CN113970792B - Radio wave perspective instrument receiving system and receiving method thereof - Google Patents
Radio wave perspective instrument receiving system and receiving method thereof Download PDFInfo
- Publication number
- CN113970792B CN113970792B CN202111247898.9A CN202111247898A CN113970792B CN 113970792 B CN113970792 B CN 113970792B CN 202111247898 A CN202111247898 A CN 202111247898A CN 113970792 B CN113970792 B CN 113970792B
- Authority
- CN
- China
- Prior art keywords
- circuit
- module
- electrically connected
- amplifying
- filtering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000001914 filtration Methods 0.000 claims abstract description 69
- 238000012545 processing Methods 0.000 claims abstract description 51
- 230000003321 amplification Effects 0.000 claims abstract description 44
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 44
- 238000006243 chemical reaction Methods 0.000 claims abstract description 24
- 239000003990 capacitor Substances 0.000 claims description 28
- 230000008878 coupling Effects 0.000 claims description 15
- 238000010168 coupling process Methods 0.000 claims description 15
- 238000005859 coupling reaction Methods 0.000 claims description 15
- 238000004891 communication Methods 0.000 claims description 12
- 238000002955 isolation Methods 0.000 claims description 6
- 238000001514 detection method Methods 0.000 abstract description 29
- 238000010586 diagram Methods 0.000 description 20
- 230000010355 oscillation Effects 0.000 description 7
- 238000004590 computer program Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 239000011435 rock Substances 0.000 description 5
- 230000006870 function Effects 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 230000003139 buffering effect Effects 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 238000003672 processing method Methods 0.000 description 3
- 238000004422 calculation algorithm Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 230000005764 inhibitory process Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 101100030351 Schizosaccharomyces pombe (strain 972 / ATCC 24843) dis2 gene Proteins 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
- G01V3/12—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with electromagnetic waves
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Life Sciences & Earth Sciences (AREA)
- Electromagnetism (AREA)
- Environmental & Geological Engineering (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Geophysics (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
The invention relates to a radio wave perspective instrument receiving system and a receiving method thereof, wherein the system comprises a frequency selecting module, a pre-amplifying module, a mixing module, an intermediate frequency amplifying and filtering module, an acquisition module, a control processing module and a power supply module; the intermediate frequency amplifying and filtering module comprises a first-stage filtering circuit, a first-stage amplifying circuit, a second-stage filtering circuit and a second-stage amplifying circuit, the acquisition module comprises an acquisition buffer circuit and an analog-to-digital conversion circuit, the second-stage amplifying circuit is electrically connected with the acquisition buffer circuit, the acquisition buffer circuit is electrically connected with the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is electrically connected with the control and processing module. Compared with the prior art, the method adopts 2 times of frequency selection, 3 times of amplification and 2 times of filtering, and can acquire weaker effective signals; the method of converting the analog signal into the digital signal is adopted to remove the interference, so as to obtain a stronger effective signal; the detection width is larger and the precision is higher.
Description
Technical Field
The invention relates to the technical field of radio wave perspective, in particular to a radio wave perspective receiving system and a receiving method thereof.
Background
Radioscopy technology has evolved over the last 50 years and its basic principle is that radio waves propagate in rock formations with their absorption of radio energy being different due to the electrical differences of the various rocks. The low-resistance rock stratum has strong radio wave energy absorption, the high-resistance rock stratum has weak radio wave energy absorption, and various perspective anomalies caused by various structures of the rock stratum and the influence of the geologic body on the radio wave energy are utilized, so that geological deduction and interpretation can be performed. As is generally known, the radiowave perspective instrument is mainly used for detecting a geological structure between two relatively parallel lanes, and adopts a mode of separating transmission and reception for detection construction, namely, one lane transmits and the other lane receives, and vice versa, the other lane transmits, the original transmitting lane changes into the receiving, and the double lanes exchange the transmitting and the receiving, so as to complete the radiowave perspective detection engineering.
From the basic principle and the construction mode, the detection width and the detection precision of the radiowave perspective instrument have close relation with the following factors: 1. the transmitting power and the transmitting efficiency of the transmitter are high, the transmitting power is high, the transmitting efficiency is high, and then the transmission distance and the detection precision are high; 2. how the receiving precision, the anti-interference capability and the stability of the receiver are; 3. the object condition is detected and how the environmental condition is detected.
In order to increase the detection width and the detection precision, some companies do not work well in improving the transmission efficiency of the transmitter, but due to the mutual inductance and self inductance of the transmitting coil, the noise of the transmitting driving circuit cannot be eliminated, the designed transmission efficiency of the transmitter is not more than 80%, and other companies do very large transmission power of the transmitter, but the method brings about a great negative influence, and is mainly expressed in the following steps: because of working in the field or under the mine, the battery is basically used for power supply, the power supply battery used by the high-power transmitter is heavy and large in size, and moreover, the power device package selected by the high-power transmitter is large, so that the whole size of the transmitter is large and heavy. Meanwhile, because the emission power is high, the emission current is high, the temperature of all emission devices is high, the power consumption is high, and the thermal noise is rapidly increased, so that the reduction of the emission efficiency is avoided. This is an objective existence as to the case of the detection object and the detection of the environmental condition, which can only improve the detection width and the detection accuracy in the detection construction method or the detection apparatus.
More information about the above solutions can also be found in the following documents:
as in chinese patent with patent publication No. CN 112014890a, an electromagnetic interference resisting device and method for a radiowave perspective receiver is disclosed, which comprises a receiving host, a signal connection cable and a tuning frequency-selecting receiving antenna; the receiving host comprises digital parts, analog parts and accessory parts; the tuning frequency-selecting receiving antenna comprises a tuning circuit and a loop antenna, and the tuning frequency-selecting receiving antenna, the signal connecting cable and the receiving host machine all adopt electromagnetic shielding structural design.
In the process of implementing the present invention, the inventor finds that the following problems exist in the prior art:
1. in the prior art, the radio wave perspective instrument receiving system has weak capability of selecting frequency, amplifying and filtering, and can not acquire weak signals.
2. In the prior art, the anti-interference capability of a radio wave perspective meter receiving system is weak, and an effective signal cannot be obtained, so that the detection precision is poor.
Disclosure of Invention
Therefore, it is necessary to provide a radiowave perspective receiving system and a receiving method thereof, which are used for solving the technical problems that in the prior art, the radiowave perspective receiving system has weak capability of frequency selection, amplification and filtering, weak anti-interference capability, incapability of obtaining weak signals and poor detection precision.
In order to achieve the above object, the present inventors provide a radio wave perspective view receiving system, which includes a frequency selecting module, a pre-amplifying module, a mixing module, an intermediate frequency amplifying and filtering module, an acquisition module, a control processing module and a power module;
the frequency selecting module, the pre-amplifying module, the mixing module, the intermediate frequency amplifying and filtering module, the acquisition module and the control processing module are sequentially connected, and the power supply module respectively provides power for the pre-amplifying module, the mixing module, the intermediate frequency amplifying and filtering module, the acquisition module and the control processing module;
the intermediate frequency amplifying and filtering module comprises a first-stage filtering circuit, a first-stage amplifying circuit, a second-stage filtering circuit and a second-stage amplifying circuit, wherein the first-stage filtering circuit, the first-stage amplifying circuit, the second-stage filtering circuit and the second-stage amplifying circuit are electrically connected in sequence, the mixing module is electrically connected with the first-stage filtering circuit, and the second-stage amplifying circuit is electrically connected with the acquisition module;
the acquisition module comprises an acquisition buffer circuit and an analog-to-digital conversion circuit, the second-stage amplifying circuit is electrically connected with the acquisition buffer circuit, the acquisition buffer circuit is electrically connected with the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is electrically connected with the control processing module.
Compared with the prior art, the technical scheme is characterized in that the frequency selection module is used for carrying out primary frequency selection, the frequency mixing module is used for carrying out secondary frequency selection, the pre-amplification module, the first-stage amplification circuit and the second-stage amplification circuit are used for carrying out tertiary amplification, the first-stage filtering circuit and the second-stage filtering circuit are used for carrying out twice filtering, the primary filtering cannot be completely filtered, one-stage filtering is added, the inhibition capacity is doubled, and therefore interference signals can be inhibited more, and the signal to noise ratio is improved. The device skillfully arranges the sequence of frequency selection, amplification and filtering, can acquire weaker effective signals, adopts a filtering mode, increases the filtering times, increases the signal to noise ratio and can better receive the effective signals. The acquisition buffer circuit is used for buffering signals, analog signals are converted into digital signals through the analog-to-digital conversion circuit, interference is conveniently removed by a digital signal processing method, more and stronger effective signals can be obtained, and accordingly the detection width and the detection accuracy are improved. The two points are combined, and compared with the existing radiowave perspective instrument receiver, the detection width is larger and the precision is higher under the same condition.
As one embodiment of the present invention, the frequency selecting module includes two or more frequency selecting circuits, and the two or more frequency selecting circuits are connected to the pre-amplifying module through a switch.
Therefore, more than two frequency selection circuits are switched through the change-over switch, only one frequency selection circuit can be selected at a time, and the frequency selection capacity and the frequency selection width are improved.
As one embodiment of the present invention, the frequency selecting circuit includes a loop antenna, a fixed capacitor, a variable capacitor, and a coupling transformer, wherein the loop antenna, the fixed capacitor, the variable capacitor, and the coupling transformer are electrically connected in sequence, and the coupling transformer is electrically connected with the pre-amplification module.
Therefore, the capacity of the variable capacitor is limited, and the capacity of the variable capacitor is greatly exceeded by the capacity needed by the frequency selection circuit, and the compatibility of the frequency selection circuit is improved by compensating through the fixed capacitor.
As one embodiment of the present invention, the pre-amplifying module includes an amplifier protection circuit, an amplifying circuit, and an attenuation circuit, wherein the amplifier protection circuit, the amplifying circuit, and the attenuation circuit are electrically connected in sequence, the frequency selecting module is electrically connected to the amplifier protection circuit, and the attenuation circuit is electrically connected to the mixing module.
Thus, the safety of the pre-amplification module is improved through the amplifier protection circuit.
As one embodiment of the present invention, the frequency mixing module includes a local oscillator clock circuit and a frequency mixing main circuit, the local oscillator clock circuit is electrically connected to the frequency mixing main circuit, the pre-amplifying module is electrically connected to the frequency mixing main circuit, and the frequency mixing main circuit is electrically connected to the intermediate frequency amplifying and filtering module.
As one embodiment of the present invention, the control processing module includes a microprocessor, a display unit, an input unit, a storage unit, and a communication unit;
the microprocessor is respectively and electrically connected with the display unit, the input unit, the storage unit and the communication unit, and the acquisition module is electrically connected with the microprocessor.
As one embodiment of the present invention, the microprocessor includes a micro-processing central unit and a signal processing core, the acquisition module is electrically connected to the micro-processing central unit, and the micro-processing central unit is electrically connected to the signal processing core.
As one embodiment of the present invention, the power supply module includes a power supply filter, a primary power supply filter circuit, an isolation power supply circuit, a secondary power supply filter circuit, and a small ripple power supply circuit, and the power supply filter, the primary power supply filter circuit, the isolation power supply circuit, the secondary power supply filter circuit, and the small ripple power supply circuit are sequentially connected.
Thus, the power filter and the primary power filter circuit filter out the interference of external noise to the internal power circuit, the isolation power circuit is mainly used for isolating the power supplies of the digital circuit and the analog circuit and preventing mutual interference between the digital circuit and the analog circuit, and the secondary power filter circuit and the small ripple power circuit are used for filtering out and inhibiting the interference of the primary power supply to the secondary power supply.
To achieve the above object, the present inventors also provide a radioscopic apparatus receiving method including a radioscopic apparatus receiving system as set forth in any one of the above-mentioned inventors, the receiving method including the steps of:
tuning frequency selection, weak signal amplification, frequency mixing frequency selection, intermediate frequency band-pass filtering, intermediate frequency amplification, high-speed acquisition, signal processing, storage and display.
Compared with the prior art, the technical scheme skillfully arranges the sequence of frequency selection, amplification and filtering, can acquire weaker effective signals, and can better receive the effective signals only by adopting a filtering mode and increasing the filtering times and increasing the signal-to-noise ratio. The acquisition buffer circuit is used for buffering signals, analog signals are converted into digital signals through the analog-to-digital conversion circuit, interference is conveniently removed by a digital signal processing method, more and stronger effective signals can be obtained, and accordingly the detection width and the detection accuracy are improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and that other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a system block diagram of a radiowave perspective receiving system according to one embodiment of the present application;
fig. 2 is a schematic structural diagram of a frequency selection module according to an embodiment of the present application;
FIG. 3 is a circuit diagram of a frequency selection module according to one embodiment of the present application;
FIG. 4 is a schematic diagram of a pre-amp module according to one embodiment of the present application;
FIG. 5 is a circuit diagram of a pre-amp module according to one embodiment of the present application;
fig. 6 is a schematic structural diagram of a mixing module according to an embodiment of the present application;
FIG. 7 is a circuit diagram of a mixing module according to one embodiment of the present application;
fig. 8 is a schematic structural diagram of an intermediate frequency amplifying and filtering module according to an embodiment of the present application;
FIG. 9 is a circuit diagram of an intermediate frequency amplification filter module according to one embodiment of the present application;
FIG. 10 is a schematic structural diagram of an acquisition module according to one embodiment of the present application;
FIG. 11 is a circuit diagram of an acquisition module according to one embodiment of the present application;
FIG. 12 is a schematic diagram of a control processing module according to an embodiment of the present application;
FIG. 13 is a schematic diagram of a power module according to an embodiment of the present disclosure;
fig. 14 is a circuit diagram of a power module according to an embodiment of the present application.
Reference numerals illustrate:
1. a frequency-selecting module, which is used for selecting the frequency of the signal,
2. a pre-amplification module, which is arranged on the front surface of the optical fiber,
3. the mixing module is used for mixing the signals,
4. an intermediate frequency amplifying and filtering module,
5. the collecting module is used for collecting the data of the sample,
6. the control processing module is used for controlling the processing module,
7. the power supply module is provided with a power supply module,
8. a loop-type antenna is provided which,
9. the capacitance of the capacitor is fixed and the capacitor is fixed,
10. the variable capacitance of the capacitor is used to control the capacitance of the capacitor,
11. the coupling transformer is used for coupling the two-phase current,
12. the protection circuit of the amplifier is provided with a protection circuit,
13. a high-frequency high-gain amplifying circuit,
14. a high-frequency attenuation circuit is provided,
15. the local oscillation clock circuit is provided with a local oscillation clock circuit,
16. the main circuit of the mixer is provided with a mixer,
17. the first stage of the filter circuit is provided with a first stage of the filter circuit,
18. the first-stage amplifying circuit comprises a first-stage amplifying circuit,
19. a second stage of the filter circuit is provided,
20. a second-stage amplifying circuit is provided,
21. the acquisition buffer circuit is used for acquiring the data of the data,
22. the analog-to-digital conversion circuit is provided with a first analog-to-digital conversion circuit,
23. the display unit is provided with a display unit,
24. the input unit is used for inputting the data,
25. a micro-processing central unit which is used for processing the data,
26. the microprocessor is provided with a microprocessor which,
27. the signal processing core(s),
28. the communication unit is used for the communication of the communication unit,
29. and a memory cell.
Detailed Description
In order to describe the technical content, constructional features, achieved objects and effects of the technical solution in detail, the following description is made in connection with the specific embodiments in conjunction with the accompanying drawings.
In the description of the present application, the terms "first," "second," and "second," are used for descriptive purposes only and are not to be construed as indicating or implying relative importance unless explicitly specified and defined otherwise; the term "plurality" means two or more, unless specified or indicated otherwise; the terms "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the description of the present specification, it should be understood that the terms "upper," "lower," "left," "right," and the like in the embodiments of the present application are described in terms of angles shown in the drawings, and should not be construed as limiting the embodiments of the present application. In the context of this document, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on the other element or be indirectly on the other element through intervening elements.
Accordingly, the embodiment of the present application provides a technical solution, please refer to fig. 1 to 13, and the embodiment relates to a radio wave perspective receiving system, which includes a frequency selecting module 1, a pre-amplifying module 2, a mixing module 3, an intermediate frequency amplifying and filtering module 4, an acquisition module 5, a control processing module 6 and a power module 7; the frequency selecting module 1, the pre-amplifying module 2, the mixing module 3, the intermediate frequency amplifying and filtering module 4, the collecting module 5 and the control processing module 6 are sequentially connected, and the power supply module 7 respectively provides power for the pre-amplifying module 2, the mixing module 3, the intermediate frequency amplifying and filtering module 4, the collecting module 5 and the control processing module 6;
the intermediate frequency amplifying and filtering module 4 comprises a first-stage filtering circuit 17, a first-stage amplifying circuit 18, a second-stage filtering circuit 19 and a second-stage amplifying circuit 20, wherein the first-stage filtering circuit 17, the first-stage amplifying circuit 18, the second-stage filtering circuit 19 and the second-stage amplifying circuit 20 are electrically connected in sequence, the mixing module 3 is electrically connected with the first-stage filtering circuit 17, and the second-stage amplifying circuit 20 is electrically connected with the acquisition module 5;
the acquisition module 5 comprises an acquisition buffer circuit 21 and an analog-to-digital conversion circuit 22, the second-stage amplification circuit 20 is electrically connected with the acquisition buffer circuit 21, the acquisition buffer circuit 21 is electrically connected with the analog-to-digital conversion circuit 22, and the analog-to-digital conversion circuit 22 is electrically connected with the control processing module 6.
In the embodiment, the signal is subjected to primary frequency selection through the frequency selection module 1, the frequency mixing module 3 is subjected to secondary frequency selection, and is subjected to tertiary amplification through the pre-amplification module 2, the first-stage amplification circuit 18 and the second-stage amplification circuit 20, the first-stage filtering circuit 17 and the second-stage filtering circuit 19 are subjected to twice filtering, the primary filtering cannot be completely filtered, one-stage filtering is added, the inhibition capacity is doubled, and therefore interference signals can be inhibited more, and the signal to noise ratio is improved; compared with the prior market radiowave perspective instrument receiver, the device can acquire weaker effective signals by skillfully arranging the sequence of frequency selection, amplification and filtering, and can better receive the effective signals by adopting a filtering mode and increasing the filtering times and increasing the signal-to-noise ratio. The acquisition buffer circuit 21 is used for buffering signals, and converting analog signals into digital signals through the analog-to-digital conversion circuit 22, so that interference can be conveniently removed by a digital signal processing method, more and stronger effective signals can be obtained, and the detection width and the detection accuracy are improved. The two points are combined, and compared with the existing radiowave perspective instrument receiver, the detection width is larger and the precision is higher under the same condition.
In some embodiments, the frequency selection module 1 includes more than two frequency selection circuits, and the more than two frequency selection circuits are connected with the pre-amplification module 2 through a change-over switch. Therefore, more than two frequency selection circuits are switched through the change-over switch, only one frequency selection circuit can be selected at a time, and the frequency selection capacity and the frequency selection width are improved.
In the embodiment, the frequency selecting module 1 comprises a frequency selecting circuit 1, a frequency selecting circuit 2, & gtand & lt- & gt, a frequency selecting circuit n which can select a plurality of frequencies, n frequency selecting circuits, only one frequency selecting circuit can be selected at a time, and only one frequency selecting circuit can be connected with the pre-amplifying module 2 at a time through switch switching.
In some embodiments, the frequency selection circuit comprises a loop antenna 8, a fixed capacitor 9, a variable capacitor 10 and a coupling transformer 11, the loop antenna 8, the fixed capacitor 9, the variable capacitor 10 and the coupling transformer 11 being electrically connected in sequence, the coupling transformer 11 being electrically connected with the pre-amplification module 2. At this time, since the capacity of the variable capacitor 10 is limited, the capacitance required by some frequency selection circuits greatly exceeds the value of the variable capacitor 10, and the fixed capacitor 9 compensates the capacitance, thereby improving the compatibility of the frequency selection circuits.
In this embodiment, each frequency selection circuit includes a loop antenna 8, a fixed capacitor 9, a variable capacitor 10, and a coupling transformer 11. The output port to of the loop antenna 8 is connected with the input port gi of the fixed capacitor 9; the output port go of the fixed capacitor 9 is connected with the input port ki of the variable capacitor 10; the output port ko of the variable capacitor 10 is connected with the input port bi of the coupling transformer 11; the coupling transformer 11 output port bo is connected to the preamplifier input port qi. The frequency selecting bandwidth of the frequency selecting circuit is 10 KHz-2000 KHz. In this embodiment, the frequency selected by the frequency selection circuit is 500KHz; the diameter of the loop antenna 8 is 500mm, 12 turns of the loop antenna are clockwise wound by enameled wires, and the inductance is 226.5uH; the coupling transformer 11 is a magnetic ring coupler with 43 turns and two parallel windings, and the primary side inductance and the secondary side inductance are 27mH; the fixed capacitance 9 is set to 220pF; the variable capacitance 10 is tuned to 85pF.
In some embodiments, as shown in fig. 4 and 5, the pre-amplifying module 2 includes an amplifier protection circuit 12, an amplifying circuit, and an attenuation circuit, where the amplifier protection circuit 12, the amplifying circuit, and the attenuation circuit are sequentially electrically connected, the frequency selection module 1 is electrically connected to the amplifier protection circuit 12, and the attenuation circuit is electrically connected to the mixing module 3. In this way, the safety of the pre-amplifier module is improved by the amplifier protection circuit 12.
In the present embodiment, the pre-amplification module 2 includes an amplifier protection circuit 12, a high-frequency high-gain amplification circuit 13, and a high-frequency attenuation circuit 14; the output end abo of the amplifier protection circuit 12 is connected with the input end fi of the high-frequency high-gain amplifying circuit 13; the output end fo of the high-frequency high-gain amplifying circuit 13 is connected with the input end si of the high-frequency attenuating circuit 14; the output so of the high-frequency attenuation circuit 14 is connected to the input hpi of the mixer module 3. In the present embodiment, the high-frequency high-gain amplifying circuit 13 is a weak signal amplifier, and the gain is essentially large, but the gain of the amplifier is often small when the high-frequency signal is transmitted, so the high-frequency high-gain amplifying circuit 13 is actually implemented by amplifying a plurality of amplifiers in series.
In the embodiment, the frequency bandwidth of the pre-amplifying module 2 when the gain is 2000 times is 0 Hz-3500 KHz, and the signal amplitude attenuation degree is 40dB. In this embodiment, the amplifier protection circuit 12 selects a combination of diode BAV199 and current limiting resistor 1.2K; an amplifier selection AD8428 in the high-frequency high-gain amplification circuit 13; the high frequency attenuation circuit 14 selects pi-resistance attenuators, both side resistances select 50.5 ohms, and the middle resistance selects 2500 ohms.
In some embodiments, as shown in fig. 6 and 7, the mixing module 3 includes a local oscillator clock circuit 15 and a mixing main circuit 16, where the local oscillator clock circuit 15 is electrically connected to the mixing main circuit 16, the pre-amplifying module 2 is electrically connected to the mixing main circuit 16, and the mixing main circuit 16 is electrically connected to the intermediate frequency amplifying and filtering module 4.
In this embodiment, the mixing module 3 includes a local oscillation clock circuit 15 and a mixing main circuit 16; the local oscillation clock input port clki of the mixing main circuit 16 is connected with the clock output port clko of the local oscillation clock circuit 15; the signal output port hpo of the mixing main circuit 16 is connected to the input port li1 of the intermediate frequency amplifying and filtering module 4. The output frequency range of the local oscillation clock circuit 15 is 10 KHz-200 MHz, and the signal frequency range of the frequency mixing main circuit 16 is 10 KHz-2000 KHz. In this embodiment, the output frequency of the local oscillation clock circuit 15 is 750KHz, and since the signal is 500KHz, the intermediate frequency signal to be obtained is 250KHz, the mixing main circuit 16 outputs both 1250KHz and 250 KHz.
As shown in fig. 8 and 9, the intermediate frequency amplification filter module 4 includes a first stage filter circuit 17, a first stage amplifier circuit 18, a second stage filter circuit 19, and a second stage amplifier circuit 20; the output port lo1 of the first-stage filter circuit 17 is connected with the input port fi1 of the first-stage amplifying circuit 18; the output port fo1 of the first-stage amplifying circuit 18 is connected with the input port li2 of the second-stage filtering circuit 19; the output port lo2 of the second-stage filter circuit 19 is connected with the input port fi2 of the second-stage amplifying circuit 20; the output port fo2 of the second-stage amplifying circuit 20 is connected with the input port gci of the high-speed acquisition module 5. The core modules of the first-stage filter circuit 17 and the second-stage filter circuit 19 respectively select a 250KHz narrow-band ceramic filter, and the first-stage amplifying circuit 18 and the second-stage amplifying circuit 20 respectively select a gain bandwidth product of 260MHz and noiseIs provided. In this embodiment; the first stage amplification circuit 18 and the second stage amplification circuit 20 each select an amplifier AD8429.
In some embodiments, as shown in fig. 10 and 11, the acquisition module 5 includes an acquisition buffer circuit 21, the intermediate frequency amplification filter module 4 is electrically connected to the acquisition buffer circuit 21, and the acquisition buffer circuit 21 is electrically connected to the control processing module 6.
In this embodiment, the high-speed acquisition module 5 includes an acquisition buffer circuit 21 and an analog-to-digital conversion circuit 22; the output port gco of the acquisition buffer circuit 21 is connected with the input port adi of the analog-to-digital conversion circuit 22; the output port ado of the analog-digital conversion circuit 22 is connected with the input port wci of the micro-control processing module 6. The amplifier in the acquisition buffer circuit 21 selects a chip with gain bandwidth product of 260MHz, noise of 5.0 nV/low power consumption, and the acquisition device in the analog-to-digital conversion circuit 22 selects a chip with conversion precision of 12 bits and conversion speed of 20MSPS low power consumption. In this embodiment, the buffer amplifier selected by the acquisition buffer circuit 21 is ADA4940-1; the AD collector selected by the analog-to-digital conversion circuit 22 is AD9235.
In some embodiments, as shown in fig. 12, the control processing module 6 includes a microprocessor 26, a display unit 23, an entry unit 24, a storage unit 29, and a communication unit 28; the microprocessor 26 is electrically connected with the display unit 23, the input unit 24, the storage unit 29 and the communication unit 28 respectively, and the acquisition module 5 is electrically connected with the microprocessor 26.
In some embodiments, the microprocessor 26 includes a microprocessor central unit 25 and a signal processing core 27, the acquisition module 5 is electrically connected to the microprocessor central unit 25, and the microprocessor central unit 25 is electrically connected to the signal processing core 27.
In this embodiment, the micro-control processing module 6 includes an FPGA microprocessor 26, a display unit 23, an input unit 24, a storage unit 29, and a communication unit 28; the port dis2 of the FPGA microprocessor 26 is connected with the port dis1 of the display unit 23; the port key2 of the FPGA microprocessor 26 is connected with the port key1 of the input unit 24; the port sram1 of the FPGA microprocessor 26 is connected with the port sram2 of the storage unit 29; the port tx1 of the FPGA microprocessor 26 is connected to the port tx2 of the communication unit 28. The FPGA microprocessor 26 selects one of the Altera Cyclone4 series products. In this embodiment, the FPGA microprocessor 26 selects EP4CE10F17 from the Cyclone4 series of products; the display unit 23 selects 5-inch TFT color liquid crystal; the input unit 24 selects two modes of resistive touch screen input and 16 keyboard input; the storage unit 29 selects the IS61WV102416ALL memory; the communication unit 28 driver selects SP3485.
Further, the FPGA microprocessor 26 includes a microprocessor central unit 25 and a signal processing core 27; the port pfv1 of the micro-processing central unit 25 is connected with the port pfv2 of the signal processing core 27; the signal processing core 27 is programmed with the hardware description language Verilog using the selected FPGA chip EP4CE10F 17.
As shown in fig. 13, the power module 7 provides power for the pre-amplifying module 2, the mixing module 3, the intermediate frequency amplifying and filtering module 4, the high-speed sampling module and the micro-control processing module 6; the power module 7 ports + V, GND and-8V are respectively connected with the pre-amplification module 2 ports + V, GND and-8V; the 7 port + V, GND of the power supply module is connected with the 3 port + V, GND of the mixing module respectively; the ports + V, GND and-8V of the power supply module 7 are respectively connected with the ports + V, GND and-8V of the intermediate frequency amplification filter module 4; the ports + V, GND and-8V of the power supply module 7 are respectively connected with the ports + V, GND and-8V of the high-speed sampling module; the port + V, GND of the power module 7 is connected with the port + V, GND of the micro control processing module 6 respectively.
In some embodiments, as shown in fig. 14, the power module 7 includes a power filter, a primary power filter circuit, an isolation power circuit, a secondary power filter circuit, and a small ripple power circuit, which are sequentially connected. Thus, the power filter and the primary power filter circuit filter out the interference of external noise to the internal power circuit, the isolation power circuit is mainly used for isolating the power supplies of the digital circuit and the analog circuit and preventing mutual interference between the digital circuit and the analog circuit, and the secondary power filter circuit and the small ripple power circuit are used for filtering out and inhibiting the interference of the primary power supply to the secondary power supply.
In this embodiment, a radio perspective view receiving method is also provided, including a radio perspective view receiving system as described above, the receiving method including the steps of:
tuning frequency selection, weak signal amplification, frequency mixing frequency selection, intermediate frequency band-pass filtering, intermediate frequency amplification, high-speed acquisition, signal processing, storage and display.
Further, the system works in the following way: LC tuning frequency selection, weak signal amplification, frequency mixing frequency selection, intermediate frequency band-pass filtering, intermediate frequency amplification, high-speed acquisition, processing by a related algorithm of a signal processing core 27, and storage and display. When the radio wave perspective instrument transmitter works, the radio wave perspective instrument transmitter transmits 500KHz transmitting signals, the tested object is received by the LC tuning circuit of the receiving device, and the LC tuning circuit outputs 500KHz signals with the maximum amplitude at the moment because the signals selected by the embodiment are also 500KHz signals, and the cleaner effective 500KHz signals are finally obtained through the processing of the analog conditioning circuit. The analog signal is then converted to a digital signal by the high-speed acquisition module 5, and then processed by the signal processing core 27 (27), algorithm flow: 64 cycles are acquired during each calculation, the absolute value peak value of each cycle is taken, and the total number of the absolute value peaks is 64, and the calculation formula is as follows:
wherein e rms -collecting 64 period absolute value peak effective averages, ai-waveform absolute peaks, i-effective collecting the i-th peak points. Handle e rms The value is stored and displayed as a value of an active signal.
Compared with the prior art, the method solves the problem that the receiving system of the radiowave perspective instrument cannot receive extremely weak effective signals in the prior engineering, and improves the detection distance and the detection precision, thereby improving the detection efficiency and the detection accuracy of the radiowave perspective instrument in the engineering. In the embodiment, 2 times of frequency selection, 3 times of amplification and 2 times of filtering are adopted, the sequence of frequency selection, amplification and filtering is skillfully arranged, and weaker effective signals can be obtained; the method of converting the analog signal into the digital signal is adopted to remove the interference, so as to obtain a stronger effective signal; under the same conditions, the detection width is larger and the precision is higher.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the statement "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article or terminal device comprising the element. Further, herein, "greater than," "less than," "exceeding," and the like are understood to not include the present number; "above", "below", "within" and the like are understood to include this number.
It will be appreciated by those skilled in the art that the various embodiments described above may be provided as methods, apparatus, or computer program products. These embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. All or part of the steps in the methods according to the above embodiments may be implemented by a program for instructing related hardware, and the program may be stored in a storage medium readable by a computer device, for performing all or part of the steps in the methods according to the above embodiments. The computer device includes, but is not limited to: personal computers, servers, general purpose computers, special purpose computers, network devices, embedded devices, programmable devices, intelligent mobile terminals, intelligent home devices, wearable intelligent devices, vehicle-mounted intelligent devices and the like; the storage medium includes, but is not limited to: RAM, ROM, magnetic disk, magnetic tape, optical disk, flash memory, usb disk, removable hard disk, memory card, memory stick, web server storage, web cloud storage, etc.
The embodiments described above are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a computer device to produce a machine, such that the instructions, which execute via the processor of the computer device, create means for implementing the functions specified in the flowchart block or blocks and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer device-readable memory that can direct a computer device to function in a particular manner, such that the instructions stored in the computer device-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer apparatus to cause a series of operational steps to be performed on the computer apparatus to produce a computer implemented process such that the instructions which execute on the computer apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
It should be noted that, although the foregoing embodiments have been described herein, the scope of the present invention is not limited thereby. Therefore, based on the innovative concepts of the present invention, alterations and modifications to the embodiments described herein, or equivalent structures or equivalent flow transformations made by the present description and drawings, apply the above technical solution, directly or indirectly, to other relevant technical fields, all of which are included in the scope of the invention.
Claims (7)
1. The radio wave perspective instrument receiving system is characterized by comprising a frequency selection module, a pre-amplification module, a mixing module, an intermediate frequency amplification filtering module, an acquisition module, a control processing module and a power supply module;
the frequency selecting module, the pre-amplifying module, the mixing module, the intermediate frequency amplifying and filtering module, the acquisition module and the control processing module are sequentially connected, and the power supply module respectively provides power for the pre-amplifying module, the mixing module, the intermediate frequency amplifying and filtering module, the acquisition module and the control processing module;
the intermediate frequency amplifying and filtering module comprises a first-stage filtering circuit, a first-stage amplifying circuit, a second-stage filtering circuit and a second-stage amplifying circuit, wherein the first-stage filtering circuit, the first-stage amplifying circuit, the second-stage filtering circuit and the second-stage amplifying circuit are electrically connected in sequence, the mixing module is electrically connected with the first-stage filtering circuit, and the second-stage amplifying circuit is electrically connected with the acquisition module;
the acquisition module comprises an acquisition buffer circuit and an analog-to-digital conversion circuit, the second-stage amplifying circuit is electrically connected with the acquisition buffer circuit, the acquisition buffer circuit is electrically connected with the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is electrically connected with the control processing module;
the frequency selecting module comprises more than two frequency selecting circuits, and the more than two frequency selecting circuits are connected with the pre-amplifying module through a change-over switch;
the frequency selecting circuit comprises a loop antenna, a fixed capacitor, a variable capacitor and a coupling transformer, wherein the loop antenna, the fixed capacitor, the variable capacitor and the coupling transformer are electrically connected in sequence, and the coupling transformer is electrically connected with the pre-amplifying module.
2. The radiowave perspective view receiving system according to claim 1, wherein the pre-amplification module comprises an amplifier protection circuit, an amplification circuit and an attenuation circuit, the amplifier protection circuit, the amplification circuit and the attenuation circuit are electrically connected in sequence, the frequency selection module is electrically connected with the amplifier protection circuit, and the attenuation circuit is electrically connected with the mixing module.
3. The radiowave perspective view receiving system according to claim 1, wherein the mixing module comprises a local oscillator clock circuit and a mixing main circuit, the local oscillator clock circuit is electrically connected with the mixing main circuit, the pre-amplifying module is electrically connected with the mixing main circuit, and the mixing main circuit is electrically connected with the intermediate frequency amplifying and filtering module.
4. The radiowave perspective view receiving system according to claim 1, wherein the control processing module comprises a microprocessor, a display unit, an input unit, a storage unit and a communication unit;
the microprocessor is respectively and electrically connected with the display unit, the input unit, the storage unit and the communication unit, and the acquisition module is electrically connected with the microprocessor.
5. The radiowave perspective view receiving system as in claim 4, wherein the microprocessor comprises a micro-processing central unit and a signal processing core, the acquisition module being electrically connected to the micro-processing central unit, the micro-processing central unit being electrically connected to the signal processing core.
6. The radiowave perspective view receiving system according to claim 1, wherein the power supply module comprises a power supply filter, a primary power supply filter circuit, an isolation power supply circuit, a secondary power supply filter circuit and a small ripple power supply circuit, which are sequentially connected.
7. A radioscopic reception method comprising the radioscopic reception system according to any one of claims 1 to 6, the reception method comprising the steps of:
tuning frequency selection, weak signal amplification, frequency mixing frequency selection, intermediate frequency band-pass filtering, intermediate frequency amplification, high-speed acquisition, signal processing, storage and display.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111247898.9A CN113970792B (en) | 2021-10-26 | 2021-10-26 | Radio wave perspective instrument receiving system and receiving method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111247898.9A CN113970792B (en) | 2021-10-26 | 2021-10-26 | Radio wave perspective instrument receiving system and receiving method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113970792A CN113970792A (en) | 2022-01-25 |
| CN113970792B true CN113970792B (en) | 2024-03-08 |
Family
ID=79588515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111247898.9A Active CN113970792B (en) | 2021-10-26 | 2021-10-26 | Radio wave perspective instrument receiving system and receiving method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113970792B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114464415B (en) * | 2022-02-23 | 2023-06-27 | 北京华芯微半导体有限公司 | Filter with sampling function and power supply filter circuit |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0903937A2 (en) * | 1997-09-22 | 1999-03-24 | Alps Electric Co., Ltd. | Digital television signal receiving tuner system |
| CN101476893A (en) * | 2009-01-20 | 2009-07-08 | 郑州紫辰科技开发有限公司 | Non-blind zone GPS receiving device and receiving method |
| CN201577148U (en) * | 2009-06-24 | 2010-09-08 | 王晓庆 | Video, control data and power common cable transmission module |
| CN102928887A (en) * | 2012-10-22 | 2013-02-13 | 北京华安奥特科技有限公司 | Integrated signal receiving device of radio trench scenograph |
| CN203084214U (en) * | 2012-12-12 | 2013-07-24 | 中国地质科学院地球物理地球化学勘查研究所 | Radio wave tunnel perspective device based on double-frequency emission double-frequency reception |
| CN203522718U (en) * | 2013-09-24 | 2014-04-02 | 广州海格通信集团股份有限公司 | Short-wave wide-band receiver with large dynamic range |
| CN204906384U (en) * | 2015-09-21 | 2015-12-23 | 福建先创技术有限公司 | GSM system many carrier frequency of digit are selected and automatic tracking apparatus |
| CN205029653U (en) * | 2015-09-29 | 2016-02-10 | 广州海格通信集团股份有限公司 | Big dipper RDSS monitors receiver |
| CN107222178A (en) * | 2017-06-05 | 2017-09-29 | 中国电子科技集团公司第四十研究所 | A kind of vector network analyzer receiving channel gain control and method |
| CN112014890A (en) * | 2020-08-28 | 2020-12-01 | 福建平潭旭坤实业有限公司 | Anti-electromagnetic interference device and method for radio wave perspective instrument receiver |
| CN213521866U (en) * | 2020-12-23 | 2021-06-22 | 四川中科微芯电子有限公司 | Receiver system adopting analog phase shift |
-
2021
- 2021-10-26 CN CN202111247898.9A patent/CN113970792B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0903937A2 (en) * | 1997-09-22 | 1999-03-24 | Alps Electric Co., Ltd. | Digital television signal receiving tuner system |
| CN101476893A (en) * | 2009-01-20 | 2009-07-08 | 郑州紫辰科技开发有限公司 | Non-blind zone GPS receiving device and receiving method |
| CN201577148U (en) * | 2009-06-24 | 2010-09-08 | 王晓庆 | Video, control data and power common cable transmission module |
| CN102928887A (en) * | 2012-10-22 | 2013-02-13 | 北京华安奥特科技有限公司 | Integrated signal receiving device of radio trench scenograph |
| CN203084214U (en) * | 2012-12-12 | 2013-07-24 | 中国地质科学院地球物理地球化学勘查研究所 | Radio wave tunnel perspective device based on double-frequency emission double-frequency reception |
| CN203522718U (en) * | 2013-09-24 | 2014-04-02 | 广州海格通信集团股份有限公司 | Short-wave wide-band receiver with large dynamic range |
| CN204906384U (en) * | 2015-09-21 | 2015-12-23 | 福建先创技术有限公司 | GSM system many carrier frequency of digit are selected and automatic tracking apparatus |
| CN205029653U (en) * | 2015-09-29 | 2016-02-10 | 广州海格通信集团股份有限公司 | Big dipper RDSS monitors receiver |
| CN107222178A (en) * | 2017-06-05 | 2017-09-29 | 中国电子科技集团公司第四十研究所 | A kind of vector network analyzer receiving channel gain control and method |
| CN112014890A (en) * | 2020-08-28 | 2020-12-01 | 福建平潭旭坤实业有限公司 | Anti-electromagnetic interference device and method for radio wave perspective instrument receiver |
| CN213521866U (en) * | 2020-12-23 | 2021-06-22 | 四川中科微芯电子有限公司 | Receiver system adopting analog phase shift |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113970792A (en) | 2022-01-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103441803B (en) | A kind of underground low frequency wireless communication system based on low-power small electric antenna | |
| CN101694156B (en) | Dipole acoustic small-signal processing unit | |
| CN101662078A (en) | Small shielding body electromagnetic shielding performance testing device, system and method therefor | |
| CN113970792B (en) | Radio wave perspective instrument receiving system and receiving method thereof | |
| CN103955004A (en) | Four-channel nuclear magnetic resonance signal full-wave acquisition system and acquisition method | |
| CN104569745A (en) | Partial discharge live detection device and method | |
| CN105652090B (en) | A kind of device and method for measuring voltage standing wave ratio | |
| CN113726455B (en) | Underground space roadway geological detection transceiver integrated machine tester | |
| CN107290697B (en) | Magnetic resonance radio frequency coil and magnetic resonance system | |
| CN107561464B (en) | Magnetic resonance radio frequency coil and magnetic resonance system | |
| CN102185639B (en) | Characteristic analyzer used for low-voltage power line carrier wave channel | |
| CN103457623B (en) | A kind of circuit of Zero intermediate frequency direct current compensation and method | |
| CN105391422A (en) | Phased array probe self-adaptive impedance match system and method based on ZigBee technology | |
| CN108123723A (en) | A kind of alignment system and method based on radiotechnics | |
| US11914092B2 (en) | Inductive magnetic sensor and electromagnetic prospecting equipment | |
| CN101971044A (en) | RF coil array comprising a coil element with two preamplifiers | |
| CN106990372A (en) | A kind of magnetic nuclear resonance radio frequency antenna circuit and its impedance matching methods | |
| CN218470980U (en) | Radio wave perspective appearance receiving equipment | |
| CN209046629U (en) | A kind of channel reception device based on millimeter wave | |
| CN218470979U (en) | Radio wave perspective appearance receiving arrangement | |
| CN204206117U (en) | A kind of amplifier of creatures' physical electric signals circuit of fast detector | |
| CN103746714B (en) | The digital compensation method of receiver radio frequency frequency response | |
| CN105203225B (en) | A kind of optical fiber grating temperature detection method and device | |
| CN203759264U (en) | Nuclear magnetic resonance bipolarity superposition de-noising device based on power frequency full cycle | |
| CN201536156U (en) | Electromagnetic shielding efficiency test device of small shielding body and radio-frequency antenna and dot frequency radiation source therein |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |