Low-noise amplifier, radio frequency front-end module and communication equipment

Abstract

The invention relates to a low noise amplifier, a radio frequency front end module and communication equipment, a power amplification unit is connected with a radio frequency output end and is connected with a radio frequency access end through an input unit, and a bypass unit is connected with the radio frequency output end and is connected with the radio frequency access end through the input unit. And the gain of the low-noise amplifier when the bypass unit is switched on is smaller than that when the bypass unit is switched off. By controlling the on-off of the bypass unit, the gain gear of the low-noise amplifier can be adjusted, the low-noise amplifier is suitable for the gain requirement of a large dynamic range, and the use convenience is improved.

Description

Technical Field

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

[0002] With the development of science and technology and the continuous progress of society, the trend of miniaturization and high performance of RF communication equipment is accelerating, which puts higher requirements on RF front-end design. RF front-end modules combine different devices into a chip with concentrated functions and strong performance. Traditional RF front-end modules use fixed gain amplifiers, which cannot meet the different gain requirements of communication equipment and have the disadvantage of low convenience of use. Summary of the invention

[0003] Based on this, it is necessary to provide a low noise amplifier (Low Noise Amplifier, LNA), a radio frequency front-end module and a communication device that can improve the convenience of use in order to address the above problems.

[0004] A low noise amplifier, comprising:

[0005] An input unit, connected to a radio frequency access terminal, and receiving a radio frequency input signal through the radio frequency access terminal;

[0006] A power amplification unit, connected to the RF output terminal and connected to the RF access terminal through the input unit, the RF output terminal being used to output a RF output signal;

[0007] A bypass unit is connected to the RF output terminal and connected to the RF access terminal through the input unit; wherein the gain of the low noise amplifier when the bypass unit is turned on is less than the gain when the bypass unit is turned off.

[0008] In one embodiment, the input unit includes an inductor Lg and a capacitor C1, a first end of the inductor Lg is connected to the RF access end, a second end of the inductor Lg is connected to a first end of the capacitor C1, and a second end C1 of the capacitor is connected to the power amplification unit and the bypass unit.

[0009] In one of the embodiments, the power amplification unit includes a power tube component and an output component, the power tube component is connected to the input unit, the bypass unit and the output component, and the output component is connected to the bypass unit and the RF output end.

[0010] In one embodiment, the power tube assembly includes a power tube M1, a power tube M2, an inductor LS and an inductor LD, the control end of the power tube M1 is connected to the input unit and the bypass unit, the first end of the power tube M1 is grounded through the inductor LS, the second end of the power tube M1 is connected to the first end of the power tube M2, the second end of the power tube M2 is connected to the output assembly, and is connected to an external power supply end through the inductor LD.

[0011] In one embodiment, the power tube assembly further includes a power supply VB, a power supply VCG, a resistor R1 and a resistor R2, the positive electrode of the power supply VB is connected to the control end of the power tube M1 through the resistor R1, the negative electrode of the power supply VB is grounded, the positive electrode of the power supply VCG is connected to the control end of the power tube M2 through the resistor R2, and the negative electrode of the power supply VCG is grounded.

[0012] In one embodiment, the power tube M1 and the power tube M2 are both MOS tubes.

[0013] In one embodiment, the output component includes a capacitor C4 and a switch SW3, the first end of the capacitor C4 is connected to the power tube component, the second end of the capacitor C4 is connected to the first end of the switch SW3, and the second end of the switch SW3 is connected to the bypass unit and the RF output end.

[0014] In one embodiment, the bypass unit includes a capacitor C2, a capacitor C3, a resistor R3, a switch SW1 and a switch SW2, the first end of the switch SW1 is connected to the input unit and the power amplification unit, the second end of the switch SW1 is connected to the first end of the capacitor C2, the second end of the capacitor C2 is connected to the first end of the capacitor C3 and is grounded through the resistor R3, the second end of the capacitor C3 is connected to the first end of the switch SW2, and the second end of the switch SW2 is connected to the RF output end and the power amplification unit.

[0015] A radio frequency front-end module comprises a matching circuit, a filter and the above-mentioned low noise amplifier, wherein the low noise amplifier is connected to a corresponding filter through a corresponding radio frequency access terminal, and the filter is connected to a corresponding matching circuit.

[0016] A communication device comprises a radio frequency antenna and the above-mentioned radio frequency front-end module.

[0017] In the above-mentioned low-noise amplifier, RF front-end module and communication equipment, the power amplifier unit is connected to the RF output terminal and connected to the RF access terminal through the input unit, and the bypass unit is connected to the RF output terminal and connected to the RF access terminal through the input unit. The gain of the low-noise amplifier when the bypass unit is turned on is less than the gain when the bypass unit is turned off. By controlling the on and off of the bypass unit, the gain gear of the low-noise amplifier can be adjusted, which is suitable for gain requirements with a large dynamic range and improves the convenience of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a structural block diagram of a low noise amplifier in one embodiment;

[0019] Figure 2 FIG. 4 is a structural schematic diagram of a low noise amplifier in one embodiment. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0022] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0023] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, operations, components, parts or combinations thereof.

[0024] In one embodiment, Figure 1As shown, a low noise amplifier is provided, including: an input unit 110, a power amplifying unit 120 and a bypass unit 130, wherein: the input unit 110 is connected to the RF access terminal, and receives the RF input signal RFIN through the RF access terminal; the power amplifying unit 120 is connected to the RF output terminal, and is connected to the RF access terminal through the input unit 110, and the RF output terminal is used to output the RF output signal RFOUT; the bypass unit 130 is connected to the RF output terminal, and is connected to the RF access terminal through the input unit 110; the gain of the low noise amplifier when the bypass unit 130 is turned on is less than the gain when the bypass unit 130 is turned off.

[0025] Among them, the specific values ​​of the gain of the low noise amplifier when the bypass unit 130 is turned on and the gain when the bypass unit 130 is turned off are not unique, and can be determined by designing the internal components of the power amplifier unit 120 and the bypass unit 130 according to actual needs, and it is only necessary to satisfy that the gain when the bypass unit 130 is turned on is less than the gain when the bypass unit 130 is turned off. The gain when the bypass unit 130 is turned on can be used as a low gain gear, and the gain when the bypass unit 130 is turned off can be used as a high gain gear. According to the actual use scenario, the power amplifier unit 120 and the bypass unit 130 are controlled to achieve the switching between the low gain gear and the high gain gear. When the low noise amplifier works in the high gain gear, the RF input signal RFIN is processed by the input unit 110, and then the power amplifier unit 120 performs power amplification to obtain the RF output signal RFOUT. When the low noise amplifier works in the low gain gear, the RF input signal RFIN is processed by the input unit 110, and then the RF output signal RFOUT is obtained by the bypass unit 130. The bypass unit 130 only needs to reduce the gain of the low noise amplifier when it is turned on, and can be implemented with a small number of components, thereby simplifying the structure and reducing the occupied space.

[0026] The function of the input unit 110 is to match the RF input impedance and improve the transmission efficiency of the RF signal. Figure 2 As shown, the input unit 110 includes an inductor Lg and a capacitor C1, a first end of the inductor Lg is connected to the RF access end, a second end of the inductor Lg is connected to the first end of the capacitor C1, and a second end of the capacitor C1 is connected to the power amplification unit 120 and the bypass unit 130. When the low noise amplifier works in a high gain gear, the RF input signal RFIN is transmitted to the power amplification unit 120 after impedance matching through the inductor Lg and the capacitor C1; when the low noise amplifier works in a low gain gear, the RF input signal RFIN is transmitted to the bypass unit 130 after impedance matching through the inductor Lg and the capacitor C1.

[0027] Furthermore, the power amplification unit 120 may include a power tube assembly 122 and an output assembly 124. The power tube assembly 122 is connected to the input unit 110, the bypass unit 130 and the output assembly 124. The output assembly 124 is connected to the bypass unit 130 and the RF output terminal. When the low noise amplifier operates at a high gain level, the power tube assembly 122 amplifies the signal power and transmits the amplified signal to the output assembly 124.

[0028] The specific structures of the power tube assembly 122 and the output assembly 124 are not unique. In one embodiment, the power tube assembly 122 includes a power tube M1, a power tube M2, an inductor LS, and an inductor LD. The control end of the power tube M1 is connected to the input unit 110 and the bypass unit 130, and is specifically connected to the second end of the capacitor C1 in the input unit 110. The first end of the power tube M1 is grounded through the inductor LS. The second end of the power tube M1 is connected to the first end of the power tube M2. The second end of the power tube M2 is connected to the output assembly 124 and is connected to the external power supply terminal VDD through the inductor LD. The power tube M1 and the power tube M2 can specifically be MOS tubes, with the gate as the control end, the source as the first end, and the drain as the second end.

[0029] Furthermore, the power tube assembly 122 may also include a power supply VB, a power supply VCG, a resistor R1, and a resistor R2. The positive electrode of the power supply VB is connected to the control end of the power tube M1 through the resistor R1, the negative electrode of the power supply VB is grounded, the positive electrode of the power supply VCG is connected to the control end of the power tube M2 through the resistor R2, and the negative electrode of the power supply VCG is grounded. Corresponding power supplies and resistors are respectively set at the control ends of the power tubes M1 and M2 to keep the control ends of the power tubes M1 and M2 in a high level state, ensuring that the power tubes M1 and M2 work stably.

[0030] In one embodiment, the output component 124 includes a capacitor C4 and a switch SW3, the first end of the capacitor C4 is connected to the power tube component 122, specifically connected to the second end of the power tube M2, the second end of the capacitor C4 is connected to the first end of the switch SW3, and the second end of the switch SW3 is connected to the bypass unit 130 and the RF output terminal. The switch SW3 can be a manual switch or a control switch. When the switch SW3 is turned on, the amplified signal output by the power tube component 122 passes through the capacitor C4 and outputs the RF output signal RFOUT through the RF output terminal. The function of the capacitor C4 is to cut off the DC signal at the output terminal and match the output impedance.

[0031] In addition, the specific structure of the bypass unit 130 is not unique, and further reference is made to Figure 2, the bypass unit 130 may include a capacitor C2, a capacitor C3, a resistor R3, a switch SW1 and a switch SW2, the first end of the switch SW1 is connected to the input unit 110 and the power amplification unit 120, specifically connected to the second end of the capacitor C1 and the control end of the power tube M1, the second end of the switch SW1 is connected to the first end of the capacitor C2, the second end of the capacitor C2 is connected to the first end of the capacitor C3, and is grounded through the resistor R3, the second end of the capacitor C3 is connected to the first end of the switch SW2, the second end of the switch SW2 is connected to the RF output end and the power amplification unit 120, specifically connected to the second end of the switch SW3. Among them, the switch SW1 and the switch SW2 can be manual switches or control switches.

[0032] Specifically, when the low noise amplifier works in the high gain gear, the switch SW1 and the switch SW2 are turned off, the switch SW3 is turned on, and the power tube assembly 122 performs power amplification on the signal output by the input unit 110, and the amplified signal output is matched by the impedance of the capacitor C4, and the radio frequency output signal RFOUT is output through the radio frequency output terminal. When the low noise amplifier works in the low gain gear, the switch SW3 is turned off, the switch SW1 and the switch SW2 are turned on, and the signal output by the input unit 110 passes through the bypass unit 130, and the radio frequency output signal RFOUT is output through the radio frequency output terminal. Through the above circuit design, the combination of the switch and the resistor network is used to make the low noise amplifier have two working states of high gain gear and low gain gear. The high gain gear can reach 19dB high gain, and the low gain gear can reach -5dB attenuation, realizing the switching of high gain and gain attenuation modes, which is suitable for system applications with a large dynamic range. The capacitor C3 and the capacitor C4 are separated by the switch SW2 and the switch SW3, which avoids the device redundancy caused by the capacitor series connection and saves the layout area.

[0033] By adding switch SW3 to the RF output end of the low noise amplifier, when the low noise amplifier works in the low gain gear, only the off capacitance Coff of switch SW3 is hung on the load end, which has little effect on the design and adjustment of the output matching, and because switch SW3 is added to the output end, it has no effect on the noise figure NF of the high gain gear. In addition, the input matching and output matching of the low noise amplifier in the low gain gear (switch SW3 is turned off, switches SW1 and SW2 are turned on) can be below -7dB, and are less affected by the peripheral matching inductance.

[0034] In one embodiment, a radio frequency front-end module is provided, including a matching circuit, a filter and the above-mentioned low noise amplifier, the low noise amplifier is connected to a corresponding filter through a corresponding radio frequency access terminal, and the filter is connected to a corresponding matching circuit. Among them, the number of matching circuits, filters and low noise amplifiers can be multiple, the matching circuit can be an LC (inductor capacitor) type matching topology structure, or an L-type dual inductor matching topology structure, and the filtering frequency band of each filter can be set according to actual needs. Furthermore, the radio frequency front-end module may also include a radio frequency switch, which connects each matching circuit and can also be connected to a radio frequency antenna. The radio frequency switch specifically includes a static contact and multiple moving contacts, the static contact is connected to the radio frequency antenna, and each moving contact is connected to the corresponding matching circuit. A single switch can be controlled to open the radio frequency switch to make each frequency band work separately; multiple switches can also be controlled to open the radio frequency switch at the same time to make several frequency bands work simultaneously during carrier aggregation.

[0035] In one embodiment, a communication device is also provided, including a radio frequency antenna and the above-mentioned radio frequency front-end module. Further, the communication device may also include a controller, which is connected to the radio frequency switch to control the on and off of the radio frequency switch. The type of controller is not unique, for example, it can be a CPU (Central Processing Unit), an MCU (Microcontroller Unit), an FPGA (Field-Programmable Gate Array) and other devices.

[0036] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0037] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A low noise amplifier, characterized in that: include: An input unit, connected to a radio frequency access terminal, and receiving a radio frequency input signal through the radio frequency access terminal; A power amplification unit, connected to the RF output terminal and connected to the RF access terminal through the input unit, the RF output terminal being used to output a RF output signal; A bypass unit is connected to the RF output terminal and connected to the RF access terminal through the input unit; wherein the gain of the low noise amplifier when the bypass unit is turned on is less than the gain when the bypass unit is turned off.

2. The low noise amplifier according to claim 1, characterized in that: The input unit includes an inductor Lg and a capacitor C1, a first end of the inductor Lg is connected to the RF access end, a second end of the inductor Lg is connected to a first end of the capacitor C1, and a second end of the capacitor C1 is connected to the power amplification unit and the bypass unit.

3. The low noise amplifier according to claim 1, characterized in that: The power amplification unit includes a power tube component and an output component. The power tube component is connected to the input unit, the bypass unit and the output component. The output component is connected to the bypass unit and the radio frequency output end.

4. The low noise amplifier according to claim 3, characterized in that: The power tube assembly includes a power tube M1, a power tube M2, an inductor LS and an inductor LD. The control end of the power tube M1 is connected to the input unit and the bypass unit, the first end of the power tube M1 is grounded through the inductor LS, the second end of the power tube M1 is connected to the first end of the power tube M2, the second end of the power tube M2 is connected to the output assembly, and is connected to an external power supply end through the inductor LD.

5. The low noise amplifier according to claim 4, characterized in that: The power tube assembly also includes a power supply VB, a power supply VCG, a resistor R1 and a resistor R2, the positive electrode of the power supply VB is connected to the control end of the power tube M1 through the resistor R1, the negative electrode of the power supply VB is grounded, the positive electrode of the power supply VCG is connected to the control end of the power tube M2 through the resistor R2, and the negative electrode of the power supply VCG is grounded.

6. The low noise amplifier according to claim 4, characterized in that: The power tube M1 and the power tube M2 are both MOS tubes.

7. The low noise amplifier according to claim 3, characterized in that: The output component includes a capacitor C4 and a switch SW3, a first end of the capacitor C4 is connected to the power tube component, a second end of the capacitor C4 is connected to a first end of the switch SW3, and a second end of the switch SW3 is connected to the bypass unit and the RF output end.

8. The low noise amplifier according to any one of claims 1 to 7, characterized in that: The bypass unit includes a capacitor C2, a capacitor C3, a resistor R3, a switch SW1 and a switch SW2, wherein a first end of the switch SW1 is connected to the input unit and the power amplification unit, a second end of the switch SW1 is connected to a first end of the capacitor C2, a second end of the capacitor C2 is connected to a first end of the capacitor C3 and is grounded through the resistor R3, a second end of the capacitor C3 is connected to a first end of the switch SW2, and a second end of the switch SW2 is connected to the RF output end and the power amplification unit.

9. A radio frequency front-end module, characterized in that: It comprises a matching circuit, a filter and a low noise amplifier as described in any one of claims 1 to 8, wherein the low noise amplifier is connected to a corresponding filter through a corresponding radio frequency access terminal, and the filter is connected to a corresponding matching circuit.

10. A communication device, characterized in that: It comprises a radio frequency antenna and the radio frequency front-end module as claimed in claim 9.

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