CN209517066U

CN209517066U - A kind of low-noise amplifier

Info

Publication number: CN209517066U
Application number: CN201821705534.4U
Authority: CN
Inventors: 陈文华; 李如亚
Original assignee: CHANGZHOU RADIO FACTORY Co Ltd
Current assignee: CHANGZHOU RADIO FACTORY Co Ltd
Priority date: 2018-10-19
Filing date: 2018-10-19
Publication date: 2019-10-18
Anticipated expiration: 2028-10-19

Abstract

The utility model provides a kind of low-noise amplifier, including NPN transistor Q1, Q2, transmission transformer T1, T2, T3, T4, coupled capacitor C1, C2, C3, C4, current-limiting resistance R1, R2, divider resistance R3, R4, load resistance R5, R6, load inductance L1, L2, power supply Vb, Vc, the utility model discloses the differential amplifier circuits amplified based on transistor common base, its base amplification circuit has wider frequency characteristic, transmission transformer T2 is used by cooperation, T3, as NPN transistor Q1, the inductance element of Q2 operating voltage, flatness in width is promoted as negative-feedback device simultaneously, reduce the influence to noise coefficient, instead of common resistance, the shortcomings that capacitance negative feedback type causes noise coefficient to increase.

Description

A kind of low-noise amplifier

Technical field

The utility model relates to microwave electron technical field more particularly to a kind of low-noise amplifiers.

Background technique

In existing low noise, ultra-linear amplifier product, common technological means has: feedforward linear technology, predistortion Technology etc..Although these technologies can reach the amplification requirement of High Linear, more using device since structure is complicated, there are one Fixed disadvantage.Such as feedforward linear technology, it is by the hoop that disappears, disappears error loop and improve the linearity, needed in the error loop that disappears Increase by one group of amplifier additionally to assist fault in enlargement signal, from performance, excessive amplifier element causes noise coefficient Variation, increase current power, reduce efficiency of amplitude and reliability, from productivity effect, increase production cost And the period.

Such as Chinese patent " CN104467690A " discloses a kind of low noise amplifier circuit, including input coupling network, Connect front-end circuit and the first amplifier element of rear end；First amplifier element is connected, to input signal with input coupling network It amplifies；First bias unit is connected with the first amplifier element, and the quiescent point control of the first amplifier element is existed Linear amplification region；Second amplifier element is connected with the first amplifier element, carries out to the output signal of the first amplifier element Amplification；Second bias unit is connected with the second amplifier element, and the quiescent point of the second amplifier element is controlled linear Amplification region.The frequency range that the technical solution is applicable in is smaller, and electronic component is more.

Summary of the invention

To overcome the problems, such as that frequency range existing in the prior art is smaller, electronic component is more, the utility model is mentioned A kind of low-noise amplifier is supplied.

The utility model is achieved through the following technical solutions above-mentioned purpose: a kind of low-noise amplifier, including NPN transistor Q1, Q2, transmission transformer T1, T2, T3, T4, coupled capacitor C1, C2, C3, C4, current-limiting resistance R1, R2, divider resistance R3, R4, Load resistance R5, R6, load inductance L1, L2 and power supply Vb, Vc, the primary Same Name of Ends connection signal of the transmission transformer T1 are defeated Enter plug X1, the secondary Same Name of Ends of the transmission transformer T1 connects all the way by being divided into two-way after connecting the coupled capacitor C1 Connect the secondary Same Name of Ends of the transmission transformer T2, another way be sequentially ingressed into the load resistance R5, the load inductance L1 and Ground；The secondary different name end of the transmission transformer T2 connects the emitter e of the NPN transistor Q1, the transmission transformer T2 Primary Same Name of Ends connect power supply Vc, the primary different name end of the transmission transformer T2 connects the current collection of the NPN transistor Q1 After the c of pole, the secondary Same Name of Ends of the transmission transformer T4 is connected serially to by the coupled capacitor C3, the NPN transistor Q1's It is grounded after the base stage b connection divider resistance R3, is accessed after the base stage b connection current-limiting resistance R1 of the NPN transistor Q1 The voltage Vb；The secondary different name end of the transmission transformer T1 is divided into two-way after connecting the coupled capacitor C2, connects all the way The secondary Same Name of Ends of the transmission transformer T3, another way are sequentially ingressed into load resistance R6, load inductance L2 and ground；The transmission The secondary different name end of transformer T3 connects the emitter e of the NPN transistor Q2, the primary Same Name of Ends of the transmission transformer T3 The power supply Vc is connected, after the primary different name end of the transmission transformer T3 connects the collector c of the NPN transistor Q2, is led to The secondary different name end that C4 is connected serially to transmission transformer T4 is crossed, after the base stage b connection divider resistance R4 of the NPN transistor Q2 It is grounded, accesses the voltage Vb, the transmission transformer T4 after the base stage b connection current-limiting resistance R2 of the NPN transistor Primary Same Name of Ends connection signal output plug X2.

On this basis, described power supply Vb, Vc are DC power supply, and the output voltage values of described power supply Vb, Vc are respectively less than NPN The pressure voltage of transistor Q1, Q2.

On this basis, described NPN transistor Q1, Q2 are all made of MLN1030.

On this basis, described transmission transformer T1, T2, T3, T4 are all made of MnZn magnetic core coiling.

On this basis, described coupled capacitor C1, C2, C3, C4 are nonpolarity chip ceramic capacitor.

On this basis, described load inductance L1, L2 are discrete.

On this basis, described current-limiting resistance R1, R2, divider resistance R3, R4, load resistance R5, R6 are in low noise amplification Power is all larger than 1/4W in the circuit of device.

Compared with prior art, the utility model has the beneficial effects that

The utility model discloses the differential amplifier circuit amplified based on transistor common base, base amplification circuit has Wider frequency characteristic uses transmission transformer T2, T3 by cooperation, as the inductance of NPN transistor Q1, Q2 operating voltage Element, while flatness in width is promoted as negative-feedback device, reduce the influence to noise coefficient, instead of common electricity The shortcomings that resistance, capacitance negative feedback type cause noise coefficient to increase；

The utility model offsets second-order products by differential amplification form, to improve input second-order intercept point IIP2；Pass through Adjusting load resistance R5, R6 load resistance value, the amplification factor of raising NPN transistor Q1, Q2, increasing signal and three rank products move State range inputs three rank section IIP3 to improve；

Amplifier circuit provided by the utility model can reach low noise, High Linear with less element Radiofrequency signal amplification characteristic.

Detailed description of the invention

Fig. 1 is the circuit diagram of the utility model.

Specific embodiment

Below in conjunction with drawings and examples, the present invention will be further described in detail.It should be appreciated that this place is retouched The specific embodiment stated only to explain the utility model, is not used to limit the utility model.

As shown in Figure 1, the utility model schematically illustrates a kind of low-noise amplifier.

The utility model discloses a kind of low-noise amplifier, as shown in Figure 1, a kind of low-noise amplifier, including NPN are brilliant Body pipe Q1, Q2, transmission transformer T1, T2, T3, T4, coupled capacitor C1, C2, C3, C4, current-limiting resistance R1, R2, divider resistance R3, The primary Same Name of Ends connection signal of R4, load resistance R5, R6, load inductance L1, L2 and power supply Vb, Vc, transmission transformer T1 are defeated Enter plug X1, by being divided into two-way after connection coupled capacitor C1, connection transmission all the way becomes the secondary Same Name of Ends of transmission transformer T1 The secondary Same Name of Ends of depressor T2, another way are sequentially ingressed into load resistance R5, load inductance L1 and ground；The secondary of transmission transformer T2 Different name end connects the emitter e of NPN transistor Q1, and the primary Same Name of Ends of transmission transformer T2 connects power supply Vc, transmission transformer After the collector c of the primary different name end connection NPN transistor Q1 of T2, time of transmission transformer T4 is connected serially to by coupled capacitor C3 Grade Same Name of Ends, is grounded after the base stage b connection divider resistance R3 of NPN transistor Q1, and the base stage b connection current limliting of NPN transistor Q1 is electric Voltage Vb is accessed after hindering R1；It is divided into two-way after the secondary different name end connection coupled capacitor C2 of transmission transformer T1, connection passes all the way The secondary Same Name of Ends of defeated transformer T3, another way are sequentially ingressed into load resistance R6, load inductance L2 and ground；Transmission transformer T3's The emitter e of secondary different name end connection NPN transistor Q2, the primary Same Name of Ends of transmission transformer T3 connect power supply Vc, and transmission becomes After the collector c of the primary different name end connection NPN transistor Q2 of depressor T3, the secondary for being connected serially to transmission transformer T4 by C4 is different Name end, is grounded after the base stage b connection divider resistance R4 of NPN transistor Q2, after the base stage b connection current-limiting resistance R2 of NPN transistor Access voltage Vb, the primary Same Name of Ends connection signal output plug X2 of transmission transformer T4.

As preferred embodiments of the present invention, power supply Vb, Vc are DC power supply, the output of described power supply Vb, Vc Voltage value is respectively less than the pressure voltage of NPN transistor Q1, Q2.

As preferred embodiments of the present invention, NPN transistor Q1, Q2 are all made of MLN1030.

As preferred embodiments of the present invention, transmission transformer T1, T2, T3, T4 are all made of MnZn magnetic core coiling.

As preferred embodiments of the present invention, coupled capacitor C1, C2, C3, C4 are nonpolarity chip ceramic capacitor.

As preferred embodiments of the present invention, load inductance L1, L2 are discrete.

As preferred embodiments of the present invention, current-limiting resistance R1, R2, divider resistance R3, R4, load resistance R5, R6 power in the circuit of low-noise amplifier is all larger than 1/4W.

The working principle of the utility model is:

By transmission transformer T1, the radiofrequency signal difference for inputting a signal into plug X1 input is the two-way letter of opposite in phase Number, positive phase signals distinguish coupled capacitor C1, transmission transformer T2 is conducted to NPN transistor Q1 emitter e；Inversion signal difference Coupled capacitor C2, transmission transformer T3 are conducted to the emitter e of NPN transistor Q2.Power supply Vb, current-limiting resistance R1, partial pressure electricity The bias voltage that R3 constitutes NPN transistor Q1 is hindered, power supply Vc adds to the collector c of NPN transistor Q1 by transmission transformer T2, The amplification working condition of NPN transistor Q1 is consequently formed as load elements in load resistance R5, load inductance L1；Positive phase signals Enter from the emitter e of NPN transistor Q1, is amplified by collector c and exported.Power supply Vb, current-limiting resistance R2, divider resistance R4 are constituted The bias voltage of NPN transistor Q2, power supply Vc add to the collector c of NPN transistor Q2, load resistance by transmission transformer T3 The amplification working condition of NPN transistor Q2 is consequently formed as load elements in R6, load inductance L2.Inversion signal is from NPN crystal The emitter e of pipe Q2 enters, and is amplified by collector c and is exported.Through the amplified two paths of signals of NPN transistor Q1, Q2 by coupling electricity Hold C3, C4 and is coupled to T4 grade both ends of transmission transformer, it is defeated from signal output plug X2 after being combined by transmission transformer T4 Out.

Compared with prior art, the utility model has the beneficial effects that

The preferred embodiment of the utility model has shown and described in above description, as previously described, it should be understood that this is practical new Type is not limited to forms disclosed herein, and should not be regarded as an exclusion of other examples, and can be used for various other groups It closes, modification and environment, and by the technology of above-mentioned introduction or related fields or can know within that scope of the inventive concept describe herein Knowledge is modified.And changes and modifications made by those skilled in the art do not depart from the spirit and scope of the utility model, then all answer In the protection scope of the appended claims for the utility model.

Claims

1. a kind of low-noise amplifier, including NPN transistor Q1, Q2, transmission transformer T1, T2, T3, T4, coupled capacitor C1, C2, C3, C4, current-limiting resistance R1, R2, divider resistance R3, R4, load resistance R5, R6, load inductance L1, L2 and power supply Vb, Vc, It is characterized by: the primary Same Name of Ends connection signal input plug X1 of the transmission transformer T1, the transmission transformer T1's For secondary Same Name of Ends by being divided into two-way after connecting the coupled capacitor C1, the secondary for connecting the transmission transformer T2 all the way is of the same name End, another way are sequentially ingressed into the load resistance R5, the load inductance L1 and ground；The secondary different name of the transmission transformer T2 End connects the emitter e of the NPN transistor Q1, and the primary Same Name of Ends of the transmission transformer T2 connects power supply Vc, the biography After the primary different name end of defeated transformer T2 connects the collector c of the NPN transistor Q1, it is connected serially to by the coupled capacitor C3 The secondary Same Name of Ends of the transmission transformer T4 is grounded after the base stage b connection divider resistance R3 of the NPN transistor Q1, The power supply Vb is accessed after the base stage b connection current-limiting resistance R1 of the NPN transistor Q1；Time of the transmission transformer T1 Grade different name end is divided into two-way after connecting the coupled capacitor C2, connects the secondary Same Name of Ends of the transmission transformer T3 all the way, separately It is sequentially ingressed into load resistance R6, load inductance L2 and ground all the way；The secondary different name end of the transmission transformer T3 connects the NPN The primary Same Name of Ends of the emitter e of transistor Q2, the transmission transformer T3 connects the power supply Vc, the transmission transformer T3 Primary different name end connect the collector c of the NPN transistor Q2 after, the secondary different name of transmission transformer T4 is connected serially to by C4 It holds, is grounded after the base stage b connection divider resistance R4 of the NPN transistor Q2, the base stage b connection institute of the NPN transistor The power supply Vb, the primary Same Name of Ends connection signal output plug X2 of the transmission transformer T4 are accessed after stating current-limiting resistance R2.

2. a kind of low-noise amplifier according to claim 1, it is characterised in that: described power supply Vb, Vc are DC power supply, The output voltage values of described power supply Vb, Vc are respectively less than the pressure voltage of NPN transistor Q1, Q2.

3. a kind of low-noise amplifier according to claim 1, it is characterised in that: described NPN transistor Q1, Q2 are all made of MLN1030。

4. a kind of low-noise amplifier according to claim 1, it is characterised in that: the transmission transformer T1, T2, T3, T4 is all made of MnZn magnetic core coiling.

5. a kind of low-noise amplifier according to claim 1, it is characterised in that: described coupled capacitor C1, C2, C3, C4 For nonpolarity chip ceramic capacitor.

6. a kind of low-noise amplifier according to claim 1, it is characterised in that: described load inductance L1, L2 are discrete Formula.

7. a kind of low-noise amplifier according to claim 1, it is characterised in that: described current-limiting resistance R1, R2, partial pressure electricity R3, R4 are hindered, load resistance R5, R6 power in the circuit of low-noise amplifier are all larger than 1/4W.