CN111049498A - Narrow-band-pass filter circuit and filter - Google Patents
Narrow-band-pass filter circuit and filter Download PDFInfo
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- CN111049498A CN111049498A CN201911368167.2A CN201911368167A CN111049498A CN 111049498 A CN111049498 A CN 111049498A CN 201911368167 A CN201911368167 A CN 201911368167A CN 111049498 A CN111049498 A CN 111049498A
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/70—Multiple-port networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source
- H03H9/72—Networks using surface acoustic waves
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/64—Filters using surface acoustic waves
Abstract
The invention provides a narrow-band-pass filter circuit and a narrow-band-pass filter, wherein the band-pass filter comprises a first resonance unit and a second resonance unit, and the first resonance unit and the second resonance unit are connected in parallel; the first resonance unit comprises a first resonance circuit and a second resonance circuit, and the first resonance circuit is connected with the second resonance circuit in series; the first resonant circuit comprises a first inductor and a first capacitor, and the second resonant circuit comprises a second inductor and a second capacitor; the first inductor is connected with the first capacitor in parallel, and the second inductor is connected with the second capacitor in parallel. The invention properly improves the structure of the traditional coupling resonant band-pass filter, and particularly, two inductors connected in parallel with the traditional coupling resonant band-pass filter are respectively added on the basis of the two capacitors connected in series, so that a narrower pass band is realized under the condition of not increasing the insertion loss of the filter.
Description
Technical Field
The invention relates to the field of filter circuits, in particular to a narrow-band-pass filter circuit and a filter.
Background
At present, band pass filters are widely used in various electronic devices, and are especially essential in transceiver circuits. The narrow-band-pass filter is a key component for realizing high selectivity of a system, and the traditional narrow-band-pass filter mainly has two realization modes: the first way is to increase the order of the filter to achieve better selectivity, but the increase of the order will increase the insertion loss of the filter, and further increase the debugging difficulty, and the actual size of the filter will also increase accordingly. Another way is to use filters made of other materials, such as (quartz) crystal filters, which are made by using the crystal piezoelectric effect, and such bandpass filters have very narrow passband and very high selectivity, but are expensive and limited by the very low fundamental frequency of the crystal cut thickness filter, and the resonant frequency is generally only tens of MHz, and it is difficult to implement higher frequency (hundreds of MHz level) applications, and therefore, the crystal filters are not ideal.
Disclosure of Invention
Therefore, a narrow band-pass filter is needed to be provided to solve the problems of large size, high cost and the like of the existing narrow band-pass filter.
In order to achieve the above object, the inventor provides a narrow-band bandpass filter circuit, the bandpass filter includes a first resonance unit and a second resonance unit, the first resonance unit and the second resonance unit are connected in parallel;
the first resonance unit comprises a first resonance circuit and a second resonance circuit, and the first resonance circuit is connected with the second resonance circuit in series; the first resonant circuit comprises a first inductor and a first capacitor, and the second resonant circuit comprises a second inductor and a second capacitor; the first inductor is connected with the first capacitor in parallel, and the second inductor is connected with the second capacitor in parallel.
As an alternative embodiment, the inductance values of the first inductor and the second inductor are the same.
As an alternative embodiment, the capacitance values of the first capacitor and the second capacitor are the same.
As an alternative embodiment, a fifth capacitor is further disposed between the first resonant circuit and the second resonant circuit, and the "first resonant circuit is connected in series with the second resonant circuit" includes:
the first capacitor is connected in series with the fifth capacitor, and the fifth capacitor is connected in series with the second capacitor.
As an alternative embodiment, the second resonant cell circuit includes a third resonant circuit and a fourth resonant circuit; the third resonant circuit and the fourth resonant circuit are connected in parallel;
the third resonant circuit comprises a third inductor and a third capacitor, and the fourth resonant circuit comprises a fourth inductor and a fourth capacitor; the third inductor is connected with the third capacitor in parallel, and the fourth inductor is connected with the fourth capacitor in parallel.
As an optional embodiment, a fifth capacitor is further disposed between the first resonant circuit and the second resonant circuit;
one end of the third resonant circuit is connected between the first capacitor and the fifth capacitor, and the other end of the third resonant circuit is grounded; one end of the fourth resonant circuit is connected between the second capacitor and the fifth capacitor, and the other end of the fourth resonant circuit is grounded.
As an alternative embodiment, the inductance values of the third inductor and the fourth inductor are the same.
As an alternative embodiment, the capacitance values of the third capacitor and the fourth capacitor are the same.
The inventor also provides a narrow-band-pass filter, the device comprises an upper dielectric substrate and a lower dielectric substrate, and a dielectric layer is arranged between the two dielectric substrates; the narrow-band-pass filter circuit is arranged on one layer of the dielectric substrate and is the narrow-band-pass filter circuit.
The invention provides a narrow-band-pass filter circuit and a narrow-band-pass filter, wherein the band-pass filter comprises a first resonance unit and a second resonance unit, and the first resonance unit and the second resonance unit are connected in parallel; the first resonance unit comprises a first resonance circuit and a second resonance circuit, and the first resonance circuit is connected with the second resonance circuit in series; the first resonant circuit comprises a first inductor and a first capacitor, and the second resonant circuit comprises a second inductor and a second capacitor; the first inductor is connected with the first capacitor in parallel, and the second inductor is connected with the second capacitor in parallel. The invention properly improves the structure of the traditional coupling resonant band-pass filter, and particularly, two inductors connected in parallel with the traditional coupling resonant band-pass filter are respectively added on the basis of the two capacitors connected in series, so that a narrower pass band is realized under the condition of not increasing the insertion loss of the filter.
Drawings
Fig. 1 is a schematic diagram of a narrow band pass filter according to an embodiment of the present invention;
FIG. 2 is a diagram of a narrow bandpass filter according to an embodiment of the invention;
fig. 3 is a schematic circuit diagram of a coupled resonant band-pass filter according to the prior art;
FIG. 4 is a circuit diagram of a narrow band pass filter according to an embodiment of the present invention;
fig. 5 is a schematic diagram illustrating an effect of a narrow band-pass filter circuit according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a narrow band-pass filter circuit according to an embodiment of the present invention.
Reference numerals:
1. a first resonance unit;
10. a first resonant circuit; 101. a first inductor; 102. a first capacitor;
30. a second resonant circuit; 301. a second inductor; 302. a second capacitor;
2. a second resonance unit;
20. a third resonant circuit; 201. a third inductor; 202. a third capacitor;
40. a fourth resonant circuit; 401. a fourth inductor; 402. a fourth capacitor;
50. a fifth capacitor;
501. a first dielectric substrate; 502. a second dielectric substrate; 503. a dielectric layer; 504. a tuning filter circuit; 505. a first port; 506. a second port.
Detailed Description
To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.
As shown in fig. 6, which is a narrow-band bandpass filter circuit according to an embodiment of the present invention, the bandpass filter includes a first resonant unit 1 and a second resonant unit 2, where the first resonant unit 1 and the second resonant unit 2 are connected in parallel;
the first resonance unit 1 comprises a first resonance circuit 10 and a second resonance circuit 30, the first resonance circuit 10 being connected in series with the second resonance circuit 30; the first resonant circuit 10 comprises a first inductance 101 and a first capacitance 102, and the second resonant circuit 30 comprises a second inductance 301 and a second capacitance 302; the first inductor 101 is connected in parallel with the first capacitor 102, and the second inductor 301 is connected in parallel with the second capacitor 302.
Because the first inductor 101 and the second inductor 301 are respectively connected in parallel on the basis of the first capacitor 102 and the second capacitor 302, in the filtering process, the design of the first inductor 101 and the second inductor 301 will enable the filter to form a transmission zero (e.g. m5 position in fig. 5) in a certain frequency band, and the formation of the zero greatly improves the selectivity of the filter, thereby more easily realizing the narrow-pass band characteristic.
Preferably, the inductance values of the first inductor 101 and the second inductor 301 are the same, and the capacitance values of the first capacitor 102 and the second capacitor 302 are the same. A fifth capacitor 50 is further disposed between the first resonant circuit 10 and the second resonant circuit 30, and the "series connection of the first resonant circuit 10 and the second resonant circuit 30" includes: the first capacitor 102 is connected in series with the fifth capacitor 50, and the fifth capacitor 50 is connected in series with the second capacitor 302.
In some embodiments, the second resonant cell circuit 2 comprises a third resonant circuit 20 and a fourth resonant circuit 40; the third resonant circuit 20 and the fourth resonant circuit 40 are connected in parallel. The third resonant circuit 20 comprises a third inductor 201 and a third capacitor 202, and the fourth resonant circuit 40 comprises a fourth inductor 401 and a fourth capacitor 402; the third inductor 201 is connected in parallel with the third capacitor 202, and the fourth inductor 401 is connected in parallel with the fourth capacitor 402. Preferably, the inductance values of the third inductor and the fourth inductor are the same. And the capacitance values of the third capacitor and the fourth capacitor are the same.
Preferably, a fifth capacitor is further disposed between the first resonant circuit and the second resonant circuit; one end of the third resonant circuit is connected between the first capacitor and the fifth capacitor, and the other end of the third resonant circuit is grounded; one end of the fourth resonant circuit is connected between the second capacitor and the fifth capacitor, and the other end of the fourth resonant circuit is grounded.
As shown in fig. 1 and 2, the invention further provides a narrow-band bandpass filter, the device comprises an upper dielectric substrate and a lower dielectric substrate, and a dielectric layer is arranged between the two dielectric substrates; one of the dielectric substrates is provided with a narrow band pass filter circuit, which is the aforementioned narrow band pass filter circuit, that is, the tuning filter circuit 504 in fig. 1 and fig. 2.
As can be seen from fig. 1 and 2, the narrowband bandpass filter includes a first dielectric substrate 501 and a second dielectric substrate 502, a dielectric layer 503 is disposed between the first dielectric substrate 501 and the second dielectric substrate 502, and a tuned filter circuit 504 is disposed on the first dielectric substrate 501. Preferably, the tuning filter circuit 504 (i.e. the narrow band pass filter mentioned above) has a first port 505 and a second port 506, and the first port 505 and the second port 506 can be used for connecting other circuits or devices. In other embodiments, the tuned filter circuit 504 may also be disposed on the second dielectric substrate 502. The medium substrate can adopt an FR-4 plate which is a composite material made of tetra-functional (Tera-Function) epoxy resin, a Filler (Filler) and glass fiber.
As shown in fig. 1, the narrow band-pass filter of the present invention uses a double-layer dielectric substrate as a substrate, and an LC filter circuit (i.e., a narrow band-pass filter circuit), a first port, and a second port as a filter body. The hardware circuit comprises a metal wire and an LC component which are positioned on the top layer of the dielectric substrate, an output port which is used as an input and an output port which is used as an output, the dielectric layer is positioned between the upper dielectric substrate and the lower dielectric substrate, and the bottom layer of the dielectric substrate is a metal stratum. The first port and the second port may be a universal radio frequency receptacle. Preferably, the narrow-band bandpass filter of the present invention has a symmetrical structure, and both the first port and the second port can be used as an input/output or an output/input port, and have port reciprocity.
Fig. 3 is a structure of a conventional coupled resonant bandpass filter, as shown in fig. 2, L1/C1 and L2/C2 are parallel resonant networks with the same inductance and capacitance values, and C3/C4/C5 are coupling capacitors, which together form a single-section coupled resonant unit.
FIG. 4 shows an improved bandpass filter structure of the present invention, in which two sets of parallel resonant networks L03/C03 and L04/C04 connected in parallel to ground and a coupling capacitor C05 form a single-section coupling resonant unit; on the basis, the newly added L01 is connected with the C01 in parallel, the newly added L02 is connected with the C02 in parallel, and the newly added L02 is connected with the C02 in parallel and connected with the LC parallel resonant network at the input end and the output end in series, wherein the inductance values of L01 and L02 are consistent, and the capacitance values of C01 and C02 are consistent, which is the improvement point of the invention.
The effect of the modified section is to form a transmission zero (where the m5 icon is located in fig. 5) on the left side of fig. 5, the formation of which greatly improves the selectivity of the filter, so that the filter as a whole is more likely to achieve a narrow pass band characteristic. If the existing structure shown in fig. 3 is adopted, C01/C02 can only ensure that the filter insertion loss is good within a certain range of values and is insensitive to the center frequency, but after the structure of the present invention is adopted, that is, the filter is connected in parallel with L01/L02, it can be seen that, taking the filter with the center frequency point of 100MHz as an example, when the inductance value of the first inductor or the second inductor is set to 20uH, the filter forms a new filtering zero point in the filtering process, and when the inductance value of the first inductor or the second inductor is continuously reduced to 1.2uH, the frequency point of the zero point is shifted to a position close to 60MHz, at this time, the lower sideband suppression of the band pass filter with f0 being 100M is greatly improved, and the cost is that the suppression degree of the band below 60MHz starts to deteriorate to about-80 dB, but-80 dB is sufficient for most applications.
The coupling resonance unit has the function of forming double resonance points, wherein L03/C03 and L04/C04 are used for forming a second resonance point, so that the function of adjusting the central frequency point of the filter (namely, the relative bandwidth is unchanged, and the absolute bandwidth is increased along with the increase of the central frequency) is achieved, the inductance L03 and the inductance L04 of the two groups of resonance networks are consistent in inductance value, the capacitance C03 and the capacitance C04 are consistent in capacitance value, the inductance and capacitance values are changed from large to small, and the second resonance point is gradually deviated to high frequency when being more deviated to low frequency.
The coupling capacitor C05 in the middle has the function of adjusting the first resonance point, the capacitance value of C05 changes from small to large, the first resonance point gradually shifts from high frequency to low frequency, and therefore, only by adjusting the first resonance point to be coincident with the second resonance point, a more ideal passband profile can be formed.
Due to the appearance of the new zero generated by the improved part, the selectivity of the filter can be effectively improved, and it can be seen from fig. 5 that in the verification example of the invention, the new zero is selected on the left side of the center frequency, and the selectivity on the left side of the filter is greatly improved. In practical application, the new zero point can be designed to the right of the center frequency by adjusting the values of L01/C01 and L02/C02, and then the right selectivity of the filter is greatly improved.
The insertion loss results of the two filters are shown in fig. 5, and fig. 5 has a total of 2 curves, wherein the solid line is the insertion loss result of the conventional coupled resonator filter, and the dotted line is the insertion loss result of the improved LC narrowband bandpass filter of the present invention.
In the insertion loss result diagram, it can be seen that the center frequency point of the two filter designs is 100MHz, and the respective-3 dB bandwidth frequency points are respectively marked by 4 points in total of m1, m2, m3 and m4 (for accuracy reasons, about-3 dB frequency point is adopted). Where m2 and m4 are two-3 dB frequency points located on the dotted line, and m1 and m3 are two-3 dB frequency points located on the solid line.
Insertion loss refers to the ratio of the filter output port power to the input port power, expressed in logarithmic form, in dB, also known as insertion attenuation. The bandwidth of the filter is typically calculated as the cut-off at a frequency point when the insertion loss is approximately-3 dB. Thus, from the data indicated in FIG. 5, the-3 dB bandwidth of the conventional filter and the improved narrow bandpass filter of the present invention can be calculated.
According to a calculation formula of relative bandwidth: relative bandwidth is absolute bandwidth/center frequency. The two filter calculations are as follows:
the-3 dB bandwidth (104.1-96.3)/100 of the traditional coupled resonant filter is 7.8%
The-3 dB bandwidth (102.3-99.1)/100 ═ 3.2% of the improved LC narrow-band-pass filter
The experimental result shows that the relative bandwidth of the improved LC narrow-band-pass filter is 3.2%, and compared with the passband of the relative bandwidth of the traditional coupling resonance filter of 7.8%, the effect is improved remarkably, and meanwhile, due to the existence of a left zero point, a dotted line rapidly drops in a range of 50MHz to 100MHz, which is also an advantage brought by the zero point.
The invention provides a narrow-band-pass filter circuit and a narrow-band-pass filter, wherein the band-pass filter comprises a first resonance unit and a second resonance unit, and the first resonance unit and the second resonance unit are connected in parallel; the first resonance unit comprises a first resonance circuit and a second resonance circuit, and the first resonance circuit is connected with the second resonance circuit in series; the first resonant circuit comprises a first inductor and a first capacitor, and the second resonant circuit comprises a second inductor and a second capacitor; the first inductor is connected with the first capacitor in parallel, and the second inductor is connected with the second capacitor in parallel. The invention properly improves the structure of the traditional coupling resonant band-pass filter, and particularly, two inductors connected in parallel with the traditional coupling resonant band-pass filter are respectively added on the basis of the two capacitors connected in series, so that a narrower pass band is realized under the condition of not increasing the insertion loss of the filter.
It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.
Claims (9)
1. A narrow-band-pass filter circuit is characterized in that the band-pass filter comprises a first resonance unit and a second resonance unit, and the first resonance unit and the second resonance unit are connected in parallel;
the first resonance unit comprises a first resonance circuit and a second resonance circuit, and the first resonance circuit is connected with the second resonance circuit in series; the first resonant circuit comprises a first inductor and a first capacitor, and the second resonant circuit comprises a second inductor and a second capacitor; the first inductor is connected with the first capacitor in parallel, and the second inductor is connected with the second capacitor in parallel.
2. The narrowband bandpass filter circuit of claim 1 wherein the first inductance and the second inductance have the same inductance value.
3. The narrowband bandpass filter circuit of claim 1 wherein the first capacitor and the second capacitor have the same capacitance value.
4. The narrowband bandpass filter circuit of claim 1 wherein a fifth capacitor is further disposed between the first resonant circuit and the second resonant circuit, and wherein the "first resonant circuit is in series with the second resonant circuit" comprises:
the first capacitor is connected in series with the fifth capacitor, and the fifth capacitor is connected in series with the second capacitor.
5. The narrowband bandpass filter circuit of claim 1 or 4, wherein the second resonant cell circuit comprises a third resonant circuit and a fourth resonant circuit; the third resonant circuit and the fourth resonant circuit are connected in parallel;
the third resonant circuit comprises a third inductor and a third capacitor, and the fourth resonant circuit comprises a fourth inductor and a fourth capacitor; the third inductor is connected with the third capacitor in parallel, and the fourth inductor is connected with the fourth capacitor in parallel.
6. The narrowband bandpass filter circuit of claim 5 further comprising a fifth capacitor disposed between the first resonant circuit and the second resonant circuit;
one end of the third resonant circuit is connected between the first capacitor and the fifth capacitor, and the other end of the third resonant circuit is grounded;
one end of the fourth resonant circuit is connected between the second capacitor and the fifth capacitor, and the other end of the fourth resonant circuit is grounded.
7. The narrowband bandpass filter circuit of claim 5 wherein the third inductance and the fourth inductance have the same inductance value.
8. The narrowband bandpass filter circuit of claim 5 wherein the third capacitor and the fourth capacitor have the same capacitance value.
9. A narrow-band-pass filter is characterized by comprising an upper dielectric substrate and a lower dielectric substrate, wherein a dielectric layer is arranged between the upper dielectric substrate and the lower dielectric substrate; a narrow-band-pass filter circuit is arranged on one layer of the dielectric substrate and is the narrow-band-pass filter circuit as claimed in any one of claims 1 to 8.
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| CN201911368167.2A CN111049498A (en) | 2019-12-26 | 2019-12-26 | Narrow-band-pass filter circuit and filter |
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| CN201911368167.2A CN111049498A (en) | 2019-12-26 | 2019-12-26 | Narrow-band-pass filter circuit and filter |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112564671A (en) * | 2020-11-25 | 2021-03-26 | 电子科技大学 | In-band ultra-low group delay fluctuation filter |
| CN112946544A (en) * | 2021-02-01 | 2021-06-11 | 中国科学院精密测量科学与技术创新研究院 | Double-resonance detection device for nuclear magnetic resonance radio frequency coil |
| CN117081542A (en) * | 2023-10-17 | 2023-11-17 | 中科海高(成都)电子技术有限公司 | Filter bank |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004248121A (en) * | 2003-02-17 | 2004-09-02 | Alps Electric Co Ltd | Band path filter |
| JP2008005182A (en) * | 2006-06-22 | 2008-01-10 | Nec Electronics Corp | Band-pass filter circuit |
| EP1988598A2 (en) * | 2007-05-02 | 2008-11-05 | NGK Sparkplug Co., Ltd. | Laminate type band pass filter and diplexer using the same |
| CN101621147A (en) * | 2009-08-11 | 2010-01-06 | 南京理工大学 | 2.4-kilomegahertz miniature band-pass filter with low loss and double-zero |
| US20110115573A1 (en) * | 2009-11-16 | 2011-05-19 | Ambit Microsystems (Shanghai) Ltd. | Band-pass filter |
| CN203104374U (en) * | 2013-01-06 | 2013-07-31 | 成都市金天之微波技术有限公司 | Inductance-capacitance coupling resonance narrow-band band-pass filter |
| CN110011638A (en) * | 2017-12-07 | 2019-07-12 | 英飞凌科技股份有限公司 | Acoustical coupling resonator trap and bandpass filter |
-
2019
- 2019-12-26 CN CN201911368167.2A patent/CN111049498A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004248121A (en) * | 2003-02-17 | 2004-09-02 | Alps Electric Co Ltd | Band path filter |
| JP2008005182A (en) * | 2006-06-22 | 2008-01-10 | Nec Electronics Corp | Band-pass filter circuit |
| EP1988598A2 (en) * | 2007-05-02 | 2008-11-05 | NGK Sparkplug Co., Ltd. | Laminate type band pass filter and diplexer using the same |
| CN101621147A (en) * | 2009-08-11 | 2010-01-06 | 南京理工大学 | 2.4-kilomegahertz miniature band-pass filter with low loss and double-zero |
| US20110115573A1 (en) * | 2009-11-16 | 2011-05-19 | Ambit Microsystems (Shanghai) Ltd. | Band-pass filter |
| CN203104374U (en) * | 2013-01-06 | 2013-07-31 | 成都市金天之微波技术有限公司 | Inductance-capacitance coupling resonance narrow-band band-pass filter |
| CN110011638A (en) * | 2017-12-07 | 2019-07-12 | 英飞凌科技股份有限公司 | Acoustical coupling resonator trap and bandpass filter |
Non-Patent Citations (1)
| Title |
|---|
| 崔万照等, 国防工业出版社 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112564671A (en) * | 2020-11-25 | 2021-03-26 | 电子科技大学 | In-band ultra-low group delay fluctuation filter |
| CN112564671B (en) * | 2020-11-25 | 2023-01-31 | 电子科技大学 | In-band ultra-low group delay fluctuation filter |
| CN112946544A (en) * | 2021-02-01 | 2021-06-11 | 中国科学院精密测量科学与技术创新研究院 | Double-resonance detection device for nuclear magnetic resonance radio frequency coil |
| CN117081542A (en) * | 2023-10-17 | 2023-11-17 | 中科海高(成都)电子技术有限公司 | Filter bank |
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