Dual-frequency electromagnetic metasurface units, arrays, and methods for enhancing downhole signal coverage

Abstract

This application relates to a dual-frequency electromagnetic metasurface unit, array, and method for enhancing downhole signal coverage. The metasurface unit includes: a dielectric layer comprising a first dielectric layer and a second dielectric layer; a metal resonant layer on the surface of the first dielectric layer, and a metal isolation layer between the two dielectric layers; a feed line at the bottom of the second dielectric layer; a first resonant plate of the metal resonant layer located in the middle of the surface of the first dielectric layer, with a first metal pillar passing through the first resonant plate and the first dielectric layer in the middle of the first resonant plate; a second resonant plate and a third resonant plate located on adjacent sides of the surface of the first dielectric layer, connected to the first resonant plate via diodes; one end of each of the second and third resonant plates having a metal pillar; and one end of the feed line connected to the metal pillar. This application provides a dual-frequency electromagnetic metasurface unit, array, and method for enhancing downhole signal coverage, which can reduce energy loss and radiation loss, and has efficient electromagnetic wave reflection capability in a lower frequency range.

Description

Technical Field

[0001] This application relates to the field of electronic countermeasures and jamming technology, and in particular to a dual-frequency electromagnetic metasurface unit, array, and method for enhancing downhole signal coverage. Background Technology

[0002] With the development of wireless communication technology, users' demands for signal transmission are gradually trending towards high speed, low latency, and high reliability. However, due to path loss during transmission of millimeter-wave electromagnetic waves, and their susceptibility to obstruction by obstacles in complex electromagnetic environments, many non-line-of-sight signal blind spots emerge, thus limiting the signal transmission of base stations. This is especially true in the coal mining industry, where the long length and numerous branches of mine tunnels severely impact electromagnetic signal transmission. Furthermore, the mining equipment within the tunnels generates electromagnetic interference, further affecting signal transmission.

[0003] In existing technologies, the signal coverage area is usually increased by deploying small base stations. However, this method is too costly, and the underground power supply system is prone to instability, leading to frequent power outages of the base stations and affecting the continuity of communication.

[0004] Currently, some passive metasurfaces exist for reflecting, transmitting, and scattering electromagnetic waves, thereby improving the transmission rate and reducing transmission delay to some extent. However, since the function of passive metasurfaces is fixed after fabrication, they lack tunability, cannot dynamically control electromagnetic waves, cannot achieve arbitrary angle reflection of electromagnetic waves, and are prone to crosstalk between operating frequencies. The beam control range is also limited by design, thus restricting the efficiency and performance of this method in practical applications.

[0005] Therefore, it is necessary to improve one or more of the problems existing in the above-mentioned related technical solutions.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this disclosure is to provide a dual-frequency electromagnetic metasurface unit, array, and method for enhancing downhole signal coverage, thereby overcoming, at least to some extent, one or more problems caused by limitations and defects in related technologies.

[0008] In a first aspect, this application provides a dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage, comprising:

[0009] The dielectric layer includes a first dielectric layer and a second dielectric layer; the surface of the first dielectric layer has a metal resonant layer; a metal isolation layer is provided between the first dielectric layer and the second dielectric layer; and a feed line is provided at the bottom of the second dielectric layer.

[0010] The metal resonant layer includes a first resonant plate, a second resonant plate, a third resonant plate, a first diode, and a second diode. The first resonant plate is located in the middle of the surface of the first dielectric layer, and a first metal pillar passing through the first resonant plate and the first dielectric layer is located in the middle of the first resonant plate. The second resonant plate and the third resonant plate are located on adjacent sides of the surface of the first dielectric layer, and are respectively connected to the first resonant plate through the first diode and the second diode. One end of the second resonant plate has a second metal pillar passing through the second resonant plate, the first dielectric layer, the metal isolation layer, and the second dielectric layer. One end of the third resonant plate has a third metal pillar passing through the third resonant plate, the first dielectric layer, the metal isolation layer, and the second dielectric layer.

[0011] One end of the feeder is connected to the second metal post and the third metal post.

[0012] In one possible implementation, the first resonant plate has a first protrusion on the side near the second resonant plate, the first resonant plate has a second protrusion on the side near the third resonant plate, the second resonant plate has a third protrusion on the side near the first resonant plate, and the third resonant plate has a fourth protrusion on the side near the first resonant plate; the first protrusion and the third protrusion are connected by a first diode, and the first protrusion and the fourth protrusion are connected by a second diode.

[0013] In one possible implementation, the first resonator is rectangular in shape, with a rectangular protrusion on the side away from the second resonator and a rectangular recess on the side away from the third resonator; the second and third resonators are rectangular in shape.

[0014] In one possible implementation, the dimensions of the first resonant plate, the second resonant plate, and the third resonant plate, and the spacing between the first resonant plate and the second and third resonant plates, are determined by analyzing the influence of the dimensions and the spacing on the electromagnetic wave phase and electromagnetic wave amplitude; the thickness of the metal resonant layer and the metal isolation layer, and the dimension of the dielectric layer, are determined by analyzing the influence of the thickness on the electromagnetic wave phase and electromagnetic wave amplitude.

[0015] In one possible implementation, the dielectric layer is an impregnated product material composed of tetrafluoroethylene and glass cloth; the metal resonant layer, the metal isolation layer, the first metal pillar, the second metal pillar, and the third metal pillar are made of copper.

[0016] In one possible implementation, the other end of the feed line is used to connect to the positive terminal of a DC bias network, which is connected to the positive terminal of the second metal pillar and the first diode via the feed line, and the positive terminal of the DC bias network is also connected to the positive terminal of the third metal pillar and the second diode via the feed line; the negative terminals of the first diode and the second diode are connected to the metal isolation layer via the first metal pillar, and the metal isolation layer is used to connect to the negative terminal of the DC bias network.

[0017] Secondly, this application provides a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage, comprising the aforementioned dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage, the array including:

[0018] An array frame includes multiple fixing slots and an outer frame, the outer frame being located outside the multiple fixing slots and having multiple sets of ribbon cable interfaces;

[0019] A dual-frequency electromagnetic metasurface unit that enhances downhole signal coverage is fixed in the mounting slot, and the feed line at the bottom is connected to the cabling interface.

[0020] In one possible implementation, the dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage further includes a digital logic control board, which is connected to the metal resonant layer via the feed line.

[0021] Thirdly, this application provides a method for manufacturing a dual-frequency electromagnetic metasurface to enhance downhole signal coverage, used to manufacture the aforementioned dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage, the method comprising:

[0022] Obtain parameters of dual-frequency electromagnetic metasurface units to enhance downhole signal coverage;

[0023] Based on the dual-frequency electromagnetic metasurface unit that enhances downhole signal coverage, the phase distribution of the preset array with different incident and reflection angles is calculated, and the specific arrangement of the basic units in the preset array is obtained.

[0024] The preset array was simulated in the frequency band of 1.8-3.8 GHz, and the far-field energy at 2.1 GHz and 3.5 GHz was monitored.

[0025] In one possible implementation, the establishment of the dual-frequency electromagnetic metasurface unit for enhanced downhole signal coverage includes:

[0026] A basic dual-frequency electromagnetic metasurface unit model for enhancing downhole signal coverage is established;

[0027] Within the frequency range of 1.8-3.8 GHz, the size of the metal resonator model and the operating state of the diode model are simulated to analyze the influence of different sizes and different diode operating states on the electromagnetic wave phase and electromagnetic wave amplitude, and the first simulation results are obtained.

[0028] Within the frequency band of 1.8-3.8 GHz, simulations were performed on different dielectric layer models to analyze the influence of different dielectric layer sizes on the electromagnetic wave phase and electromagnetic wave amplitude, and the second simulation results were obtained.

[0029] Based on the first and second simulation results, the optimal dual-frequency electromagnetic metasurface unit parameters for enhancing downhole signal coverage are obtained in the 2.1 GHz and 3.5 GHz frequency bands, which have the highest electromagnetic wave amplitude and the electromagnetic wave phase difference closest to 180°.

[0030] The technical solution provided in this application may include the following beneficial effects:

[0031] This application, through the above-mentioned technical solution, can achieve dynamic beam control by optimizing the structure of the metasurface unit and adding diodes, thereby reducing energy loss and radiation loss. It has efficient electromagnetic wave reflection capability in a lower frequency range, and the low-frequency signal can better penetrate buildings and obstructions, further enhancing the signal's penetration capability and adaptability.

[0032] By utilizing metasurfaces to arbitrarily control the propagation direction of electromagnetic waves, the shortcomings of traditional electromagnetic signals, which can only passively adapt to the wireless environment, can be overcome. Furthermore, it can avoid crosstalk between operating frequencies and achieve beam modulation at larger angles across two frequencies. The incident angle of electromagnetic waves can be adjusted according to specific application scenarios, making it more suitable for engineering applications and thus enhancing signal coverage in mines.

[0033] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0035] Figure 1This diagram illustrates the structure of a dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage in an exemplary embodiment of this disclosure.

[0036] Figure 2 A perspective schematic diagram of a dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0037] Figure 3 This diagram illustrates the overall dimensions of a dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage in an exemplary embodiment of this disclosure.

[0038] Figure 4 This is a schematic diagram showing the dimensions of the connection between the first and second metal layers of a dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage in an exemplary embodiment of this disclosure;

[0039] Figure 5 A schematic diagram showing the dimensions of the connection between the first and third metal layers of a dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage in an exemplary embodiment of this disclosure;

[0040] Figure 6 This diagram illustrates the dimensions of a dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage in an exemplary embodiment of this disclosure.

[0041] Figure 7 A structural diagram of the surface of a dual-frequency electromagnetic metasurface array that enhances downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0042] Figure 8 A schematic diagram of the bottom feed line of a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage in an exemplary embodiment of this disclosure is shown;

[0043] Figure 9 A schematic flowchart of a method for manufacturing a dual-frequency electromagnetic metasurface to enhance downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0044] Figure 10 A flowchart illustrating the method for determining parameters of a dual-frequency electromagnetic metasurface unit to enhance downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0045] Figure 11 This diagram illustrates a comparison of the phase amplitude distribution of a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage in an exemplary embodiment of this disclosure.

[0046] Figure 12 A comparison diagram of phase coding at 2.1 GHz for a dual-frequency electromagnetic metasurface array that enhances downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0047] Figure 13A comparison diagram of phase coding at 3.5 GHz for a dual-frequency electromagnetic metasurface array that enhances downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0048] Figure 14 A 2.1 GHz three-dimensional long-range scattering comparison diagram of a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0049] Figure 15 This image shows a 3.5 GHz three-dimensional long-range scattering comparison of a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage in an exemplary embodiment of this disclosure.

[0050] Figure 16 A comparison diagram of the 2.1 GHz one-dimensional scattering direction of a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0051] Figure 17 A comparison diagram of the 3.5 GHz one-dimensional scattering direction of a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage in an exemplary embodiment of this disclosure is shown.

[0052] Figure 18 The diagram shows a comparison of branch tunnel models of a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage in an exemplary embodiment of this disclosure.

[0053] Figure label:

[0054] 100. Dual-frequency electromagnetic metasurface unit for enhanced downhole signal coverage; 110. Metal resonant layer; 111. First resonant plate; 112. First through-hole; 113. Second resonant plate; 1131. Second through-hole; 114. Third resonant plate; 1141. Third through-hole; 120. Diode; 121. First diode; 122. Second diode; 130. First dielectric layer; 131. Fourth through-hole; 132. Fifth through-hole; 133. Sixth through-hole; 140. Metal isolation layer; 141. Seventh through-hole; 142. Eighth through-hole; 150. Second dielectric layer; 151. Ninth through-hole; 152. Tenth through-hole; 160. Feeder; 170. First metal pillar; 180. Second metal pillar; 190. Third metal pillar;

[0055] 200. Dual-frequency electromagnetic metasurface array to enhance downhole signal coverage; 210. Cable interface. Detailed Implementation

[0056] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0057] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0058] This example embodiment first provides a dual-frequency electromagnetic metasurface unit 100 to enhance downhole signal coverage, referenced... Figure 1-8 As shown, the unit comprises, from top to bottom, a metal resonant layer 110, a first dielectric layer 130, a metal isolation layer 140, a second dielectric layer 150, and a feed line 160, and may include:

[0059] The dielectric layer includes a first dielectric layer 130 and a second dielectric layer 150; the surface of the first dielectric layer 130 has a metal resonant layer 110; a metal isolation layer 140 is provided between the first dielectric layer 130 and the second dielectric layer; and a feed line 160 is provided at the bottom of the second dielectric layer.

[0060] Optionally, the dielectric layer is made of a composite material of tetrafluoroethylene and glass cloth, with a relative permittivity of 2.65 and a dielectric loss factor of 0.001.

[0061] It should be noted that the metal isolation layer 140 can also serve as a grounding layer.

[0062] The metal resonant layer 110 includes a first resonant plate 111, a second resonant plate 113, a third resonant plate 114, a first diode 121, and a second diode 122. The first resonant plate 111 is located at the center of the surface of the first dielectric layer 130, and the center of the first resonant plate 111 has a first metal pillar 170 that passes through the first resonant plate 111 and the first dielectric layer 130. The second resonant plate 113 and the third resonant plate 114 are respectively located on adjacent sides of the surface of the first dielectric layer 130, and are respectively connected by the first diode 121 and the second diode 122. The first resonant plate 111 is connected to the second resonant plate 113; one end of the second resonant plate 113 has a second metal pillar 180 passing through the second resonant plate 113, the first dielectric layer 130, the metal isolation layer 140, and the second dielectric layer 150; one end of the third resonant plate 114 has a third metal pillar 190 passing through the third resonant plate 114, the first dielectric layer 130, the metal isolation layer 140, and the second dielectric layer 150; optionally, the metal resonant layer 110, the metal isolation layer 140, and the metal pillar are made of copper, and the diode is a PIN diode. The first diode 121 and the second diode 122 are respectively positioned in the X and Y directions. One end of the feed line 160 is connected to the second metal pillar 180 and the third metal pillar 190.

[0063] The first resonant plate 111 has a first through hole 112 in the middle, and the first dielectric layer 130 has a fourth through hole 131 in the middle, with the first through hole 112 and the fourth through hole 131 aligned. The second resonant plate 113 has a second through hole 1131 at one end, the first dielectric layer 130 has a fifth through hole 132, the metal isolation layer 140 has a seventh through hole 141, and the second dielectric layer 150 has a ninth through hole 151, with the second through hole 1131, the fifth through hole 132, the seventh through hole 141, and the ninth through hole 151 aligned. The third resonant plate 114 has a third through hole 1141 at one end, the first dielectric layer 130 has a sixth through hole 133, the metal isolation layer 140 has an eighth through hole 142, and the second dielectric layer 150 has a tenth through hole 152, with the third through hole 1141, the sixth through hole 133, the eighth through hole 142, and the tenth through hole 152 aligned.

[0064] Optionally, the second resonant plate 113 and the third resonant plate 114 above and to the left of the metal resonant layer 110 are made of two identical rectangular metal strips, and two copper metal pillars with a radius of 0.2 mm are introduced at the upper right and lower left respectively. At the same time, metal through holes with a radius of 0.4 mm are etched at the same position in the middle metal isolation layer 140.

[0065] It should be noted that the diode operates in either a conducting or cut-off state. The other end of the feed line 160 is used to connect to the positive terminal of the DC bias network. The positive terminal of the DC bias network is connected to the positive terminal of the first diode 121 via the feed line 160, the second metal pillar 180, and the positive terminal of the DC bias network is connected to the positive terminal of the second diode 122 via the feed line 160, the third metal pillar 190, and the third metal pillar 190. The negative terminals of the first diode 121 and the second diode 122 are connected to the metal isolation layer 140 via the first metal pillar 170. The metal isolation layer 140 is used to connect to the negative terminal of the DC bias network, thereby controlling the operating state of the PIN diode through the DC bias network.

[0066] Further, optionally, the first resonant plate 111 has a first protrusion on the side near the second resonant plate 113, the first resonant plate 111 has a second protrusion on the side near the third resonant plate 114, the second resonant plate 113 has a third protrusion on the side near the first resonant plate 111, and the third resonant plate 114 has a fourth protrusion on the side near the first resonant plate 111; the first protrusion and the third protrusion are connected by a first diode 121, and the first protrusion and the fourth protrusion are connected by a second diode 122.

[0067] In one embodiment, the first resonator 111 is rectangular, with a rectangular protrusion on the side away from the second resonator 113 and a rectangular recess on the side away from the third resonator 114, thereby changing the resonant response to x-polarized waves and y-polarized waves at different frequency points.

[0068] Through the above unit, it is possible to independently manipulate x-polarized waves and y-polarized waves at different frequencies, and to achieve phase modulation of orthogonal polarized waves at different frequencies through the special metal resonant layer 110 of the above unit.

[0069] In one embodiment, the dimensions of the first resonant plate 111, the second resonant plate 113, and the third resonant plate 114, and the spacing between the first resonant plate 111 and the second resonant plate 113 and the third resonant plate 114, are determined by analyzing the influence of the dimensions and the spacing on the electromagnetic wave phase and electromagnetic wave amplitude; the thicknesses of the metal resonant layer 110 and the metal isolation layer 140, and the dimensions of the dielectric layer, are determined by analyzing the influence of the thicknesses on the electromagnetic wave phase and electromagnetic wave amplitude.

[0070] It should be noted that, as Figure 11As shown, by maximizing the electromagnetic wave amplitude and minimizing the electromagnetic wave phase difference to 180°, the optimal dimensions of the dual-frequency electromagnetic metasurface unit 100, metal resonator layer 110, and dielectric layer for enhancing downhole signal coverage are determined. Specifically, the amplitude and phase distribution diagrams of the dual-frequency active metasurface unit under simulated vertical electromagnetic wave incidence are shown. We define the off state of the diode on the metasurface as "0" and the on state as "1," with the numbers before and after the slash " / " representing the operating states of the PIN diodes in the y and x directions, respectively. Figure 11 It can be seen that the reflectivity reaches above 0.85 at frequencies of 2.1 GHz and 3.5 GHz, and the phase difference between the four diode switching states is close to 180°. Regardless of the switching state of the PIN diode in the y-direction, the PIN diode can achieve a 180° phase change when switching between "0" and "1" in the x-direction. Similarly, regardless of the switching state of the PIN diode in the x-direction, the PIN diode can achieve a 180° phase change when switching between "0" and "1" in the y-direction, indicating that the designed active metasurface unit can operate independently at 2.1 GHz and 3.5 GHz.

[0071] Optional, such as Figure 3-6 As shown, the dimensions of the metal resonant layer 110, metal isolation layer 140, and dielectric layer of a dual-frequency electromagnetic metasurface unit 100 for optimal downhole signal coverage are provided. X1-19 represent the dimensions of the metal resonant layer 110, metal isolation layer 140, and dielectric layer, where X1 is 46 mm, X2 is 24.6 mm, X3 is 34.8 mm, X4 is 1.3 mm, X5 is 22 mm, X6 is 3.6 mm, and X7 is 10 mm. The thicknesses of the metal resonant layer 110 and the metal isolation layer 140 are 0.035 mm: 0.4 mm, X8 is 14 mm, X9 is 4.3 mm, X10 is 5.95 mm, X11 is 35 mm, X12 is 2 mm, X13 is 0.25 mm, X14 is 1.5 mm, X15 is 0.85 mm, X16 is 0.25 mm, X17 is 1.5 mm, X18 is 1.5 mm, and X19 is 1 mm.

[0072] This example embodiment also provides a dual-frequency electromagnetic metasurface array 200 to enhance downhole signal coverage, see reference. Figure 7-8 As shown, the array may include:

[0073] The array frame includes multiple fixing slots and an outer frame, the outer frame being located outside the multiple fixing slots and having multiple sets of ribbon cable interfaces 210;

[0074] A dual-frequency electromagnetic metasurface unit 100 for enhancing downhole signal coverage is fixed in the fixing groove, and the feed line 160 at the bottom is connected to the cable interface 210.

[0075] The number of ribbon cable interfaces 210 corresponds to the number of fixed slots. For example, the fixed slots of the array frame are 10×10, which can accommodate 100 units. Each unit has 2 diodes, for a total of 200 diodes. A total of 200 feed lines 160 are required to connect to 20 sets of ribbon cable interfaces 210 with 10 holes each, and to control the diodes to switch between on and off working states. The feed lines 160 can be DuPont wires.

[0076] In one embodiment, the dual-frequency electromagnetic metasurface array 200 for enhancing downhole signal coverage further includes a digital logic control board connected to the metal resonant layer 110 via the feed line 160. The core of the digital logic control board is a 32-bit microcontroller from STMicroelectronics based on the ARM Cortex-M core.

[0077] The digital logic control board uses a shift register to output 225 independent control signals to drive the dual-frequency electromagnetic metasurface that enhances downhole signal coverage to work at different frequency points.

[0078] This example embodiment also provides a method for manufacturing a dual-frequency electromagnetic metasurface to enhance downhole signal coverage. This method can be applied to a terminal device, such as a mobile terminal like a mobile phone, desktop computer, personal digital assistant, laptop, tablet, or smartwatch. (Reference) Figures 9-10 As shown, the method may include the following steps:

[0079] Step S100: Obtain the parameters of the dual-frequency electromagnetic metasurface unit 100 to enhance downhole signal coverage.

[0080] Step S200: Based on the dual-frequency electromagnetic metasurface unit 100 that enhances downhole signal coverage, calculate the preset array phase distribution with different incident angles and reflection angles to obtain the specific arrangement of the basic units in the preset array.

[0081] It should be noted that, as Figures 12-13 As shown, the phase distribution of the preset array with different incident angles and reflection angles is calculated using MATLAB software, thereby obtaining the specific arrangement of the basic units in the array.

[0082] Step S300: Simulate the preset array in the frequency band of 1.8-3.8 GHz and monitor the far-field energy at 2.1 GHz and 3.5 GHz.

[0083] It should be noted that, as Figures 14-17 As shown, the preset array was simulated in the frequency band of 1.8-3.8 GHz using CST Microwave Studio software, and the far-field energy at 2.1 GHz and 3.5 GHz was monitored.

[0084] Depend on Figures 12-17 It can also be seen that the deflection angle of the electromagnetic wave reaches the preset value, and the energy of the main lobe of the reflected wave also converges in this direction.

[0085] Furthermore, a method for obtaining parameters of the dual-frequency electromagnetic metasurface unit 100 to enhance downhole signal coverage includes:

[0086] Step S110: Establish a basic dual-frequency electromagnetic metasurface unit 100 model to enhance downhole signal coverage.

[0087] Step S120: Within the frequency range of 1.8-3.8 GHz, simulate the size of the metal resonator layer 110 model and the working state of the diode model, analyze the influence of different sizes and different diode working states on the electromagnetic wave phase and electromagnetic wave amplitude, and obtain the first simulation results.

[0088] It should be noted that the CST Microwave Studio software was used to simulate the size of the metal resonator layer 110 model and the operating state of the diode model in the frequency band of 1.8-3.8 GHz, so as to obtain the influence of metal resonator layer 110 with different sizes and diode operating states on phase and amplitude.

[0089] Step S130: Simulate the dimensions of different dielectric layer models within the frequency band of 1.8-3.8 GHz, analyze the influence of different dielectric layer dimensions on the electromagnetic wave phase and electromagnetic wave amplitude, and obtain the second simulation results.

[0090] It should be noted that simulation models of dielectric layer thickness and length were performed using CST Microwave Studio software in the 1.8-3.8 GHz frequency band to obtain the influence of different dielectric layer sizes on phase and amplitude.

[0091] Step S140: Based on the first simulation results and the second simulation results, obtain the optimal dual-frequency electromagnetic metasurface unit parameters for enhancing downhole signal coverage in the frequency range of 2.1GHz and 3.5GHz, which have the highest electromagnetic wave amplitude and the electromagnetic wave phase difference closest to 180°.

[0092] The dual-frequency active metasurface array of this application has signal blind spot compensation capability, such as Figure 18As shown, to verify the signal gap-filling capability, branch tunnels were constructed in the electromagnetic simulation software FEKO. These tunnels were 5 meters wide and 6 meters high, with the main tunnel being 120 meters long and the two branch tunnels approximately 77 meters long. The entire tunnel was constructed of concrete with a relative permittivity of 4.3, a conductivity of 0.005 S / m, and a permeability close to vacuum. At the tunnel's beginning, base station antennas radiating 2.1 GHz and 3.5 GHz wireless signals were deployed to radiate wireless signals into the main tunnel, concealed at the top of the tunnel for easy observation of signal strength. A ray tracing model (SRT) was used to simulate the wireless propagation of electromagnetic waves. Within the tunnel, the base station antenna height was defined as 1.5 mm, and a dual-band active metasurface was deployed at the center of the branch tunnel intersection. Signal strength monitoring was conducted both when only the base station was present and when both the base station and the DDCM were present. Under the radiation of base station antennas operating at 2.1 GHz and 3.5 GHz with an initial power of 100 mW, the signal strength at the intersection of the main tunnels was -64.7 dBm and -69.3 dBm, respectively, while the signal strength at the bottom of the tunnels was -70.43 dBm and -74.9 dBm, respectively. However, due to the obstruction of the tunnel walls, the wireless signal concentrated in the main tunnel, and signal blind spots existed at non-line-of-sight locations such as the branch tunnels on the left and right sides due to the obstruction of the tunnel walls. Multiplying the signal strength at the location where the metasurface was deployed in the center of the tunnel by the reflection efficiency of the metasurface yields the initial strength of the reflected signal. After deploying a dual-frequency active metasurface in the center of the tunnel, the branch tunnels were completely covered by wireless signals, with signal strengths at the bottom of the branch tunnels of approximately -90 dBm and -93.6 dBm, respectively, achieving full electromagnetic signal coverage.

[0093] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0094] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise expressly specified.

[0095] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0096] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0097] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0098] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage, characterized in that, include: The dielectric layer includes a first dielectric layer and a second dielectric layer; The surface of the first dielectric layer has a metal resonant layer; A metal isolation layer is provided between the first dielectric layer and the second dielectric layer; a feed line is provided at the bottom of the second dielectric layer; The metal resonant layer includes a first resonant plate, a second resonant plate, a third resonant plate, a first diode, and a second diode. The first resonant plate is located in the middle of the surface of the first dielectric layer, and a first metal pillar passing through the first resonant plate and the first dielectric layer is located in the middle of the first resonant plate. The second resonant plate and the third resonant plate are located on adjacent sides of the surface of the first dielectric layer, and are respectively connected to the first resonant plate through the first diode and the second diode. One end of the second resonant plate has a second metal pillar passing through the second resonant plate, the first dielectric layer, the metal isolation layer, and the second dielectric layer. One end of the third resonant plate has a third metal pillar passing through the third resonant plate, the first dielectric layer, the metal isolation layer, and the second dielectric layer. One end of the feeder is connected to the second metal post and the third metal post; The other end of the feed line is used to connect to the positive terminal of the DC bias network. The positive terminal of the DC bias network is connected to the positive terminal of the second metal pillar and the first diode through the feed line. The positive terminal of the DC bias network is also connected to the positive terminal of the second diode through the third metal pillar. The negative terminals of the first diode and the second diode are connected to the metal isolation layer through the first metal pillar. The metal isolation layer is used to connect to the negative terminal of the DC bias network.

2. The dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage according to claim 1, characterized in that, The first resonant plate has a first protrusion on the side near the second resonant plate, the first resonant plate has a second protrusion on the side near the third resonant plate, the second resonant plate has a third protrusion on the side near the first resonant plate, and the third resonant plate has a fourth protrusion on the side near the first resonant plate; the first protrusion and the third protrusion are connected by a first diode, and the first protrusion and the fourth protrusion are connected by a second diode.

3. The dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage according to claim 2, characterized in that, The first resonant plate is rectangular in shape, with a rectangular protrusion on the side away from the second resonant plate and a rectangular recess on the side away from the third resonant plate; the second resonant plate and the third resonant plate are rectangular in shape.

4. The dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage according to claim 3, characterized in that, The dimensions of the first resonant plate, the second resonant plate, and the third resonant plate, and the spacing between the first resonant plate, the second resonant plate, and the third resonant plate, are determined by analyzing the influence of the dimensions and the spacing on the phase and amplitude of the electromagnetic wave; the thickness of the metal resonant layer and the metal isolation layer, and the dimension of the dielectric layer, are determined by analyzing the influence of the thickness on the phase and amplitude of the electromagnetic wave.

5. The dual-frequency electromagnetic metasurface unit for enhancing downhole signal coverage according to claim 1, characterized in that, The dielectric layer is an impregnated product material composed of tetrafluoroethylene and glass cloth; the metal resonant layer, the metal isolation layer, the first metal pillar, the second metal pillar and the third metal pillar are made of copper.

6. A dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage, characterized in that, The array comprises dual-frequency electromagnetic metasurface units for enhancing downhole signal coverage as described in any one of claims 1 to 5, the array including: An array frame includes multiple fixing slots and an outer frame, the outer frame being located outside the multiple fixing slots and having multiple sets of ribbon cable interfaces; A dual-frequency electromagnetic metasurface unit that enhances downhole signal coverage is fixed in the mounting slot, and the feed line at the bottom is connected to the cabling interface.

7. The dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage according to claim 6, characterized in that, Also includes: The digital logic control board is connected to the metal resonant layer via the feed line.

8. A method for manufacturing a dual-frequency electromagnetic metasurface to enhance downhole signal coverage, characterized in that, The method is used to manufacture a dual-frequency electromagnetic metasurface array for enhancing downhole signal coverage as described in any one of claims 6 to 7, the method comprising: Obtain parameters of dual-frequency electromagnetic metasurface units to enhance downhole signal coverage; Based on the dual-frequency electromagnetic metasurface unit that enhances downhole signal coverage, the phase distribution of the preset array with different incident and reflection angles is calculated to obtain the specific arrangement of the units within the preset array; The preset array was simulated in the frequency band of 1.8-3.8 GHz, and the far-field energy at 2.1 GHz and 3.5 GHz was monitored.

9. The method for manufacturing a dual-frequency electromagnetic metasurface to enhance downhole signal coverage according to claim 8, characterized in that, Establish a dual-frequency electromagnetic metasurface unit to enhance downhole signal coverage, including: A dual-frequency electromagnetic metasurface unit model for enhancing downhole signal coverage is established; Within the frequency range of 1.8-3.8 GHz, the size of the metal resonator model and the operating state of the diode model were simulated to analyze the influence of different sizes and different diode operating states on the electromagnetic wave phase and electromagnetic wave amplitude, and the first simulation results were obtained. Within the frequency band of 1.8-3.8 GHz, simulations were performed on different dielectric layer models to analyze the influence of different dielectric layer sizes on the electromagnetic wave phase and electromagnetic wave amplitude, and the second simulation results were obtained. Based on the first and second simulation results, the optimal dual-frequency electromagnetic metasurface unit parameters for enhancing downhole signal coverage are obtained in the 2.1 GHz and 3.5 GHz frequency bands, which have the highest electromagnetic wave amplitude and the electromagnetic wave phase difference closest to 180°.

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