Layered single-component high-bandwidth mountable hollow coil, preparation method and detection device

Abstract

The present invention belongs to the field of semi-aeronautical transient electromagnetic geophysical exploration, and provides a layered single-component high-bandwidth mountable hollow coil, a preparation method and a detection device. The layered single-component high-bandwidth mountable hollow coil comprises a winding frame, a mounting protection frame and a cover plate; the mounting protection frame is provided with a winding frame groove, an electrical component mounting groove and a plurality of mounting holes; the winding frame is a hollow structure, and a differential pair signal is formed by layered and segmented winding, and the wound winding frame is mounted as a whole in the winding frame groove; the electrical component mounting groove is provided with an electrical component, and the electrical component mounting groove is provided with a cover plate; the mounting hole is used to pass a leveling wire to level the coil.

Description

Technical Field

[0001] The invention belongs to the field of semi-aeronautical transient electromagnetic geophysical exploration, and in particular relates to a layered single-component high-bandwidth mountable hollow coil, a preparation method and a detection device. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Semi-airborne EM (SAEM) is different from ground-based electromagnetic method and airborne electromagnetic method. It usually uses a high-power transmitter on the ground and carries the receiving end on a flying platform, achieving a balance between detection depth and work efficiency. It has become a hot topic in deep detection research in recent years and has been applied to mineral resource exploration, groundwater, geothermal resource exploration, geological mapping, environmental monitoring and other fields.

[0004] The receiving coil is an important part of the semi-aeronautical electromagnetic receiving system. The dynamic range of the traditional ground transient electromagnetic receiving signal is large. The transient signal decays quickly in the early stage and has a large amplitude (from tens of microseconds to hundreds of microseconds, the amplitude decays from about 10 volts to millivolts or even microvolts); while the mid- and late-stage signals decay slowly and have a small amplitude (from hundreds of microseconds to a few milliseconds or even a few seconds, the amplitude decays from millivolts or microvolts to microvolts or nanovolts). The early transient signal reflects the shallow underground structure, and the late signal reflects the deep underground structure. Since the semi-aeronautical transient electromagnetic receiving coil is located in the air, it is greatly reduced compared to the ground signal (the receiving and transmitting distance is 1 km, the transmitting current is about 10 amperes, the flight altitude is 300-400 meters, the receiving physical effective area is about 30 square meters, and the overall receiving amplitude is less than 1 microvolt). Therefore, it is of great significance to make a low-noise, high-bandwidth, lightweight hollow induction coil.

[0005] At present, due to the limited number of related winding equipment on the market, most of the traditional receiving induction hollow coils are wound manually, with relatively poor winding accuracy, and it is difficult to control the noise and bandwidth of the coils; at the same time, the winding efficiency is relatively low, and the repeatability of each batch of coils is not high. After some coils are wound, the wires are exposed, and some are simply protected by electrical tape. Due to the relatively harsh outdoor construction environment, without good protection measures, the coils are easily damaged. Summary of the invention

[0006] In order to solve the technical problems existing in the above background technology, the present invention provides a layered single-component high-bandwidth mountable hollow coil, a preparation method and a detection device, wherein the hollow coil adopts a layered and segmented differential winding hollow induction coil, which can effectively reduce the noise of the coil and increase the bandwidth of the coil. At the same time, a semi-automatic winding method is provided to make the winding of the coil more precise, and the coil is assembled by a winding frame plus an external protection frame to increase the life of the coil.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A first aspect of the present invention provides a layered single-component high-bandwidth mountable air-core coil.

[0009] A layered single-component high-bandwidth mountable air-core coil, comprising:

[0010] Winding frame, mounting protection frame and cover plate;

[0011] The mounting protection frame is provided with a winding frame groove, an electrical component mounting groove and a plurality of mounting holes;

[0012] The winding skeleton is a hollow structure, and adopts layered and segmented winding to form a differential pair signal. The wound winding skeleton is integrally mounted in the winding skeleton slot;

[0013] The electrical component installation groove is provided with an electrical component, and a cover plate is provided on the electrical component installation groove;

[0014] The mounting hole is used to pass a leveling wire through to level the coil.

[0015] As an embodiment, a winding mold is installed in the winding frame.

[0016] As an implementation mode, the winding skeleton is fixed to the winding mold through a top screw, and the winding mold is fixed to the motor through a motor shaft fixing hole.

[0017] As an embodiment, the overall shape of the winding mold is a circular ring supported in a cross shape.

[0018] As an implementation mode, the winding frame has two sections of winding grooves, and a layer of insulating film is used to separate the winding layers, so as to realize the segmented and layered winding of the coil.

[0019] As an implementation method, after the wire winding of the frame is completed, it is embedded into the winding frame fixing groove of the mounting protection frame and is sealed and fixed by using a sealant.

[0020] As an implementation mode, the mounting holes are evenly distributed on the mounting protection frame.

[0021] A second aspect of the present invention provides a method for preparing the layered single-component high-bandwidth mountable air-core coil as described above, comprising:

[0022] Test the bandwidth of air-core coil;

[0023] Calculate the distributed capacitance of the air-core coil based on the tested air-core coil bandwidth;

[0024] Calculate the matching resistance of the air-core coil based on the distributed capacitance of the air-core coil;

[0025] Mounting and leveling air core coils.

[0026] As an implementation method, the overall distributed capacitance of the hollow coil is calculated according to f=1 / sqrt(2πLC); wherein f is the resonant frequency point, which is the same as the bandwidth of the hollow coil; L is the inductance value of the hollow coil; C is the distributed capacitance value of the hollow coil; and sqrt is a square root operation.

[0027] A third aspect of the present invention provides a detection device.

[0028] A detection device includes a receiving module, wherein the receiving module includes the layered single-component high-bandwidth mountable air-core coil as described above.

[0029] The beneficial effects of the present invention are:

[0030] (1) The present invention provides a layered single-component high-bandwidth mountable hollow coil design, which adopts a layered and segmented method to wind the hollow induction coil, effectively increasing the bandwidth of the coil, and adopts a differential coil winding method to reduce the overall noise of the coil; using low-density, wear-resistant materials to reduce the weight of the coil. The coil winding mold is made to increase the coil winding tightness and improve the coil linearity, while greatly improving the winding efficiency, and the four side positions have special slots and holes for mounting wires, making the coil more stable during flight.

[0031] (2) The present invention includes a winding skeleton, a winding mold, a mounting protection skeleton, and a cover plate; wherein the winding skeleton has two sections of winding grooves, and a layer of insulating film is used to separate the winding layers before winding, thereby realizing the segmented and layered winding of the coil; the winding skeleton is fixed to the winding mold by a top screw, and the winding mold is fixed to the motor by a motor shaft fixing hole; after the skeleton is wound, it is embedded in the winding skeleton fixing groove of the mounting protection skeleton, and is sealed and fixed by using a sealant; the circuit board and the battery are respectively embedded in the corresponding installation grooves and covered with a cover plate. Finally, a glass fiber rope is used to pass through the mounting holes and grooves of the mounting protection skeleton to level the coil, and a semi-automatic winding method is used to make the winding of the coil more precise. The coil is assembled by a winding skeleton plus an external protection skeleton, thereby increasing the life of the coil.

[0032] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 This is a structural diagram of a layered single-component high-bandwidth mountable hollow coil winding skeleton according to an embodiment of the present invention;

[0035] Figure 2 This is a cross-sectional structural diagram of a layered single-component high-bandwidth mountable hollow coil winding skeleton according to an embodiment of the present invention;

[0036] Figure 3 It is a side view structural diagram of a layered single-component high-bandwidth mountable hollow coil winding mold according to an embodiment of the present invention;

[0037] Figure 4 A three-dimensional structural diagram of a layered single-component high-bandwidth mountable hollow coil winding mold according to an embodiment of the present invention;

[0038] Figure 5 This is a structural diagram of a layered single-component high-bandwidth mountable hollow coil mounting protection skeleton according to an embodiment of the present invention;

[0039] Figure 6 This is a structural diagram of a cover plate with a layered single-component, high-bandwidth and air-core coil mountable structure according to an embodiment of the present invention;

[0040] Figure 7 This is an overall assembly diagram of a layered single-component high-bandwidth mountable air-core coil according to an embodiment of the present invention;

[0041] Figure 8 A winding assembly diagram of a layered single-component high-bandwidth mountable air-core coil according to an embodiment of the present invention;

[0042] FIG. 9( a ) is a connection diagram for a coil bandwidth test according to an embodiment of the present invention;

[0043] FIG. 9( b ) is a frequency diagram of a coil bandwidth test according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0045] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0046] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0047] Embodiment 1

[0048] This embodiment provides a layered single-component high-bandwidth mountable air-core coil, comprising:

[0049] Winding frame, mounting protection frame and cover plate;

[0050] The mounting protection frame is provided with a winding frame groove, an electrical component mounting groove and a plurality of mounting holes;

[0051] The winding skeleton is a hollow structure, and adopts layered and segmented winding to form a differential pair signal. The wound winding skeleton is integrally mounted in the winding skeleton slot;

[0052] The electrical component installation groove is provided with an electrical component, and a cover plate is provided on the electrical component installation groove;

[0053] The mounting hole is used to pass a leveling wire through to level the coil.

[0054] The winding frame includes a winding groove, a middle baffle, two side baffles, a middle wire groove, and a side wire groove. The winding frame adopts 3D printing technology, and the material is 8000 series resin with low density. The shape is ring-shaped; the overall size is 484mm in outer diameter, 474.4mm in inner diameter, and 33.6mm in width. As shown in the attachment Figure 1 and Figure 2 As shown in the winding skeleton, label 1 is the winding groove with a groove width of 13mm; label 2 is the middle baffle with a width of 2.6mm; label 3 is the baffles on both sides with a width of 2.5mm; label 4 is the middle wire groove; label 5 is the side wire groove, and label 6 is a layer of insulating film.

[0055] The winding mold includes an outer baffle, a winding frame fixing platform, a threading hole, a winding mold support rod, a motor shaft fixing hole, and a top screw hole. Considering the characteristics of the winding mold such as small deformation after long-term use, less influence by temperature, etc., and easy processing, the whole is made of aluminum alloy CNC processing, which has a certain degree of oxidation resistance. The overall shape is a cross-shaped supported ring, with a maximum outer diameter of 500mm and a thickness of 22mm. As shown in the attachment Figure 3 and Figure 4 As shown in the winding mold, label 7 is the outer baffle, label 8 is the winding frame fixing platform, label 9 is the threading hole, label 10 is the winding mold support rod, label 11 is the motor shaft fixing hole, and label 12 is the top screw hole.

[0056] The mounting protection frame includes a winding frame fixing slot, mounting wire holes and slots, a battery slot, a posture circuit board fixing slot, and an analog signal processing circuit board fixing slot. The mounting protection frame is made of a high molecular PE material with low density, good strength and wear resistance. The overall size is 582mm in length, 502mm in width, and 40mm in thickness. The appearance is as shown in the attached Figure 5 As shown in the mounting protection frame, label 13 is the winding frame fixing groove; label 14 is the mounting wire hole and groove; label 15 is the battery slot; label 16 is the posture circuit board fixing slot; label 17 is the analog signal processing circuit board fixing slot.

[0057] The cover plate includes a power switch interface, a power indicator light, an analog signal interface, a digital signal interface, and a fixing hole. The cover plate mainly protects the battery and coil circuit part to prevent rain splashing and outdoor dust from entering; the outer surface is made of 2.0mm acrylic material for silk screen printing. Figure 6 As shown in the cover plate, reference numeral 18 is a power switch interface, reference numeral 19 is a power indicator light, reference numeral 20 is an analog signal interface, reference numeral 21 is a digital signal interface, and reference numeral 22 is a fixing hole.

[0058] The winding frame is made of 8000 series resin 3D light-curing printing technology, with an overall accuracy of ±0.1mm and a ring shape. Figure 1 As shown; the overall dimensions are weight, diameter 484mm, inner diameter 474.4mm, width 33.6mm. The resonant frequency of the hollow induction coil is approximately Generally, the resonant frequency point is taken as the upper limit of the bandwidth. Under the same winding conditions, the general inductance L value does not change much, so in order to increase the bandwidth of the winding coil, it is necessary to change the winding parameters to reduce the distributed capacitance C. The distributed capacitance is generated due to the potential difference between different wires. For multi-layer tightly wound hollow induction coils, it mainly consists of the capacitance between adjacent wires in the same layer and the interlayer capacitance between different layers.

[0059] Under the same winding conditions, according to the capacitor formula Where ε is a constant, S is the product of the coil width and length of each layer, d is the distance between coil layers, and k is the electrostatic force constant. It can be seen that by increasing the distance between different layers and the distance between lines in the same layer, the distributed capacitance C value can be effectively reduced. Although the dielectric constant also increases, the increase in dielectric constant has a smaller impact than the increase in distance. To reduce the distance between different layers, this embodiment uses the following additional Figure 1 and Figure 2 The 0.15mm polyimide film of No. 6 is used for isolation, increasing the distance between layers and increasing the insulation performance between layers. Polyimide film has the functions of light weight, high temperature resistance and insulation. It is generally used for insulation between layers of small transformers. Other materials with the same function can also be used.

[0060] The same layer is divided into two sections for winding, with a spacing of 2.6mm in between, which can reduce the distributed capacitance between the same layers and Figure 1 The middle tap is connected to the ground at the middle wire slot of No. 5. The two winding sections can be divided into two groups of differential signals with the same amplitude and opposite signals, which is beneficial to remove the common mode signal generated by crosstalk between the windings and reduce the overall noise of the coil. Figure 1 The number 5 in the winding skeleton and the cross-sectional diagram is used for the start of winding, to feed the input wire into the winding groove and clamp the winding wire to prevent the winding wire head from falling off and being unable to be wound when the motor rotates; the number 3 is used to limit the start and end of the two-segment winding to prevent the winding wire from slipping out of the winding skeleton.

[0061] The winding mold is made of aluminum alloy and CNC precision engraving. Aluminum alloy is not easy to deform and prevents oxidation. The maximum outer diameter is 500mm and the thickness is 22mm. Other metal materials are generally acceptable, but aluminum alloy is relatively light, easy to process, and not easy to deform. Relatively speaking, the cost is low. Plastic materials are generally easy to deform or shrink due to temperature. Figure 3 and Figure 4 The winding skeleton fixing table with number 8 in the winding mold is used to fix the winding skeleton. After the winding skeleton is placed in the winding mold, the jackscrews in the jackscrew holes with number 12 are used to fix the winding skeleton in four directions; the winding mold as a whole is supported by the outer ring of the mold support rod with number 10; there is a fixing screw inside number 11. After the fixing screw is screwed to the output shaft of the winding motor, the winding mold is fixed tightly with another screw outside; the enameled wire passes through the winding mold through the threading hole with number 9 to connect to the winding skeleton. The winding mold and the winding skeleton are driven to rotate by the rotation of the motor to complete the automatic winding.

[0062] The mounting protection frame is mainly used to protect the winding frame, assemble the circuit and level the mounting. The mounting frame is made of high molecular PE (HDPE) material and is made by mold opening. Figure 6 As shown in the figure, the body dimensions are 582mm, the width is 502mm, and the thickness is 40mm. HDPE has a low density and is relatively light. It is not easily deformed by temperature and has good wear resistance, which can meet the role of protecting the winding skeleton. The wound winding skeleton is placed in the attached Figure 6 In the winding skeleton fixing groove of No. 13, the winding skeleton is fixed by pouring 704 silicone rubber sealant for curing; the mounting wire hole and groove of No. 14 are used to bind the mounting wire, and the reserved holes and grooves on the outer wall are used to fix the mounting wire and provide mounting binding positions. Without the mounting wire groove and hole, the position of the coil will be offset during the movement of the coil, and the attitude of the noise coil will change greatly, which is not conducive to signal measurement. No. 15 is the battery slot, which powers the analog circuit board through the power switch. The battery uses two 7.4V / 1000mA batteries. No. 16 is the analog circuit board fixing groove, and the analog circuit board is fixed in the fixing groove using a hexagonal copper column. No. 17 is the digital circuit board fixing groove, and the digital circuit board is also fixed in the fixing groove using a hexagonal copper column. Among them, the analog circuit board fixing groove and the digital circuit board fixing groove use 0.2mm copper foil for electromagnetic shielding around the circle to prevent the electromagnetic radiation generated from affecting the coil receiving signal.

[0063] The cover is used to protect the battery, analog circuit board and digital circuit board from rain, dust and other damage. The cover is printed with 2.0mm acrylic board, and the surface of the cover has relevant instructions printed on it. The overall size is 91mm long and 81mm wide. Figure 6 The cover plate 18 is the power switch interface of the hollow induction coil, which is used to control whether the coil is powered; 19 is the power indicator light, which lights up when the power switch is turned on and the battery is normal, and turns off when the battery is too low. 20 is the analog signal interface, which is used to transmit the induced voltage measured by the induction coil.

[0064] Reference numeral 21 is a digital signal interface, which is used to transmit the coil attitude data. The attitude data and analog data are transmitted using separate wires. If they are transmitted in the same cable, the digital signal will interfere with the analog acquisition data. The interference can be removed after separate transmission.

[0065] This embodiment is a layered single-component high-bandwidth mountable hollow coil design, the overall assembly diagram is as shown in the attached Figure 7 and Figure 8As shown in the assembly diagram of the winding skeleton and the mounting protection skeleton. The winding skeleton is wound in layers and sections to form a differential pair signal, and then placed in the winding skeleton slot of the mounting protection skeleton as a whole, and sealed and cured with silicone rubber. The battery slot, analog circuit board slot, and digital circuit board slot are shielded by copper foil for radiation, and then the battery, analog circuit board, and digital circuit board are assembled in the corresponding slots of the mounting protection skeleton and fixed with screws. Finally, the cover is fixed to the corresponding position of the mounting protection skeleton with screws. The safety buckle uses a fiberglass rope to mount and level the coil as a whole through the mounting holes and slots (4 positions) of the mounting winding skeleton.

[0066] The coil winding adopts segmented and layered winding, and obtains differential pair signals at the same time, effectively improving the overall bandwidth of the coil and reducing common mode interference during the coil winding process. The coil is made of lightweight materials as a whole, so that the coil is large but not heavy, effectively increasing the endurance of the aircraft.

[0067] Embodiment 2

[0068] The method for preparing the layered single-component high-bandwidth mountable hollow coil described in the first embodiment above comprises the following steps:

[0069] Step 1, air-core coil bandwidth test:

[0070] Connect one end of the air-core coil to the signal generator and the other end to one end of an external resistor with the same internal resistance as the coil. Connect the signal generator and the external resistor to ground. Transmit a sweep signal through the signal generator and use a spectrum analyzer to measure the frequency response curve at both ends of the external resistor. The first resonance point is the coil bandwidth. The connection diagram and frequency response diagram of the coil bandwidth test are shown in Figure 9(a) and Figure 9(b).

[0071] Step 2, calculation of the distributed capacitance of the hollow coil:

[0072] The overall distributed capacitance of the air-core coil can be calculated according to the resonance frequency formula f = 1 / sqrt (2πLC). In the formula, f is the resonance frequency point and the same as the bandwidth of the air-core coil; L is the inductance of the air-core coil, which can be measured by a digital bridge; C is the distributed capacitance of the air-core coil. sqrt is the square root operation.

[0073] Step 3, calculation of hollow coil matching resistance:

[0074] According to the formula R≈0.5*sqrt(L / C), the matching resistance value when the damping coefficient of the air-core coil is 1 can be approximately calculated. Where L is the inductance of the air-core coil, and C is the distributed capacitance of the air-core coil.

[0075] Step 4: Mount and level the hollow coil.

[0076] The hollow coil is equipped with 4 mounting holes, through which glass fiber ropes are passed. A circular level bubble is provided above the hollow induction coil, through which the length of the 4 mounting ropes is adjusted, and finally the hollow coil is leveled. The adjusted 4 mounting ropes are fixed to the aluminum alloy mounting buckle, and the hollow coil is mounted and disassembled from the drone through the aluminum alloy mounting buckle.

[0077] In one or more embodiments, a detection device is further provided, comprising a receiving module, wherein the receiving module comprises the layered single-component high-bandwidth mountable air-core coil as described above.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A layered single-component high-bandwidth mountable air-core coil, characterized in that: include: Winding frame, mounting protection frame and cover plate; The mounting protection frame is provided with a winding frame groove, an electrical component installation groove and a plurality of mounting holes; The winding skeleton is a hollow structure, and adopts layered and segmented winding to form a differential pair signal. The wound winding skeleton is integrally mounted in the winding skeleton slot; The electrical component installation groove is provided with an electrical component, and a cover plate is provided on the electrical component installation groove; The mounting hole is used to pass a leveling wire to level the coil; The winding frame has two winding grooves, and a layer of insulating film is used to separate the winding layers, so as to realize the segmented and layered winding of the coil; Increase the distance between different layers and the distance between wires in the same layer, reduce the distributed capacitance C value, and improve the bandwidth of the winding coil; The same layer is divided into two sections for winding, and the middle of the two sections is separated to reduce the distributed capacitance between the same layers; the middle tap is led out at the middle wire slot, and the middle tap is grounded. The two sections of winding can be divided into two groups of differential signals with the same amplitude and opposite signals to remove the common mode signal generated by crosstalk between the windings and reduce the overall noise of the coil; The winding skeleton adopts 3D printing technology, and the material is 8000 series resin with low density, and the shape is ring-shaped; The winding skeleton fixing platform in the winding mold is used to fix the winding skeleton; after the winding skeleton is placed in the winding mold, the jackscrews in the jackscrew holes are used to fix the winding skeleton in four directions; the winding mold as a whole is supported by the mold support rod for the outer ring; there is a fixing screw inside the motor shaft fixing hole, and after the fixing screw is screwed on the output shaft of the winding motor, the winding mold is fixed tightly by another screw on the outside; the enameled wire passes through the winding mold through the threading hole to connect to the winding skeleton; the winding mold and the winding skeleton are driven to rotate by the rotation of the motor to complete the automatic winding.

2. The layered single-component high-bandwidth mountable air-core coil according to claim 1, characterized in that: A winding mould is arranged inside the winding frame.

3. The layered single-component high-bandwidth mountable air-core coil according to claim 2, characterized in that: The winding frame is fixed to the winding mold through a top screw, and the winding mold is fixed to the motor through a motor shaft fixing hole.

4. The layered single-component high-bandwidth mountable air-core coil according to claim 2, characterized in that: The overall shape of the winding mold is a circular ring supported in a cross shape.

5. The layered single-component high-bandwidth mountable air-core coil according to claim 1, characterized in that: After the wire winding of the frame is completed, it is embedded into the wire winding frame fixing groove of the mounting protection frame and is sealed and fixed by using sealant.

6. The layered single-component high-bandwidth mountable air-core coil according to claim 1, characterized in that: The mounting holes are evenly distributed on the mounting protection frame.

7. A method for preparing a layered single-component high-bandwidth mountable hollow coil as claimed in any one of claims 1 to 6, characterized in that: include: Test the bandwidth of air-core coil; Calculate the distributed capacitance of the air-core coil based on the tested air-core coil bandwidth; Calculate the matching resistance of the air-core coil based on the distributed capacitance of the air-core coil; Mounting and leveling air core coils.

8. The method for preparing the layered single-component high-bandwidth mountable hollow coil according to claim 7, characterized in that: According to f=1 / sqrt(2πLC), the overall distributed capacitance of the hollow coil is calculated; where f is the resonant frequency point, which is the same as the bandwidth of the hollow coil; L is the inductance value of the hollow coil; C is the distributed capacitance value of the hollow coil; and sqrt is the square root operation.

9. A detection device, characterized in that: It comprises a receiving module, and the receiving module comprises a layered single-component high-bandwidth mountable air-core coil as claimed in any one of claims 1 to 6.

Images