阅读说明：本技术 一种单端输入差分输出宽带低噪声放大电路 (Single-ended input differential output broadband low-noise amplification circuit ) 是由 苏杰 朱勇 徐祎喆 于 2020-11-26 设计创作，主要内容包括：本发明申请一种单端输入差分输出宽带低噪声放大电路,属于宽带低噪声放大器制造领域。本申请包括第一增益模块,第二增益模块,以及噪声抵消模块；第一增益模块对从输入端输入的射频信号进行放大得到包括第一沟道热噪声的第一放大信号并进行反馈；第二增益模块上述反馈的信号经输入端的匹配阻抗分压后得到的信号进行反向放大,得到包括第二沟道噪声热的第二放大信号；噪声抵消模块对沟道热噪声的进行抵消,并将剩余信号合并输出为第三放大信号。本申请采用了前反馈电路设计,在保证电路稳定性以及输入阻抗匹配的前提下,可以使宽带低噪声放大器可以达到较低的噪声的噪声系数,且没有采用电感做负载,可以减少芯片面积降低成本。(The invention discloses a single-ended input differential output broadband low-noise amplifier circuit, and belongs to the field of broadband low-noise amplifier manufacturing. The noise cancellation system comprises a first gain module, a second gain module and a noise cancellation module; the first gain module amplifies a radio frequency signal input from an input end to obtain a first amplified signal comprising first channel thermal noise and feeds the first amplified signal back; the second gain module performs reverse amplification on a signal obtained after the feedback signal is subjected to voltage division by the matched impedance of the input end to obtain a second amplified signal including second channel noise heat; the noise cancellation module cancels channel thermal noise, and combines and outputs the residual signals into a third amplified signal. The design of the front feedback circuit is adopted, the noise coefficient of lower noise of the broadband low-noise amplifier can be achieved on the premise that the circuit stability and the input impedance matching are guaranteed, the inductor is not adopted as a load, and the chip area and the cost can be reduced.)

1. A single-ended input differential output broadband low noise amplifier circuit, comprising:

a first gain module, a second gain module, and a noise cancellation module;

the first gain module amplifies a radio frequency signal input from an input end to obtain a first amplified signal comprising first channel thermal noise, and feeds the first amplified signal back to the input end to obtain a first feedback signal comprising the first feedback channel thermal noise;

the second gain module performs reverse amplification on a second feedback signal which is obtained by dividing the voltage of the first feedback signal through the matched impedance of the input end and comprises second feedback channel thermal noise to obtain a second amplified signal which comprises second channel noise heat;

and after the noise cancellation module carries out isolation buffering on the first amplification signal comprising the first channel thermal noise, the noise cancellation module cancels the first channel thermal noise and the second channel thermal noise, and combines and outputs the first amplification signal and the second amplification signal into a third amplification signal.

2. The single-ended input differential output broadband low noise amplification circuit of claim 1, further comprising,

and the signal differential output module is used for differentially outputting the third amplified signal.

3. The single-ended input differential output broadband low noise amplification circuit of claim 1,

the first gain module comprises a complementary common source amplifier consisting of two MOS tubes with different structure types and a resistor.

4. The single-ended input differential output broadband low noise amplification circuit according to claim 1, wherein the second gain module comprises a cascode amplifier composed of two MOS transistors of the same structure type.

5. The single-ended input differential output broadband low noise amplification circuit according to claim 1, comprising a source follower consisting of a MOS transistor.

6. The single-ended input differential output broadband low noise amplification circuit of claim 2,

the signal differential output module comprises a signal differential output module which comprises a complementary common source amplifier consisting of two MOS tubes with different structure types and a resistor.

7. The single-ended input differential output broadband low noise amplification circuit of claim 1,

the gain of the second gain module can completely cancel the second channel thermal noise and the first channel thermal noise.

8. The single-ended input differential output broadband low noise amplification circuit of claim 1, further comprising a rectification module.

Technical Field

The invention relates to the field of manufacturing of broadband low-noise amplifiers, in particular to a single-ended input differential output broadband low-noise amplifying circuit.

Background

A wideband low noise amplifier is a low noise amplifier for amplifying wideband radio frequency signals. The broadband low-noise amplifier widely used in the prior art adopts an inductor as a load, but the area of a noise chip is large, and the cost is high. In addition, a parallel resistor negative feedback structure circuit is widely adopted in the prior art, a feedback resistor is introduced between a grid electrode and a drain electrode of a field effect tube, the feedback resistor can greatly restrict broadband and noise, two parameters of the broadband and the noise need to be compromised, the final noise coefficient is above 3dB, meanwhile, the gain of the circuit can be reduced, and the circuit has the problem of stability. Another circuit structure commonly used in the prior art is a common-gate input circuit structure, which directly introduces thermal noise of a load into an input terminal, so that the noise coefficient is also relatively large.

In addition, in the common low noise amplifier with single-ended input and differential output in the prior art, the balun is adopted to convert the single-ended input signal into the differential signal and then enter the circuit to work, but the balun structure is essentially a transformer, so that the inductor area is large, and the cost is high.

Disclosure of Invention

The application provides a single-ended input differential output broadband low-noise amplifier circuit, adopts the noise elimination technique of feedforward, improves amplifier circuit's stability, reduce cost and chip area.

In order to achieve the above object, the present application provides a single-ended input differential output broadband low noise amplifier circuit, including:

a first gain module, a second gain module, and a noise cancellation module;

the first gain module amplifies a radio frequency signal input from the input end to obtain a first amplified signal comprising first channel thermal noise, and feeds the first amplified signal back to the input end to obtain a first feedback signal comprising the first feedback channel thermal noise;

the second gain module performs reverse amplification on a second feedback signal which is obtained by dividing the first feedback signal by the distribution impedance of the first gain module and comprises second feedback channel thermal noise to obtain a second amplified signal comprising second channel noise heat;

the noise cancellation module performs isolation and caching on a first amplification signal comprising first channel thermal noise, cancels the first channel thermal noise and second channel thermal noise, and combines and outputs the first amplification signal and the second amplification signal into a third amplification signal.

The beneficial effects of this application are that, adopted the design of feedforward circuit, under the prerequisite of guaranteeing circuit stability and input impedance matching, can make broadband low noise amplifier can reach the noise figure of lower noise to do not adopt the inductance to do the load, can reduce chip area reduce cost.

Drawings

Fig. 1 is a schematic diagram of an embodiment of a single-ended input differential output broadband low noise amplifier circuit according to the present application;

FIG. 2 is a schematic diagram of an embodiment of a single-ended input differential output broadband low noise amplifier circuit according to the present application;

FIG. 3 is a schematic diagram of an embodiment of a single-ended input differential output broadband low noise amplifier circuit according to the present application;

FIG. 4 is a schematic diagram of an embodiment of a single-ended input differential output broadband low noise amplifier circuit according to the present application;

FIG. 5 is a schematic diagram of an embodiment of a single-ended input differential output broadband low noise amplifier circuit according to the present application;

fig. 6 is a schematic diagram of an embodiment of a single-ended input differential output broadband low noise amplifier circuit according to the present application.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the scope of the present invention can be more clearly defined.

It should be noted that, herein, relationships such as first and second, etc., are intended to distinguish one entity or operation from another entity or operation without necessarily requiring or implying any actual such relationship or order between such actual operations. Furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include elements inherent in the list. The term "comprising", without further limitation, means that the element so defined is not excluded from the group of processes, methods, articles, or devices that include the element.

Fig. 1 is a schematic diagram illustrating an embodiment of a single-ended input differential output broadband low noise amplifier circuit according to the present invention.

In the specific embodiment shown in fig. 1, the single-ended input differential output broadband low noise amplifier circuit of the present application includes a module 101, a module 102, and a module 103.

The first gain module is represented by the module 101 shown in fig. 1.

In a specific embodiment of the present application, the first gain module amplifies a radio frequency signal input from an input terminal to obtain a first amplified signal including first channel thermal noise, and feeds back the first amplified signal to the input terminal to obtain a first feedback signal including the first feedback channel thermal noise.

Fig. 4 shows a specific embodiment of the present application, and in the embodiment shown in fig. 4, the first gain block includes a complementary common source amplifier.

In the embodiment shown in fig. 4, the complementary common-source amplifier of the first gain module is composed of an NMOS transistor, a PMOS transistor, and a resistor.

In a specific embodiment of the present application, the resistor in the complementary common-source amplifier may feed back the signal amplified by the complementary common-source amplifier to the signal input terminal.

In an embodiment of the present application, the resistor in the common-source amplifier may implement self-biasing of the NMOS transistor and the PMOS transistor, so that the current is matched between the NMOS transistor and the PMOS transistor.

In an embodiment of the present application, the sum of transconductances of the NMOS transistor and the PMOS transistor in the common-source amplifier is equal to 20ms, so that impedance matching with an input impedance of 50 ohms can be obtained.

In a specific example of the present application, the impedance matching of the NMOS transistor and the PMOS transistor in the common-source amplifier is obtained by repeatedly debugging under the condition that the impedance matching is influenced by the channel effect and the feedback resistance.

The second gain module is represented by the module 102 shown in fig. 1.

In a specific embodiment of the application, the second module performs inverse amplification on a second feedback signal including second feedback channel thermal noise, which is obtained by dividing the first feedback signal by the matched impedance of the input terminal, to obtain a second amplified signal including second channel thermal noise.

In a specific embodiment of the present application, the matching impedance of the input terminal is provided by a dc blocking capacitor of the input terminal.

In a specific embodiment of the present application, the second gain module includes a cascode amplifier.

In a specific embodiment of the present application, the second gain module includes two MOS transistors of the same type.

Fig. 4 shows an embodiment of the present application, and in the embodiment shown in fig. 4, the cascode amplifier of the second gain module includes two NMOS transistors.

In a specific embodiment of the present application, a first feedback signal fed back from the first gain module is subjected to voltage division by the matching impedance of the input terminal, and then is reversely amplified by a cascode amplifier composed of two NMOS transistors to obtain a second amplified signal.

In a specific embodiment of the present application, a first channel thermal noise in a first feedback signal fed back from the first gain module is subjected to voltage division by the matching impedance of the input terminal, and then is reversely amplified by a cascode amplifier composed of two NMOS transistors, so as to obtain a second channel thermal noise signal.

In a specific embodiment of the present application, the gain of the cascode amplifier is adjusted according to the gain of the complementary common-source amplifier in the first gain module.

In a specific example of the present application, the gain of the cascode amplifier is a value that a noise coefficient of the amplifier after the second channel thermal noise signal amplified by the cascode amplifier and the first channel thermal noise signal are cancelled is lower than 3 dB.

In a specific example of the present application, the gain of the cascode amplifier is a value that completely cancels the first channel thermal noise signal and the second channel thermal noise signal amplified by the cascode amplifier, so as to further make the noise figure of the amplifier be 2.29 to 2.37dB and the gain be 19dB in the range of 700M to 2.2G. .

Block 103 shown in fig. 1 represents a noise cancellation block.

In a specific embodiment of the present application, after the noise cancellation module performs isolation buffering on the first amplified signal including the first channel thermal noise, the noise cancellation module cancels the first channel thermal noise and the second channel thermal noise, and combines and outputs the first amplified signal and the second amplified signal as a third amplified signal.

In an embodiment of the present application, the noise cancellation module includes a source follower.

In the embodiment of the present application shown in fig. 4, the source follower includes an NMOS transistor.

In an embodiment of the present application, the source follower performs isolation buffering on the first amplified signal.

In a specific embodiment of the present application, the noise cancellation module cancels a first channel thermal noise signal in the first amplified signal passing through the source follower and a second channel thermal noise signal in the second amplified signal.

In a specific embodiment of the present application, the noise cancellation module performs noise cancellation on a first channel thermal noise signal in the first amplified signal and a second channel thermal noise signal in the second amplified signal passing through the source follower, so that a noise figure of the amplifier is lower than 3 dB.

In a specific embodiment of the present application, the noise cancellation module fully cancels the first channel thermal noise signal in the first amplified signal passing through the source follower and the second channel thermal noise signal in the second amplified signal, so that the noise figure of the amplifier is 2.29 to 2.37dB and the gain is 19dB in a range of 700M to 2.2G.

In a specific embodiment of the present application, the noise cancellation module combines the first amplified signal and the second amplified signal after the noise signal cancellation, and outputs the combined signal as a third amplified signal.

In a specific embodiment of the present application, the single-ended input differential output broadband low noise amplification circuit of the present application further includes a signal differential output module.

Fig. 2 shows a specific embodiment of the present application, wherein a signal differential output module is represented by a module 204, and is used for differentially outputting a third amplified signal, instead of converting an input signal into a differential signal input by using a conventional balun structure, a signal output at a single end is converted into a differential output signal, so that the chip circuit area can be reduced, and the chip circuit cost can be reduced.

In an embodiment of the present application, the differential output module outputs two differential output signals through two output ports, and converts a single-ended output signal into a differential output signal instead of converting an input signal into a differential signal input by using a conventional balun structure, so as to reduce a chip circuit area and reduce a chip circuit cost.

In a specific embodiment of the present application, one of the two input ends of the differential output module is connected to a complementary common source amplifier, which can perform inverse amplification with a gain of 1 on the third amplified signal, and the complementary common source amplifier is used to convert the signal output from the single end into a differential output signal, so as to replace a conventional balun structure to convert the input signal into a differential signal input, thereby reducing the circuit area of the chip and reducing the circuit cost of the chip.

Fig. 5 shows a specific example of the present application, and in the specific example of the present application shown in fig. 5, the complementary common-source amplifier of the differential output module includes a complementary common-source stage amplifier composed of an NMOS transistor, a PMOS transistor, and a resistor.

Fig. 3 shows a specific embodiment of the single-ended input differential output broadband low noise amplifier circuit of the present application.

The single-ended input differential output broadband low noise amplifier circuit of the present application is shown in fig. 3, wherein the block 305 represents a rectifier block, which can provide the required dc current for the amplifiers of the first gain block, the second gain block, and the third gain block.

In a specific embodiment of the present application, the rectifier module includes two current mirrors and a current drawing unit.

Fig. 6 shows an embodiment of the present application, and in the embodiment shown in fig. 6, the current mirror of the rectifier module includes two PMOS transistors.

In the specific example shown in fig. 6, the current drawing unit of the rectifier module comprises two PMOS transistors.

In the embodiments provided in the present application, it should be understood that the disclosed method and system may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, for example, the division of the units is only one division of logical functions, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or units through some interfaces, and may be in a typical, mechanical or other form.

The units described as separate but not illustrated may or may not be physically separate, and components displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and all equivalent structural changes made by using the contents of the specification and the drawings, which are directly or indirectly applied to other related technical fields, are included in the scope of the present application.