifier 1123 after entering the RF low noise amplifier 1123.

[0073] Based on this, in order to ensure that the RF low noise amplifier 1123 has good voltage amplification performance, the RF low noise amplifier 1123 is also required to have a certain out-of-band attenuation function in the non-working frequency band to prevent interference signals with frequencies outside the working frequency band of the RF low noise amplifier 1123 from entering the RF transceiver 12. At the same time, in order to reduce the risk of damage to the RF low noise amplifier 1123, the RF low noise amplifier 1123 is also required to have a good input power protection function, so that when a high-power RF signal enters the RF low noise amplifier 1123, the RF low noise amplifier 1123 can be protected from being damaged.

[0074] However, the low noise amplifiers in the related art do not have both the out-of-band attenuation function and the input power protection function.

[0075] In view of this, the embodiments of the present application provide a low noise amplifier, a radio frequency front-end module and an electronic device. By setting an input protection module between the input terminal and the ground terminal of the low noise amplifier, the input protection module can not only filter out non-target radio frequency signals whose frequencies are in the non-working frequency band of the low noise amplifier and are received at the input terminal of the radio frequency low amplifier, thereby preventing non-target radio frequency signals from entering the amplification module of the low noise amplifier, but also discharge high-power radio frequency signals whose power is greater than or equal to a preset power threshold received at the input terminal of the low noise amplifier to the ground through the ground terminal, thereby preventing high-power radio frequency signals from damaging the low noise amplifier, thereby enabling the low noise amplifier to have both out-of-band attenuation function and input power protection function.

[0076] See also Figure 2 , is a schematic diagram of the structure of a low noise amplifier provided in an embodiment of the present application.

[0077] like Figure 2 As shown, the low noise amplifier may include an input protection module 201 , an input matching module 202 , an amplification module 203 and an output matching module 204 .

[0078] The input protection module 201 can be connected between the input terminal IN of the low noise amplifier and the ground terminal. The input protection module 201 can be used to filter out non-target RF signals whose frequencies are in the non-working frequency band of the low noise amplifier and are received by the input terminal IN of the low noise amplifier, and can be used to discharge high-power RF signals whose powers are greater than or equal to a preset power threshold received by the input terminal IN of the low noise amplifier to the ground through the ground terminal of the low noise amplifier.

[0079] Among them, the operating frequency band of the low noise amplifier may refer to a specific frequency range in the spectrum in which the low noise amplifier can effectively amplify the signal. The operating frequency band of the low noise amplifier may vary depending on the actual usage scenario. For example, when the RF receiving link where the low noise amplifier is located needs to receive RF signals with a frequency within 2.35 GHz to 2.45 GHz, a low noise amplifier with an operating frequency band of 2.35 GHz to 2.45 GHz can be used to effectively amplify RF signals with a frequency within 2.35 GHz to 2.45 GHz.

[0080] The frequency is in the non-working frequency band of the low noise amplifier, that is, the frequency is not in the working frequency band of the low noise amplifier. The non-target RF signal may include a RF signal with a frequency less than the lower limit of the working frequency band of the low noise amplifier and / or a RF signal with a frequency greater than the upper limit of the working frequency band of the low noise amplifier. Exemplarily, assuming that the working frequency band of the low noise amplifier is 2.35 GHz to 2.45 GHz, the non-target RF signal may include a RF signal with a frequency less than 2.35 GHz and / or a frequency greater than 2.45 GHz.

[0081] The preset power threshold is related to the degree of protection of the low noise amplifier. The lower the preset power threshold, the higher the degree of protection of the low noise amplifier, and the less likely the low noise amplifier is to be damaged.

[0082] The input matching module 202 may be connected between the input terminal IN of the low noise amplifier and the input matching terminal of the amplifying module 203 . The input matching module 202 may be used to transmit the RF signal to be amplified received by the input terminal IN of the low noise amplifier to the amplifying module 203 .

[0083] The amplification module 203 may be used to amplify the RF signal to be amplified to obtain an amplified RF signal, and transmit the amplified RF signal to the output matching module 204 .

[0084] The output matching module 204 can be connected to the output matching terminal of the amplifying module 203, the power supply terminal VDD of the low noise amplifier and the output terminal OUT of the low noise amplifier. The output matching module 204 can be used to output the amplified RF signal.

[0085] From the above, it can be seen that the low-noise amplifier provided in the embodiment of the present application, by setting an input protection module between the input end and the ground end of the low-noise amplifier, the input protection module can not only filter out non-target RF signals whose frequencies are in the non-working frequency band of the low-noise amplifier and are received at the input end of the RF low-noise amplifier, thereby preventing the non-target RF signals from entering the amplification module of the low-noise amplifier, but also can discharge the high-power RF signals whose power is greater than or equal to the preset power threshold received at the input end of the low-noise amplifier to the ground through the ground end, thereby preventing the high-power RF signals from damaging the low-noise amplifier, thereby enabling the low-noise amplifier to have both out-of-band attenuation function and input power protection function.

[0086] See also Figure 3 , is a structural diagram of a low noise amplifier provided in another embodiment of the present application.

[0087] like Figure 3 As shown, in an optional implementation, the input protection module 201 may include a first suppression protection unit 2011. The first suppression protection unit 2011 may be connected between the input terminal IN of the low noise amplifier and the ground terminal.

[0088] The first suppression protection unit 2011 can be used to filter out non-target RF signals whose frequencies are less than the lower limit of the working frequency band of the low noise amplifier received by the input terminal IN of the low noise amplifier, so as to prevent non-target RF signals whose frequencies are less than the lower limit of the working frequency band of the low noise amplifier from entering the amplification module 203, thereby suppressing non-target RF signals whose frequencies are less than the lower limit of the working frequency band of the low noise amplifier; and the first suppression protection unit 2011 can also be used to discharge high-power RF signals whose power is greater than or equal to the preset power threshold received by the input terminal IN of the low noise amplifier to the ground through the ground terminal of the low noise amplifier. Among them, the lower limit of the working frequency band of the low noise amplifier refers to the smaller frequency boundary value of the two frequency boundary values ​​used to limit the working frequency band of the low noise amplifier. Exemplarily, assuming that the working frequency band of the low noise amplifier is 2.35GHz to 2.45GHz, the lower limit of the working frequency band of the low noise amplifier can be 2.35GHz.

[0089] It can be seen from the above that the low noise amplifier provided in this embodiment, by setting a first suppression protection unit in the input protection module, can suppress non-target RF signals with a frequency less than the lower limit of the working frequency band of the low noise amplifier from entering the amplification module, while preventing high-power RF signals with a power greater than or equal to a preset power threshold from causing damage to the low noise amplifier; in addition, by discharging the high-power RF signal to the ground through the ground terminal, an electrostatic protection function can also be achieved.

[0090] See also Figure 4 , is a schematic diagram of the circuit principle of a low noise amplifier provided in an embodiment of the present application.

[0091] like Figure 4 As shown, in a specific implementation, the first suppression protection unit 2011 may include a first inductor L1 , a first variable capacitor Cb1 , and a power protection subunit 20111 .

[0092] Among them, the first end of the first inductor L1 can be connected to the input terminal IN of the low noise amplifier, the second end of the first inductor L1 can be connected to the first end of the power protection subunit 20111 and the first end of the first variable capacitor Cb1, and the second end of the power protection subunit 20111 and the second end of the first variable capacitor Cb1 can both be grounded.

[0093] In this embodiment, the power protection subunit 20111 may include a working state and a non-working state.

[0094] Optionally, when there is no high-power RF signal input with a power greater than or equal to a preset power threshold at the input terminal IN of the low-noise amplifier, the power protection subunit 20111 is in a non-working state. At this time, the power protection subunit 20111 is equivalent to a parasitic capacitor, which is connected in parallel with the first variable capacitor Cb1 to form a new capacitor, and the new capacitor is connected in series with the first inductor L1 between the input terminal IN of the low-noise amplifier and the ground terminal, forming an inductor-capacitor (LC) series resonant circuit with adjustable resonant frequency. Since the LC series resonant circuit presents a low impedance at the resonant frequency, the RF signal with a frequency equal to the resonant frequency of the LC series resonant circuit received by the receiving terminal IN of the low-noise amplifier can be discharged to the ground through the ground terminal of the low-noise amplifier, so as to filter out the RF signal with a frequency equal to the resonant frequency of the LC series resonant circuit, thereby suppressing the RF signal with a frequency equal to the resonant frequency of the LC series resonant circuit from entering the amplification module 203, and playing a role in electrostatic protection.

[0095] Based on this, in a specific application, the capacitive reactance value of the first variable capacitor Cb1 can be adjusted according to the frequency of the non-target RF signal to be filtered out. By adjusting the capacitive reactance value of the first variable capacitor Cb1, the resonant frequency of the LC series resonant circuit can be adjusted, thereby filtering out non-target RF signals of different frequencies.

[0096] In a specific application, the LC series resonant circuit can be configured to filter out non-target RF signals whose frequencies are less than the lower limit of the operating frequency band of the low noise amplifier. Exemplarily, when it is necessary to filter out non-target RF signals of multiple different frequencies whose frequencies are less than the lower limit of the operating frequency band of the low noise amplifier, the capacitive reactance value of the first variable capacitor Cb1 can be adjusted so that the resonant frequencies of the LC series resonant circuit are respectively equal to the frequencies of the multiple non-target RF signals to be filtered out, thereby filtering out non-target RF signals of multiple different frequencies whose frequencies are less than the lower limit of the operating frequency band of the low noise amplifier. For example, when it is necessary to filter out non-target RF signals with a frequency of 800 megahertz (MHz), the resonant frequency of the LC series resonant circuit can be adjusted to 800 MHz by adjusting the capacitive reactance value of the first variable capacitor Cb1, thereby filtering out non-target RF signals with a frequency of 800 MHz from entering the amplification module 203.

[0097] It can be understood that, since the power protection subunit 20111 can be connected in parallel with the first variable capacitor Cb1 to form a new variable capacitor in a non-operating state, the adjustable range of the capacitive reactance value of the variable capacitor can be widened, thereby widening the adjustable range of the resonant frequency of the LC series resonant circuit, so that the LC series resonant circuit can filter out more non-target RF signals of different frequencies, thereby enhancing the out-of-band attenuation function of the low noise amplifier. In addition, the LC series resonant circuit exhibits inductive reactance characteristics within the operating frequency band of the low noise amplifier, and can also achieve the best matching of noise and gain of the low noise amplifier.

[0098] In a specific application, in order to adjust the capacitive reactance value of the first variable capacitor Cb1, the first variable capacitor Cb1 may be connected to a controller. The controller may be used to adjust the capacitive reactance value of the first variable capacitor Cb1.

[0099] Exemplarily, the controller may store a correspondence between the frequencies of multiple first signals to be suppressed and the capacitive reactance values ​​of the first variable capacitor Cb1. The capacitive reactance value of the first variable capacitor Cb1 corresponding to each pre-stored frequency of the first signal to be suppressed can make the resonant frequency of the LC series resonant circuit equal to the frequency of the first signal to be suppressed, so that the LC series resonant circuit can filter out the first signal to be suppressed. Among them, the frequencies of multiple first signals to be suppressed can all be less than the lower limit of the working frequency band of the low noise amplifier. Based on this, when it is necessary to filter out a non-target RF signal whose frequency is less than the lower limit of the working frequency band of the low noise amplifier, the controller can determine the target capacitive reactance value of the first variable capacitor Cb1 corresponding to the non-target RF signal based on the correspondence between the frequencies of multiple pre-stored first signals to be suppressed and the capacitive reactance value of the first variable capacitor Cb1, and adjust the actual capacitive reactance value of the first variable capacitor Cb1 to the target capacitive reactance value, so that the LC series resonant circuit can filter out the non-target RF signal.

[0100] Optionally, when an RF signal with a power greater than or equal to a preset power threshold is input to the input terminal IN of the low noise amplifier, the power protection subunit 20111 is turned on, that is, the power protection subunit 20111 enters a working state from a non-working state. At this time, the impedance of the power protection subunit 20111 to the ground is almost 0, so that a high-power RF signal with a power greater than or equal to the preset power threshold can be discharged to the ground through the ground terminal of the low noise amplifier, thereby preventing the high-power RF signal from damaging the low noise amplifier.

[0101] It can be seen from the above that by setting the first inductor, the first variable capacitor and the power protection subunit in the first suppression protection unit, and connecting the first inductor and the first variable capacitor in series, and connecting the power protection subunit and the first variable capacitor in parallel, when the power protection subunit is in a non-working state, the power protection subunit, the first variable capacitor and the first inductor constitute an LC series resonant circuit with an adjustable resonant frequency, and the resonant frequency of the LC series resonant circuit can be adjusted by adjusting the capacitive reactance value of the first variable capacitor, thereby filtering out non-target RF signals with a frequency equal to the resonant frequency of the LC series resonant circuit; at the same time, when a high-power RF signal with a power greater than a preset power threshold is input to the input end of the low-noise amplifier, the power protection subunit can be put into a working state, and since the resistance to ground is 0 when the power protection subunit is in a working state, the high-power RF signal can be discharged to the ground through the grounding terminal, thereby preventing the high-power RF signal from damaging the low-noise amplifier.

[0102] See also Figure 5 , is a schematic diagram of the circuit principle of a low noise amplifier provided in another embodiment of the present application.

[0103] like Figure 5 As shown, in a specific implementation, the power protection subunit 20111 may include at least one first diode D1 and / or at least one second diode D2. At least one first diode D1 may be used to form a forward power protection path of the power protection subunit 20111, and the forward power protection path may be used to discharge a high-power RF signal whose voltage is higher than the ground voltage to the ground through the ground terminal of the low-noise amplifier. At least one second diode D2 may be used to form a negative power protection path of the power protection subunit 20111, and the negative power protection path may be used to discharge a negative high-power signal whose voltage is lower than the ground voltage to the ground through the ground terminal of the low-noise amplifier.

[0104] In a specific application, the number of the first diodes D1 and the number of the second diodes D2 may be the same or different. The embodiment of the present application does not specifically limit the number of the first diodes D1 and the number of the second diodes D2.

[0105] Optionally, when the power protection subunit 20111 includes a first diode D1 and a second diode D2, the positive electrode of the first diode D1 can be commonly connected to the negative electrode of the second diode D2 and used as the first end of the power protection subunit 20111, and the negative electrode of the first diode D1 can be commonly connected to the positive electrode of the second diode D2 and used as the second end of the power protection subunit 20111. In this case, the preset power threshold can include a first power threshold and a second power threshold. The first power threshold can be the product of the conduction voltage of the first diode D1 and the input current of the low-noise amplifier; the second power threshold can be the product of the conduction voltage of the second diode D2 and the input current of the low-noise amplifier. The power protection subunit 20111 can discharge a high-power non-target radio frequency signal with a power greater than the first power threshold and a voltage greater than the ground terminal voltage to the ground; or can discharge a high-power non-target radio frequency signal with a power greater than the second power threshold and a voltage less than the ground terminal to the ground.

[0106] Optionally, when the power protection subunit 20111 includes a plurality of first diodes D1 and a second diode D2, the positive electrode of the first first diode D1 can be commonly connected to the negative electrode of the second diode D2 and used as the first end of the power protection subunit 20111, the negative electrode of the last first diode D1 can be commonly connected to the positive electrode of the second diode D2 and used as the second end of the power protection subunit 20111, and the positive electrode of the i-th first diode D1 can be connected to the negative electrode of the (i - 1)-th first diode D1. Wherein, 1 < i ≤ n, and n is the number of the first diodes D1. In this case, the preset power threshold can include a third power threshold and a second power threshold. The third power threshold can be the product of the sum of the conduction voltages of the plurality of first diodes D1 and the input current of the low-noise amplifier. The power protection subunit 20111 can discharge a high-power non-target radio frequency signal with a power greater than the third power threshold and a voltage greater than the ground terminal voltage to the ground; or can discharge a high-power non-target radio frequency signal with a power greater than the second power threshold and a voltage less than the ground terminal to the ground.

[0107] Optionally, when the power protection subunit 20111 includes a first diode D1 and multiple second diodes D2, the positive electrode of the first diode D1 can be commonly connected to the negative electrode of the first second diode D2 and serve as the first end of the power protection subunit 20111, and the negative electrode of the first diode D1 can be commonly connected to the positive electrode of the last second diode D2 and serve as the second end of the power protection subunit 20111. The negative electrode of the j-th second diode D2 can be connected to the positive electrode of the (j - 1)-th second diode D2. Here, 1 < j ≤ m, and m is the number of second diodes D2. In this case, the preset power threshold can include a first power threshold and a fourth power threshold. The fourth power threshold can be the product of the sum of the conduction voltages of the multiple second diodes D2 and the input current of the low-noise amplifier. The power protection subunit 20111 can discharge a high-power non-target radio frequency signal with a power greater than the first power threshold and a voltage greater than the ground terminal voltage to the ground; or can discharge a high-power non-target radio frequency signal with a power greater than the fourth power threshold and a voltage less than the ground terminal to the ground.

[0108] Optionally, when the power protection subunit 20111 includes multiple first diodes D1 and multiple second diodes D2, the positive electrode of the first first diode D1 can be commonly connected to the negative electrode of the first second diode D2 and serve as the first end of the power protection subunit 20111, and the negative electrode of the last first diode D1 can be commonly connected to the positive electrode of the last second diode D2 and serve as the second end of the power protection subunit 20111. The positive electrode of the i-th first diode D1 can be connected to the negative electrode of the (i - 1)-th first diode D1, and the negative electrode of the j-th second diode D2 can be connected to the positive electrode of the (j - 1)-th second diode D2. Here, 1 < j ≤ m, and m is the number of second diodes D2; 1 < j ≤ m, and m is the number of second diodes D2. In this case, the preset power threshold can include a third power threshold and a fourth power threshold. The power protection subunit 20111 can discharge a high-power non-target radio frequency signal with a power greater than the third power threshold and a voltage greater than the ground terminal voltage to the ground; or can discharge a high-power non-target radio frequency signal with a power greater than the fourth power threshold and a voltage less than the ground terminal to the ground.

[0109] For the low-noise amplifier provided in this embodiment, when a high-power radio frequency signal with a power greater than the preset power threshold is input to the input terminal IN of the low-noise amplifier, it can make each first diode D1 and / or each second diode D2 in the power protection subunit 20111 be in a conducting state, so that the power protection subunit 20111 enters a working state, achieving the purpose of discharging the high-power radio frequency signal to the ground through the ground terminal of the low-noise amplifier.

[0110] In a specific application, for example, the first diode D1 and the second diode D2 may include but are not limited to silicon-based diodes or complementary metal oxide semiconductors (CMOS), etc. The embodiment of the present application does not specifically limit the specific types of the first diode D1 and the second diode D2.

[0111] This embodiment provides a positive power protection path and a negative power protection path, so as to simultaneously filter out high-power RF signals with a voltage greater than the ground voltage and high-power RF signals with a voltage less than the ground voltage, thereby facilitating comprehensive protection of the low-noise amplifier.

[0112] In other embodiments, the input matching module 202 can also be used to match the input impedance of the low noise amplifier with the output impedance of the pre-stage circuit to ensure that the RF signal output by the pre-stage circuit can be transmitted to the amplification module 203 with maximum power. The pre-stage circuit may refer to a circuit located before the input end of the low noise amplifier in the signal transmission direction. Exemplarily, the pre-stage circuit may include Figure 1 The second filter 1122 and the receiving antenna 132, etc.

[0113] Based on this, please continue to refer to Figure 5 In a specific implementation, the input matching module 202 may include a second inductor L2. The second inductor L2 may be connected between the input terminal IN of the low noise amplifier and the input matching terminal of the amplification module 203. In a specific application, the input impedance of the low noise amplifier may be adjusted by adjusting the inductance value of the second inductor L2. By selecting a suitable inductance value for the second inductor L2, the input impedance of the low noise amplifier may be adjusted to a state matching the output impedance of the preceding circuit, thereby facilitating the reduction of the reflection of the radio frequency signal at the input terminal IN of the low noise amplifier, so that the radio frequency signal can be more effectively transmitted from the preceding circuit to the amplification module 203.

[0114] In some other embodiments, the input matching module 202 can also be used to isolate the DC signal to prevent the DC signal from entering the amplification module 203. Figure 5 In another specific implementation, the input matching module 202 may further include a first fixed capacitor Cg1. The first fixed capacitor Cg1 may be connected in series with the second inductor L2 between the input terminal IN of the low noise amplifier and the input matching terminal of the amplification module 203. The first fixed capacitor Cg1 may be used to isolate the DC signal received by the input terminal IN of the low noise amplifier to prevent the DC signal from entering the amplification module 203 and affecting the linear amplification operating point of the amplification module 203.

[0115] In other embodiments, the first fixed capacitor Cg1 can participate in the input impedance matching of the low noise amplifier. For example, the input impedance of the low noise amplifier can be adjusted by adjusting the inductive reactance value of the second inductor L2 and the capacitive reactance value of the first fixed capacitor Cg1 to adjust the input impedance of the low noise amplifier to match the output impedance of the previous stage circuit.

[0116] In another specific implementation, the amplification module 203 may include a transistor with a signal amplification function. The number of transistors included in the amplification module 203 may be set according to actual needs, and the embodiment of the present application does not specifically limit it.

[0117] For example, when the amplifying module 203 includes two transistors, the two transistors may be configured as a common source and common gate structure. The specific structure of the amplifying module 203 is described below by taking the amplifying module 203 adopting the common source and common gate structure as an example.

[0118] Please continue reading Figure 5 , the amplifier module 203 adopting the common source and common gate structure may include a first transistor Q1, a second transistor Q2 and a third inductor L3. Among them, the first transistor Q1 can be used as a common source transistor, and the second transistor Q2 can be used as a common gate transistor. Based on this, the gate of the first transistor Q1 can be used as the input matching end of the amplifier module 203, the source of the first transistor Q1 can be grounded through the third inductor L3, the drain of the first transistor Q1 can be connected to the source of the second transistor Q2, and the drain of the second transistor can be used as the output matching end of the amplifier module 203. The first transistor Q1 and the second transistor Q2 can be used to perform voltage amplification processing on the radio frequency signal received by the amplifier module 203. The third inductor L3 can be used to reduce the nonlinear distortion of the first transistor Q1 and improve the working stability of the first transistor Q1; it can also be used to improve the input matching and output matching of the low noise amplifier to ensure the effective transmission of the radio frequency signal.

[0119] In specific applications, the first transistor Q1 and the second transistor Q2 may include but are not limited to silicon-based CMOS, silicon-germanium heterojunction bipolor transistor (SiGeHBT), GaAs pseudomorphic high electron mobility transistor (GaAs PHEMT) and GaN high electron mobility transistor (GaN HEMT), etc. The embodiment of the present application does not specifically limit the specific types of the first transistor Q1 and the second transistor Q2.

[0120] It is understandable that in order to ensure that the first transistor Q1 and the second transistor Q2 both operate in the linear amplification region, so as to linearly amplify the RF signal to be amplified without introducing excessive distortion and noise, the gate of the first transistor Q1 and the gate of the second transistor Q2 may also be provided with a bias network. Figure 5 The gate of the first transistor Q1 may be connected to a first bias network, and the first bias network may be used to provide a bias voltage for the first transistor Q1 to ensure that the first transistor Q1 operates in a linear amplification region. The gate of the second transistor Q2 may be connected to a second bias network, and the second bias network may be used to provide a bias voltage for the second transistor Q2 to ensure that the second transistor Q2 operates in a linear amplification region.

[0121] In some other embodiments, the first bias network may be further connected to a controller. The controller may also be used to control the bias voltage output by the first bias network, thereby adjusting the operating point of the first transistor Q1.

[0122] In some other embodiments, the second bias network may be further connected to a controller. The controller may also be used to control the bias voltage output by the second bias network, thereby adjusting the operating point of the second transistor Q2.

[0123] In a specific application, the first bias network and the second bias network can be arranged inside the low noise amplifier according to actual needs as part of the internal structure of the low noise amplifier; or the first bias network and the second bias network can be arranged outside the low noise amplifier to reduce the area of ​​the low noise amplifier. The embodiment of the present application does not impose any limitation on the specific arrangement of the first bias network and the second bias network. In addition, the specific structure of the first bias network and the second bias network can also be arranged according to actual needs, and the embodiment of the present application does not impose any special limitation on it.

[0124] In some other embodiments, in order to prevent a DC signal from being input to the gate of the second transistor Q2, thereby affecting the linear operating point of the second transistor Q2, the gate of the second transistor Q3 may also be grounded via a capacitor (not shown).

[0125] In other embodiments, the output matching module 204 can also be used to match the output impedance of the low noise amplifier with the input impedance of the subsequent circuit to ensure that the RF signal output by the low noise amplifier can be transmitted to the subsequent circuit with maximum power. The subsequent circuit may refer to a circuit located after the output end of the low noise amplifier in the signal transmission direction. Exemplarily, the subsequent circuit may include Figure 1 The RF transceiver in the .

[0126] Based on this, in a specific implementation, the output matching module 204 may include a first resistor R1, a fifth inductor L5, and a second fixed capacitor Cg2. The first end of the first resistor R1, the first end of the fifth inductor L5, and the first end of the second fixed capacitor Cg2 may be commonly connected to the power supply terminal VDD of the low noise amplifier, and the second end of the first resistor R1, the second end of the fifth inductor L5, and the second end of the second fixed capacitor Cg2 may be commonly connected to the output matching terminal of the amplification module 203.

[0127] In a specific application, the output impedance of the low noise amplifier can be adjusted by adjusting the impedance value of the first resistor R1, the inductive reactance value of the fifth inductor L5, and / or the capacitive reactance value of the second fixed capacitor Cg2. By selecting a suitable impedance value for the first resistor R1, and / or selecting a suitable inductive reactance value for the fifth inductor L5, and / or selecting a suitable capacitive reactance value for the second fixed capacitor Cg2, the output impedance of the low noise amplifier can be adjusted to a state matching the input impedance of the subsequent circuit, which is beneficial to reducing the reflection of the radio frequency signal by the subsequent circuit, so that the radio frequency signal can be more effectively transmitted from the low noise amplifier to the subsequent circuit.

[0128] In some other embodiments, the output matching module 204 can also be used to isolate the DC signal to prevent the DC signal from flowing to the subsequent circuit. Figure 5 In another specific embodiment, the output matching module 204 may include a third fixed capacitor Cg3. A first end of the third fixed inductor Cg3 may be connected to the output matching end of the amplification module 203, and a second end of the third fixed inductor Cg3 may be connected to the output end OUT of the low noise amplifier. The third fixed inductor Cg3 may be used to isolate the DC signal to ensure that the DC signal does not flow to the subsequent circuit, thereby maintaining the stability of the RF receiver.

[0129] See also Figure 6 , is a schematic diagram of the circuit principle of a low noise amplifier provided in yet another embodiment of the present application.

[0130] and Figure 5 Compared with the corresponding low noise amplifier, the first inductor L1 and the second inductor L2 of the low noise amplifier in this embodiment are coupled, that is, the first inductor L1 and the second inductor L2 can be coupled as a transformer. Among them, the coupling coefficient between the first inductor L1 and the second inductor L2 can be set according to actual needs, and it is not particularly limited here. In this embodiment, the area of ​​the low noise amplifier can be reduced by coupling the first inductor L1 and the second inductor L2.

[0131] See also Figure 7 , is a structural diagram of a low noise amplifier provided in yet another embodiment of the present application.

[0132] and Figure 3-Figure 6 Compared with the corresponding low noise amplifier, the input protection module 201 of the low noise amplifier in this embodiment includes not only the first suppression protection unit 2011, but also a second suppression unit 2012. The second suppression unit 2012 can be coupled with the second inductor L2 in the amplification module 203, and the second suppression unit 2012 can be grounded.

[0133] The second suppression unit 2012 can be used to suppress non-target RF signals received at the input end IN of the low noise amplifier and having a frequency greater than the upper limit value of the operating frequency band of the low noise amplifier, so as to avoid non-target RF signals with a frequency greater than the upper limit value of the operating frequency band of the low noise amplifier from entering the amplification module 203, thereby achieving suppression of non-target RF signals with a frequency greater than the upper limit value of the operating frequency band of the low noise amplifier.

[0134] The upper limit value of the operating frequency band of the low noise amplifier may refer to the larger frequency boundary value of the two frequency boundary values ​​used to limit the operating frequency band of the low noise amplifier. Exemplarily, assuming that the operating frequency band of the low noise amplifier is 2.35 GHz to 2.45 GHz, the upper limit value of the operating frequency band of the low noise amplifier may be 2.45 GHz.

[0135] It can be seen from the above that the low noise amplifier provided in this embodiment can not only filter out non-target RF signals with a frequency less than the lower limit of the working frequency band of the low noise amplifier, but also filter out non-target RF signals with a frequency greater than the upper limit of the working frequency band of the low noise amplifier by setting the first suppression protection unit and the second suppression unit in the input protection module, thereby preventing RF signals in the non-working frequency band of the low noise amplifier from entering the amplification module, and at the same time preventing high-power RF signals from damaging the low noise amplifier, so that the low noise amplifier has both out-of-band attenuation function and input power protection function.

[0136] See also Figure 8 , is a schematic diagram of the circuit principle of a low noise amplifier provided in yet another embodiment of the present application.

[0137] like Figure 8 As shown, in a specific implementation, the second suppression unit 2012 may include a second variable capacitor Cb2 and a fourth inductor L4. The first end of the second variable capacitor Cb2 may be connected to the first end of the fourth inductor L4, the second end of the second variable capacitor Cb2 may be connected to the ground together with the second end of the fourth inductor L4, and the fourth inductor L4 may be coupled with the third inductor L3, that is, the fourth inductor L4 and the third inductor L3 may be coupled to form a transformer. The coupling coefficient between the fourth inductor L4 and the third inductor L3 may be set according to actual needs, and is not particularly limited here.

[0138] In this embodiment, the second variable capacitor Cb2 and the fourth inductor L4 form an LC parallel resonant circuit with adjustable resonant frequency. The LC parallel resonant circuit presents high impedance at the resonant frequency, so it is possible to suppress the RF signal received by the receiving end IN of the low-noise amplifier with a frequency equal to the resonant frequency of the LC parallel resonant circuit.

[0139] Based on this, in a specific application, the capacitive reactance value of the second variable capacitor Cb2 can be adjusted according to the frequency of the non-target RF signal to be filtered out. By adjusting the capacitive reactance value of the second variable capacitor Cb2, the resonant frequency of the LC parallel resonant circuit can be adjusted, thereby suppressing non-target RF signals of different frequencies.

[0140] In a specific application, the LC parallel resonant circuit can be configured to suppress non-target RF signals whose frequencies are greater than the upper limit of the operating frequency band of the low noise amplifier. Exemplarily, when it is necessary to suppress non-target RF signals of multiple different frequencies whose frequencies are greater than the upper limit of the operating frequency band of the low noise amplifier, the resonant frequencies of the LC parallel resonant circuit can be adjusted to be equal to the frequencies of the multiple non-target RF signals that need to be suppressed by adjusting the capacitive reactance value of the second variable capacitor Cb2, thereby achieving suppression of non-target signals of multiple different frequencies whose frequencies are greater than the upper limit of the operating frequency band of the low noise amplifier. For example, when it is necessary to suppress non-target RF signals with a frequency of 3 GHz from entering the amplification module 203, the resonant frequency of the LC parallel resonant circuit can be adjusted to 3 GHz by adjusting the capacitive reactance value of the second variable capacitor Cb2, thereby suppressing non-target RF signals with a frequency of 3 GHz from entering the amplification module 203.

[0141] In a specific application, in order to adjust the capacitive reactance value of the second variable capacitor Cb2, the second variable capacitor Cb2 may be connected to a controller. The controller may be used to adjust the capacitive reactance value of the second variable capacitor Cb2.

[0142] Exemplarily, the controller may store a correspondence between the frequencies of multiple second signals to be suppressed and the capacitive reactance values ​​of the second variable capacitor Cb2. The capacitive reactance value of the second variable capacitor Cb2 corresponding to the frequency of each pre-stored second signal to be suppressed can make the resonant frequency of the LC parallel resonant circuit equal to the frequency of the second signal to be suppressed, so that the LC parallel resonant circuit can suppress the second signal to be suppressed. Among them, the frequencies of multiple second signals to be suppressed can all be greater than the upper limit of the working frequency band of the low noise amplifier. Based on this, when it is necessary to suppress a non-target RF signal whose frequency is greater than the upper limit of the working frequency band of the low noise amplifier, the controller can determine the target capacitive reactance value of the second variable capacitor Cb2 corresponding to the non-target RF signal based on the correspondence between the frequencies of multiple pre-stored second signals to be suppressed and the capacitive reactance value of the second variable capacitor Cb2, and adjust the actual capacitive reactance value of the second variable capacitor Cb2 to the target capacitive reactance value, so that the LC parallel resonant circuit can suppress the non-target RF signal.

[0143] It can be seen from the above that by configuring the second suppression unit as an LC parallel resonance circuit coupled to the third inductor and grounded, and configuring the resonant frequency of the LC parallel resonance to be greater than the upper limit value of the operating frequency band of the low noise amplifier, it is possible to suppress non-target RF signals greater than the upper limit value of the operating frequency band of the low noise amplifier.

[0144] Based on the same technical concept, the present application embodiment also provides a radio frequency front-end module. Fig. 9 , is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of the present application. Fig. 9 As shown, the RF front-end module can be used to connect the RF transceiver and the antenna. The RF front-end module may include a RF receiving link, and the RF receiving link may include Figure 2-Figure 8 The low noise amplifier in the embodiment corresponding to any one of the figures, the input end of the low noise amplifier can be used to connect to a receiving antenna, and the output end of the low noise amplifier can be used to connect to a radio frequency receiver.

[0145] Based on the same technical concept, the present application embodiment also provides a mobile communication module or a wireless communication module. Fig.10 , is a schematic diagram of the structure of a mobile communication module or a wireless communication module provided in an embodiment of the present application. Fig.10 As shown, the mobile communication module or wireless communication module may include a radio frequency transceiver and Fig. 9 The RF receiving link shown may be connected between the antenna and the RF transceiver.

[0146] Based on the same technical concept, the present application also provides an electronic device, see Fig.11, is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Fig.11 As shown, the electronic device may include Fig.10 The mobile communication module and / or wireless communication module shown.

[0147] In the above embodiments, the description of each embodiment has its own emphasis. For the parts not described or recorded in detail in a certain embodiment, please refer to the relevant description of other embodiments. It should be understood that the size of the sequence number of each step in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0148] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state drive (SSD)), etc.

[0149] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

[0150] The above is only a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited thereto, and any changes or replacements within the technical scope disclosed in the embodiment of the present application should be included in the protection scope of the embodiment of the present application. Therefore, the protection scope of the embodiment of the present application should be based on the protection scope of the claims.

Claims

1. A low noise amplifier, characterized in that: It includes an input protection module, an input matching module, an amplification module and an output matching module; The input protection module is connected between the input terminal and the ground terminal of the low noise amplifier, and is used to filter out non-target radio frequency signals received by the input terminal whose frequencies are in the non-working frequency band of the low noise amplifier, and to discharge high-power radio frequency signals received by the input terminal whose power is greater than or equal to a preset power threshold to the ground through the ground terminal; The input matching module is connected between the input end and the input matching end of the amplifying module, and is used to transmit the radio frequency signal to be amplified received by the input end to the amplifying module; The amplification module is used to amplify the radio frequency signal to be amplified to obtain an amplified radio frequency signal, and transmit the amplified radio frequency signal to the output matching module; The output matching module is connected to the output matching end of the amplifying module, the power supply end of the low noise amplifier and the output end of the low noise amplifier, and is used to output the amplified RF signal; The input protection module includes a first suppression protection unit; The first suppression protection unit is connected between the input terminal and the ground terminal of the low noise amplifier; the first suppression protection unit is used to filter out non-target radio frequency signals with a frequency less than the lower limit of the working frequency band received by the input terminal, and to discharge the high-power radio frequency signals with a power greater than or equal to a preset power threshold received by the input terminal to the ground through the ground terminal; The first suppression protection unit includes a first inductor, a first variable capacitor and a power protection subunit; a first end of the first inductor is connected to the input end, a second end of the first inductor is connected to a first end of the power protection subunit and a first end of the first variable capacitor, and a second end of the power protection subunit and a second end of the first variable capacitor are both connected to the ground end; The power protection subunit includes a working state and a non-working state; when the high-power RF signal is not input at the input end, the power protection subunit is in a non-working state and electrically presents a parasitic capacitor; the parasitic capacitor, the first variable capacitor and the first inductor constitute an LC series resonant circuit with an adjustable resonant frequency; by adjusting the capacitive reactance value of the first variable capacitor, the resonant frequency of the LC series resonant circuit is equal to the frequency of the non-target RF signal, and the LC series resonant circuit is used to filter out non-target RF signals with a frequency equal to the resonant frequency of the LC series resonant circuit; the resonant frequency of the LC series resonant circuit is configured to be less than the lower limit value of the working frequency band; when the high-power RF signal is input at the input end, the power protection subunit is in a working state and is used to discharge the high-power RF signal to the ground through the ground terminal.

2. The low noise amplifier according to claim 1, characterized in that: The first variable capacitor is also connected to a controller; the controller is used to determine the target capacitive reactance value of the first variable capacitor corresponding to the non-target RF signal to be filtered out based on the correspondence between the frequencies of multiple pre-stored first signals to be suppressed and the capacitive reactance values ​​of the first variable capacitor, and adjust the capacitive reactance value of the first variable capacitor to the target capacitive reactance value; the frequency of the first signal to be suppressed is less than the lower limit value of the working frequency band.

3. The low noise amplifier according to claim 1, characterized in that: The power protection subunit includes at least one first diode and at least one second diode; The at least one first diode is used to form a forward power protection path of the power protection subunit, and the forward power protection path is used to discharge a high-power radio frequency signal with a voltage higher than the ground voltage to the ground through the ground terminal; The at least one second diode is used to form a negative power protection path of the power protection subunit, and the negative power protection path is used to discharge a high-power radio frequency signal with a voltage lower than the ground terminal voltage to the ground through the ground terminal.

4. The low noise amplifier according to claim 1, characterized in that: The input matching module includes a second inductor, which is connected between the input end of the low-noise amplifier and the input matching end of the amplification module; the second inductor is used to achieve matching between the input impedance of the low-noise amplifier and the output impedance of the previous stage circuit; the previous stage circuit refers to a circuit located before the input end of the low-noise amplifier in the signal transmission direction.

5. The low noise amplifier according to claim 4, characterized in that: The first inductor and the second inductor are coupled to each other.

6. The low noise amplifier according to any one of claims 1 to 5, characterized in that: The amplification module includes a first transistor, a second transistor and a third inductor; The gate of the first transistor serves as an input matching terminal of the amplifying module, the source of the first transistor is connected to the ground terminal through the third inductor, the drain of the first transistor is connected to the source of the second transistor, and the drain of the second transistor serves as an output matching terminal of the amplifying module.

7. The low noise amplifier according to claim 6, characterized in that: The input protection module further includes a second suppression unit, the second suppression unit is connected to the ground terminal and is coupled with the third inductor; The second suppression unit is used to suppress non-target radio frequency signals whose frequencies are greater than an upper limit value of the working frequency band.

8. The low noise amplifier according to claim 7, characterized in that: The second suppression unit includes a second variable capacitor and a fourth inductor; the first end of the second variable capacitor is connected to the first end of the fourth inductor, the second end of the second variable capacitor and the second end of the fourth inductor are both connected to the ground end, and the fourth inductor is coupled to the third inductor; The second variable capacitor and the fourth inductor form an LC parallel resonant circuit with adjustable resonant frequency, and the LC parallel resonant circuit is used to suppress non-target radio frequency signals having a frequency equal to the resonant frequency of the LC parallel resonant circuit; the resonant frequency of the LC parallel resonant circuit is greater than the upper limit value of the operating frequency band.

9. A radio frequency front-end module, characterized in that: It includes a radio frequency receiving link; the radio frequency receiving link includes a low noise amplifier as described in any one of claims 1 to 8, the input end of the low noise amplifier is used to connect to an antenna, and the output end of the low noise amplifier is used to connect to a radio frequency receiver.

10. An electronic device, characterized in that: It comprises a processor and the radio frequency front-end module as claimed in claim 9, wherein the processor is connected to the radio frequency front-end module.

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