CN104467690A - Low-noise amplifier circuit - Google Patents
Low-noise amplifier circuit Download PDFInfo
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- CN104467690A CN104467690A CN201410729362.4A CN201410729362A CN104467690A CN 104467690 A CN104467690 A CN 104467690A CN 201410729362 A CN201410729362 A CN 201410729362A CN 104467690 A CN104467690 A CN 104467690A
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Abstract
The invention discloses a low-noise amplifier circuit. The low-noise amplifier circuit comprises an input coupling network, a first amplifier element, a first biasing unit, a second amplifier element and a second biasing unit, wherein a front-end circuit and the rear-end first amplifier element are connected by the input coupling network; the first amplifier element is connected with the input coupling network and used for amplifying an input signal; the first biasing unit is connected with the first amplifier element, and used for controlling a quiescent operating point of the first amplifier element in a linear amplifying zone; the second amplifier element is connected with the first amplifier element and used for amplifying an output signal of the first amplifier element; the second biasing unit is connected with the second amplifier element, and used for controlling a quiescent operating point of the second amplifier element in the linear amplifying zone. According to the technical scheme, a high-input impedance wideband and low-noise amplifier is adopted, the wideband amplifier realizes pre-amplifying decoupling through high-input impedance, provides a wider frequency band, provides a low noise coefficient, and supports the application of multi-nuclear magnetic resonance imaging; the design complexity is reduced, the circuit is convenient to debug, and element materials are saved.
Description
Technical field
The invention belongs to rf signal reception integrated circuit (IC) design field, be specifically related to a kind of low noise amplifier circuit.
Background technology
At medical imaging field, magnetic resonance imaging is a kind of Noninvasive, the imaging technique that can present good soft tissue contrast.Its know-why utilizes to strengthen under magnetic field condition outside, superimposed RF signal makes the atomic nucleus of target area generation covibration send the radiofrequency signal of some strength, this radiofrequency signal is received afterwards by receiving coil, and the amplifier on receiver carries out signal amplification, be delivered to spectrometer etc. and carry out follow-up further signal transacting, being finally converted into can for the image of diagnosis focus.
In existing magnetic resonance imaging (MRI) system, each nuclear gyromagnetic ratio (precession frequency namely under unit external magnetic field strength) is different.Because hydrogen atom is present in human body overwhelming majority tissue, occupy larger specific gravity, and hydrogen atom magnetic rotaion comparison is higher, in clinical magnetic resonance imaging, therefore utilizes hydrogen atom to carry out imaging as target atoms more.In some medical research process, also can utilize other atomic nucleus as target atoms to carry out magnetic resonance imaging (such as: phosphorus), or excite multiple atomic nucleus to carry out magnetic resonance imaging simultaneously.
Due under identical B0 field (i.e. additional high-intensity magnetic field), the precession frequency that different atomic nucleus produces is different, cause when needs carry out magnetic resonance imaging to multiple atomic nucleus, the frequency of the radiofrequency signal that receiver receives also changes thereupon, has relatively big difference with when only carrying out hydrogen nuclei imaging.When particularly adopting traditional low noise amplifier to multinuclear imaging, the embodiment that frequency is different is outstanding especially.
As shown in Figure 1, existing low noise amplifier more than 110 adopts low input impedance, by matching network 105, the amplifier 110 of low input impedance is formed a high impedance by impedance variation at coil 100 two ends, puts the effect of decoupling before completing.The low noise amplifier 110 of low input impedance adopts input lc circuit, to obtain minimum noise factor.The discrete device of its lc circuit many employings high q-factor, utilizes the discrete device of high q-factor to obtain the narrow available bandwidth of a bandwidth.Relative three dB bandwidth is only a few MHz to MHz more than 10, the so just use of restriction low noise amplifier circuit in multinuclear imaging.Because when the field intensity of B0 field is 3T, the precession frequency of hydrogen nuclei 1H is 127.728MHz=42.576MH/T*3T, the precession frequency of phosphorus atoms core 31P is 51.705MHz=17.235MHz/T*3T, these two different atomic nucleus are when identical B0 field, and precession frequency difference reaches about 70MHz.Adopt the low input impedance low noise amplifier of prior art to be difficult to cover frequency band wide like this, and low-noise factor is provided.
Therefore corresponding multiple atom imaging in practice, current mode is the low noise amplifier adopting multiple corresponding different frequency, makes circuit design more complicated like this, is unfavorable for the debugging of circuit, and cause the waste of components and parts.
Summary of the invention
The problem to be solved in the present invention be to provide a kind of can at the low noise amplifier of magnetic resonance imaging system multinuclear imaging applications, do not need corresponding different atomic nucleus precession frequency that multiple low noise amplifier is set, make simplicity of design, be convenient to circuit debugging, and save components and parts material.
To achieve these goals, the invention provides a kind of low noise amplifier, comprising:
Input coupling network, connects front-end circuit and rear end first amplifier element, for realizing the impedance matching of front end, back-end circuit;
First amplifier element, has the amplifier element of high input impedance, is connected, amplifies input signal with input coupling network;
First bias unit, is connected with the first amplifier element, by the quiescent operation point control online property amplification region of the first amplifier element;
Second amplifier element, is connected with the first amplifier element, amplifies the output signal of the first amplifier element;
Second bias unit, is connected with the second amplifier element, by the quiescent operation point control online property amplification region of the second amplifier element;
Described second bias unit and the second amplifier element composition second level amplifying circuit, in the amplifying circuit of the described second level, the connected mode of each circuit element is that broadband connects setting.
Further, described input coupling network comprises electric capacity C1 and inductance L 1, and described electric capacity C1 is used for every the RF-coupled effect of direct sum, and described inductance L 1 is for being biased and increasing stable effect.
Further, described first amplifier element and described first bias unit composition first order amplifying circuit, described first amplifier element is High Electron Mobility Transistor integrated circuit component, described input coupling network is connected with the gate pole of described High Electron Mobility Transistor integrated circuit component, described second amplifier element is dipole triode integrated circuit component, cascode mode is adopted to connect between described first order amplifying circuit and described second level amplifying circuit, described second level amplifying circuit is extremely connected with the Drain of described High Electron Mobility Transistor integrated circuit component.
Further, in described first order amplifying circuit, each circuit element connected mode is that common source connects setting.
Further, described first bias unit comprises the resistance R1, the electric capacity C2 that are connected with the first source electrode of described High Electron Mobility Transistor integrated circuit component, and the electric capacity C3 to be connected with the second source electrode of described High Electron Mobility Transistor integrated circuit component, wherein resistance R1, electric capacity C2 and electric capacity C3 other end ground connection.
Further, each element connected mode of described second level amplifying circuit is that common base connects setting.
Further, described second bias unit comprise be connected with the emitter of described dipole triode integrated circuit component resistance R2, resistance R4, DC power supply DC, and the resistance R3 to be connected with the base stage of described dipole triode integrated circuit component, wherein the other end of resistance R2 is connected with the base stage of described dipole triode integrated circuit component, resistance R3, resistance R4 and DC power supply DC other end ground connection.
Further, described second level amplifying circuit also comprises filter unit, and described filter unit is connected, for the filtering of radiofrequency signal with the base stage of described dipole triode integrated circuit component.
Further, described filter unit comprises electric capacity C3, and described electric capacity C3 one end is connected with the base stage of described dipole triode integrated circuit component, other end ground connection.
Technical solution of the present invention is compared to the advantage of prior art, adopt high input impedance wideband low noise amplifier, decoupling is put before its high input impedance achieves, wide-band amplifier provides wider frequency band, and lower noise factor is provided, supports the application of multiple nmr imaging, reduce design complexities, be convenient to circuit debugging, save components and parts material.
Accompanying drawing explanation
Fig. 1 is prior art receiver circuit connection diagram;
Fig. 2 is each module diagram of low noise amplifier circuit of the present invention;
Fig. 3 is low noise amplifier circuit connection diagram of the present invention;
Fig. 4 is the two-band noise schematic diagram of first order amplifying circuit of the present invention.
Embodiment
In order to enable above-mentioned purpose of the present invention, feature, advantage more aobvious and understandable, below in conjunction with accompanying drawing, the specific embodiment of the present invention is further described.
Fig. 2 is each module diagram of low noise amplifier circuit of the present invention, refers to Fig. 2.
Design philosophy of the present invention is the high input impedance wideband low noise amplifying circuit adopting two-layer configuration, comprise: the input coupling network 205 between coil 200 and the first amplifier element 210, connect front-end circuit and rear end first amplifier element, for realizing the impedance matching of front end, back-end circuit; There is the first amplifier element 210 of high input impedance, be connected with input coupling network, input signal is amplified; For ensureing first bias unit 215 of the quiescent point of the first amplifier element 210 in linear amplification region; Be connected with the first amplifier element, to the second amplifier element 220 that the output signal of the first amplifier element is amplified; For ensureing second bias unit 225 of the quiescent point of the second amplifier element 220 in linear amplification region; In another embodiment, also comprise and being connected with the second amplifier element 220, for the filter unit 230 of radiofrequency signal filtering.Eventually pass through the radiofrequency signal after two-stage circuit amplification, held by out and output to subsequent conditioning circuit.First amplifier element and the first bias unit composition first order amplifying circuit, the second amplifier element and the second bias unit composition second level amplifier circuit.In the amplifying circuit of the second level, the connected mode of each circuit element is that broadband connects setting.
Preferably, first amplifier element adopts High Electron Mobility Transistor (HEMT, High ElectronMobility Transistor) integrated circuit (IC), second amplifier element adopts bipolar junction transistor triode (BJT, Bipolar Junction Transistor) integrated circuit, and second level amplifying circuit adopts the Amplifier Design in broadband.The composite design of cascode structure (CASCODE structure) is adopted between High Electron Mobility Transistor and bipolar junction transistor triode.
Fig. 3 is low noise amplifier circuit connection diagram of the present invention, refer to Fig. 3, first order amplifying circuit adopts High Electron Mobility Transistor (HEMT, High Electron Mobility Transistor) integrated circuit (IC), HEMT adopts common source to connect the structure of (COMMON SOURCE).Four ports of HEMT are respectively drain pole, gate pole (gate pole) and two source electrodes (source pole), with bipolar junction transistor triode (BJT, Bipolar Junction Transistor) feature of comparing HEMT has lower noise factor, and the input impedance of HEMT is higher, the approximate range of its input impedance is between hundreds of ohm is to one kilohm.
Input coupling network 205 is connected between HEMT and coil (Coil), its input coupling network 205 is made up of electric capacity C1 and inductance L 1, C1 be used for isolated DC electricity and and L1 together play the effect that regulating winding (Coil) and subsequent conditioning circuit match, C1 electric capacity is used for every the RF-coupled effect of direct sum, because the low noise utilizing first order amplifier to have by oneself and the characteristic of high impedance, do not need to utilize C1 electric capacity to mate; L1 inductance is used for biased and increases stable effect.Input coupling network 205 is connected with the gate pole (Gate pole) of HEMT in first order amplifier circuit side.
In addition, in order to ensure that the quiescent point of HEMT is in linear amplification region and is provided with the first bias unit 215, wherein C2 and C3 is bypass (bypass) electric capacity of Source pole, and R1 is the biasing resistor of HEMT.C2 with R1 one end is extremely connected with a Source of HEMT, C2 and R1 other end ground connection.Second Source of C3 with HEMT is extremely connected, other end ground connection.
By emulation HEMT first order amplifier circuit, Fig. 4 is to the simulation result noise circle diagram under 50MHz and 128MHz two frequency ranges, can see from Fig. 4 that its minimum noise factor is all close to high impedance areas, transverse axis in figure | Zin (Ω) | the absolute value of indication circuit input impedance Zin (Ω), the longitudinal axis represents the phase angle that its input impedance Zin (Ω) is corresponding.Can be seen by emulation 50MHz and 128MHz two points, these two frequency ranges etc. noise circle very close.When frequency f req=50MHz, the m1 point place in Fig. 4 can be found, its noise factor ns figure=0.073063, counterpart impedance impedance=241.15 ohm (getting system features impedance is 50 ohm); When frequency f req=128MHz, find the m2 point place in Fig. 4, noise factor ns figure=0.073063, counterpart impedance impedance=283.45 ohm (system features impedance is 50 ohm).Therefore high input impedance and low-noise factor two requirements can be completed.
Second level amplifying circuit adopts the IC of BJT, and carries out Amplifier Design in wide band mode.The collector electrode of BJT is extremely connected with the Drain of HEMT.The bipolar junction transistor triode (BJT) of the second level adopts common base to connect the structure of (COMMON BASE).Because BJT adopt be grounded base design, grounded base design is the characteristic in broadband, bandwidth range at hundreds of MHz to an about GMHz.Filter unit 230 is made up of electric capacity C3, and its one end is connected with the base stage of BJT, other end ground connection, for the filtering of radiofrequency signal.
Second biasing circuit 225 comprises resistance R2, R3, R4 and DC power supply DC, ensures that the quiescent point of BJT is in linear amplification region.Wherein R3, R4, R5 are the biasing resistors of BJT, and be provided as HEMT and power and do an adjustable extent, resistance R2 one end is connected with the emitter of BJT, and one end is connected with resistance R3.Resistance R3 one end is connected with R2, and jointly links the base stage of BJT, resistance R3 other end ground connection.Resistance R4 is connected with the emitter of BJT one end respectively with DC power supply DC, other end ground connection.In the implementation process of technical solution of the present invention, these resistance values can be adjusted according to the operating voltage of HEMT.COMMON BASE is exactly the amplifier architecture in a broadband, affords redress to the gain of whole link, and completes the output matching in broadband.And can utilize high input impedance complete coil before put decoupling.
The feature of high input impedance wideband low noise amplifier of the present invention is that high input impedance puts decoupling before realization; Wide-band amplifier, can cover wider frequency band, and provide lower noise factor; Corresponding circuit components in multinuclear application, can be reduced in broadband.
Although the present invention discloses as above with preferred embodiment; so itself and be not used to limit the present invention, any those skilled in the art, without departing from the spirit and scope of the present invention; when doing a little amendment and perfect, therefore protection scope of the present invention is when being as the criterion of defining with claims.
Claims (9)
1. a low noise amplifier circuit, is characterized in that, comprising:
Input coupling network, connects front-end circuit and rear end first amplifier element, for realizing the impedance matching of front end, back-end circuit;
First amplifier element, has the amplifier element of high input impedance, is connected, amplifies input signal with input coupling network;
First bias unit, is connected with the first amplifier element, by the quiescent operation point control online property amplification region of the first amplifier element;
Second amplifier element, is connected with the first amplifier element, amplifies the output signal of the first amplifier element;
Second bias unit, is connected with the second amplifier element, by the quiescent operation point control online property amplification region of the second amplifier element;
Described second bias unit and the second amplifier element composition second level amplifying circuit, in the amplifying circuit of the described second level, the connected mode of each circuit element is that broadband connects setting.
2. low noise circuit as claimed in claim 1, it is characterized in that, described input coupling network comprises electric capacity C1 and inductance L 1, and described electric capacity C1 is used for every the RF-coupled effect of direct sum, and described inductance L 1 is for being biased and increasing stable effect.
3. low noise amplifier circuit as claimed in claim 1, it is characterized in that, described first amplifier element and described first bias unit composition first order amplifying circuit, described first amplifier element is High Electron Mobility Transistor integrated circuit component, described input coupling network is connected with the gate pole of described High Electron Mobility Transistor integrated circuit component, described second amplifier element is dipole triode integrated circuit component, cascode mode is adopted to connect between described first order amplifying circuit and described second level amplifying circuit, described second level amplifying circuit is extremely connected with the Drain of described High Electron Mobility Transistor integrated circuit component.
4. low noise amplifier circuit as claimed in claim 3, is characterized in that, in described first order amplifying circuit, each circuit element connected mode is that common source connects setting.
5. low noise amplifier circuit as claimed in claim 4, it is characterized in that, described first bias unit comprises the resistance R1, the electric capacity C2 that are connected with the first source electrode of described High Electron Mobility Transistor integrated circuit component, and the electric capacity C3 to be connected with the second source electrode of described High Electron Mobility Transistor integrated circuit component, wherein resistance R1, electric capacity C2 and electric capacity C3 other end ground connection.
6. low noise amplifier circuit as claimed in claim 3, is characterized in that, each element connected mode of described second level amplifying circuit is that common base connects setting.
7. low noise amplifier circuit as claimed in claim 6, it is characterized in that, described second bias unit comprise be connected with the emitter of described dipole triode integrated circuit component resistance R2, resistance R4, DC power supply DC, and the resistance R3 to be connected with the base stage of described dipole triode integrated circuit component, wherein the other end of resistance R2 is connected with the base stage of described dipole triode integrated circuit component, resistance R3, resistance R4 and DC power supply DC other end ground connection.
8. low noise amplifier circuit as claimed in claim 6, it is characterized in that, described second level amplifying circuit also comprises filter unit, and described filter unit is connected, for the filtering of radiofrequency signal with the base stage of described dipole triode integrated circuit component.
9. as right wants the low noise amplifier circuit as described in 8, it is characterized in that, described filter unit comprises electric capacity C3, and described electric capacity C3 one end is connected with the base stage of described dipole triode integrated circuit component, other end ground connection.
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| CN201410729362.4A CN104467690A (en) | 2014-12-04 | 2014-12-04 | Low-noise amplifier circuit |
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| CN201410729362.4A CN104467690A (en) | 2014-12-04 | 2014-12-04 | Low-noise amplifier circuit |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105759230A (en) * | 2016-02-25 | 2016-07-13 | 哈尔滨医科大学 | Quad-band radio frequency surface coil for multi-nuclear magnetic resonance imaging (MRI) |
| CN107367702A (en) * | 2016-05-13 | 2017-11-21 | 上海联影医疗科技有限公司 | The matching process and gridding radio-frequency coil of a kind of multiport coil |
| CN108566167A (en) * | 2016-09-26 | 2018-09-21 | 深圳市华讯方舟卫星通信有限公司 | Low noise amplifier circuit |
| CN108649910A (en) * | 2018-06-26 | 2018-10-12 | 深圳先进技术研究院 | A kind of preamplifier |
| CN114513171A (en) * | 2022-02-15 | 2022-05-17 | 电子科技大学 | Low noise amplifier of S wave band based on HEMT |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1568035A (en) * | 2003-07-07 | 2005-01-19 | 深圳市中兴通讯股份有限公司 | Module arrangement of broadband low-noise amplifier device |
| CN1877986A (en) * | 2005-06-09 | 2006-12-13 | 昂科公司 | Distortion cancellation in a transimpedance amplifier circuit |
| CN201298824Y (en) * | 2008-11-05 | 2009-08-26 | 深圳市同洲电子股份有限公司 | Narrowband low-noise amplifying circuit and digital television receiving terminal |
| CN102664595A (en) * | 2011-12-12 | 2012-09-12 | 中国科学院深圳先进技术研究院 | Preliminary amplifier and magnetic resonance amplifying device |
| CN104113288A (en) * | 2013-04-22 | 2014-10-22 | 中国科学技术大学 | Low-temperature low-noise amplifier |
-
2014
- 2014-12-04 CN CN201410729362.4A patent/CN104467690A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1568035A (en) * | 2003-07-07 | 2005-01-19 | 深圳市中兴通讯股份有限公司 | Module arrangement of broadband low-noise amplifier device |
| CN1877986A (en) * | 2005-06-09 | 2006-12-13 | 昂科公司 | Distortion cancellation in a transimpedance amplifier circuit |
| CN201298824Y (en) * | 2008-11-05 | 2009-08-26 | 深圳市同洲电子股份有限公司 | Narrowband low-noise amplifying circuit and digital television receiving terminal |
| CN102664595A (en) * | 2011-12-12 | 2012-09-12 | 中国科学院深圳先进技术研究院 | Preliminary amplifier and magnetic resonance amplifying device |
| CN104113288A (en) * | 2013-04-22 | 2014-10-22 | 中国科学技术大学 | Low-temperature low-noise amplifier |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105759230A (en) * | 2016-02-25 | 2016-07-13 | 哈尔滨医科大学 | Quad-band radio frequency surface coil for multi-nuclear magnetic resonance imaging (MRI) |
| CN107367702A (en) * | 2016-05-13 | 2017-11-21 | 上海联影医疗科技有限公司 | The matching process and gridding radio-frequency coil of a kind of multiport coil |
| CN108566167A (en) * | 2016-09-26 | 2018-09-21 | 深圳市华讯方舟卫星通信有限公司 | Low noise amplifier circuit |
| CN108566167B (en) * | 2016-09-26 | 2023-05-16 | 深圳市华讯方舟卫星通信有限公司 | Low noise amplifying circuit |
| CN108649910A (en) * | 2018-06-26 | 2018-10-12 | 深圳先进技术研究院 | A kind of preamplifier |
| CN114513171A (en) * | 2022-02-15 | 2022-05-17 | 电子科技大学 | Low noise amplifier of S wave band based on HEMT |
| CN114513171B (en) * | 2022-02-15 | 2023-05-23 | 电子科技大学 | S-band low-noise amplifier based on HEMT |
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Address after: 201807 Shanghai city Jiading District Industrial Zone Jiading Road No. 2258 Applicant after: Shanghai Lianying Medical Technology Co., Ltd Address before: 201807 Shanghai city Jiading District Industrial Zone Jiading Road No. 2258 Applicant before: SHANGHAI UNITED IMAGING HEALTHCARE Co.,Ltd. |
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Application publication date: 20150325 |