CN113970792A - Radio wave perspective instrument receiving system and receiving method thereof - Google Patents
Radio wave perspective instrument receiving system and receiving method thereof Download PDFInfo
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Abstract
The invention relates to a receiving system and a receiving method of a radio wave perspective instrument, wherein the system comprises a frequency selection module, a pre-amplification module, a frequency mixing module, an intermediate frequency amplification 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-level filtering circuit, a first-level amplifying circuit, a second-level filtering circuit and a second-level amplifying circuit, the acquisition module comprises an acquisition buffer circuit and an analog-to-digital conversion circuit, the second-level 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 method adopts 2-time frequency selection, 3-time amplification and 2-time filtering, and can obtain weaker effective signals; an analog signal is converted into a digital signal processing method to remove interference, and a stronger effective signal is obtained; 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 receiving system and a receiving method of a radio wave perspective instrument.
Background
The radio wave radioscopy technology has matured considerably over the last 50 years, and its basic principle is that radio waves propagate in rock formations and absorb energy differently due to the different electrical properties of the various rocks. The low-resistance rock stratum has strong absorption to the radio wave energy, the high-resistance rock stratum has weak absorption to the radio wave energy, and geological inference and explanation can be carried out by utilizing various perspective abnormalities caused by the influence of various structures of the rock stratum and geologic bodies on the radio wave energy. It is known that radio wave perspective instrument is mainly used for detecting geological structure between two opposite parallel roadways, and adopts a mode of separating transmission and reception to carry out detection construction, namely one roadway transmits and the other roadway receives, or vice versa, the other roadway transmits, the original transmitting roadway is changed into receiving, and the two roadways exchange transmission and receiving to complete the radio wave perspective detection engineering.
From the above basic principle and construction method, the detection width and detection accuracy of the radiowave perspective instrument have close relationship with the following factors: 1. the transmitter has high and low emission power and emission efficiency, and high transmission power and emission efficiency, so that the transmission distance and the detection precision are high; 2. how to the receiving precision, anti-interference capability and stability of the receiver; 3. how 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 a lot of work on the aspect of improving the transmission efficiency of a transmitter, but due to the existence of mutual inductance and self-inductance of a transmitting coil, the noise of a transmission driving circuit cannot be eliminated, the maximum transmission efficiency of the designed transmitter does not exceed 80%, and other companies make the transmission power of the transmitter large, but the negative influence is brought, and the method mainly comprises the following steps: because the high-power transmitter works in the field or under a mine, batteries are basically used for supplying power, the power supply batteries used by the high-power transmitter are heavy and have large volume, and the power devices selected by the high-power transmitter are large in package, so that the whole transmitter has large volume and heavy weight. Meanwhile, the large transmission power means that the transmission current is high, all the transmitting devices have high temperature and large power consumption, and the thermal noise is rapidly increased, so that the reduction of the transmission efficiency is avoided. This is objective as to the detection object condition and the detection environmental condition, and it is only possible to improve the detection width and the detection accuracy in the detection construction method or the detection apparatus.
More information about the above solution can also be found in the following documents:
for example, chinese patent publication No. CN 112014890a discloses an anti-electromagnetic interference device and method for a radio wave perspective receiver, which includes a receiving host, a signal connection cable, and a tuning frequency-selecting receiving antenna; the receiving host comprises digital components, analog components and accessory components; 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 are all designed by adopting electromagnetic shielding structures.
In the process of implementing the invention, the inventor finds that the following problems exist in the prior art:
1. in the prior art, a receiving system of a radio wave perspective instrument has weak frequency selection, amplification and filtering capabilities and cannot acquire weak signals.
2. In the prior art, a receiving system of a radio wave perspective instrument has weak anti-interference capability, and cannot obtain effective signals, so that the detection precision is poor.
Disclosure of Invention
Therefore, a radio wave perspective instrument receiving system and a radio wave perspective instrument receiving method need to be provided, and the radio wave perspective instrument receiving system is used for solving the technical problems that in the prior art, the radio wave perspective instrument receiving system is poor in frequency selection, amplification and filtering capability, weak in anti-interference capability, incapable of obtaining weak signals and poor in detection accuracy.
In order to achieve the above object, the inventor provides a receiving system of a radio wave perspective instrument, comprising a frequency selection module, a pre-amplification module, a frequency mixing module, an intermediate frequency amplification and filtering module, an acquisition module, a control processing module and a power supply module;
the frequency selection module, the pre-amplification module, the frequency mixing module, the intermediate frequency amplification and filtering module, the acquisition module and the control processing module are sequentially connected, and the power supply module respectively supplies power to the pre-amplification module, the frequency mixing module, the intermediate frequency amplification and filtering module, the acquisition module and the control processing module;
the intermediate frequency amplifying and filtering module comprises a first-stage filter circuit, a first-stage amplifying circuit, a second-stage filter circuit and a second-stage amplifying circuit, the first-stage filter circuit, the first-stage amplifying circuit, the second-stage filter circuit and the second-stage amplifying circuit are sequentially and electrically connected, the frequency mixing module is electrically connected with the first-stage filter 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 amplification 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.
Different from the prior art, the frequency selection module is used for carrying out frequency selection for the first time, the frequency mixing module is used for carrying out frequency selection for the second time, the preamplifier module, the first-stage amplifier circuit and the second-stage amplifier circuit are used for amplifying for three times, the first-stage filter circuit and the second-stage filter circuit carry out filtering for two times, the filtering cannot be completely filtered out by one time, one-stage filtering is added, the inhibition capacity is doubled, therefore, interference signals can be inhibited better, and the signal-to-noise ratio is improved. The device skillfully arranges the order of frequency selection, amplification and filtering, can acquire weaker effective signals, and can better receive the effective signals only by increasing the filtering frequency and the signal-to-noise ratio by increasing the filtering frequency. 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 through a digital signal processing method, more and stronger effective signals can be obtained, and therefore the detection width and the detection precision are improved. By combining the two points, compared with the existing radio wave perspective instrument receiver, the detection width is larger and the detection precision is higher under the same condition.
As an embodiment of the present invention, the frequency selection module includes two or more frequency selection circuits, and the two or more frequency selection circuits are connected to the pre-amplification module through a switch.
Therefore, more than two frequency selection circuits are switched through the selector switch, only one frequency selection circuit can be selected at a time, the frequency selection capability is improved, and the frequency selection width is increased.
As an embodiment of the present invention, the frequency selection circuit includes a loop antenna, a fixed capacitor, a variable capacitor, and a coupling transformer, the loop antenna, the fixed capacitor, the variable capacitor, and the coupling transformer are sequentially electrically connected, and the coupling transformer is electrically connected to the pre-amplification module.
Therefore, as the capacity of the variable capacitor is limited, the capacitance required by some frequency selection circuits greatly exceeds the variable capacitance value, and the fixed capacitor is used for compensation, so that the compatibility of the frequency selection circuit is improved.
As an embodiment of the present invention, the pre-amplification module includes an amplifier protection circuit, an amplification circuit, and an attenuation circuit, the amplifier protection circuit, the amplification circuit, and the attenuation circuit are sequentially electrically connected, the frequency selection module is electrically connected to the amplifier protection circuit, and the attenuation circuit is electrically connected to the frequency mixing module.
Thus, the safety of the pre-amplification module is improved through the amplifier protection circuit.
As an embodiment of the present invention, the frequency mixing module includes a local oscillator clock circuit and a main frequency mixing circuit, the local oscillator clock circuit is electrically connected to the main frequency mixing circuit, the preamplifier module is electrically connected to the main frequency mixing circuit, and the main frequency mixing circuit is electrically connected to the intermediate frequency amplifying and filtering module.
As an embodiment of the present invention, the control processing module includes a microprocessor, a display unit, an entry unit, a storage unit, and a communication unit;
the microprocessor is respectively electrically connected with the display unit, the recording unit, the storage unit and the communication unit, and the acquisition module is electrically connected with the microprocessor.
As an embodiment of the present invention, the microprocessor includes a microprocessor central processing unit and a signal processing core, the acquisition module is electrically connected to the microprocessor central processing unit, and the microprocessor central processing unit is electrically connected to the signal processing core.
As an embodiment of the present invention, the power module includes a power filter, a primary power filter circuit, an isolation power circuit, a secondary power filter circuit, and a small ripple power circuit, and the power filter, the primary power filter circuit, the isolation power circuit, the secondary power filter circuit, and the small ripple power circuit are sequentially connected.
Therefore, the power filter and the primary power filter circuit filter the interference of external noise to the internal power circuit, the isolation power circuit is mainly used for isolating the power of the digital circuit and the analog circuit to prevent mutual interference between the digital circuit and the analog circuit, and the secondary power filter circuit and the small ripple power circuit filter and restrain the interference of the primary power to the secondary power supply.
To achieve the above object, the inventor further provides a radio radioscopy receiving method, including the radio radioscopy receiving system according to any of the above 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.
Different from the prior art, the technical scheme skillfully arranges the sequence of frequency selection, amplification and filtering, can obtain weaker effective signals, and can better receive the effective signals only by adopting a filtering mode and increasing the filtering times to increase 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 through a digital signal processing method, more and stronger effective signals can be obtained, and therefore the detection width and the detection precision are improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used 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 it is obvious for a person skilled in the art to obtain other drawings based on the drawings without any creative effort.
FIG. 1 is a system block diagram of a radiowave radioscopy receiving system according to an 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 an embodiment of the present application;
FIG. 4 is a schematic structural diagram of a pre-amplification module according to an embodiment of the present application;
FIG. 5 is a circuit diagram of a pre-amplification module according to one embodiment of the present application;
FIG. 6 is a block diagram of a mixer module according to an embodiment of the present disclosure;
FIG. 7 is a circuit diagram of a mixer module according to an embodiment of the present application;
fig. 8 is a schematic structural diagram of an if amplifying and filtering module according to an embodiment of the present application;
fig. 9 is a circuit diagram of an if filter module according to an embodiment of the present application;
FIG. 10 is a schematic structural diagram of an acquisition module according to an 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 block diagram of a control processing module according to an embodiment of the present application;
FIG. 13 is a schematic structural diagram of a power module according to an embodiment of the present application;
fig. 14 is a circuit diagram of a power module according to an embodiment of the present application.
Description of reference numerals:
1. a frequency-selecting module for selecting the frequency of the received signal,
2. a pre-amplification module,
3. a frequency-mixing module for mixing the frequency of the received signal,
4. an intermediate frequency amplifying and filtering module is used for amplifying and filtering the signals,
5. a collection module for collecting the collected data,
6. a control processing module for controlling the operation of the computer,
7. a power supply module for supplying power to the power supply module,
8. a loop-type antenna is provided, which is,
9. the capacitance is fixed and the capacitance is fixed,
10. the variable capacitance is a variable capacitance that is,
11. a coupling transformer is arranged on the base plate,
12. an amplifier protection circuit for protecting the amplifier from the external,
13. a high-frequency high-gain amplifying circuit,
14. a high-frequency attenuation circuit for attenuating a high frequency,
15. a local oscillator clock circuit for generating a local oscillator clock signal,
16. the main circuit of the frequency mixer is provided with a frequency mixer,
17. a first-stage filter circuit for filtering the signal,
18. a first-stage amplifying circuit, a second-stage amplifying circuit,
19. a second-stage filter circuit for filtering the signal,
20. a second-stage amplifying circuit,
21. a collection buffer circuit is arranged in the device,
22. an analog-to-digital conversion circuit for converting analog signals,
23. a display unit for displaying the image of the object,
24. a recording unit for recording the information of the user,
25. a micro-processing Central Processing Unit (CPU),
26. a microprocessor for controlling the operation of the microprocessor,
27. a signal processing core for processing the signals,
28. a communication unit for communicating with the communication unit,
29. and a memory unit.
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.
In the description of the present application, unless explicitly stated or limited otherwise, the terms "first", "second", and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless specified or indicated otherwise; the terms "connected," "fixed," and the like are to be construed broadly and may, for example, be fixedly connected, detachably connected, integrally connected, or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", and the like used in the embodiments of the present application are described with reference to the angles shown in the drawings, and should not be construed as limiting the embodiments of the present application. In addition, in this context, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on "or" under "the other element or be indirectly on" or "under" the other element via an intermediate element.
Therefore, the present embodiment provides a technical solution, please refer to fig. 1 to 13, and the present embodiment relates to a radio wave perspective instrument receiving system, which includes a frequency selecting module 1, a pre-amplifying module 2, a frequency 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 selection module 1, the pre-amplification module 2, the frequency mixing module 3, the intermediate frequency amplification and filtering module 4, the acquisition module 5 and the control processing module 6 are sequentially connected, and the power supply module 7 respectively supplies power to the pre-amplification module 2, the frequency mixing module 3, the intermediate frequency amplification and filtering module 4, the acquisition module 5 and the control processing module 6;
the intermediate frequency amplifying and filtering module 4 comprises a first-stage filter circuit 17, a first-stage amplifying circuit 18, a second-stage filter circuit 19 and a second-stage amplifying circuit 20, the first-stage filter circuit 17, the first-stage amplifying circuit 18, the second-stage filter circuit 19 and the second-stage amplifying circuit 20 are sequentially and electrically connected, the frequency mixing module 3 is electrically connected with the first-stage filter 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, a signal is subjected to primary frequency selection through the frequency selection module 1, frequency selection for the second time is performed through the frequency mixing module 3, amplification is performed for three times through the pre-amplification module 2, the first-stage amplification circuit 18 and the second-stage amplification circuit 20, filtering is performed twice through the first-stage filtering circuit 17 and the second-stage filtering circuit 19, the primary filtering cannot be completely filtered, one-stage filtering is added, and the suppression capability is doubled, so that an interference signal can be suppressed more, and the signal-to-noise ratio is improved; compared with the receiver of the radio wave perspective instrument in the current market, the device can acquire weaker effective signals, and the adopted filtering mode and the adopted filtering times are increased to improve the signal-to-noise ratio so as to better receive the effective signals. The acquisition buffer circuit 21 is used for buffering signals, analog signals are converted into digital signals through the analog-to-digital conversion circuit 22, interference is conveniently removed through a digital signal processing method, more and stronger effective signals can be obtained, and therefore the detection width and the detection precision are improved. By combining the two points, compared with the existing radio wave perspective instrument receiver, the detection width is larger and the detection 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 to the pre-amplification module 2 through a switch. Therefore, more than two frequency selection circuits are switched through the selector switch, only one frequency selection circuit can be selected at a time, and the frequency selection capability and the frequency selection width are improved.
In this embodiment, the frequency selection module 1 includes a frequency selection circuit 1, a frequency selection circuit 2, and n frequency selection circuits for selecting multiple frequencies, where n frequency selection circuits can only select one frequency selection circuit at a time, and only one frequency selection circuit can be selected at a time to connect with the pre-amplification module 2 by switching the switches.
In some embodiments, the frequency selection circuit includes 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 are sequentially electrically connected, and the coupling transformer 11 is electrically connected to the pre-amplification module 2. At this time, because 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 is used for compensation, so that the compatibility of the frequency selection circuits is improved.
In the present embodiment, each frequency selection circuit includes a loop antenna 8, a fixed capacitor 9, a variable capacitor 10, and a coupling transformer 11. An output port to of the loop antenna 8 is connected with an input port gi of the fixed capacitor 9; an output port go of the fixed capacitor 9 is connected with an 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 output port bo of the coupling transformer 11 is connected to the preamplifier input port qi. The frequency selection bandwidth range of the frequency selection circuit is 10 KHz-2000 KHz. In this embodiment, the frequency selected by the frequency selection circuit is 500 KHz; the diameter of the loop antenna 8 is 500mm, and an enameled wire is used for clockwise winding for 12 turns, so that the inductance is 226.5 uH; the coupling transformer 11 is a 43-turn magnetic ring coupler with two parallel windings, and the primary side inductance and the secondary side inductance are 27 mH; the fixed capacitor 9 is fixed at 220 pF; the variable capacitance 10 is tuned to 85 pF.
In some embodiments, as shown in fig. 4 and fig. 5, the pre-amplification module 2 includes an amplifier protection circuit 12, an amplifying circuit, and an attenuating circuit, the amplifier protection circuit 12, the amplifying circuit, and the attenuating circuit are electrically connected in sequence, the frequency selection module 1 is electrically connected to the amplifier protection circuit 12, and the attenuating circuit is electrically connected to the frequency mixing module 3. Thus, the safety of the preamplifier module is improved by the amplifier protection circuit 12.
In this 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 amplification 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 attenuation circuit 14; the output so of the high-frequency attenuation circuit 14 is connected to the input hpi of the mixer module 3. In this embodiment, the high-frequency high-gain amplifier circuit 13 is specifically a weak signal amplifier, which essentially requires a large gain, but the gain of the amplifier is often small when the high-frequency signal is received, so that the high-frequency high-gain amplifier circuit 13 is actually completed by amplifying a plurality of amplifiers in series.
In this embodiment, the frequency bandwidth of the pre-amplification module 2 with a gain of 2000 times is 0Hz to 3500KHz, and the attenuation of the signal amplitude is 40 dB. In this embodiment, the amplifier protection circuit 12 selects the diode BAV199 and the current limiting resistor 1.2K to be used in combination; the amplifier in the high-frequency high-gain amplifier circuit 13 selects AD 8428; the high-frequency attenuation circuit 14 selects a pi resistance attenuator, the resistors on both sides are both selected to be 50.5 ohms, and the middle resistor is selected to be 2500 ohms.
In some embodiments, as shown in fig. 6 and fig. 7, the frequency mixing module 3 includes a local oscillator clock circuit 15 and a main frequency mixing circuit 16, the local oscillator clock circuit 15 is electrically connected to the main frequency mixing circuit 16, the pre-amplifier module 2 is electrically connected to the main frequency mixing circuit 16, and the main frequency mixing circuit 16 is electrically connected to the intermediate frequency amplifying and filtering module 4.
In this embodiment, the frequency mixing module 3 includes a local oscillator clock circuit 15 and a main frequency mixing circuit 16; a local oscillator clock input port clki of the frequency mixing main circuit 16 is connected with a clock output port clko of the local oscillator clock circuit 15; the signal output port hpo of the main mixer circuit 16 is connected to the input port li1 of the if amplifying and filtering module 4. The output frequency range of the local oscillator clock circuit 15 is 10 KHz-200 MHz, and the signal frequency range of the main frequency mixing circuit 16 is 10 KHz-2000 KHz. In this embodiment, the output frequency of the local oscillator clock circuit 15 is 750KHz, and since 500KHz is selected as the signal and 250KHz is selected as the intermediate frequency signal to be obtained, the output frequency of the main mixer circuit 16 has two types, 1250KHz and 250 KHz.
As shown in fig. 8 and 9, the if amplifying and filtering module 4 includes a first stage filter circuit 17, a first stage amplifying circuit 18, a second stage filter circuit 19 and a second stage amplifying circuit 20; an output port lo1 of the first-stage filter circuit 17 is connected with an 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; an output port lo2 of the second-stage filter circuit 19 is connected with an 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 both select a narrow-band ceramic filter of 250KHz, and the first stage amplifying circuit 18 and the second stage amplifying circuit 20 both select a gain-bandwidth product of 260MHz and a noise of 260MHz
The high-speed amplifier of (1). In this embodiment; the first-stage amplification circuit 18 and the second-stage amplification circuit 20 each select the amplifier AD 8429.
In some embodiments, as shown in fig. 10 and 11, the acquisition module 5 includes an acquisition buffer circuit 21, the intermediate frequency amplification and filtering 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; an output port gco of the acquisition buffer circuit 21 is connected with an input port adi of the analog-to-digital conversion circuit 22; the output ado of the analog-to-digital conversion circuit 22 is connected with the input wci of the micro control processing module 6. The amplifier in the acquisition buffer circuit 21 selects a low-power chip with a gain bandwidth product of 260MHz and a noise of 5.0nV, and the acquisition device in the analog-to-digital conversion circuit 22 selects a low-power chip with a conversion precision of 12 bits and a conversion speed of 20 MSPS. In this embodiment, the buffer amplifier selected by the acquisition buffer circuit 21 is ADA 4940-1; the AD collector selected by the analog-to-digital conversion circuit 22 is AD 9235.
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 recording 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 entry 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 FPGA microprocessor 26 port key2 is connected with the entry unit 24 port key 1; the FPGA microprocessor 26 port sram1 is connected with the storage unit 29 port sram 2; the FPGA microprocessor 26 port tx1 is connected to the communication unit 28 port tx 2. The FPGA microprocessor 26 selects one of the Altera Cyclone4 series of products. In this embodiment, the FPGA microprocessor 26 selects EP4CE10F17 from Cyclone4 series 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 IS61WV102416ALL memory; the communication unit 28 driver selects SP 3485.
Further, an FPGA microprocessor 26, which 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 by using a hardware description language Verilog in the selected FPGA chip EP4CE10F 17.
As shown in fig. 13, the power module 7 provides power for the pre-amplification module 2, the frequency mixing module 3, the intermediate frequency amplification and filtering module 4, the high-speed sampling module, and the micro-control processing module 6; the ports +8V, GND and-8V of the power supply module 7 are respectively connected with the ports +8V, GND and-8V of the preamplifier module 2; the port +8V, GND of the power supply module 7 is connected with the port +8V, GND of the frequency mixing module 3 respectively; ports +8V, GND and-8V of the power supply module 7 are respectively connected with ports +8V, GND and-8V of the intermediate frequency amplification filtering module 4; ports +8V, GND and-8V of the power supply module 7 are respectively connected with ports +8V, GND and-8V of the high-speed sampling module; and the power supply module 7 port +8V, GND is connected with the micro control processing module 6 port +8V, GND respectively.
In some embodiments, as shown in fig. 14, the power supply module 7 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, which are connected in sequence. Therefore, the power filter and the primary power filter circuit filter the interference of external noise to the internal power circuit, the isolation power circuit is mainly used for isolating the power of the digital circuit and the analog circuit to prevent mutual interference between the digital circuit and the analog circuit, and the secondary power filter circuit and the small ripple power circuit filter and restrain the interference of the primary power to the secondary power supply.
In this embodiment, a radio radioscopy receiving method is further provided, which includes the above radio radioscopy receiving system, and the receiving method includes the following steps:
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 mode: LC tuning frequency selection → weak signal amplification → frequency mixing frequency selection → intermediate frequency band-pass filtering → intermediate frequency amplification → high-speed acquisition → signal processing kernel 27 related algorithm processing → storage and display. When the device works, the transmitter of the radio wave perspective instrument transmits a 500KHz transmitting signal, the transmitting signal penetrates through a measured object and is received by the LC tuning circuit of the receiving device, and because the signal selected by the embodiment is also a 500KHz signal, the LC tuning circuit outputs the 500KHz signal with the maximum amplitude value, and finally, a clean and effective 500KHz signal is obtained through the processing of the analog conditioning circuit. Then the high-speed acquisition module 5 converts the analog signal into a digital signal, and the signal processing core 27(27) processes the digital signal, and the algorithm flow is as follows: 64 periods are collected during each calculation, the absolute value peak value of each period is taken, the total number is 64, and the calculation formula is as follows:
wherein, erms-collects the effective average value of the absolute value wave crest of 64 periods, Ai-the absolute peak value of the wave form, and i-effectively collects the ith wave crest point. The value of the erms is stored and displayed as the value of a valid signal.
The method solves the problem that the existing receiving system of the radio wave perspective instrument in the engineering can not receive the extremely weak effective signal, and improves the detection distance and the detection precision, thereby improving the detection efficiency and the accuracy of the radio wave perspective instrument in the engineering. In the embodiment, 2-time frequency selection, 3-time amplification and 2-time filtering are adopted, the sequence of frequency selection, amplification and filtering is skillfully arranged, and weaker effective signals can be obtained; an analog signal is converted into a digital signal processing method to remove interference, and a stronger effective signal is obtained; under the same condition, the detection width is larger and the detection accuracy is higher.
It is noted that, herein, relational terms such as first and second, and the like may be 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. Also, 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 phrases "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the number.
As will be appreciated by one skilled in the art, the above-described embodiments may be provided as a method, apparatus, or computer program product. 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 embodiments may be implemented by a program instructing associated hardware, where the program may be stored in a storage medium readable by a computer device and used to execute all or part of the steps in the methods according to the embodiments. The computer devices, including but 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, U disk, removable hard disk, memory card, memory stick, network server storage, network cloud storage, etc.
The various 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 flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a computer apparatus to produce a machine, such that the instructions, which execute via the processor of the computer apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer device to function in a particular manner, such that the instructions stored in the computer-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 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 radio wave perspective instrument receiving system is characterized by comprising a frequency selection module, a pre-amplification module, a frequency mixing module, an intermediate frequency amplification and filtering module, an acquisition module, a control processing module and a power supply module;
the frequency selection module, the pre-amplification module, the frequency mixing module, the intermediate frequency amplification and filtering module, the acquisition module and the control processing module are sequentially connected, and the power supply module respectively supplies power to the pre-amplification module, the frequency mixing module, the intermediate frequency amplification and filtering module, the acquisition module and the control processing module;
the intermediate frequency amplifying and filtering module comprises a first-stage filter circuit, a first-stage amplifying circuit, a second-stage filter circuit and a second-stage amplifying circuit, the first-stage filter circuit, the first-stage amplifying circuit, the second-stage filter circuit and the second-stage amplifying circuit are sequentially and electrically connected, the frequency mixing module is electrically connected with the first-stage filter 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 amplification 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.
2. The radiowave fluoroscope receiving system according to claim 1, wherein the frequency selecting module comprises two or more frequency selecting circuits, and the two or more frequency selecting circuits are connected to the pre-amplifying module through a switch.
3. The radiowave fluoroscope receiving system according to claim 2, wherein the frequency selecting circuit comprises a loop antenna, a fixed capacitor, a variable capacitor and a coupling transformer, 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 to the pre-amplification module.
4. The radiowave fluoroscope 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 to the amplifier protection circuit, and the attenuation circuit is electrically connected to the frequency mixing module.
5. The radiowave fluoroscope receiving system according to claim 1, wherein the frequency mixing module comprises a local oscillator clock circuit and a main frequency mixing circuit, the local oscillator clock circuit is electrically connected with the main frequency mixing circuit, the pre-amplifying module is electrically connected with the main frequency mixing circuit, and the main frequency mixing circuit is electrically connected with the intermediate frequency amplifying and filtering module.
6. The radiowave fluoroscope receiving system according to claim 1, wherein the control processing module comprises a microprocessor, a display unit, an entry unit, a storage unit, and a communication unit;
the microprocessor is respectively electrically connected with the display unit, the recording unit, the storage unit and the communication unit, and the acquisition module is electrically connected with the microprocessor.
7. The radiowave fluoroscope receiving system according to claim 6, wherein the microprocessor comprises a microprocessor central unit and a signal processing core, the acquisition module is electrically connected with the microprocessor central unit, and the microprocessor central unit is electrically connected with the signal processing core.
8. The radiowave fluoroscopy receiving system according to claim 1, wherein the power supply module includes a power supply filter, a primary power supply filter circuit, an isolated 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 isolated power supply circuit, the secondary power supply filter circuit, and the small ripple power supply circuit are connected in sequence.
9. A radio wave clairvoyance reception method comprising the radio wave clairvoyance reception system according to any one of claims 1 to 8, 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.
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Cited By (1)
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| CN114464415A (en) * | 2022-02-23 | 2022-05-10 | 北京华芯微半导体有限公司 | Filter with sampling function and power supply filter circuit |
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| CN113970792B (en) | 2024-03-08 |
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