Low noise amplifier, radio frequency device and low noise amplification method

Abstract

The present invention provides a low-noise amplifier, a radio frequency device and a low-noise amplification method, wherein the low-noise amplifier includes: an input matching module, an output matching module, a first amplification module, n second amplification modules and m current multiplexing modules; the input matching module matches the impedance of the radio frequency input signal; the first amplification module is cascaded with each second amplification module and amplifies the signal step by step; each second amplification module includes a transistor, the first end of the transistor is used as the input end, and the second end is used as the output end; the output matching module matches the impedance of the signal after multi-stage amplification; the m current multiplexing modules are respectively set corresponding to m of the n second amplification modules, collect the multiplexed current signal of the third end of the corresponding transistor and output it to the first amplification module. The present invention collects the multiplexed current signal of at least one second amplification module through the current multiplexing module and merges it into the output end of the first amplification module to increase the current density of the radio frequency circuit of the first amplification module.

Description

Technical Field

[0001] The present invention relates to the field of wireless communications, and in particular to a low noise amplifier, a radio frequency device and a low noise amplification method. Background Art

[0002] With the rapid development of modern wireless communication technology, the system's requirements for RF receivers are getting higher and higher. As one of the most critical components of the RF front end, the low noise amplifier's main function is to reduce noise interference while amplifying the antenna's received signal. With the continuous improvement of chip integration and performance, chip power consumption has also become an important indicator affecting chip performance. Excessive power consumption will have a negative impact on the chip. As the chip temperature continues to rise, the chip's performance and stability will both decline. In addition, for systems such as modern active phased array receivers, the number of low noise amplifiers can easily reach thousands, and the total power consumption of the system has increased significantly. Low power consumption design is also needed to reduce the total power consumption of the system.

[0003] The low-power design in commonly used amplifiers is often achieved by sharing the same DC current. Taking a three-stage low-noise amplifier as an example, the amplifier circuit is composed of three cascaded transistors. Since the transistor cascade is realized by connecting the source and drain, this results in only one current path for the current. Therefore, the three transistors share the same DC current. However, such a setting has high noise and due to such a setting, only the drain of the last-stage amplifier module can be loaded with a bias voltage. After the bias voltage of the last-stage transistor is set, the bias voltage of each transistor can no longer be adjusted, which limits the output dynamic range of the amplifier.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a low noise amplifier, a radio frequency device and a low noise amplification method, which are used to solve the problems of high noise and inability to adjust the output dynamic range in the prior art.

[0006] To achieve the above object and other related objects, the present invention provides a low noise amplifier, comprising:

[0007] An input matching module, an output matching module, a first amplifying module, n second amplifying modules and m current multiplexing modules; wherein n is an integer greater than or equal to 1 and m is less than or equal to n;

[0008] The input matching module receives a radio frequency input signal and is used to perform impedance matching on the radio frequency input signal to obtain a matching signal;

[0009] The first amplifying module is cascaded with each of the second amplifying modules and an input end of the first amplifying module receives the matching signal, so as to perform step-by-step power amplification on the matching signal; wherein each of the second amplifying modules comprises a transistor, a first end of the transistor serves as an input end of the second amplifying module, and a second end of the transistor serves as an output end of the second amplifying module;

[0010] The output matching module is connected to the output end of the second amplifying module of the nth stage, and is used to perform impedance matching on the matching signal after multi-stage power amplification to obtain a radio frequency output signal;

[0011] The m current multiplexing modules are respectively arranged in one-to-one correspondence with m of the n second amplifying modules, and are used to collect the multiplexed current signal of the third end of the transistor in the corresponding second amplifying module and output it to the output end of the first amplifying module to increase the current density of the first amplifying module.

[0012] Optionally, the input matching module includes a first capacitor, a second capacitor and a first inductor; the RF input signal is connected to the input end of the first amplification module via the first capacitor; the first end of the first inductor is connected to the node between the first capacitor and the first amplification module, and the second end is connected to a first bias voltage; the first end of the second capacitor is connected to the node between the first bias voltage and the first inductor, and the second end is connected to a reference ground.

[0013] Optionally, the second amplifying module further includes a first voltage supply unit; the first voltage supply unit is arranged at the first end of the transistor, and is used to provide a bias voltage for the first end of the transistor.

[0014] Optionally, the second amplification module further includes a second voltage supply unit; the second voltage supply unit is arranged at the second end of the transistor, and is used to provide a bias voltage for the second end of the transistor.

[0015] Optionally, the output matching module includes a second inductor and a third capacitor; the signal output by the nth second amplification module is sequentially obtained through the second inductor and the third capacitor connected in series to obtain the RF output signal.

[0016] Optionally, the current multiplexing module includes a fourth capacitor, a first resistor and a third inductor; the multiplexed current signal is connected to the output end of the first amplification module via the first resistor and the third inductor in sequence; the first plate of the fourth capacitor is connected to the third end of the corresponding transistor, and the second plate is connected to the reference ground.

[0017] Optionally, the low-noise amplifier also includes n isolation matching modules; each isolation matching module is arranged in a one-to-one correspondence with each second amplification module, and is arranged before the input end of each second amplification module, and is used to receive the DC signal in the output signal of the previous stage amplification module and isolate and output it to the input end of the next stage amplification module. The isolation matching module is also used to impedance match the signal output by the previous stage amplification module and output it.

[0018] Optionally, the isolation matching module includes a fourth inductor and a fifth capacitor; the fourth inductor and the fifth capacitor are arranged in series to form a first series structure; the first end of the first series structure receives the signal output by the previous stage amplification module, and the second end is connected to the corresponding input end of the second amplification module.

[0019] Optionally, when the second amplifying module further includes a second voltage supply unit, the second voltage supply unit is connected to a node between the fourth inductor and the fifth capacitor, and provides a bias voltage for the second end of the transistor via the fourth inductor.

[0020] Optionally, the low noise amplifier further includes a feedback module; the feedback module is connected in parallel with the nth second amplifying module, and is used to collect the signal output by the nth second amplifying module and feed it back to the input end of the nth second amplifying module.

[0021] Optionally, the low noise amplifier further includes a stabilization module; the stabilization module is arranged between the input end of any current multiplexing module and a reference ground to improve the stability of the low noise amplifier.

[0022] To achieve the above object and other related objects, the present invention provides a radio frequency device including the above-mentioned low noise amplifier.

[0023] To achieve the above object and other related objects, the present invention provides a low noise amplification method, which is implemented based on the above low noise amplifier and includes:

[0024] The multiplexed current signals of the third terminals of the transistors in the m second amplifying modules are collected and output to the output terminal of the first amplifying module, so as to increase the current density of the first amplifying module.

[0025] Optionally, when the second amplification module further includes a second voltage supply unit, the output voltage of each second voltage supply unit is adjusted respectively to change the dynamic gain range of the low noise amplifier.

[0026] As described above, the low noise amplifier, radio frequency device and low noise amplification method of the present invention have the following beneficial effects:

[0027] The present invention provides a new type of current multiplexing module, which collects and merges the multiplexed current signal of at least one second amplifying module into the output end of the first amplifying module to increase the current density of the RF circuit of the first amplifying module, so that the noise curve is closer to the minimum value, and the noise coefficient of the low-noise amplifier is reduced. In addition, a second power supply unit is provided in the second amplifying module to ensure that the bias voltage of the second end of the transistor in the second amplifying module can be adjusted to achieve a larger dynamic range of the low-noise amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shown is a schematic diagram of a framework of a low noise amplifier of the present invention.

[0029] Figure 2 Shown is a schematic diagram of the framework of another low noise amplifier of the present invention.

[0030] Figure 3 Display as Figure 2 Schematic diagram of the structure of a low noise amplifier.

[0031] Component number description

[0032] 1- low noise amplifier; 11- input matching module; 12- first amplifying module; 13- second amplifying module; 131- transistor; 132- first voltage supply unit; 133- second voltage supply unit; 14- output matching module; 15- current multiplexing module; 16- feedback module; 17- isolation matching module; 18- stabilization module. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] See also Figure 1~Figure 3 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0035] Example

[0036] like Figure 1~Figure 3As shown, this embodiment provides a low noise amplifier 1, including: an input matching module 11, an output matching module 14, a first amplification module 12, n second amplification modules 13 and m current multiplexing modules; wherein n is an integer greater than or equal to 1 and m is less than or equal to n.

[0037] like Figure 1~Figure 3 As shown, the input matching module 11 receives a radio frequency input signal RFin, and is used to perform impedance matching on the radio frequency input signal RFin to obtain a matching signal.

[0038] Specifically, the input matching module 11 includes a first capacitor C1, a second capacitor C2 and a first inductor L1; the RF input signal RFin is connected to the input end of the first amplification module 12 via the first capacitor C1; the first end of the first inductor L1 is connected to the node between the first capacitor C1 and the first amplification module 12, and the second end is connected to the first bias voltage VG1; the first end of the second capacitor C2 is connected to the node between the first bias voltage VG1 and the first inductor L1, and the second end is connected to the reference ground.

[0039] As an example, in this embodiment, the RF input signal RFin is input through the RF signal input port. The first capacitor C1 in the input matching module 11 is used to isolate the first bias voltage VG1 and the RF signal input port to avoid interference between the DC signal and the RF signal. The first inductor L1 is used as a power supply inductor, and in this embodiment is used to bias the input end (the control end of the transistor in this embodiment) of the subsequent first amplification module 12. At the same time, the LC network composed of the first capacitor C1 in the input matching module 11 and the first inductor L1 can perform corresponding impedance matching on the input RF input signal RFin and output it. In this embodiment, the second capacitor C2 is used as a power decoupling capacitor to filter out high-frequency noise and ensure voltage stability.

[0040] It should be noted that the actual connection relationship of the input matching module 11 is not limited to this embodiment, and any setting that can perform input impedance matching on the RF input signal Rfin and provide a corresponding bias voltage is within the protection scope of this embodiment.

[0041] like Figure 1~Figure 3 As shown, the first amplifying module 12 is cascaded with each of the second amplifying modules 13 and the input end of the first amplifying module 12 receives the matching signal, which is used to perform step-by-step power amplification on the matching signal. The input end of the first amplifying module 12 receives the matching signal, and the output end is connected to the first second amplifying module 13.

[0042] Specifically, Figure 1~Figure 3As shown, the first amplifying module 12 includes a transistor for preliminarily amplifying the matching signal.

[0043] In this embodiment, the transistor is set as a first MOS tube M1 (set as a HMET tube in this embodiment), the source of the first MOS tube M1 is connected to the reference ground, the gate receives the matching signal, and the drain is connected to output the amplified matching signal. At the same time, in this embodiment, the drain of the first MOS tube M1 also receives the multiplexed current signal fed back by the current multiplexing module to increase the current density of the RF loop in the transistor, so that the overall noise curve of the low noise amplifier 1 is closer to the minimum value, and the noise coefficient is reduced.

[0044] It should be noted that the specific structure of the first amplification module 12 is not limited to this embodiment, and any setting that can preliminarily amplify the matching signal and receive subsequent feedback multiplexed current signals to change the current density of the entire RF circuit is within the protection scope of this embodiment.

[0045] like Figure 1~Figure 3 As shown, the second amplifying modules 13 of each stage are sequentially connected in series.

[0046] Specifically, each of the second amplifying modules 13 includes a transistor, a first end of the transistor serves as an input end of the second amplifying module 13, and a second end of the transistor serves as an output end of the second amplifying module 13. The first end of each transistor 131 receives an output signal of a previous module (in this embodiment, the previous module of the first-stage second amplifying module 13 is the first amplifying module 12, and the previous stage of the remaining second amplifying modules corresponds to the second amplifying modules 13), and the second end outputs the amplified output signal.

[0047] As an example, each transistor 131 is configured as a MOS tube, with a gate as a first terminal, a drain as a second terminal, and a source as a third terminal connected to a reference ground.

[0048] In this embodiment, the number of the second amplifying modules 13 is 2. The number of the second amplifying modules 13 is not limited to this embodiment. Figure 2 and Figure 3 The first amplifying module 12 and the two second amplifying modules 13 form a three-stage amplifying structure.

[0049] Specifically, each of the second amplifying modules 13 further includes a first voltage supply unit 132 ; the first voltage supply unit 132 is disposed at the first end of each transistor 131 , and is used to provide a bias voltage for the first end of each transistor 131 .

[0050] As an example, Figure 1~Figure 3As shown, the first voltage supply unit 132 includes a second resistor R2; the first end of the second resistor R2 is connected to the second bias voltage VG2, and the second end is connected to the first end of each corresponding transistor. In this embodiment, the second bias voltage VG2 is connected to the gate of each MOS tube via the second resistor R2 as a gate bias.

[0051] In this embodiment, the voltages provided by the first voltage supply units 132 in the second amplifying modules 13 of each stage may be different. That is, in this embodiment, the gates of the MOS tubes are loaded with different bias voltages, such as Figure 3 As shown, the first-stage second amplifying module 13 receives the second bias voltage VG2 , and the second-stage second amplifying module 13 receives the third bias voltage VG3 , and the voltage values ​​of the second bias voltage VG2 and the third bias voltage VG3 are different.

[0052] It should be noted that the specific setting of the first power supply voltage 132 is not limited to this embodiment, and any configuration that can provide a bias voltage for the first end of each second amplifying module 13 is within the protection scope of this embodiment.

[0053] Specifically, each of the second amplifying modules 13 further includes a second voltage supply unit 133 ; the second voltage supply unit 133 is disposed at the second end of each transistor, and is used to provide a bias voltage for the second end of each transistor.

[0054] As an example, Figure 1~Figure 3 As shown, the second voltage supply unit 133 includes a fifth inductor L5 and a sixth capacitor C6; the first end of the fifth inductor L5 is connected to the first gain voltage VD1, and the second end is connected to the second end of the corresponding transistor; the first electrode plate of the sixth capacitor C6 is connected to the first end of the fifth inductor L5, and the second electrode plate is connected to the reference ground, for power supply decoupling of the gain voltage VD1.

[0055] In this embodiment, the voltages provided by the second voltage supply units 133 in the second amplifying modules 13 of each stage may be different. That is, in this embodiment, the bias voltages loaded on the drains of the MOS tubes are different, such as Figure 3 As shown, the first-stage second amplifying module 13 receives the first gain voltage VD1 , and the second-stage second amplifying module 13 receives the second gain voltage VD2 . The voltage values ​​of the first gain voltage VD1 and the second gain voltage VD2 are different.

[0056] It should be noted that, in this embodiment, the gain voltage set in the second amplification module 13 is adjustable. By adjusting the magnitude of each gain voltage to change the bias voltage input to the drain of each MOS tube, the dynamic range of the final low noise amplifier 1 can be changed.

[0057] It should be further explained that the specific configuration of the second voltage supply unit 133 is not limited to this embodiment, and any configuration that can provide a bias voltage for the second end of each second amplifying module 13 is within the protection scope of this embodiment.

[0058] like Figure 1~Figure 3 As shown, the output matching module 14 is connected to the output end of the nth stage second amplifying module 13, and is used to perform impedance matching on the matching signal after multi-stage power amplification to obtain a radio frequency output signal RFout.

[0059] Specifically, the output matching module 14 includes a second inductor L2 and a third capacitor C3; the output signal of the n-th stage second amplification module 13 is sequentially connected in series to obtain the RF output signal.

[0060] In this embodiment, the third capacitor C3 in the output matching module 14 is used to avoid interference between the DC signal and the RF signal during signal output; the second inductor L2 is set as a peaking inductor. A peaking inductor is a specially designed inductor that has the characteristic of reaching a maximum inductance value at a specific frequency, while the inductance value decreases at other frequencies. Peaking inductance is usually achieved by using a specific coil structure and material, such as using an air core or a ferrite core, and adjusting the number of turns and distribution of the coil to improve high-frequency gain.

[0061] At the same time, the LC network composed of the third capacitor C3 and the second inductor L2 in the output matching module 14 can output the multi-stage amplified signal with corresponding impedance matching.

[0062] It should be noted that the actual connection relationship of the output matching module 14 is not limited to this embodiment, and any setting that can perform corresponding impedance matching output on the signal after multi-stage amplification is within the protection scope of this embodiment.

[0063] like Figure 1~Figure 3 As shown, the m current multiplexing modules 15 are respectively arranged in a one-to-one correspondence with m of the n second amplifying modules 13, and are used to collect the multiplexed current signal of the third end of the transistor in the corresponding second amplifying module 13 and output it to the output end of the first amplifying module 12, so as to increase the current density of the first amplifying module 12.

[0064] Specifically, the current multiplexing module 15 includes a fourth capacitor C4, a first resistor R1 and a third inductor L3; the multiplexed current signal is connected to the output end of the first amplification module 12 via the first resistor R1 and the third inductor L3 in sequence. The first plate of the fourth capacitor C4 is connected to the third end of the corresponding transistor, and the second plate is connected to the reference ground. Among them, the third inductor L3 and the fourth capacitor C4 are matched, and the third inductor L3, while participating in the matching, acts as a radio frequency choke to block the passage of the radio frequency signal. On the one hand, the fourth capacitor C4 provides a path to the ground for the radio frequency signal to improve stability, and on the other hand, it acts as a device for adjusting the circuit gain and gain flatness to adjust the gain characteristics of the overall circuit. The first resistor R1 provides effective isolation for the inductance and capacitance of the current multiplexing loop to prevent circuit stability problems caused by resonance.

[0065] In this embodiment, the current multiplexing module 15 samples the source current signal of each MOS tube and connects it to the output end of the first amplification module through the degeneration inductor, thereby improving the current utilization rate through circuit multiplexing, thereby ensuring that the low-noise amplifier 1 of this embodiment has a better noise suppression effect than other amplifiers that do not have input stage current multiplexing.

[0066] It should be noted that the number of second amplifying modules 13 and the number of current multiplexing modules 15 do not need to be exactly the same. As long as the multiplexed current signal of a second amplifying module 13 can be collected by at least one current multiplexing module 15 and output to the first amplifying module 13 to achieve multiplexing, it is within the protection scope of this embodiment. At the same time, it can be inferred that when the number of second amplifying modules 13 and current multiplexing modules 15 is equal, that is, when each second amplifying module 13 can multiplex the current through the current multiplexing module 15, the noise suppression effect of the low noise amplifier 1 is the best. Therefore, in this embodiment, if Figure 3 As shown, two second amplification modules 13 are provided, and preferably two current multiplexing modules 15 are provided, which are respectively denoted as the first current multiplexing module 15 and the second current multiplexing module 15. Among them, the first current multiplexing module 15 (with Figure 3 The current multiplexing module 15 below the first stage (for example) collects the source-drain current of the second MOS tube M2 (set as a HEMT tube in this embodiment) in the first stage second amplification module 13, which is recorded as the second current Id2. The second current Id2 flows back to the first amplification module 12 through the second degeneration inductor T2, the first resistor R1, and the third inductor L3; at the same time, the signal collected by the first stage second amplification module 13 contains part of the RF signal, which is connected to the reference ground through the fourth capacitor C4 to avoid interference. Similarly, the second current multiplexing module 15 (for example) Figure 3For example, the current multiplexing module 15 above collects the source-drain current of the third MOS tube M3 (set as a HEMT tube in this embodiment) in the second-stage second amplification module 13, which is recorded as the third current Id3 and also flows back to the first amplification module 12 via the third degeneration inductor T3, the first resistor R1, and the third inductor L3.

[0067] It should be further explained that, in this embodiment, the source degeneration inductance (also called source inductance or source trace inductance) is a concept used in semiconductor devices, in transistors (such as MOSFET, MOS tube and other devices). In the design of amplifiers or other high-frequency circuits, the source of the transistor is connected to a node of the circuit, and the current flows from this node through the source pin and the trace to the source of the transistor. The source degeneration inductance may refer to the inductance characteristics carried by the trace itself: the inductance characteristics of the source pin and the trace itself; in high-frequency operation, even a very short trace may show a significant effect due to its inherent inductance characteristics. It may also be the inductance characteristics carried by parasitic effects: at high frequencies, the source trace may form parasitic capacitance with the surrounding conductors or ground planes, and this parasitic capacitance and trace inductance may work together to form one or more parasitic resonant circuits near the source. In this embodiment, the source of each transistor is set to be connected to the reference ground using a microstrip line as a transmission line, and the inductance characteristics shown therein are used as degeneration inductance.

[0068] like Figure 1~Figure 3 As shown, the low noise amplifier 1 further includes n isolation matching modules 17 .

[0069] Specifically, each isolation matching module 17 is arranged in a one-to-one correspondence with each second amplification module 13, and is arranged before the input end of the corresponding second amplification module, and is used to receive the DC signal in the output signal of the previous module (in this embodiment, the previous module of the first-stage second amplification module 13 is the first amplification module 12, and the second amplification module 13 corresponding to the previous stage of the remaining second amplification modules) and isolate and output it to the input end of the next-stage amplification module; the isolation matching module 17 is also used to impedance match the signal output by the previous-stage amplification module and output it.

[0070] As an example, the isolation matching module 17 includes a fourth inductor L4 and a fifth capacitor C5. The fourth inductor L4 and the fifth capacitor C5 are arranged in series to form a first series structure; the first end of the first series structure receives the output signal of the previous module, and the second end is connected to the input end of the corresponding second amplification module 13. An LC network is formed by the fourth inductor L4 and the fifth capacitor C5 to perform inter-stage impedance matching to ensure the matching effect of the signal. In addition, in this embodiment, the fifth capacitor C5 is set as a DC isolation capacitor of the circuit to avoid DC signal interference between the front and rear modules. The fourth inductor L4 is set as a peaking inductor to improve the high-frequency gain.

[0071] In this embodiment, when the second amplifying module 13 further includes a second voltage supply unit 133 , the second voltage supply unit 133 is connected to a node between the fourth inductor L4 and the fifth capacitor C5 , and provides a bias voltage for the second end of each transistor via the fourth inductor L4 .

[0072] It should be noted that, in this embodiment, when the second voltage supply unit 133 is set to provide a bias voltage for the second end of each transistor, the bias voltage can be input to the second end of the corresponding transistor through the inductor through the relationship between the inductor and the capacitor in the isolation matching module 17, and will not flow into the input end of the next module. In addition, the second power supply voltage 133 and the isolation matching module 17 can be set separately, and the second voltage supply unit 133 can be directly connected to the second end of each transistor without connecting through the fourth inductor L4.

[0073] It should be further explained that, in actual use, the specific structure of the isolation matching module 17 is not limited to this embodiment. For example, in some embodiments, only a capacitor is provided, or other components are added. As long as the isolation matching module 17 can be used to relatively isolate the signals between the two modules, it is within the protection scope of this embodiment. In addition, in this embodiment, for better signal performance, it is preferred to set up multiple isolation matching modules 17. In actual use, it is also possible not to set up the isolation matching module 17 and directly amplify the signal based on each amplification module (first amplification module 12, second amplification module 13).

[0074] like Figure 1~Figure 3 As shown, the low noise amplification module also includes a feedback module 16 .

[0075] Specifically, the feedback module 16 is connected in parallel with the nth second amplifying module 13 to collect the output signal of the nth second amplifying module 13 and feed it back to the input end of the nth second amplifying module 13 .

[0076] As an example, the feedback module 16 includes a third resistor R3, a sixth inductor L6 and a seventh capacitor C7. The output signal of the n-th stage second amplifier module 13 is fed back to the input end of the n-th stage second amplifier module 13 via the seventh capacitor C7, the sixth inductor L6 and the third resistor R3 which are sequentially connected in series to form a second series structure; the negative feedback is formed by the second series structure to form a gate-drain negative feedback loop, providing a gain curve with a positive slope, improving the circuit gain flatness and enhancing the overall stability of the circuit.

[0077] It should be noted that, in the present embodiment, the feedback module 16 is arranged in parallel with the n-th second amplification module 13. In the present embodiment, the second end of the fifth inductor L5 in the n-th amplification module 13 is not directly connected to the drain of the third transistor M3. In the present embodiment, the output matching module 14 includes the second inductor L2 and the third capacitor C3. The second inductor L2 can be arranged between the seventh capacitor C7 and the drain of the third MOS tube M3, that is, the second voltage VD2 flows into the drain of the third MOS tube M3 via the fifth inductor L5 and the second inductor L2, and the equivalent relationship of the circuit is not changed. In actual connection, the second inductor L2 can also be arranged after the seventh capacitor C7, and is not directly connected to the drain of the third MOS tube M3, that is, the second voltage VD2 flows directly into the drain of the third MOS tube M3 via the fifth inductor L5.

[0078] It should be further explained that the specific structural setting of the feedback module 16 is not limited to this embodiment, and any setting that can feed back the output signal of the last-stage second amplification module 13 is within the protection scope of this embodiment. Based on the low-noise amplifier 1 provided in this embodiment, the feedback module 16 can also be connected in parallel with a multi-stage amplification structure in which the first amplification module 12 and each stage of the second amplification module 13 are arranged in series, and is not limited to the connection relationship of this embodiment.

[0079] like Figure 1~Figure 3 As shown, the low noise amplification module further includes a stabilization module 18 .

[0080] Specifically, the stabilization module 18 is disposed between the input end of any current multiplexing module 15 and the reference ground to improve the stability of the low noise amplifier 1 .

[0081] Preferably, in order to avoid introducing inter-stage impedance interference, the stabilization module 18 is arranged between the input end of the last current multiplexing module 15 and the reference ground.

[0082] As an example, the stabilization module 18 includes a fourth resistor R4 and an eighth capacitor C8. The fourth resistor R4 and the eighth capacitor C8 are connected in series to form a third series structure, and are arranged between the input end of the nth current multiplexing module 15 and the reference ground. The third series structure provides a loop to the ground for the low-frequency signal, which can weaken the problem of low-frequency gain increase and even low-frequency oscillation caused by the current multiplexing structure, and improve the stability of the circuit.

[0083] It should be noted that each MOS tube in the low noise amplifier 1 of this embodiment can be set as an NMOS tube or a HEMT tube, and the PMOS tube can be set according to corresponding principles, which is not limited to this embodiment.

[0084] This embodiment further provides a radio frequency device, including: the above-mentioned low noise amplifier 1.

[0085] Specifically, in this embodiment, taking the receiving channel as an example, the received signal in the RF device passes through the receiving antenna, duplexer, switch, low noise amplifier 1 of this embodiment, filter, and output to the RF transceiver. The sending channel can be set accordingly with reference to the receiving channel.

[0086] In this embodiment, the low noise amplifier 1 provided in this embodiment is used to improve the receiving sensitivity of the radio frequency device, improve the communication quality, and enhance the signal detection capability.

[0087] like Figure 1 As shown, this embodiment also provides a low noise amplification method, which is implemented based on the above-mentioned low noise amplifier 1 and includes:

[0088] The multiplexed current signals of the third terminals of the transistors in the m second amplifying modules 13 are collected and output to the output terminal of the first amplifying module 12 , so as to increase the current density of the first amplifying module 12 .

[0089] Specifically, it is preferred to set i=n, ​​that is, each second amplifying module 13 corresponds to a current multiplexing module 15 to achieve current multiplexing, so as to increase the current density of the radio frequency loop in the first amplifying module 12 .

[0090] The working principle of this embodiment is further explained below:

[0091] like Figure 3 As shown, the source-drain current of the second MOS tube M2 is the second current Id2, and the source-drain current of the third MOS tube M3 is the third current Id3. By inputting the current of the second current Id2 and the third current Id3 into the transistor, that is, the drain of the first MOS tube receives the first current Id1 to satisfy: Id1=Id2+Id3. Compared with the setting of directly amplifying through three-stage transistors and only having one shared current path in some comparative examples, the low-noise amplifier 1 of this embodiment collects and reuses the current of the subsequent amplification module, improves the utilization rate of the current, improves the current density of the first amplification module 12, makes the noise curve of the low-noise amplifier 1 more in line with the minimum value, and reduces the noise coefficient. At the same time, compared with the setting of some comparative examples in which the current through the three-stage transistor is gathered in the last-stage transistor to reduce the system power consumption, the noise performance of the low-noise amplifier 1 of this embodiment has significant advantages.

[0092] Specifically, when the second amplifying modules 13 further include a second voltage supply unit 133 , the voltage output by each second voltage supply unit 133 is adjusted respectively to change the dynamic gain range of the low noise amplifier.

[0093] In this embodiment, compared with other comparative examples in which only the drain of the last-stage transistor is connected to the bias voltage and once the bias voltage of the terminal is determined, the bias voltage of one of the transistors cannot be adjusted in a directional manner, resulting in a limited output dynamic range, the low-noise amplifier 1 in this embodiment uses the second power supply unit 133 to provide different gain voltages, such as by adjusting the first gain voltage VD1 and the second gain voltage VD2, the dynamic range of the low-noise amplifier 1 can also be adjusted and amplified. The specific principle is as follows: the dynamic range generally refers to the difference or ratio between the maximum and minimum signal ranges that the amplifier circuit can handle. Since the first gain voltage VD1 and the second gain voltage VD2 in this embodiment can be adjusted, the saturation point of each transistor can be adjusted to adjust the saturation voltage. When the saturation voltage is higher, the peak value of the large signal amplified by the low-noise amplifier 1 will also be higher, and no clipping distortion will be generated, that is, by adjusting the static operating point of each transistor, the distortion caused by a part of the operating point entering the saturation region of the amplifier circuit in a dynamic state is avoided.

[0094] Therefore, the low noise amplifier 1, the radio frequency device and the low noise amplification method of this embodiment provide a new current multiplexing structure, which can increase the current density of the radio frequency loop of the transistor by sinking the last two stages of current into the drain of the transistor, so that the noise curve is closer to the minimum value and the noise coefficient is reduced. At the same time, the drain bias voltage of the last two stages of transistors can be adjusted to achieve a larger dynamic range.

[0095] In summary, the present invention provides a low-noise amplifier, a radio frequency device and a low-noise amplification method, wherein the low-noise amplifier includes: an input matching module, an output matching module, a first amplification module, n second amplification modules and m current multiplexing modules; the input matching module matches the impedance of the radio frequency input signal; the first amplification module is cascaded with each second amplification module and amplifies the signal step by step; each second amplification module includes a transistor, the first end of the transistor is used as the input end, and the second end is used as the output end; the output matching module matches the impedance of the signal after multi-stage amplification; the m current multiplexing modules are respectively set corresponding to m of the n second amplification modules, collect the multiplexed current signal of the third end of the corresponding transistor and output it to the first amplification module. The present invention collects the multiplexed current signal of at least one second amplification module through the current multiplexing module and merges it into the output end of the first amplification module to improve the current density of the radio frequency circuit of the first amplification module. Therefore, the present invention effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0096] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A low noise amplifier, characterized in that: The low noise amplifier at least comprises: an input matching module, an output matching module, a first amplification module, n second amplification modules and m current multiplexing modules; wherein n is an integer greater than or equal to 1 and m is less than or equal to n; The input matching module receives a radio frequency input signal and is used to perform impedance matching on the radio frequency input signal to obtain a matching signal; The first amplifying module is cascaded with each of the second amplifying modules and the input end of the first amplifying module receives the matching signal, so as to perform step-by-step power amplification on the matching signal; wherein each of the second amplifying modules includes a transistor, the first end of the transistor serves as the input end of the second amplifying module, and the second end serves as the output end of the second amplifying module; the second amplifying module also includes a second voltage supply unit; the second voltage supply unit is arranged at the second end of the transistor, and is used to provide a bias voltage for the second end of the transistor, and to change the dynamic gain range of the low noise amplifier by adjusting the bias voltage at the second end of the transistor; The output matching module is connected to the output end of the second amplifying module of the nth stage, and is used to perform impedance matching on the matching signal after multi-stage power amplification to obtain a radio frequency output signal; The m current multiplexing modules are respectively arranged in one-to-one correspondence with m of the n second amplifying modules, and are used to collect the multiplexed current signal of the third terminal of the transistor in the corresponding second amplifying module and output it to the output terminal of the first amplifying module, so as to improve the current density of the first amplifying module; The current multiplexing module includes a fourth capacitor, a first resistor and a third inductor; The multiplexed current signal is connected to the output end of the first amplification module via the first resistor and the third inductor in sequence; The first plate of the fourth capacitor is connected to the third terminal of the corresponding transistor, and the second plate is connected to the reference ground.

2. The low noise amplifier according to claim 1, characterized in that: The input matching module includes a first capacitor, a second capacitor and a first inductor; The RF input signal is connected to the input end of the first amplification module via the first capacitor; A first end of the first inductor is connected to a node between the first capacitor and the first amplification module, and a second end of the first inductor is connected to a first bias voltage; A first end of the second capacitor is connected to a node between the first bias voltage and the first inductor, and a second end of the second capacitor is connected to a reference ground.

3. The low noise amplifier according to claim 1, characterized in that: The second amplifying module further includes a first voltage supply unit; the first voltage supply unit is arranged at the first end of the transistor, and is used to provide a bias voltage for the first end of the transistor.

4. The low noise amplifier according to claim 1, characterized in that: The output matching module includes a second inductor and a third capacitor; The signal output by the nth second amplifying module is sequentially transmitted through the second inductor and the third capacitor which are arranged in series to obtain the radio frequency output signal.

5. The low noise amplifier according to any one of claims 1 to 4, characterized in that: The low noise amplifier also includes n isolation matching modules; Each of the isolation matching modules is arranged in one-to-one correspondence with each of the second amplification modules, and is arranged before the input end of each of the second amplification modules, and is used to receive the DC signal in the output signal of the previous stage amplification module and isolate and output it to the input end of the next stage amplification module. The isolation matching module is also used to impedance match and output the signal output by the previous stage amplification module.

6. The low noise amplifier according to claim 5, characterized in that: The isolation matching module includes a fourth inductor and a fifth capacitor; The fourth inductor and the fifth capacitor are arranged in series to form a first series structure; The first end of the first series structure receives a signal output by a previous stage amplification module, and the second end is connected to an input end of the corresponding second amplification module.

7. The low noise amplifier according to claim 6, characterized in that: When the second amplifying module further includes a second voltage supply unit, the second voltage supply unit is connected to a node between the fourth inductor and the fifth capacitor, and provides a bias voltage for the second end of the transistor via the fourth inductor.

8. The low noise amplifier according to claim 1, characterized in that: The low noise amplifier further includes a feedback module; the feedback module is connected in parallel with the nth second amplifying module and is used to collect the signal output by the nth second amplifying module and feed it back to the input end of the nth second amplifying module.

9. The low noise amplifier according to claim 1, characterized in that: The low noise amplifier further comprises a stabilizing module; the stabilizing module is arranged between the input end of any current multiplexing module and the reference ground to improve the stability of the low noise amplifier.

10. A radio frequency device, characterized in that: The radio frequency device comprises a low noise amplifier as described in any one of claims 1 to 9.

11. A low noise amplification method, implemented based on the low noise amplifier according to any one of claims 1 to 9, characterized in that: The multiplexed current signals of the third terminals of the transistors in the m second amplifying modules are collected and output to the output terminal of the first amplifying module, so as to increase the current density of the first amplifying module.

12. The low noise amplification method according to claim 11, characterized in that: When the second amplification module further includes a second voltage supply unit, the output voltage of each second voltage supply unit is adjusted respectively to change the dynamic gain range of the low noise amplifier.

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