CN2779421Y - Active transmitting-receiving probe for downfield NMR - Google Patents
Active transmitting-receiving probe for downfield NMR Download PDFInfo
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- CN2779421Y CN2779421Y CN 200520023366 CN200520023366U CN2779421Y CN 2779421 Y CN2779421 Y CN 2779421Y CN 200520023366 CN200520023366 CN 200520023366 CN 200520023366 U CN200520023366 U CN 200520023366U CN 2779421 Y CN2779421 Y CN 2779421Y
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- impedance inverter
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- magnetic resonance
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Abstract
The utility model relates to an active transmitting-receiving probe for low magnetic field NMR, which belongs to an electric communication field and is used for providing an NMR probe which is suitable for being used under the condition of a low magnetic field. The utility model has the technical scheme that the utility model is composed of a transmission interface, a reception interface, a resonant circuit, a lambda/4 impedance inverter circuit and a preamplification circuit, wherein the input and the output ends of the transmission interface, the resonant circuit 13, the lambda/4 impedance inverter circuit 14 and the preamplification circuit are connected with adjacent circuits in sequence, and the output end of the preamplification circuit is connected with the reception interface. The lambda/4 impedance inverter circuit is a pi type impedance inverter circuit formed from an inductance coil L3 and capacitors C3, C4, and the other end of the capacitors C3, C4 is connected to the ground. The utility model can realize the signal isolation of the transmission part and the reception part of an NMR instrument under the condition of the low magnetic field, signal-to-noise ratio is improved by the preamplification circuit, and good signals can be obtained. The utility model is used for measuring samples of different diameters without changing the probe, and operation is convenient.
Description
Technical field
The utility model relates to a kind of downfield small cores magnetic resonance emission receiving transducer, belongs to technical field of telecommunications.
Background technology
At present, in the nuclear magnetic resonance testing tool, it is the cable of signal wavelength lambda 1/4th that the highfield nmr probe generally can adopt length according to different frequency, realizes the isolation of radiating portion and receiving unit.But for the downfield NMR system, because signal wavelength is very long, radiating portion and receiving unit can not adopt the cable of wavelength X 1/4th to isolate.In addition, existing nmr probe generally is connected with the instrument prime amplifier by quarter-wave cable, and when downfield, this may cause harmful effect to the signal to noise ratio (S/N ratio) of instrument.In sum, existing nmr probe is not suitable for nuclear magnetic resonance testing tool use under the downfield condition.
Summary of the invention
The utility model is used to overcome the defective of prior art and a kind of active emission receiving transducer of the nuclear magnetic resonance apparatus of using under the downfield condition that is applicable to is provided.
The technical scheme that addresses the above problem is:
The active emission receiving transducer of a kind of downfield nuclear magnetic resonance, it is made up of emission interface, receiving interface, resonant circuit, λ/4 impedance inverter circuits, pre-amplification circuit, the input/output terminal of described emission interface, resonant circuit 13, λ/4 impedance inverter circuits 14, pre-amplification circuit is connected with adjacent circuit successively, the output terminal of pre-amplification circuit is connected with receiving interface, described λ/4 impedance inverter circuits are formed π type impedance inverter circuit by telefault L3, capacitor C 3, C4, the other end ground connection of capacitor C 3, C4.
The active emission receiving transducer of above-mentioned downfield nuclear magnetic resonance, described resonant circuit 13 is made up of switch K1, emission receiving coil L1, L2, capacitor C 1, C2, coil L1, L2, capacitor C 2 are formed antiresonant circuit, two stationary contacts of switch K1 join with the end points of coil L1, L2 respectively, its moving contact connects an end points of capacitor C 1, another end points of the latter is connected to the input end of λ/4 impedance inverter circuits, the diameter difference of described emission receiving coil L1, L2.
The active emission receiving transducer of above-mentioned downfield nuclear magnetic resonance, described pre-amplification circuit is made up of amplifier K1, coupling platform capacitor C 5, C6, and amplifier K1 adopts RAM6 to amplify chip.
The active emission receiving transducer of above-mentioned downfield nuclear magnetic resonance, behind emission interface, set up the small-signal cut-off circuit, described small-signal cut-off circuit is made up of diode D1, D2, D3, D4, wherein, diode D1, D3 and D2, D4 are divided into two groups, every group of two diode reverse parallel connections then are serially connected two groups of diodes again.
The active emission receiving transducer of above-mentioned downfield nuclear magnetic resonance, described reception holding circuit is made up of diode D5, D6, and they are respectively with between the forward and reverse input end and ground that is connected to pre-amplification circuit.
The utility model can be implemented under the downfield condition isolation to the radiating portion and the receiving unit of nuclear magnetic resonance apparatus, pre-amplification circuit is set has improved signal to noise ratio (S/N ratio), be more suitable for the requirement of downfield nuclear magnetic resonance apparatus test, these practical each parts that will pop one's head in are installed concentratedly in shielding box, reduce the radiation and the external interference of probe, improved the usability of probe.
Description of drawings
Fig. 1 is the utility model structural representation;
Fig. 2 is the utility model electrical schematic diagram;
Mark is as follows among the figure: large sample hole 1, small sample hole 2, tuning capacity 3, resistance trimming anticapacitance 4, circuit board 5, probe cover plate fixing threaded hole 6, power interface and control interface 7, probe install and fix screw 8, small sample emission receiving coil 9, large sample emission receiving coil 10, probe cassette 11; small-signal cut-off circuit 12; resonant circuit 13, λ/4 impedance inverter circuits 14, pre-amplification circuit 15 receive holding circuit 16.
Embodiment
As can see from Figure 1; large sample hole 1 (emission receiving coil L1) and small sample hole 2 (emission receiving coil L2) are arranged on probe cassette 11; they are used for measuring large sample and small sample (sample receiver bottle) respectively, switch K1, λ/4 impedance inverter circuits are installed on the circuit board 5, receive holding circuit, pre-amplification circuit, small-signal cut-off circuit and power supply.
Show among Fig. 2 that the utility model is made up of emission interface, receiving interface, small-signal cut-off circuit, resonant circuit, λ/4 impedance inverter circuits, pre-amplification circuit (K), reception holding circuit.Emission interface LK1 adopts BNC socket, and receiving interface LK2 adopts the SMA socket, and they can reduce electromagnetic interference (EMI).The small-signal cut-off circuit is made up of diode D1, D2, D3, D4, diode D1, D2 are in series, and D3, D4 are in series, the diode parallel connected in reverse phase of two groups of polyphones, the small-signal that is lower than two diode drops so just can not pass through, and plays the effect that the blocking-up small-signal disturbs.Resonant circuit is made up of switch K1, emission receiving coil L1, L2, capacitor C 1, C2, and coil L1, L2, capacitor C 2 compose in parallel resonant circuit, and capacitor C 2 is that resonance frequency is adjusted electric capacity, and its numerical range is several pF; Switch K1 plays the effect of selecting coil L1, L2, can measure large sample and small sample respectively.λ/4 impedance inverter circuits are formed π type impedance inverter circuit by telefault L3, capacitor C 3, C4, and the pass of it and wavelength is: C=λ f, f=1/2 π * √ LC (c is the light velocity).Pre-amplification circuit is made up of amplifier K1, capacitor C 5, C6, plays the effect of amplifying signal.
Switch K1 in the utility model can be one group of transfer contact of relay, also can be electronic switching circuit, or manual change-over switch.If electronic switching circuit in when operation, sends signal by control signal to electronic switching circuit earlier, make the on-off circuit action, so as to selecting suitable coil L1 or L2, thereby be suitable for measuring large sample or small sample.
Impedance matching circuit in the utility model plays the buffer action of λ/4 line cables in measurement, its characteristic impedance and frequency of operation are adjustable, and such network can play many effects with cable, has avoided the inconvenience of using long cable to bring.When the emission pumping signal, its output impedance approximates infinity; Turn off when pumping signal, during the small-signal responded in the receiving coil, its input impedance equivalence is 50 Ω.According to the nmr probe that said structure is made, very high signal to noise ratio (S/N ratio) is arranged, can obtain good signal.And it measures the sample of different-diameter, need not change probe, and operation is very much convenient.
Claims (5)
1. active emission receiving transducer of downfield nuclear magnetic resonance, it is characterized in that: it is made up of emission interface, receiving interface, resonant circuit, λ/4 impedance inverter circuits, pre-amplification circuit, the input/output terminal of described emission interface, resonant circuit [13], λ/4 impedance inverter circuits [14], pre-amplification circuit [15] is connected with adjacent circuit successively, the output terminal of pre-amplification circuit is connected with receiving interface, described λ/4 impedance inverter circuits are formed π type impedance inverter circuit by telefault L3, capacitor C 3, C4, the other end ground connection of capacitor C 3, C4.
2. the active emission receiving transducer of downfield nuclear magnetic resonance according to claim 1, it is characterized in that: described resonant circuit [13] is made up of switch K1, emission receiving coil L1, L2, capacitor C 1, C2, coil L1, L2, capacitor C 2 are formed antiresonant circuit, two stationary contacts of switch K1 join with the end points of coil L1, L2 respectively, its moving contact connects an end points of capacitor C 1, another end points of the latter is connected to the input end of λ/4 impedance inverter circuits, the diameter difference of described emission receiving coil L1, L2.
3. the active emission receiving transducer of downfield nuclear magnetic resonance according to claim 2 is characterized in that: described pre-amplification circuit [15] is made up of amplifier K1, coupling capacitance C5, C6, and amplifier K1 adopts RAM6 to amplify chip.
4. the active emission receiving transducer of downfield nuclear magnetic resonance according to claim 3, it is characterized in that: behind emission interface, set up small-signal cut-off circuit [12], described small-signal cut-off circuit is made up of diode D1, D2, D3, D4, wherein, diode D1, D3 and D2, D4 are divided into two groups, every group of two diode reverse parallel connections then are serially connected two groups of diodes again.
5. the active emission receiving transducer of downfield nuclear magnetic resonance according to claim 4 is characterized in that: described reception holding circuit [16] is made up of diode D5, D6, and they are respectively with between the forward and reverse input end and ground that is connected to pre-amplification circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520023366 CN2779421Y (en) | 2005-01-14 | 2005-01-14 | Active transmitting-receiving probe for downfield NMR |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520023366 CN2779421Y (en) | 2005-01-14 | 2005-01-14 | Active transmitting-receiving probe for downfield NMR |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2779421Y true CN2779421Y (en) | 2006-05-10 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200520023366 Expired - Fee Related CN2779421Y (en) | 2005-01-14 | 2005-01-14 | Active transmitting-receiving probe for downfield NMR |
Country Status (1)
| Country | Link |
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| CN (1) | CN2779421Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102175196A (en) * | 2011-01-20 | 2011-09-07 | 清华大学 | Coupling matching device for electromagnetic ultrasonic thickness measuring probe |
| CN106133531A (en) * | 2014-04-01 | 2016-11-16 | 罗森伯格高频技术有限及两合公司 | Contact assembly, particularly HF measure head |
| CN110793993A (en) * | 2018-08-01 | 2020-02-14 | 中国石油化工股份有限公司 | Nuclear magnetic resonance probe and nuclear magnetic resonance device with dual cores for joint measurement |
-
2005
- 2005-01-14 CN CN 200520023366 patent/CN2779421Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102175196A (en) * | 2011-01-20 | 2011-09-07 | 清华大学 | Coupling matching device for electromagnetic ultrasonic thickness measuring probe |
| CN102175196B (en) * | 2011-01-20 | 2012-08-22 | 清华大学 | Coupling matching device for electromagnetic ultrasonic thickness measuring probe |
| CN106133531A (en) * | 2014-04-01 | 2016-11-16 | 罗森伯格高频技术有限及两合公司 | Contact assembly, particularly HF measure head |
| CN106133531B (en) * | 2014-04-01 | 2020-10-20 | 罗森伯格高频技术有限及两合公司 | Contact arrangement, in particular HF measuring head |
| CN110793993A (en) * | 2018-08-01 | 2020-02-14 | 中国石油化工股份有限公司 | Nuclear magnetic resonance probe and nuclear magnetic resonance device with dual cores for joint measurement |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |