Antenna structure

Abstract

According to an embodiment of the present disclosure, an antenna structure provided around a side periphery of a discharge tube providing a space in which plasma is generated may be provided. The antenna structure comprises n unit antennas, and each unit antenna of the n unit antennas comprises a first arc-shaped section with a first curvature radius, a second arc-shaped section with a second curvature radius and an arc connection section connecting the first arc-shaped section and the second arc-shaped section, and the m-th unit antenna and the (m + 1)-th unit antenna, which are adjacent to each other, are disposed such that an angle formed by the arc connection section of the m-th unit antenna and the arc connection section of the (m + 1)-th unit antenna with respect to the center of the discharge tube is 360 / n degrees.

Description

Technical Field

[0001] The present invention relates to an antenna structure. More specifically, the present invention relates to an antenna structure designed to improve the durability and efficiency of a plasma induction system. Background Art

[0002] Plasma processing technology using plasma is used not only in semiconductor, display, and medical device technologies but also in a wide range of industries, such as environmental technologies including air, water, and soil purification, and energy technologies including solar cells and hydrogen energy. In plasma processing technology, active research is being conducted on inductively coupled discharge for forming high-density plasma at low power.

[0003] Inductively coupled discharge is typically generated by applying electric power to an antenna structure, and when considering the stability, durability, and efficiency of a system for initiating plasma, the shape or structure of the antenna structure should be regarded as a very important technical variable.

[0004] Meanwhile, the scale of the system for initiating plasma or the density of the plasma can vary according to the requirements of the industrial field, and as the scale of the system increases or the density of the plasma increases, the electric power or frequency applied to the antenna structure increases, thereby causing some problems in terms of the durability of the antenna structure and the stability of the system.

[0005] The present disclosure proposes an antenna structure designed to ensure the stability and durability of the system while meeting the required system scale or plasma density. Summary of the Invention

[0006] Technical Problem

[0007] One object achieved by the present disclosure is to provide an antenna structure having strong inductive coupling during the generation of inductively coupled plasma.

[0008] One object achieved by the present disclosure is to provide an antenna structure to increase the stability and durability of a system in a plasma induction system that excites plasma by receiving high-frequency power of several MHz.

[0009] One object achieved by the present disclosure is to provide an antenna structure to apply a relatively weak voltage to an antenna adjacent to the outer wall of a discharge tube during the process of exciting plasma into the discharge tube (or dielectric tube).

[0010] One object achieved by the present disclosure is to provide an antenna structure that is easy to design and manufacture.

[0011] One object achieved by the present disclosure is to minimize the use of auxiliary gas in inductively coupled plasma (ICP) induction.

[0012] The object of the present disclosure is not limited to the above object, and from the following detailed description and the drawings, those skilled in the art to which the present disclosure pertains should clearly understand other objects not described herein.

[0013] Means for Solving the Problem

[0014] According to one embodiment, an antenna structure provided around a side periphery of a discharge tube is provided, and the discharge tube provides a space in which plasma is generated. The antenna structure includes: n unit antennas including a first unit antenna to an nth unit antenna, where n is a natural number greater than or equal to 2, and each of the n unit antennas includes: a first arc section having a first radius of curvature and including a first end and a second end, a second arc section having a second radius of curvature and including a third end and a fourth end, and an arc connection section connecting the second end of the first arc section and the third end of the second arc section. Wherein, the mth unit antenna and the (m + 1)th unit antenna are arranged such that an angle formed by a first virtual line and a second virtual line is 360 / n degrees, where the first virtual line connects the center of the discharge tube and the arc connection section of the mth unit antenna, where the second virtual line connects the center of the discharge tube and the arc connection section of the (m + 1)th unit antenna, where the mth unit antenna and the (m + 1)th unit antenna are adjacent, and m is a natural number less than n, and where the first radius of curvature is different from the second radius of curvature.

[0015] The technical solution of the present disclosure may not be limited to the above, and from this specification and the drawings, those skilled in the art to which the present disclosure pertains should clearly understand other technical solutions not described herein.

[0016] Advantageous Effects of the Invention

[0017] According to an exemplary embodiment, the stability and durability of the plasma induction system can be improved.

[0018] According to an exemplary embodiment, since ion loss in the discharge tube in the plasma induction system can be reduced, plasma can be stably induced and maintained.

[0019] According to an exemplary embodiment, damage to the discharge tube in the plasma induction system can be prevented.

[0020] According to an exemplary embodiment, an antenna structure having the above effects can be easily manufactured, and the manufacturing cost can be reduced.

[0021] According to an exemplary embodiment, the cost can be reduced according to the amount of auxiliary gas used in plasma discharge.

[0022] The effects of the present disclosure may not be limited to the above, and those skilled in the art to which the present disclosure pertains should clearly understand other effects not described herein according to this specification and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a block diagram of a plasma induction system according to an exemplary embodiment.

[0024] Figure 2 is a view showing a radio frequency (RF) generator according to an exemplary embodiment.

[0025] Figure 3 is a view showing an antenna structure and a discharge tube according to an exemplary embodiment.

[0026] Figure 4 and Figure 5 are views showing a conventional antenna structure, respectively.

[0027] Figure 6 is a view showing the structure and shape of one layer of an antenna structure according to a first exemplary embodiment.

[0028] Figure 7 is a view showing the connection relationship between antenna segments in an antenna structure according to a first exemplary embodiment.

[0029] Figure 8 is a view showing the voltage depending on the position in an antenna structure according to an exemplary embodiment.

[0030] Figure 9 is a view showing a layer antenna of an antenna structure according to an exemplary embodiment.

[0031] Figure 10 is a view showing a layer antenna of an antenna structure according to another exemplary embodiment.

[0032] Figure 11 is a view showing an antenna structure according to a second exemplary embodiment.

[0033] Figure 12 is a view showing an antenna structure according to a third exemplary embodiment.

[0034] Figure 13 is a view showing an antenna structure according to a fourth exemplary embodiment.

[0035] Figure 14 (a) of is a view showing a unit antenna according to an exemplary embodiment.

[0036] Figure 14 (b) of is a plan view of a unit antenna according to an exemplary embodiment.

[0037] Figure 15 (a) shows a view of an antenna structure composed of unit antennas according to an exemplary embodiment.

[0038] Figure 15 (b) is a plan view of the antenna structure according to an exemplary embodiment.

[0039] Figure 16 (a) is a plan view of a unit antenna according to another exemplary embodiment.

[0040] Figure 16 (b) is a plan view of an antenna structure composed of unit antennas according to another exemplary embodiment.

[0041] Figure 17 is a plan view of a unit antenna according to another exemplary embodiment.

[0042] Figure 18 is a plan view of an antenna structure composed of unit antennas according to another exemplary embodiment.

[0043] Figure 19 shows a view of a capacitor module according to an exemplary embodiment.

[0044] Figure 20 shows a view of a capacitor module inserted between unit antennas according to an exemplary embodiment.

[0045] Figure 21 is a diagram of a gas reforming system according to an exemplary embodiment.

[0046] Figure 22 is a diagram of a pretreatment unit according to an exemplary embodiment.

[0047] Figure 23 shows a view of a plasma induction system for gas reforming according to an exemplary embodiment.

[0048] Figure 24 shows a flowchart of a plasma reforming method according to an exemplary embodiment.

[0049] Figure 25 shows a view of a main antenna structure with different adjusted parasitic capacitances according to an exemplary embodiment.

[0050] Figure 26 shows a view of a lower swirl generator according to an exemplary embodiment. Detailed Description

[0051] According to an embodiment, an antenna structure provided around a side periphery of a discharge tube is provided, and the discharge tube provides a space in which plasma is generated. The antenna structure includes: n unit antennas including a first unit antenna to an nth unit antenna, where n is a natural number greater than or equal to 2, and each of the n unit antennas includes: a first arcuate section (acr section) having a first radius of curvature and including a first end and a second end, a second arcuate section having a second radius of curvature and including a third end and a fourth end, and an arc connection section connecting the second end of the first arcuate section and the third end of the second arcuate section, where the mth unit antenna and the (m + 1)th unit antenna are arranged such that an angle formed by a first virtual line and a second virtual line is 360 / n degrees, where the first virtual line connects the center of the discharge tube and the arc connection section of the mth unit antenna, where the second virtual line connects the center of the discharge tube and the arc connection section of the (m + 1)th unit antenna, where the mth unit antenna and the (m + 1)th unit antenna are adjacent, and m is a natural number less than n, and where the first radius of curvature is different from the second radius of curvature.

[0052] The first radius of curvature corresponds to the side periphery of the discharge tube, and the second radius of curvature has a value greater than the first radius of curvature.

[0053] The first arcuate section has a first central angle, and the first central angle is equal to or less than 360 / n degrees.

[0054] The second arcuate section has a second central angle, and the second central angle is less than the first central angle.

[0055] n is a natural number greater than or equal to 3, m is a natural number less than (n - 1), and when the (m + 2)th unit antenna and the (m + 1)th unit antenna are adjacent, the fourth end of the second arcuate section of the mth unit antenna and the first end of the first arcuate section of the (m + 2)th unit antenna are electrically connected.

[0056] An inter-turn capacitor is electrically inserted between the fourth end of the second arcuate section of the mth unit antenna and the first end of the first arcuate section of the (m + 2)th unit antenna.

[0057] The n unit antennas are arranged in a first plane to form a first layer antenna.

[0058] The first radius of curvature is less than the second radius of curvature, the first arcuate sections of the first to nth unit antennas constitute the inner turn of the first layer antenna to surround the discharge tube, and the second arcuate sections of the first to nth unit antennas constitute the outer turn of the first layer antenna to surround the inner turn.

[0059] n antennas are arranged clockwise or counterclockwise in a first plane, and a second arc section of the m-th unit antenna is arranged to surround at least a part of a first arc section of the (m + 1)-th unit antenna.

[0060] The antenna structure further includes: a second-layer antenna, which is composed of p unit antennas different from the n unit antennas, where p is a natural number greater than or equal to 2. The second-layer antenna is arranged in a second plane spaced a predetermined distance from the first plane. One unit antenna among the n unit antennas and one unit antenna among the p unit antennas are electrically connected through an interlayer capacitor.

[0061] n is 3. A fourth end of a second arc section of a first unit antenna is connected to a first end of a first arc section of a third unit antenna through a first inter-turn capacitor, and a fourth end of a second arc section of the third unit antenna is connected to a first end of a first arc section of a second unit antenna through a second inter-turn capacitor.

[0062] According to one embodiment, a method for reforming a gas using a plasma induction system is provided. The plasma induction system includes: a discharge tube, an ignition antenna structure surrounding the discharge tube, a main antenna structure surrounding the discharge tube and arranged to be spaced apart from the ignition antenna structure, a first RF generator configured to apply power to the ignition antenna structure, a second RF generator configured to apply power to the main antenna structure, an auxiliary gas inlet tube for allowing an auxiliary gas to flow into the discharge tube, an exhaust port for discharging the gas inside the discharge tube, and an outlet for discharging the reformed gas inside the discharge tube. The method includes: injecting the auxiliary gas into the discharge tube; applying power to the ignition antenna structure so that a plasma is excited inside the discharge tube; applying power to the main antenna structure so that the ignited plasma is maintained when a first pre-configured condition is met; injecting the gas to be reformed into the discharge tube; stopping the injection of the auxiliary gas; discharging the gas in the discharge tube until a second preset condition is met; and discharging the synthesis gas in which the gas to be reformed has been reformed by the plasma.

[0063] Through the following detailed description with reference to the accompanying drawings, the above objects, features, and advantages of the present disclosure will become more apparent. Since the present disclosure can be modified in various ways and has various embodiments, specific embodiments will be shown in the drawings and described in detail in the detailed description.

[0064] In the drawings, for clarity, the thicknesses of layers and regions are enlarged. Further, it should be understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element or layer, or intervening layers or intervening elements may be present therebetween. Throughout the specification, like reference numerals in principle denote like elements. Additionally, in the drawings of each embodiment, elements having the same function within the same scope are described using the same reference numerals, and redundant explanations will be omitted.

[0065] The numbers (e.g., first, second, etc.) used to describe the present disclosure are merely identification symbols for distinguishing one element from other elements.

[0066] In addition, the terms "module" and "unit" used for elements in the following description are given or mixed and are used only for ease of preparing the specification, and do not have a meaning or function for distinguishing from each other per se.

[0067] In the following embodiments, the singular form is intended to include the plural form unless the context clearly indicates otherwise.

[0068] In the following embodiments, terms such as "comprising" or "having" mean the presence of the features or components described herein, without excluding the possibility of adding one or more other features or components.

[0069] For ease of description, the dimensions of components may be enlarged or reduced. For example, the dimensions and thicknesses of the components shown in the drawings are provided selectively, and the present disclosure is not necessarily limited thereto.

[0070] When an embodiment can be implemented in another way, a specific process may be performed in a different order from that described. For example, two processes described in sequence may be performed substantially simultaneously, or may be performed in the reverse order of that described.

[0071] In the following embodiments, when a film, region, or component is connected, it includes not only the case where the film, region, and component are directly connected, but also the case where the film, region, and component are indirectly connected with other films, regions, and components therebetween.

[0072] For example, in the specification, when a film, region, and component are electrically connected, it includes not only the case where the film, region, and component are directly electrically connected, but also the case where the film, region, and component are indirectly electrically connected with another film, region, and component therebetween.

[0073] [Organizational terms]

[0074] The present invention relates to an antenna structure. More specifically, the present invention relates to an antenna structure designed to improve the durability and efficiency of a plasma induction system.

[0075] In this specification, plasma processing is a process of generating plasma and using the generated plasma, and is used for semiconductor processes, display processes, nano processes, environmental improvement, etc. In this specification, as plasma processing, semiconductor processes such as plasma ashing, plasma chemical vapor deposition (CVD), plasma etching, sputtering, surface modification, etc. are described as main examples, but the technical idea of the present disclosure is not limited thereto.

[0076] Plasma is a phase in which matter is decomposed into electrons with negative charges and ions with positive charges due to high energy applied thereto, and can be excited or generated in various ways. Inductively coupled plasma is plasma generated by an induced electric field or a capacitive electric field formed in a specific space by power supplied to a coil or an antenna, and can generally be driven by high-frequency power such as radio frequency (RF). At the same time, for ease of description, it is assumed hereinafter that the plasma generated by the plasma generation system is inductively coupled plasma, but the technical idea of the present disclosure is not limited thereto.

[0077] An antenna structure including the above antenna may refer to an object that receives electric power and forms an induced electric field or a capacitive electric field for plasma generation. The antenna structure can be designed in various ways according to the purpose and specifications of the plasma induction system, and the shape or structure of the antenna structure may have a significant impact on the efficiency or durability of the plasma induction system.

[0078] [Plasma Induction System]

[0079] Hereinafter, with reference to Figure 1 the plasma induction system and its configuration will be described.

[0080] Figure 1 is a diagram of a plasma induction system 100 according to an exemplary embodiment.

[0081] With reference to Figure 1 , the plasma induction system 100 may include an RF generator 1000, an antenna structure 2000, and a discharge tube 3000.

[0082] The RF generator 1000 may supply electric power to the antenna structure 2000. For example, the RF generator 1000 may apply alternating current power having a specific driving frequency to the antenna structure 2000. Here, the alternating current power may be understood to mean alternating current or alternating voltage.

[0083] The RF generator 1000 can monitor the impedance of the antenna structure 2000 and / or the electric power applied to the antenna structure 2000. Specifically, the RF generator 1000 can obtain information about the current or voltage flowing through the antenna structure 2000, as described below.

[0084] The RF generator 1000 can change the drive frequency of the alternating current power supplied to the antenna structure 2000. The RF generator 1000 can change the drive frequency of the supplied alternating current power based on the impedance of the antenna structure 2000 and / or the electric power applied to the antenna structure 2000.

[0085] The antenna structure 2000 can be electrically connected to the RF generator 1000. For example, one end of the RF generator 1000 can be electrically connected to one end of the antenna structure 2000, and the other end of the RF generator 1000 can be electrically connected to the other end of the antenna structure 2000. The RF generator 1000 can be connected to the antenna structure 2000 through separate electrical components.

[0086] In the present disclosure, one end or the other end can refer to the end of an object, but is not limited to only meaning the endpoint of the object or must include the endpoint. For example, electrically connecting one end of the antenna structure 2000 and one end of the RF generator 1000 can mean that any one endpoint of the antenna structure 2000 or a portion adjacent to the endpoint is connected to a terminal of the RF generator 1000 through a conductor such as a wire. Additionally, one end or the other end can refer to the end of a part of an object, and this can be understood as the endpoint of the part, a part including the endpoint, or a part spaced a predetermined distance from the endpoint.

[0087] As described above, one end or the other end can be an expression representing a part of an object, and such an expression itself can not limit the structure or property of the object or the connection relationship between the objects. For example, when the antenna structure 2000 is composed of multiple antenna segments and one end of one antenna segment is connected to the other end of another antenna segment, the two antenna segments can be integrally formed as one body or can be implemented in a physically separable form.

[0088] The antenna structure 2000 can form an electromagnetic field within the discharge tube 3000 and excite plasma generation. For example, the antenna structure 2000 can form an electromagnetic field inside the discharge tube 3000 by receiving electric power from the RF generator 1000, and can then excite plasma generation. More specifically, the electromagnetic field formed by the antenna structure 2000 inside the discharge tube 3000 can periodically change its direction due to the alternating current supplied by the RF generator 1000, and the gas supplied to the discharge tube 3000 can receive energy through the periodically changing electromagnetic field and can undergo a phase change to plasma.

[0089] The antenna structure 2000 can substantially have a coil-like shape around the outer surface of a discharge tube (or a dielectric tube).

[0090] However, even when a power supply for high frequency and high power and for plasma formation can be supplied to the antenna structure, the antenna structure can have a specially designed structure for its purpose, the generation of plasma, and the maintenance of plasma density.

[0091] The antenna structure 2000 can have a layered structure. For example, the same or very similar structures can be stacked in the longitudinal direction of the discharge tube (or the dielectric tube).

[0092] One layer of the antenna structure 2000 can be composed of multiple turns. For example, one layer of the antenna structure 2000 can be composed of two turns. Alternatively, one layer of the antenna structure 2000 can be composed of three or more turns.

[0093] The antenna structure 2000 can include at least one capacitive element. For example, multiple antennas constituting the antenna structure 2000 can be electrically connected to each other through the capacitive element. In addition, the antenna structure 2000 can also include a capacitive element connected to the RF generator 1000.

[0094] Meanwhile, the capacitive element described in the present disclosure can represent an electric condenser, a capacitor, a multilayer ceramic capacitor, a supercapacitor, or an equivalent circuit of a capacitive element having a function of storing electric energy.

[0095] The discharge tube 3000 can create an environment for exciting plasma. For example, the discharge tube 3000 can define an internal space for exciting plasma.

[0096] The discharge tube 3000 can provide a space for exciting plasma generation. The discharge tube 3000 can have a tube shape (or a hollow cylindrical shape). However, the shape of the discharge tube 3000 is not limited to the tube shape, and any shape can be sufficient when it includes an internal space for generating plasma.

[0097] A gas for generating plasma (e.g., NF3, Ar, CO2, CH4, O2, He, and / or H2) can flow into the discharge tube 3000. For example, the discharge tube 3000 can be fluidly connected to at least one gas storage unit, and the gas can flow into the discharge tube 3000 from the gas storage unit through a mass flow controller (MFC).

[0098] The discharge tube 3000 can be made of various materials. For example, the discharge tube 3000 can be made of a non-conductive material or a material with high thermal conductivity. Specifically, the discharge tube 3000 can be made of aluminum nitride (AlN), aluminum oxide (Al2O3), silicon nitride (SiN), silicon nitride (Si3N4), silicon dioxide (SiO2), yttrium oxide (Y2O3), or silicon carbide (SiC). In addition, the discharge tube 3000 can be made of a material that does not generate particles for plasma induction by reacting with the gas flowing into the discharge tube 3000.

[0099] The discharge tube 3000 can be fluidly connected to the process chamber. Here, the process chamber defines the space where the plasma process is performed, and it can be understood as the chamber into which the results (e.g., active species) generated in the discharge tube 3000 can flow. For example, the discharge tube 3000 and the process chamber can be connected by a conduit, and the fluid can move from the discharge tube 3000 to the process chamber through the conduit.

[0100] The internal environment of the discharge tube 3000 can be controlled. Specifically, the temperature or pressure inside the discharge tube 3000 can be controlled to have an appropriate value or be maintained within a specific range for plasma induction. To this end, the discharge tube 3000 can include a temperature control unit such as a heating wire or a thermoelectric element. In addition, the discharge tube 3000 can include a pressure control unit for controlling the internal pressure. The pressure control unit can control the internal pressure of the discharge tube 3000 by monitoring the pressure inside the discharge tube 3000 and discharging the gas inside the discharge tube 3000.

[0101] The discharge tube 3000 can be connected to an exhaust port and an outlet port.

[0102] The exhaust port can perform the function of supplying the gas inside the discharge tube 3000 to an external exhaust system. In other words, when the discharge tube 3000 and the external exhaust system are fluidly connected to each other through the exhaust port and there is gas to be discharged from the discharge tube 3000, the exhaust pump can be operated so that the gas in the discharge tube 3000 is transferred to the exhaust system.

[0103] The outlet port can mean the passage through which the gas (such as active species or synthesis gas) reformed by the plasma in the discharge tube 3000 is discharged. The outlet port is connected to the chamber where the wafer is located in the semiconductor plasma process or to the post-processing part of the gas reforming system described later, and serves as the passage for supplying the gas reformed in the discharge tube 3000 to the necessary location.

[0104] Hereinafter, the above-mentioned RF generator 1000 and antenna structure 2000 will be described in more detail.

[0105] [RF Generator]

[0106] Figure 2 is a view showing a radio frequency (RF) generator according to an embodiment of the present disclosure.

[0107] Referring Figure 2 , the RF generator 1000 may include an alternating current (AC) power supply 1100, a rectifier 1200, an inverter 1300, a sensor module 1400, and a controller 1500. The RF generator 1000 may convert a first AC power supplied from the AC power supply 1100 into a second AC power and supply the second AC power to a load. For example, the RF generator 1000 may convert the first AC power used in a general household or industry into a second AC power having a frequency of several hundred kHz to several tens of MHz and a magnitude of several kW or more, and supply the second AC power to the load.

[0108] The load may include a plasma generator 2000 and a plasma generated by the plasma generator 2000. The load may have a resonance frequency that varies over time according to plasma induction.

[0109] The rectifier 1200 may convert the output of the AC power supply 1100 into direct current (DC). The rectifier 1200 may convert the first AC power supplied from the AC power supply 1100 into DC power and apply the DC power to both ends of the inverter 1300. At the same time, in this specification, DC power may be interpreted to mean DC or a DC voltage.

[0110] The inverter 1300 may receive DC power from the rectifier 1200 and supply a second AC power to the load. For example, the inverter 1300 may receive a switching signal from the controller 1500 and may supply the second AC power to the load using the received switching signal.

[0111] The inverter 1300 may include at least one switching element controlled by a switching signal, and the second AC power supplied from the inverter 1300 to the load may have a driving frequency set based on the switching signal provided from the controller 1500 to the inverter 1300.

[0112] For example, the inverter 1300 may be implemented in a full-bridge type. Specifically, the inverter 1300 may include first to fourth switches S1, S2, S3, and S4. The first to fourth switches S1, S2, S3, and S4 may be turned on or off by receiving a switching signal from the controller 1500. When the first switch S1 and the third switch S3 are turned on and the second switch S2 and the fourth switch S4 are turned off, a positive voltage may be applied to the load, and when the first switch S1 and the third switch S3 are turned off and the second switch S2 and the fourth switch S4 are turned on, a negative voltage may be applied to the load. As described above, the inverter 1300 alternately applies a positive voltage and a negative voltage to the load, thereby being able to apply an AC power having a specific frequency.

[0113] The method of implementing the inverter 1300 is not limited to the above method and may mean a configuration including a circuit structure that performs the function of converting DC power into AC power.

[0114] Depending on the frequency control method, the inverter 1300 can be controlled, for example, in a time delay type, a Pulse Width Modulation (PWM) type, or a combination thereof.

[0115] Meanwhile, a capacitive element can be provided between the rectifier 1200 and the inverter 1300. For example, the RF generator 1000 includes a capacitor connected in parallel with the rectifier 1200 and the inverter 1300, and this capacitor can release the AC component of the power applied to the inverter 1300 to the ground node GND.

[0116] The controller 1500 can generate a switching signal. Specifically, the controller 1500 can generate the above switching signal by receiving data sensed from the sensor module 1400 described later. For example, the controller 1500 can be implemented to generate a switching signal by obtaining data related to the resonance frequency (such as the current and voltage of the load) from the sensor module 1400. Specifically, the controller 1500 can generate a switching signal based on obtaining phase difference data or a delay time using the phase data of the current applied to the load and the phase data of the voltage applied to the load obtained from the sensor module 1400.

[0117] Depending on hardware, software, or a combination thereof, the controller 1900 can be implemented as a device such as a central processing unit (CPU), a microprocessor, a processor core, a multiprocessor, an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA).

[0118] The sensor module 1400 can obtain data related to the resonance frequency of the load or data related to the power supplied to the load from the controller 1500.

[0119] Although not shown in Figure 2 the sensor module 1400 can include a current transformer, a filter, and a comparator. The sensor module 1400 can receive the current or voltage signal flowing through the current transformer to the load, convert the current or voltage signal into a current or voltage signal with a different magnitude, filter the converted current or voltage using the filter, and output the phase data to the controller 1500 through the comparator.

[0120] The current transformer can be inductively coupled to the wire between the inverter 1300 and the load, and can convert and supply the voltage or current signal applied to the load to the filter. Specifically, the current transformer can convert the current flowing through the wire connected to the load into a voltage signal.

[0121] The filter can remove the DC component from the input current or voltage signal, and then output the current or voltage signal to the comparator. To this end, the filter can perform high-pass filtering or low-pass filtering.

[0122] The comparator can obtain phase data. For example, the comparator can obtain phase data by comparing the voltage signal obtained from the current transformer or the filter with a preset value. The phase data can refer to the phase data of the current applied to the load.

[0123] Of course, at least one component included in the sensor module 1400 can be omitted and can be implemented in another way.

[0124] As described above, the RF generator 1000 can control the driving frequency of the second AC power supplied to the load based on the data on the resonant frequency of the load. In other words, the RF generator 1000 can track the resonant frequency of the load that changes according to plasma generation, and can output the driving frequency of the second AC power to correspond to the resonant frequency of the load. Therefore, unnecessary power consumption can be prevented, and the durability of the plasma system can be improved.

[0125] Meanwhile, although Figure 2 not shown in the figure, the RF generator 1000 can include a memory. The memory can store various data. The various data can be stored in the memory temporarily or semi-permanently. For example, the memory can be a hard disk drive (HDD), a solid state drive (SSD), a flash memory, a read-only memory (ROM), a random access memory, etc. The memory can be implemented in a type that is set in the RF generator 1000 or detachably attached to the RF generator 1000.

[0126] In addition, the RF generator 1000 can include an input unit for receiving an input from a user. The input unit can receive a user input from the user. The user input can be in various forms, including key input, touch input, and voice input. The input unit can be a comprehensive concept, which can include not only traditional types such as a keypad, a keyboard, and a mouse, but also a touch sensor that can detect a user's touch, and various other types of input devices that can detect or receive various forms of user input.

[0127] In addition, the RF generator 1000 may include an output unit for providing information to a user. The output unit may output information about the state of the plasma induction system 100 (e.g., sensor values measured by the sensor module 1400, the driving frequency of the RF generator 1000, the temperature of the antenna structure 2000, etc.), and may provide information to the user. The output unit may be a general concept that includes a display for outputting an image, a speaker for outputting sound, a haptic device for generating vibration, and various other types of output devices.

[0128] At least one of the components of the above RF generator 1000 may be omitted. For example, in the case of not including the sensor module 1400, the RF generator 1000 may obtain electrical data about the load from an external sensor. Again, for example, in the case of not including the AC power supply 1100 and the rectifier 1200, the RF generator 1000 may receive DC power or rectified DC power from an external source.

[0129] [Antenna Structure]

[0130] Figure 3 is a view showing an antenna structure 2000 and a discharge tube 3000 according to an exemplary embodiment.

[0131] Referring to Figure 3 , the antenna structure 2000 may be disposed around the discharge tube 3000. For example, the antenna structure 2000 may have an annular shape and may be arranged to surround the discharge tube 3000.

[0132] The antenna structure 2000 may be composed of multiple turns. For example, the antenna structure 2000 may include a first antenna disposed to surround the discharge tube 3000 with a first radius of curvature in a first plane and a second antenna disposed to surround the first antenna with a second radius of curvature greater than the first radius of curvature in the first plane. The antenna structure 2000 may not always be composed of two turns, and the antenna structure 2000 may be composed of m turns (or m layers, where m is a natural number greater than 1).

[0133] The antenna structure 2000 may be composed of multiple layers. For example, the antenna structure 2000 may include a first antenna disposed to surround the discharge tube 3000 with a first radius of curvature in a first plane and a second antenna disposed to surround the discharge tube 3000 with the first radius of curvature in a second plane different from the first plane. Herein, the first antenna and the second antenna may have different radii of curvature. The antenna structure 2000 may not always be composed of two layers, and the antenna structure 2000 may be composed of n layers (n is a natural number greater than 1). In this case, the antenna shapes of each layer in the antenna structure 2000 may be substantially the same.

[0134] The antenna structure 2000 may be composed of multiple turns and multiple layers. For example, the antenna structure 2000 may include: a first antenna arranged to surround the discharge tube 3000 in a first plane with a first radius of curvature; a second antenna arranged to surround the first antenna in the first plane with a second radius of curvature greater than the first radius of curvature; a third antenna arranged to surround the discharge tube 3000 in a second plane with the first radius of curvature; and a fourth antenna arranged to surround the third antenna in the second plane with the second radius of curvature. Herein, the first antenna and the third antenna may have different radii of curvature, and the second antenna and the fourth antenna may also have different radii of curvature. In this case, the antenna shape of each layer may be substantially the same.

[0135] The antenna structure 2000 may include at least one antenna as described above, and at least each antenna may include at least one antenna segment. The structure or shape of the antenna structure 2000 may vary according to the interconnection relationship between the above-mentioned multiple antenna segments. The structure and shape of the antenna structure 2000 will be described in detail later.

[0136] Meanwhile, depending on the type of process using plasma, the antenna structure 2000 may be required to increase the discharge holding force and induced electromotive force required for plasma formation. For example, the amount of reaction gas used in the process may be reduced to increase the purity of the process product or reduce the process cost.

[0137] In this case, in order to maintain the existing discharge performance, it is necessary to increase the frequency or scale of the electric power applied to the antenna structure 2000, resulting in problems such as arc faults between antenna segments, breakage of the discharge tube 3000 due to an increase in the voltage of the antenna structure 2000, and a decrease in efficiency due to ion loss.

[0138] In addition, the size of the discharge tube 3000 may be determined according to the scale or specification of the plasma induction system 100. For example, depending on the size of the plasma induction system 100, the diameter of the discharge tube 3000 may be classified as less than 20 mm, 20 mm to 80 mm, more than 80 mm, etc. The magnitude of the electric power applied to the antenna structure 2000 and / or the driving frequency of the electric power may vary in order to excite plasma according to the diameter of the discharge tube 3000.

[0139] At this time, as the diameter of the discharge tube 3000 may increase, the magnitude of the electric power applied to the antenna structure 2000 and / or the driving frequency of the electric power may increase, resulting in an increase in the voltage in the portion of the antenna structure 2000 adjacent to the discharge tube 3000, and resulting in ion loss generated by the plasma inside the discharge tube 3000 and damage to the inner wall of the discharge tube 3000.

[0140] Since the durability, efficiency, and stability of the plasma induction system 100 may be hindered, it is necessary to prevent the above problems.

[0141] In the present disclosure, the configuration and structure of the antenna structure 2000 will be described, which can meet the requirements of the above plasma process and accordingly minimize the occurrence of problems.

[0142] [Problems of Existing Antenna Structures]

[0143] Hereinafter, reference will first be made to Figure 4 and Figure 5 to describe the problems of existing antenna structures.

[0144] Figure 4 and Figure 5 are views respectively showing conventional antenna structures 10 and 20. Figure 4 and Figure 5 both show the conventional antenna structures 10 and 20 arranged to surround the discharge tube 3000, and specifically show a cross-section perpendicular to the central axis of the discharge tube 3000. Additionally, although not shown in Figure 4 and Figure 5 , the conventional antenna structures 10 and 20 are electrically connected to the RF generator 1000. Therefore, a specific voltage (or current) is applied to the conventional antenna structures 10 and 20, and Figure 4 and Figure 5 show graphs of the voltage applied according to the positions in the conventional antenna structures 10 and 20 (positions according to the rotation angle based on the center point CP).

[0145] Referring to Figure 4 , the first conventional antenna structure 10 may include an internal antenna surrounding the discharge tube 3000 and an external antenna surrounding the internal antenna, and the internal antenna and the external antenna are connected to each other. Specifically, the internal antenna may extend from point A to point B along the outer diameter surface of the discharge tube 3000, the external antenna may extend from point C to point D, and point B of the internal antenna and point C of the external antenna are connected to each other. In addition, although not shown here, point A and point D of the first conventional antenna structure 10 may be respectively connected to both ends of the RF generator 1000, such that the first conventional antenna structure 10 can receive voltage from the RF generator 1000.

[0146] Referring to Figure 4, when voltage V2 is applied to both ends of the first conventional antenna structure 10 based on the ground voltage V0, voltage V0 to voltage V1 can be applied from point A to point B of the internal antenna of the first conventional antenna structure 10, and voltage V1 to voltage V2 can be applied from point C to point D of the external antenna of the first conventional antenna structure 10. Here, voltage V1 can be understood as the intermediate value of voltage V0 and voltage V2, and when V0 is 0V, voltage V1 can correspond to 1 / 2 of the value of voltage V2. Therefore, when voltage is applied to the first conventional antenna structure 10, the magnitude of the voltage can increase from the internal antenna to the external antenna. When the voltage applied to the first conventional antenna structure 10 increases, the voltages applied to the internal antenna and the external antenna may also increase, such that the electric field strength formed inside the discharge tube 3000 by the internal antenna may increase, and ion loss and damage to the discharge tube 3000 may be inevitable.

[0147] Reference Figure 5 , the second conventional antenna structure 20 may include an internal antenna surrounding the discharge tube 3000 and an external antenna surrounding the internal antenna, and the internal antenna and the external antenna may be connected to each other through a capacitive element. Specifically, the internal antenna extends from point A to point B along the outer diameter surface of the discharge tube 3000, the external antenna extends from point C to point D, and point B of the internal antenna and point C of the external antenna are respectively connected to both ends of the capacitive element. Additionally, although not shown here, point A and point D of the second conventional antenna structure 20 may be connected to both ends of the RF generator 1000, such that the second conventional antenna structure 20 can receive voltage from the RF generator 1000.

[0148] The antenna is an inductive element and may have different characteristics from the capacitive element. In particular, when a positive voltage is applied to the antenna through an AC power supply, a negative voltage may be applied to the capacitive element, and when a negative voltage is applied to the antenna through an AC power supply, a positive voltage may be applied to the capacitive element. In other words, when a voltage increase occurs in the antenna, a voltage drop may occur in the capacitive element, and when a voltage drop occurs in the antenna, a voltage increase may occur in the capacitive element. Additionally, the capacitance reactance of the capacitive element can be determined based on the inductive reactance of the internal antenna and the inductive reactance of the external antenna, such that the voltage applied to the internal antenna or the external antenna can correspond to the voltage applied to the capacitive element.

[0149] Reference Figure 5, when a voltage V2 is applied to both ends of the second conventional antenna structure 20 based on the ground voltage V0, the voltage V0 can be applied to the voltage V1 from point A to point B of the internal antenna of the second conventional antenna structure 20, and similarly, the voltage V0 can be applied to the voltage V1 from point C to point D of the external antenna of the second conventional antenna structure 20. Here, the voltage V1 can be understood as an intermediate value between the voltage V0 and the voltage V2. Since a voltage drop or a voltage rise occurs in the capacitive element provided between the internal antenna and the external antenna, voltages of substantially the same magnitude can be applied to the internal antenna and the external antenna of the second conventional antenna structure 20 according to the position.

[0150] However, as the magnitude of the voltage applied to the second conventional antenna structure 20 increases, the magnitude of the voltage applied to the internal antenna also increases, and compared with Figure 4 the first conventional antenna structure 10, the intensity of the electric field formed inside the discharge tube 3000 may not change significantly, so the problems of ion loss and damage to the discharge tube 3000 may still exist.

[0151] [New Design - First Exemplary Embodiment]

[0152] Hereinafter, the antenna structure 2000 according to the first exemplary embodiment will be described with reference to Figures 6 to 9 to reduce the intensity of the electric field formed in the discharge tube 3000.

[0153] As described above, the antenna structure 2000 can be provided on the outer surface of the discharge tube 3000 and can receive alternating current to form an electric field and a magnetic field in the internal space of the discharge tube 3000. In addition, the gas flowing into the discharge tube 3000 can be ionized by the electric field and magnetic field formed by the antenna structure 2000 and can collide with each other to generate plasma.

[0154] As described above, the antenna structure 2000 can be implemented in the form of a coil surrounding the discharge tube 3000. In addition, the antenna structure 2000 can be composed of m turns and n layers, and each turn can include x antenna segments. Hereinafter, for the sake of explanation, the antenna structure 2000 can be composed of two turns and seven layers, and each turn can include three antenna segments, but the technical idea of the present disclosure is not limited thereto.

[0155] Each layer of the antenna structure 2000 may include at least an internal antenna located close to the discharge tube 3000 and an external antenna located farther than the internal antenna based on the discharge tube 3000.

[0156] In addition, adjacent layers in the antenna structure 2000 can be electrically connected to each other. For example, the external antenna of the first layer and the internal antenna of the second layer can be electrically connected to each other in the antenna structure 2000. In this case, adjacent layers in the antenna structure 2000 can be connected by conductors or interlayer capacitive elements.

[0157] Hereinafter, reference will be made to Figure 6 and Figure 7 to describe the shape and structure of each layer of the antenna structure 2000 according to the first exemplary embodiment.

[0158] Figure 6 is a view showing the structure and shape of a layer of the antenna structure 2000 according to the first exemplary embodiment.

[0159] A layer of the antenna structure 2000 can be composed of a plurality of antenna segments. For example, the antenna structure 2000 can include a plurality of internal antenna segments and a plurality of external antenna segments. Specifically, with reference to Figure 6 , a layer of the antenna structure 2000 can include first to third internal antenna segments 2110, 2210, and 2310 and first to third external antenna segments 2120, 2220, and 2320.

[0160] The first to third internal antenna segments 2110, 2210, and 2310 can be disposed adjacent to the discharge tube 3000 to form an internal antenna. As Figure 6 shown, the first to third internal antenna segments 2110, 2210, and 2310 can have a radius of curvature corresponding to the outer diameter of the discharge tube 3000 and can be disposed in the same plane, rotating 120° with respect to the center point CP of the discharge tube 3000.

[0161] The first to third external antenna segments 2120, 2220, and 2320 can be disposed to surround the internal antenna to form an external antenna. For example, as Figure 6 shown, the first external antenna segment 2120 can be disposed outside the third internal antenna segment 2310, the second external antenna segment 2220 can be disposed outside the first internal antenna segment 2110, and the third external antenna segment 2320 can be disposed outside the second internal antenna segment 2210. The first to third external antenna segments 2120, 2220, and 2320 can be disposed on the same plane, rotating 120° with respect to the center point CP of the discharge tube 3000.

[0162] In Figure 6Among them, the first to third internal antenna segments 2110, 2210, and 2310 can be set when rotating in the clockwise direction, and the first to third external antenna segments 2120, 2220, and 2320 can also be set when rotating in the clockwise direction. However, the internal antenna segments and the external antenna segments can be set when rotating in the counterclockwise direction. As will be described later, each of the internal antenna segments and the external antenna segments can respectively have a radius of curvature, a central angle, and a length.

[0163] The first internal antenna segment 2110 has an arc shape, and the radius of curvature of the first internal antenna segment 2110 can be designed in consideration of the outer diameter of the discharge tube 3000. For example, the radius of curvature of the first internal antenna segment 2110 can be substantially the same as the outer diameter of the discharge tube 3000, so that the first internal antenna segment 2110 is set to contact the discharge tube 3000. Again, for example, the radius of curvature of the first internal antenna segment 2110 can be greater than the outer diameter of the discharge tube 3000, so that the first internal antenna segment 2110 is set and spaced apart from the discharge tube 3000 by a certain distance.

[0164] The second internal antenna segment 2210 has an arc shape, and the radius of curvature of the second internal antenna segment 2210 can be designed in consideration of the outer diameter of the discharge tube 3000. For example, the radius of curvature of the second internal antenna segment 2210 can be substantially the same as the outer diameter of the discharge tube 3000, so that the second internal antenna segment 2210 is set to contact the discharge tube 3000. Again, for example, the radius of curvature of the second internal antenna segment 2210 can be greater than the outer diameter of the discharge tube 3000, so that the second internal antenna segment 2210 is set and spaced apart from the discharge tube 3000 by a certain distance.

[0165] The third internal antenna segment 2310 can have an arc shape, and the radius of curvature of the third internal antenna segment 2310 can be designed in consideration of the outer diameter of the discharge tube 3000. For example, the radius of curvature of the third internal antenna segment 2310 can be substantially the same as the outer diameter of the discharge tube 3000, so that the third internal antenna segment 2310 is set to contact the discharge tube 3000. Again, for example, the radius of curvature of the third internal antenna segment 2310 can be greater than the outer diameter of the discharge tube 3000, so that the third internal antenna segment 2310 is set and spaced apart from the discharge tube 3000 by a certain distance.

[0166] The radii of curvature of the first to third internal antenna segments 2110, 2210, and 2310 can be substantially the same. Needless to say, the first to third internal antenna segments 2110, 2210, and 2310 can have different radii of curvature.

[0167] Each of the first to third internal antenna segments 2110, 2210, and 2310 may have a central angle of less than 120°. Each central angle of the first to third internal antenna segments 2110, 2210, and 2310 may be more than 90°. The central angles of the first to third internal antenna segments 2110, 2210, and 2310 may be substantially the same. Needless to say, the first to third internal antenna segments 2110, 2210, and 2310 may have central angles of different sizes.

[0168] The first to third internal antenna segments 2110, 2210, and 2310 may have substantially the same length. The sum of the lengths of the first to third internal antenna segments 2110, 2210, and 2310 may be less than the length of a circumference with a radius equal to the radius of curvature of any one of the internal antenna segments. Needless to say, the first to third internal antenna segments 2110, 2210, and 2310 may have different lengths.

[0169] The first external antenna segment 2120 may have an arc shape, and the radius of curvature of the first external antenna segment 2120 may be designed in consideration of the radius of curvature of the third internal antenna segment 2310. For example, the radius of curvature of the first external antenna segment 2120 may be greater than the radius of curvature of the third internal antenna segment 2310 to maintain a predetermined interval from the third internal antenna segment 2310.

[0170] The second external antenna segment 2220 may have an arc shape, and the radius of curvature of the second external antenna segment 2220 may be designed in consideration of the radius of curvature of the first internal antenna segment 2110. For example, the radius of curvature of the second external antenna segment 2220 may be greater than the radius of curvature of the first internal antenna segment 2110 to maintain a predetermined interval from the first internal antenna segment 2110.

[0171] The third external antenna segment 2320 may have an arc shape, and the radius of curvature of the third external antenna segment 2320 may be designed in consideration of the radius of curvature of the second internal antenna segment 2210. For example, the radius of curvature of the third external antenna segment 2320 may be greater than the radius of curvature of the second internal antenna segment 2210 to maintain a predetermined interval from the second internal antenna segment 2210.

[0172] The radii of curvature of the first to third external antenna segments 2120, 2220, and 2320 may be substantially the same. Needless to say, the first to third external antenna segments 2120, 2220, and 2320 may have different radii of curvature.

[0173] Each of the first to third external antenna segments 2120, 2220, and 2320 may have a central angle of less than 120°. Each central angle of the first to third external antenna segments 2120, 2220, and 2320 may be more than 90°. The central angles of the first to third external antenna segments 2120, 2220, and 2320 may be substantially the same. Needless to say, the first to third external antenna segments 2120, 2220, and 2320 may have central angles of different sizes.

[0174] Meanwhile, the central angles of the first to third external antenna segments 2120, 2220, and 2320 may be less than the central angles of the first to third internal antenna segments 2110, 2210, and 2310. Accordingly, it is possible to prevent one end of the internal antenna segment or a part extending therefrom and a part connecting the antenna segments from overlapping the external antenna segments.

[0175] The first to third external antenna segments 2120, 2220, and 2320 may have substantially the same length. The sum of the lengths of the first to third external antenna segments 2120, 2220, and 2320 may be less than the length of a circumference having a radius equal to the radius of curvature of any one of the external antenna segments. Needless to say, the first to third external antenna segments 2120, 2220, and 2320 may have different lengths from each other.

[0176] [Connection relationship between internal antenna and external antenna]

[0177] Figure 7 is a view showing the connection relationship between antenna segments in the antenna structure 2000 according to the first exemplary embodiment.

[0178] Refer to Figure 7 , the first to third internal antenna segments 2110, 2210, and 2310 may be connected to the first to third external antenna segments 2120, 2220, and 2320 in the following manner.

[0179] The first internal antenna segment 2110 may be electrically connected to the first external antenna segment 2120. The other end 2112 of the first internal antenna segment may be electrically connected to one end 2121 of the first external antenna segment. The other end 2112 of the first internal antenna segment may be connected to one end 2121 of the first external antenna segment through a first connection section. Herein, the first connection section may be implemented as a U shape, but is not limited thereto.

[0180] Meanwhile, one end 2111 of the first internal antenna segment may be electrically connected to one end of the RF generator 1000. In this case, the first auxiliary capacitance element SC1 may be electrically inserted between one end 2111 of the first internal antenna segment and the RF generator 1000.

[0181] The first external antenna segment 2120 may be electrically connected to the second internal antenna segment 2210. The other end 2122 of the first external antenna segment may be electrically connected to one end 2211 of the second internal antenna segment. The other end 2122 of the first external antenna segment may be connected to one end 2211 of the second internal antenna segment through the first inter-turn capacitance element ITC1.

[0182] The second internal antenna segment 2210 may be electrically connected to the second external antenna segment 2220. The other end 2212 of the second internal antenna segment may be electrically connected to one end 2221 of the second external antenna segment. The other end 2212 of the second internal antenna segment may be connected to one end 2221 of the second external antenna segment through the second connection section. Here, the second connection section may be implemented as a U shape, but is not limited thereto.

[0183] The second external antenna segment 2220 may be electrically connected to the third internal antenna segment 2310. The other end 2222 of the second external antenna segment may be electrically connected to one end 2311 of the third internal antenna segment. The other end 2222 of the second external antenna segment may be connected to one end 2311 of the third internal antenna segment through the second inter-turn capacitance element ITC2.

[0184] The third internal antenna segment 2310 may be electrically connected to the third external antenna segment 2320. The other end 2312 of the third internal antenna segment may be electrically connected to one end 2321 of the third external antenna segment. The other end 2312 of the third internal antenna segment may be connected to one end 2321 of the third external antenna segment through the third connection section. Here, the third connection section may be implemented as a U shape, but is not limited thereto.

[0185] Meanwhile, the other end 2322 of the third external antenna segment may be electrically connected to an antenna segment of another layer. However, when the antenna structure 2000 is configured as one layer, the other end 2322 of the third external antenna segment may be electrically connected to the other end of the RF generator 1000. In this case, the second auxiliary capacitance element SC2 may be electrically inserted between the other end 2322 of the third external antenna segment and the RF generator 1000. However, either the first auxiliary capacitance element SC1 or the second auxiliary capacitance element SC2 may be omitted.

[0186] When the antenna segments in the antenna structure 2000 are connected as described above, the first internal antenna segment 2110, the first external antenna segment 2120, the first inter-turn capacitance element ITC1, the second internal antenna segment 2210, the second external antenna segment 2220, the second inter-turn capacitance element ITC2, the third internal antenna segment 2310, and the third external antenna segment 2320 may be connected in series in this order based on the RF generator 1000.

[0187] The first external antenna segment 2120 and the first inter-turn capacitance element ITC1 are electrically inserted between the first internal antenna segment 2110 and the second internal antenna segment 2210.

[0188] In addition, the second external antenna segment 2220 and the second inter-turn capacitance element ITC2 can be electrically inserted between the second internal antenna segment 2210 and the third internal antenna segment 2210.

[0189] In addition, the second inter-turn capacitance element ITC2 and the third internal antenna segment 2310 can be electrically inserted between the second external antenna segment 2220 and the third external antenna segment 2320.

[0190] [New antenna structure voltage]

[0191] Hereinafter, reference will be made to Figure 8 describe the voltage applied to the antenna segments within the antenna structure 2000.

[0192] Figure 8 is a view showing the voltage according to the position within the antenna structure 2000 according to an exemplary embodiment.

[0193] Reference Figure 8 , the antenna structure 2000 can be implemented in a form in which the first internal antenna segment 2110, the first external antenna segment 2120, the first inter-turn capacitance element ITC1, the second internal antenna segment 2210, the second external antenna segment 2220, the second inter-turn capacitance element ITC2, the third internal antenna segment 2310, and the third external antenna segment 2320 are connected in series in order as Figure 6 and Figure 7 shown.

[0194] Meanwhile, it is assumed that a voltage V2 is applied to both ends of the antenna structure 2000 based on the voltage V0 in order to compare with Figure 4 and Figure 5 the conventional antenna structures 10 and 20. In addition, it is assumed that the voltage applied to each antenna segment in the antenna structure 2000 is substantially the same, and the inductance of the antenna segment and the capacitance of the inter-turn capacitance element are appropriately selected such that the sum of the rising voltages in the antenna segment corresponds to the sum of the falling voltages in the inter-turn capacitance element, or the sum of the falling voltages in the antenna segment corresponds to the sum of the rising voltages in the inter-turn capacitance element. For example, the values of the total combined inductance of the antenna segments and the total combined capacitance of the capacitance elements can be set to satisfy the condition that the resonance frequency becomes the basic driving frequency.

[0195] Reference Figure 8 , a voltage V4 can be applied to both ends of the first to third internal antenna segments 2110, 2210, and 2310 based on the voltage V0. In addition, a voltage V3 can be applied to both ends of the first to third external antenna segments 2120, 2220, and 2320 based on the voltage V4.

[0196] When, for ease of calculation, the voltage V0 is 0V, the voltage V3 can be a value that is 1 / 3 of the voltage V2, and this is because the layer antenna is divided into three parts based on the inter-turn capacitance elements, and substantially the same voltage is distributed to each part.

[0197] In addition, the voltage V4 can be a value that is an intermediate value between the voltage V3 and the voltage V0, and this is because substantially the same voltage is applied to the internal antenna segment and the external antenna segment. This means that when the voltage V0 is 0V, the voltage V4 is a value that is 1 / 6 of the voltage V2.

[0198] Meanwhile, the voltage V3 can be understood as a value lower than the voltage V1 because in a conventional antenna structure, the voltage V1 corresponds to a value of 1 / 2 of the voltage V2. In addition, the maximum value of the voltage applied to the first to third internal antenna segments 2110, 2210, and 2310 that constitute the internal antenna is V4, which is also significantly lower than the maximum value V1 of the voltage applied to the internal antenna in the conventional antenna structures 10 and 20.

[0199] Therefore, when comparing the antenna structure 2000 according to an exemplary embodiment of the present disclosure with the conventional antenna structures 10 and 20, the potential difference generated between the antenna segments of the antenna structure 2000 can be reduced, arc discharge within the antenna structure 2000 can be prevented, ion loss for plasma induction can be reduced, the degree of wear on the inner surface of the discharge tube 3000 adjacent to the antenna structure 2000 due to ion bombardment can be reduced, and the parasitic resistance between the antenna segments can be reduced, thereby improving the reliability and efficiency of the system.

[0200] [Layer connection_series]

[0201] Hereinafter, reference will be made to Figure 9 Describe a method of arranging layer antennas located on different layers in the antenna structure 2000 and a process of connecting the layer antennas to each other.

[0202] Figure 9 is a view showing the layer antennas of the antenna structure 2000 according to an exemplary embodiment.

[0203] When the antenna structure 2000 can be composed of multiple layers, the layer antenna can refer to an antenna provided on each layer, and can include Figure 6 the multiple antenna segments described in Figure 7 and each antenna segment is connected in the manner described in

[0204] The antenna structure 2000 according to an exemplary embodiment of the present disclosure may be composed of multiple layers and may include layer antennas provided in each layer. Hereinafter, for ease of explanation, a method of connecting two adjacent layer antennas to each other will be described, and other layer antennas may also be connected in the same manner.

[0205] Referring Figure 9 , the antenna structure 2000 may at least include a first layer antenna 2001 and a second layer antenna 2002.

[0206] The first layer antenna 2001 and the second layer antenna 2002 may be electrically connected to each other. For example, any one external antenna segment of the first layer antenna 2001 and any one internal antenna segment of the second layer antenna 2002 may be electrically connected to each other. Specifically, the third external antenna segment 2320 of the first layer antenna 2001 and the fourth internal antenna segment 2410 of the second layer antenna 2002 may be electrically connected to each other. In this case, the other end 2322 of the third external antenna segment of the first layer antenna may be electrically connected to one end 2411 of the fourth internal antenna segment of the second layer antenna.

[0207] The first layer antenna 2001 and the second layer antenna 2002 may be connected to each other through a capacitive element. For example, an inter layer capacitive element (ILC) may be electrically inserted between the other end 2322 of the third external antenna segment of the first layer antenna and one end 2411 of the fourth internal antenna segment of the second layer antenna.

[0208] The first layer antenna 2001 and the second layer antenna 2002 may be connected to each other through a conductor.

[0209] The second layer antenna 2002 and the third layer antenna may be electrically connected to each other by using the method of connecting the first layer antenna 2001 and the second layer antenna 2002. Similarly, the third layer antenna and the fourth layer antenna, the fourth layer antenna and the fifth layer antenna, the fifth layer antenna and the sixth layer antenna, and the sixth layer antenna and the seventh layer antenna may be electrically connected respectively.

[0210] The first layer antenna to the seventh layer antenna may be provided on the first plane to the seventh plane respectively. The intervals between the first to seventh planes may be set to be the same. Alternatively, the intervals between the first to seventh planes may be set to be different as needed.

[0211] Each layer antenna in the first layer antenna 2001 and the seventh layer antenna can be electrically connected to the RF generator 1000. For example, one end 2111 of the first internal antenna segment of the first layer antenna can be electrically connected to one end of the RF generator 1000, and the other end of the third external antenna segment of the seventh layer antenna can be electrically connected to the other end of the RF generator 1000. In this case, the first auxiliary capacitance element SC1 can be electrically inserted between one end 2111 of the first internal antenna segment of the first layer antenna and the RF generator 1000. In addition, the second auxiliary capacitance element SC2 can be electrically inserted between the other end of the third external antenna segment of the seventh layer antenna and the other end of the RF generator 1000. However, either the first auxiliary capacitance element SC1 or the second auxiliary capacitance element SC2 can be omitted.

[0212] As described above, each layer antenna in the antenna structure 2000 can include at least two inter-turn capacitance elements. At the same time, the inter-turn capacitance elements may be relatively large compared to the layer antennas. For example, the inter-turn capacitance element can have a preset height in the longitudinal direction of the discharge tube 3000, and the height of the inter-turn capacitance element can be greater than the distance between the layer antennas or the spacing between the planes of each layer antenna.

[0213] When the height of the inter-turn capacitance element is relatively large and the adjacent layer antennas are arranged in the same phase, the distance between the inter-turn capacitance elements may become narrow, resulting in interference or physical collision. Therefore, it may be necessary to set the layer antennas according to specific rules described later.

[0214] The adjacent layer antennas of the antenna structure 2000 can be arranged to be spaced apart from each other by up to a preset rotation angle. Refer to Figure 8 , the second layer antenna 2002 can be arranged to rotate approximately 30° relative to the first layer antenna 2001. Specifically, when the first layer antenna 2001 rotates 0° based on the reference line, the second layer antenna 2002 can rotate approximately 30° based on the reference line.

[0215] Similarly, adjacent layer antennas among the first layer antenna to the seventh layer antenna can be arranged in a state where they are spaced apart from each other by up to 30° with respect to the reference line. Thus, it is possible to prevent the inter-turn capacitance elements of each layer antenna from colliding with or interfering with each other. Specifically, when the layer antennas are arranged according to the above rules, the inter-turn capacitance elements of the first layer antenna 2001 can be rotated by approximately 120° and approximately 240° respectively based on the reference line, and the inter-turn capacitance elements of the fifth layer antenna can be arranged while being rotated by approximately 240° and approximately 360° respectively. Here, the inter-turn capacitance element of the first layer antenna rotated by approximately 240° based on the reference line and the inter-turn capacitance element of the fifth layer antenna rotated by approximately 240° based on the reference line can be in the same phase with each other, but the first layer antenna and the fifth layer antenna can be sufficiently spaced apart from each other to prevent interference or physical collision between the inter-turn capacitance elements of the first layer antenna and the inter-turn capacitance elements of the fifth layer antenna.

[0216] The rotation angle by which adjacent layer antennas can be spaced apart from each other is determined based on the size (e.g., height) of the inter-turn capacitance element, the spacing distance between the layer antennas (or the spacing between the planes on which the layer antennas are arranged), the number of antenna segments per turn constituting the layer antenna, and / or the size (e.g., thickness of the antenna segment) of the layer antenna.

[0217] For example, when the number of antenna segments per turn constituting the layer antenna is x, the rotation angle can be determined to be less than or equal to (180 / x)°. Specifically, when the height of the inter-turn capacitance element is greater than twice the spacing distance between the layer antennas and the number of antenna segments per turn constituting the layer antenna is 3, the rotation angle can be determined to be less than 60°.

[0218] As another example, when the number of layer antennas constituting the antenna structure 2000 is y, the rotation angle can be determined to be less than or equal to (180 / (y - 1))°. Specifically, when the number of layer antennas constituting the antenna structure 2000 is 7, the rotation angle can be determined to be less than or equal to 30°.

[0219] When the layer antennas within the antenna structure 2000 are connected as described above, all components of the antenna structure 2000 in a series connection state can be electrically connected to the RF generator 1000.

[0220] At this time, in the first layer antenna 2001, as Figure 8 shown by the distributed voltage, and the voltage applied to the internal antenna segment adjacent to the discharge tube 3000 can be relatively low.

[0221] In addition, by connecting the first layer antenna 2001 and the second layer antenna 2002 to each other through an inter-layer capacitance element (ILC), it is possible to Figure 8A voltage distribution is performed in the second-layer antenna 2002 as in the first-layer antenna 2001, where the external antenna segments and the internal antenna segments are connected to each other through inter-turn capacitance elements.

[0222] As a result, the voltage applied to the internal antenna segments of each layer antenna in the antenna structure 2000 can be relatively low, thereby preventing ion loss or damage to the inner wall of the discharge tube 3000 as described above, and improving the durability, efficiency, and stability of the plasma induction system 100.

[0223] [Layer connection - Parallel]

[0224] Hereinafter, another method of connecting layer antennas located on different layers in the antenna structure 2000 will be described with reference to Figure 10 the description of connecting layer antennas located on different layers in the antenna structure 2000.

[0225] As Figure 9 described, when the antenna structure 2000 is composed of multiple layers, the layer antennas can refer to the antennas provided on each layer, and can include Figure 6 the multiple antenna segments shown, and each antenna segment can be connected to each other in the Figure 7 described manner.

[0226] Hereinafter, for the sake of convenience of explanation, a method of connecting two adjacent layer antennas to each other will be described, and other layer antennas can also be connected in the same manner.

[0227] Referring to Figure 10 , the antenna structure 2000 can include at least a first-layer antenna 2001 and a second-layer antenna 2002.

[0228] The first-layer antenna 2001 can include first to third internal antenna segments 2110, 2210, and 2310 constituting the internal antenna and first to third external antenna segments 2120, 2220, and 2320 constituting the external antenna. The second-layer antenna 2002 can include fourth to sixth internal antenna segments 2410, 2510, and 2610 constituting the internal antenna and fourth to sixth external antenna segments 2420, 2520, and 2620 constituting the external antenna.

[0229] The antenna structure 2000 can further include first to third inter-layer capacitance elements ILC1, ILC2, and ILC3 inserted between the layer antennas.

[0230] The first-layer antenna 2001 and the second-layer antenna 2002 can be electrically connected to each other. For example, any one antenna segment of the first-layer antenna 2001 can be electrically connected to the corresponding antenna segment of the second-layer antenna 2002. Specifically, the external antenna segments of the first-layer antenna 2001 and the internal antenna segments of the second-layer antenna 2002 can be connected one-to-one.

[0231] The first-layer antenna 2001 and the second-layer antenna 2002 can be connected in parallel in the following manner.

[0232] First, the first external antenna segment 2120 of the first-layer antenna 2001 can be electrically connected to the fifth internal antenna segment 2510 of the second-layer antenna 2002. Specifically, the other end 2122 of the first external antenna segment and one end 2511 of the fifth internal antenna segment can be electrically connected to each other.

[0233] The first interlayer capacitance element ILC1 can be electrically inserted between the other end 2122 of the first external antenna segment and one end 2511 of the fifth internal antenna segment. In other words, the first external antenna segment 2120 and the fifth internal antenna segment 2510 can be connected to each other through the first interlayer capacitance element ILC1.

[0234] Meanwhile, when one end 2111 of the first internal antenna segment is electrically connected to one end of the RF generator 1000 and the other end 2522 of the fifth external antenna segment is electrically connected to the other end of the RF generator 1000, the RF generator 1000, the first internal antenna segment 2110, the first external antenna segment 2120, the first interlayer capacitance element ILC1, the fifth internal antenna segment 2510, and the fifth external antenna segment 2520 can form a first closed circuit.

[0235] Alternatively, when the antenna structure 2000 is implemented with three or more layers, the fifth external antenna segment 2520 can be electrically connected to the internal antenna segment on the next layer in the same manner, and similarly, the corresponding antenna segments on each layer can be electrically connected. Finally, the external antenna segment of the last layer can be electrically connected to the RF generator 1000 to form a first closed circuit.

[0236] The second external antenna segment 2220 of the first-layer antenna 2001 can be electrically connected to the sixth internal antenna segment 2610 of the second-layer antenna 2002. Specifically, the other end 2222 of the second external antenna segment and one end 2611 of the sixth internal antenna segment can be electrically connected to each other.

[0237] The second interlayer capacitance element ILC2 can be electrically inserted between the other end 2222 of the second external antenna segment and one end 2611 of the sixth internal antenna segment. In other words, the second external antenna segment 2220 and the sixth internal antenna segment 2610 can be connected to each other through the second interlayer capacitance element ILC2.

[0238] Meanwhile, when one end 2211 of the second internal antenna segment is electrically connected to one end of the RF generator 1000 and the other end 2622 of the sixth external antenna segment is electrically connected to the other end of the RF generator 1000, the RF generator 1000, the second internal antenna segment 2210, the second external antenna segment 2220, the second interlayer capacitance element ILC2, the sixth internal antenna segment 2610, and the sixth external antenna segment 2620 can be sequentially connected in series to form a second closed circuit.

[0239] Alternatively, when the antenna structure 2000 is implemented with three or more layers, the sixth external antenna segment 2620 is electrically connected to the corresponding internal antenna segment on the next layer in the same manner, and similarly, the corresponding antenna segments on each layer can be electrically connected to each other. Finally, the external antenna segment of the last layer can be electrically connected to the RF generator 1000 to form a second closed circuit.

[0240] The third external antenna segment 2320 of the first-layer antenna 2001 can be electrically connected to the fourth internal antenna segment 2410 of the second-layer antenna 2002. Specifically, the other end 2322 of the third external antenna segment and one end 2411 of the fourth internal antenna segment can be electrically connected to each other.

[0241] The third interlayer capacitance element ILC3 can be electrically inserted between the other end 2322 of the third external antenna segment and one end 2411 of the fourth internal antenna segment. In other words, the third external antenna segment 2320 and the fourth internal antenna segment 2410 can be connected to each other through the third interlayer capacitance element ILC3.

[0242] Meanwhile, when one end 2311 of the third internal antenna segment is electrically connected to one end of the RF generator 1000 and the other end 2422 of the fourth external antenna segment is electrically connected to the other end of the RF generator 1000, the RF generator 1000, the third internal antenna segment 2310, the third external antenna segment 2320, the third interlayer capacitance element ILC3, the fourth internal antenna segment 2410, and the fourth external antenna segment 2420 can form a first closed circuit.

[0243] Alternatively, when the antenna structure 2000 is implemented with three or more layers, the fourth external antenna segment 2420 can be electrically connected to the internal antenna segment on the next layer in the same manner, and similarly, the corresponding antenna segments on each layer can be electrically connected to each other. Finally, the external antenna segment of the last layer can be electrically connected to the RF generator 1000 to form a third closed circuit.

[0244] A plurality of closed circuits can be formed between the antenna structure 2000 and the RF generator 1000. Here, the number of closed circuits to be formed can be the same as the number of antenna segments constituting one turn. For example, as described above, when one turn of the antenna structure 2000 is composed of three antenna segments, first to third closed circuits can be formed between the antenna structure 2000 and the RF generator 1000, and each closed circuit can be connected in parallel with each other based on the RF generator 1000.

[0245] At this time, when looking at each closed circuit, it can be observed that the sequential connection of the internal antenna segments, external antenna segments, and capacitive elements is repeated according to the number of layers. This ultimately means that the voltage distribution described in Figure 8 can be achieved in each closed circuit, and in addition, it means that a relatively low voltage can be applied to the internal antenna segments.

[0246] Therefore, the voltage applied to the internal antenna segments of each layer of the antenna can be relatively low, thereby preventing ion loss or damage to the inner wall of the discharge tube 3000, and improving the durability, efficiency, and stability of the plasma induction system 100.

[0247] As described above, the antenna segments can be connected in series with each other to form a closed circuit, and can be connected in parallel with each other to form a plurality of closed circuits. In the series connection method and the parallel connection method, the resonance conditions according to the total inductance and total capacitance of the antenna structure 2000 may not change significantly, so the driving frequency of the electric power applied to the antenna structure 2000 may not change significantly. At the same time, although the impedance of the antenna structure 2000 from the RF generator 1000 changes according to the connection method. Therefore, even if the same power is applied to the antenna structure 2000, the amount of current flowing into the antenna structure 2000 may vary. For example, when the antenna structure 2000 has the same number of layers and the same number of turns, the parallel connection method can have a smaller resistance component than the series connection method, so when higher power consumption is preferred under the same input voltage, the parallel connection method can be adopted.

[0248] However, different from that described in Figure 9 , any layer of the antenna of the antenna structure 2000 can be arranged in a way that is in phase with another adjacent layer of the antenna. For example, referring to Figure 10 , when the antenna structure 2000 is composed of seven layers, the first layer of the antenna 2001 and the second layer of the antenna 2002 can maintain the same angle (for example, 0°) with respect to the reference line. At the same time, as shown in Figure 9 , the adjacent layers of the antenna in the antenna structure 2000 can also be spaced apart by up to a preset rotation angle from each other.

[0249] [New Design - Second Exemplary Embodiment]

[0250] Hereinafter, reference will be made toFigure 11 Describe another type of antenna structure 2000. Unless otherwise specified below, the content of the antenna structure 2000 according to the first exemplary embodiment described in Figures 6 to 9 can be applied in the same manner.

[0251] Figure 11 is a view showing the antenna structure 2000 according to the second exemplary embodiment.

[0252] Refer to Figure 11 , the antenna structure 2000 may include a first internal antenna segment 2110, a second internal antenna segment 2210, a first external antenna segment 2120, and a second external antenna segment 2220. The first internal antenna segment 2110 and the second internal antenna segment 2120 may form an internal antenna, and the first external antenna segment 2120 and the second external antenna segment 2220 may form an external antenna.

[0253] Each of the first internal antenna segment 2110 and the second internal antenna segment 2210 may have a central angle of less than 180°. The central angle of each of the first internal antenna segment 2110 and the second internal antenna segment 2210 may be 120° or more. Needless to say, the first internal antenna segment 2110 and the second internal antenna segment 2210 may have central angles of different sizes.

[0254] Each of the first external antenna segment 2120 and the second external antenna segment 2220 may have a central angle of less than 180°. The central angle of each of the first external antenna segment 2120 and the second external antenna segment 2220 may be 120° or more. Needless to say, the first external antenna segment 2120 and the second external antenna segment 2220 may have central angles of different sizes.

[0255] Meanwhile, the central angles of the first external antenna segment 2120 and the second external antenna segment 2220 may be smaller than the central angles of the first internal antenna segment 2110 and the second internal antenna segment 2210. Therefore, it is possible to prevent one end of the internal antenna segment or a portion extending therefrom and a portion connecting the antenna segments from overlapping with the external antenna segment.

[0256] In the antenna structure 2000 according to the second exemplary embodiment, the antenna segments may be connected in parallel to the RF generator 1000 in the following manner.

[0257] The first internal antenna segment 2110 can be electrically connected to the RF generator 1000 and the first external antenna segment 2120. Specifically, one end 2111 of the first internal antenna segment can be electrically connected to one end of the RF generator 1000, and the other end 2112 of the first internal antenna segment can be connected to one end 2121 of the first external antenna segment. In this case, the first auxiliary capacitance element SC1 can be electrically inserted between one end 2111 of the first internal antenna segment and one end of the RF generator 1000.

[0258] The first external antenna segment 2120 can be electrically connected to the RF generator 1000 and the first internal antenna segment 2110. Specifically, one end 2121 of the first external antenna segment can be connected to the other end 2112 of the first internal antenna segment, and the other end 2122 of the first external antenna segment can be connected to the other end of the RF generator 1000. In this case, the second capacitance element SC2 can be electrically inserted between the other end 2122 of the first external antenna segment and the other end of the RF generator 1000.

[0259] The second internal antenna segment 2210 can be electrically connected to the RF generator 1000 and the second external antenna segment 2220. Specifically, one end 2211 of the second internal antenna segment can be connected to one end of the RF generator 1000, and the other end 2212 of the second internal antenna segment can be connected to one end 2221 of the second external antenna segment. In this case, the first auxiliary capacitance element SC1 can be electrically inserted between one end 2211 of the second internal antenna segment and one end of the RF generator 1000.

[0260] The second external antenna segment 2220 can be connected to the RF generator 1000 and the second internal antenna segment 2210. Specifically, one end 2221 of the second external antenna segment can be connected to the other end 2212 of the second internal antenna segment, and the other end 2222 of the second external antenna segment can be connected to the other end of the RF generator 1000. In this case, the second auxiliary capacitance element SC2 can be electrically inserted between the other end 2222 of the second external antenna segment and the other end of the RF generator 1000.

[0261] Although the antenna structure 2000 according to the second exemplary embodiment has been described above as being implemented as a single layer, the technical idea of the present disclosure is not limited thereto, and the antenna structure 2000 according to the second exemplary embodiment may include a multi-layer antenna, and each layer antenna may be designed to have the above structure. In this case, each layer antenna can be through Figure 9 or Figure 10connected by the method described in. For example, the other end 2122 of the first external antenna segment can be electrically connected to one end of any internal antenna segment on another layer through the first interlayer capacitance element ILC1, and the other end 2222 of the second external antenna segment can also be electrically connected to one end of any internal antenna segment on another layer through the second interlayer capacitance element ILC2.

[0262] As described above, the RF generator 1000, the first internal antenna segment 2110, and the first external antenna segment 2120 can form a closed circuit, and the RF generator 1000, the second internal antenna segment 2210, and the second external antenna segment 2220 can form another closed circuit. In other words, the antenna structure 2000 and the RF generator 1000 can form a parallel circuit.

[0263] When the number of turns of the antenna structure 2000 is even and the number of antenna segments constituting each turn is even, the antenna structure 2000 and the RF generator 1000 can be connected in parallel to have at least two or more closed circuits.

[0264] In such a parallel connection structure, the resistance component of the antenna structure 2000 can be reduced as described above, so that power consumption can be greatly obtained even under a low applied voltage. In particular, in the case of the second exemplary embodiment, the antenna structure 2000 can be configured by a series connection method, but it can be particularly implemented by a parallel connection method. More specifically, in the antenna structure 2000 according to the second exemplary embodiment, not only the antenna segments in each layer are symmetric, but also the antenna segments in all layers are symmetric, so that the impedance can be stably managed even when the plasma induced in the discharge tube 3000 is biased to either side.

[0265] In addition, when the antenna structure 2000 and the RF generator 1000 are electrically connected through the above parallel connection structure, the voltage applied to the internal antenna adjacent to the discharge tube 3000 can be relatively reduced without using a capacitance element.

[0266] For example, when the voltage V2 based on the voltage V0 is applied to the antenna structure 2000 through the two ends P and Q of the RF generator 1000 in Figure 10 , the voltage V0 to V1 can be applied to the first internal antenna segment 2110 and the second internal antenna segment 2210, and the voltage V1 to V2 can be applied to the first external antenna segment 2210 and the second external antenna segment 2220.

[0267] [New Design - Third Exemplary Embodiment]

[0268] Hereinafter, another type of antenna structure 2000 will be described with reference to Figure 12 Unless otherwise specified below, according to Figures 6 to 9The content of the antenna structure 2000 of the first exemplary embodiment described in [reference] can be applied in the same manner.

[0269] Figure 12 is a view showing the antenna structure 2000 according to the third exemplary embodiment.

[0270] Referring to Figure 12 , the antenna structure 2000 may include first to fourth internal antenna segments 2110, 2210, 2310, and 2410 constituting an internal antenna, first to fourth external antenna segments 2120, 2220, 2320, and 2420 constituting an external antenna, and first and second inter-turn capacitance elements ITC1 and ITC2.

[0271] Each of the first to fourth internal antenna segments 2110, 2210, 2310, and 2410 may have a central angle of less than 90°. The central angle of each of the first to fourth internal antenna segments 2110, 2210, 2310, and 2410 may be 72° or more. The first to fourth internal antenna segments 2110, 2210, 2310, and 2410 may have central angles of different sizes.

[0272] Each of the first to fourth external antenna segments 2120, 2220, 2320, and 2420 may have a central angle of less than 90°. The central angle of each of the first to fourth external antenna segments 2120, 2220, 2320, and 2420 may be 72° or more. The first to fourth external antenna segments 2120, 2220, 2320, and 2420 may have central angles of different sizes.

[0273] Meanwhile, the central angles of the first to fourth external antenna segments 2120, 2220, 2320, and 2420 may be smaller than the central angles of the first to fourth internal antenna segments 2110, 2210, 2310, and 2410. Accordingly, it is possible to prevent one end of the internal antenna segment or a portion extending therefrom and a portion connecting the antenna segments from overlapping the external antenna segment.

[0274] In the antenna structure 2000 according to the third exemplary embodiment, the antenna segments may be connected in parallel to the RF generator 1000 as follows.

[0275] The first internal antenna segment 2110 may be electrically connected to the RF generator 1000 and the first external antenna segment 2120. Specifically, one end 2111 of the first internal antenna segment may be electrically connected to one end of the RF generator 1000, and the other end 2112 of the first internal antenna segment may be connected to one end 2121 of the first external antenna segment. In this case, a first auxiliary capacitance element SC1 may be electrically inserted between one end 2111 of the first internal antenna segment and one end of the RF generator 1000.

[0276] The first external antenna segment 2120 can be electrically connected to the second internal antenna segment 2210. Specifically, the other end 2122 of the first external antenna segment can be electrically connected to one end 2211 of the second internal antenna segment. In this case, the first inter-turn capacitance element ITC1 can be electrically inserted between the other end 2212 of the first external antenna segment and one end 2211 of the second internal antenna segment.

[0277] The second internal antenna segment 2210 can be electrically connected to the second external antenna segment 2220. Specifically, the other end 2212 of the second internal antenna segment can be connected to one end 2221 of the second external antenna segment.

[0278] The second external antenna segment 2220 can be electrically connected to the RF generator 1000. Specifically, the other end 2222 of the second external antenna segment can be electrically connected to the other end of the RF generator 1000. In this case, the second auxiliary capacitance element SC2 can be electrically inserted between the other end 2222 of the second external antenna segment and the other end of the RF generator 1000.

[0279] The third internal antenna segment 2310 can be electrically connected to the RF generator 1000 and the third external antenna segment 2320. Specifically, one end 2311 of the third internal antenna segment can be electrically connected to one end of the RF generator 1000, and the other end 2312 of the third internal antenna segment can be connected to one end 2321 of the third external antenna segment. In this case, the first auxiliary capacitance element SC1 can be electrically inserted between one end 2311 of the third internal antenna segment and one end of the RF generator 1000.

[0280] The third external antenna segment 2320 can be electrically connected to the fourth internal antenna segment 2410. Specifically, the other end 2322 of the third external antenna segment can be electrically connected to one end 2411 of the fourth internal antenna segment. In this case, the second inter-turn capacitance element ITC2 can be electrically inserted between the other end 2322 of the third external antenna segment and one end 2411 of the fourth internal antenna segment.

[0281] The fourth internal antenna segment 2410 can be electrically connected to the fourth external antenna segment 2420. Specifically, the other end 2412 of the fourth internal antenna segment can be connected to one end 2421 of the fourth external antenna segment.

[0282] The fourth external antenna segment 2420 can be electrically connected to the RF generator 1000. Specifically, the other end 2422 of the fourth external antenna segment can be electrically connected to the other end of the RF generator 1000. In this case, the second auxiliary capacitance element SC2 can be electrically inserted between the other end 2422 of the fourth external antenna segment and the other end of the RF generator 1000.

[0283] Although the antenna structure 2000 according to the third exemplary embodiment is described above as being implemented as a single layer, the technical idea of the present disclosure is not limited thereto, and the antenna structure 2000 according to the third exemplary embodiment may include a plurality of layer antennas, and each layer antenna may be designed to have the above-described structure. In this case, each layer antenna may be connected by Figure 9 or Figure 10 the method described in. For example, the other end 2222 of the second external antenna segment may be electrically connected through a first interlayer capacitance element ILC1 to one end of an antenna segment in the other layer that is in phase with the first internal antenna segment 2110 among the internal antenna segments, and the other end 2422 of the fourth external antenna segment may also be electrically connected through a second interlayer capacitance element ILC2 to one end of an antenna segment in the other layer that is in phase with the third internal antenna segment 2310.

[0284] As described above, the RF generator 1000, the first internal antenna segment 2110, the first external antenna segment 2120, the first inter-turn capacitance element ITC1, the second internal antenna segment 2210, and the second external antenna segment 2220 may form a closed circuit, and the RF generator 1000, the third internal antenna segment 2310, the third external antenna segment 2320, the second inter-turn capacitance element ITC2, the fourth internal antenna segment 2410, and the fourth external antenna segment 2420 may form another closed circuit.

[0285] As described in the second exemplary embodiment, since the antenna structure 2000 according to the third exemplary embodiment has two turns in one layer and four antenna segments form each turn, the antenna structure 2000 and the RF generator 1000 may be connected in parallel with each other to have at least two closed circuits.

[0286] Meanwhile, different from the second exemplary embodiment, since the antenna structure 2000 according to the third exemplary embodiment includes an inter-turn capacitance element, the magnitude of the voltage applied to each antenna segment (especially the first to fourth antenna segments 2110, 2210, 2310, 2410 that form the internal antenna) may be lower than the magnitude of the voltage in the second exemplary embodiment. However, since the antenna structure 2000 according to the third exemplary embodiment additionally includes an inter-turn capacitance element, the design may be more complex than that of the second exemplary embodiment.

[0287] In the above, the case where the antenna structure 2000 includes at least one layer antenna but each layer antenna is composed of two turns and each turn includes two to four antenna segments is mainly described. However, the technical concept of the present disclosure is not limited thereto, and one layer of the antenna structure 2000 may be composed of three or more turns, and each turn may include five or more antenna segments.

[0288] [New Design - Fourth Exemplary Embodiment]

[0289] Hereinafter, reference will be made to Figure 13 to describe another type of antenna structure 2000 formed in the discharge tube 3000. Unless otherwise specified below, the content of the antenna structure 2000 according to the first exemplary embodiment described in Figures 6 to 9 can be applied in the same manner.

[0290] Figure 13 is a view showing the antenna structure 2000 according to the fourth exemplary embodiment. In the antenna structure 2000 according to the fourth exemplary embodiment, the antenna segments can form a three - turn antenna in each layer. Specifically, the intermediate antenna segments can be disposed between the inner antenna segments and the outer antenna segments.

[0291] Referring to Figure 13 , the antenna structure 2000 can include a first inner antenna segment 2110, a second inner antenna segment 2210, a third inner antenna segment 2310, a first intermediate antenna segment 2130, a second intermediate antenna segment 2230, a third intermediate antenna segment 2330, a first outer antenna segment 2120, a second outer antenna segment 2220, and a third outer antenna segment 2320. The first to third inner antenna segments 2110, 2210, and 2310 can form an inner antenna, the first to third intermediate antenna segments 2130, 2230, and 2330 can form an intermediate antenna, and the first to third outer antenna segments 2120, 2220, and 2320 can form an outer antenna.

[0292] In the antenna structure 2000 according to the fourth exemplary embodiment, the antenna segments can be connected in parallel to the RF generator 1000 as follows. The first inner antenna segment 2110, the first intermediate antenna segment 2130, and the first outer antenna segment 2120 can be connected in series and electrically connected to both ends of the RF generator 1000. Additionally, the second inner antenna segment 2210, the second intermediate antenna segment 2230, and the second outer antenna segment 2220 can be connected in series and electrically connected to both ends of the RF generator 1000. Furthermore, the third inner antenna segment 2310, the third intermediate antenna segment 2330, and the third outer antenna segment 2320 can be connected in series and electrically connected to both ends of the RF generator 1000.

[0293] The antenna structure 2000 according to the fourth exemplary embodiment can be composed of a single layer or multiple layers.

[0294] [Shape of Antenna Structure]

[0295] Hereinafter, referring to Figure 14 and Figure 15A method of constructing the antenna structure 2000 using the unit antennas 4100, 4200, and 4300 is described. The following description assumes that the antenna structure 2000 consists of two turns, and each turn has a shape including three antenna segments, as Figure 6 shown.

[0296] Figure 14 is a view showing a unit antenna according to an exemplary embodiment.

[0297] Referring to Figure 14 , the first unit antenna 4100 may include a first connection section 4110, a first arc section 4120, a first arc connection section 4130, a second arc section 4140, and a second connection section 4150.

[0298] The first unit antenna 4100 may be implemented in a manner that integrates the above components. Alternatively, the first unit antenna 4100 may be constructed by assembling the above components (including the interconnecting members).

[0299] As Figure 14 shown, the first connection section 4110, the first arc section 4120, the first arc connection section 4130, the second arc section 4140, and the second connection section 4150 may be arranged in a counterclockwise direction. The above configuration may be arranged in a clockwise direction.

[0300] The first connection section 4110 may refer to the section for electrically connecting the first unit antenna 4100 to an external component. For example, the first connection section 4110 may be electrically connected to any one of the RF generator 1000, another unit antenna in the same layer, or an antenna in another layer.

[0301] At least a part of the first connection section 4110 may not be located in the same plane as the other components of the first unit antenna 4100. At least a part of the first connection section 4110 may be curved. For example, referring to Figure 14 the (a) of

[0302] The first arcuate section 4120 may refer to a part that surrounds at least a portion of the discharge tube 3000 and forms an electric field or a magnetic field inside the discharge tube 3000 by receiving a voltage or a current.

[0303] The first arcuate section 4120 may be understood as corresponding to Figure 6 a part of the first internal antenna section 2110 shown in

[0304] Specifically, the first arcuate section 4120 may have a first radius of curvature, and the first radius of curvature may be designed based on the outer diameter of the discharge tube 3000.

[0305] In addition, the central angle of the first arcuate section 4120 may be designed to be 120° or less and / or 90° or more.

[0306] The first arc connection section 4130 may refer to a part where the first arcuate section 4120 and the second arcuate section 4140 are connected to each other. The first arc connection section 4130 may be understood as corresponding to Figure 7 the configuration of the first connection section described in

[0307] The first arc connection section 4130 may be implemented as a U shape. However, the shape of the first arc connection section 4130 is not limited thereto, and any shape that can connect the first arcuate section 4120 and the second arcuate section 4140 may be sufficient.

[0308] The first arc connection section 4130 may be designed not to collide with the connection section of another unit antenna, as described later.

[0309] Similar to the first arcuate section 4120, the second arcuate section 4140 may have an arcuate shape and may refer to a part that forms an electric field or a magnetic field inside the discharge tube 3000 by receiving a voltage or a current.

[0310] The second arcuate section 4140 is configured to form a part of the external antenna and may have a radius of curvature greater than that of the first arcuate section 4120.

[0311] The second arcuate section 4140 may be understood as corresponding to Figure 6 a part corresponding to the first external antenna section 2120 shown in

[0312] Specifically, the second arc section 4140 may have a second radius of curvature, and the second radius of curvature may be designed in consideration of the first radius of curvature. For example, the second radius of curvature may be set to be larger than the first radius of curvature by a preset size. Alternatively, the second radius of curvature may be designed to be spaced apart from the fifth arc section 4320 of the third unit antenna 4300, which will be described later, by up to a preset distance.

[0313] In addition, the central angle of the second arc section 4140 may be designed to be less than 120° and / or more than 90°.

[0314] The second connection section 4150 may refer to a part for electrically connecting the first unit antenna 4100 to an external component. For example, the second connection section 4150 may be electrically connected to the RF generator 1000, any unit antenna of another unit antenna in the same layer, or an antenna in another layer.

[0315] The second connection section 4150 may be located in the same plane as the first arc section 4120 and the second arc section 4140.

[0316] Alternatively, the second connection section 4150 may include a curved shape similar to the first connection section 4110 described above.

[0317] In this case, at least one of the first connection section 4110 and the second connection section 4150 may include a curved shape. This is used to prevent the first connection section 4110 and the second connection section 4150 from colliding with the arc connection section of another unit antenna, as will be described later.

[0318] Figure 15 is a view showing an antenna structure 2000 composed of unit antennas according to an exemplary embodiment.

[0319] Reference Figure 15 , the antenna structure 2000 may include: a first unit antenna 4100, which includes a first connection section 4110, a first arc section 4120, a first arc connection section 4130, a second arc section 4140, and a second connection section 4150; a second unit antenna 4200, which includes a third connection section 4210, a third arc section 4220, a second arc connection section 4230, a fourth arc section 4240, and a fourth connection section 4250; and a third unit antenna 4300, which includes a fifth connection section 4310, a fifth arc section 4320, a third arc connection section 4330, a sixth arc section 4340, and a sixth connection section 4350.

[0320] As Figure 15As shown, the first to third unit antennas 4100, 4200, and 4300 may have substantially the same shape. Therefore, each configuration of the second unit antenna 4200 and the third unit antenna 4300 may correspond to each configuration of the first unit antenna 4100, and thus duplicate content may be omitted.

[0321] The first to third unit antennas 4100, 4200, and 4300 may be arranged such that the arc sections of each unit antenna may form an inner turn or an outer turn. For example, as Figure 15 shown, the first arc section 4120 of the first unit antenna 4100, the third arc section 4220 of the second unit antenna 4200, and the fifth arc section 4320 of the third unit antenna 4300 may form an inner turn, and the second arc section 4140 of the first unit antenna 4100, the fourth arc section 4240 of the second unit antenna 4200, and the sixth arc section 4340 of the third unit antenna 4300 may form an outer turn.

[0322] The first to third unit antennas 4100, 4200, and 4300 may be arranged to rotate up to a preset angle. For example, the second unit antenna 4200 may be arranged to rotate up to about 120° from the first unit antenna 4100, and the third unit antenna 4300 may be arranged to rotate up to about 120° from the second unit antenna 4200.

[0323] In this case, the angle formed by each arc connection section of adjacent unit antennas among the first to third unit antennas 4100, 4200, and 4300 with respect to the center of the antenna structure 2000 or the center point of the discharge tube 3000 may be specified.

[0324] Here, adjacent unit antennas to each other may mean that each arc connection section of two unit antennas is close together in the clockwise or counterclockwise direction. Alternatively, adjacent unit antennas to each other may mean that the arc sections constituting the inner turn in each unit antenna are adjacent to each other, or the arc sections constituting the outer turn in each unit antenna are adjacent to each other.

[0325] For example, in Figure 15 the first unit antenna 4100 may be considered adjacent to both the second unit antenna 4200 and the third unit antenna 4300, and in this case, the angle formed by the virtual line connecting the first arc connection section 4130 of the first unit antenna 4100 to the center of the discharge tube 3000, the virtual line connecting the second arc connection section 4230 of the second unit antenna 4200 to the center of the discharge tube 3000, or the virtual line connecting the third arc connection section 4330 of the third unit antenna 4300 to the center of the discharge tube 3000 may be about 120°.

[0326] In addition, when the antenna structure 2000 is composed of a plurality of unit antennas, for example, the first to the a-th unit antennas (a is a natural number greater than or equal to 2), in the b-th unit antenna and the (b + 1)-th unit antenna adjacent to each other, the angle formed by the first virtual line connecting the arc connection section of the b-th unit antenna and the center of the discharge tube 3000 and the second virtual line connecting the arc connection section of the (b + 1)-th antenna and the center of the discharge tube 3000 can be about 360 / a° (b is a natural number less than a).

[0327] When the first to the third unit antennas 4100, 4200, and 4300 are rotated and arranged as described above, the shape of each unit antenna can be designed such that there is no collision between the unit antennas. Here, as Figure 15 shown, it is assumed that the first to the third unit antennas 4100, 4200, and 4300 are arranged based on the first to the third reference lines that divide the xy plane into three parts. Although for the sake of easy explanation, the description focuses on the first unit antenna 4100, it should be noted in advance that this also applies to the second unit antenna 4200 and the third unit antenna 4300.

[0328] For example, the first to the third unit antennas 4100, 4200, and 4300 can be designed such that the connection section of one unit antenna does not collide with the arc connection section of another unit antenna. Specifically, any one of the first connection section 4110 of the first unit antenna 4100 and the second arc connection section 4230 of the second unit antenna 4200 can include a bent portion such that the first connection section 4110 of the first unit antenna 4100 and the second arc connection section 4230 of the second unit antenna 4200 do not collide with each other. More specifically, as Figure 15 (a) of shows, the second arc connection section 4230 can be located on the xy plane, and at least a part of the first connection section 4110 can be designed to be bent. Conversely, the first connection section 4110 can be positioned on the xy plane, and the second arc connection section 4230 can be designed to be bent. In addition, the first connection section 4110 of the first unit antenna 4100 can be designed to be spaced from the first reference line by up to a preset distance such that the first connection section 4110 of the first unit antenna 4100 and the second arc connection section 4230 of the second unit antenna 4200 do not collide with each other in the xy plane.

[0329] As another example, the first arc connection section 4130 of the first unit antenna 4100 and the sixth connection section 4250 of the third unit antenna 4300 can be designed not to collide with each other. Specifically, referring to Figure 15 (b) of, the sixth connection section 4250 can be designed to be spaced from the second reference line by up to a preset distance so as not to collide with the first arc connection section 4130.

[0330] In the following, reference will be made to Figure 16 describe another method of configuring the antenna structure 2000 using two unit antennas. In the following, it is assumed that the antenna structure 2000 consists of two turns, and each turn has a shape including two antenna segments, as Figure 11 shown. Therefore, Figure 11 the content described in

[0331] Figure 16 is a view showing a unit antenna according to an exemplary embodiment ( Figure 16 (a)) and an antenna structure 2000 composed of unit antennas 4100 and 4200 ( Figure 16 (b)).

[0332] Referring to Figure 16 (a) of, the first unit antenna 4100 may include a first connection section 4110, a first arc section 4120, a first arc connection section 4130, a second arc section 4140, and a second connection section 4150.

[0333] It can be understood that Figure 16 the first unit antenna 4100 shown in (a) of Figure 14 has the same components as the first unit antenna 4100 shown in

[0334] Specifically, in Figure 16 (a) of, the central angles of the first arc section 4120 and the second arc section 4140 can be designed to be less than 180° and / or greater than or equal to 120°.

[0335] Referring to Figure 16 (b) of, the antenna structure 2000 may be composed of a first unit antenna 4100 and a second unit antenna 4200. The first unit antenna 4100 includes a first connection section 4110, a first arc section 4120, a first arc connection section 4130, a second arc section 4140, and a second connection section 4150. The second unit antenna 4200 includes a third connection section 4210, a third arc section 4220, a second arc connection section 4230, a fourth arc section 4240, and a fourth connection section 4250.

[0336] Referring to Figure 16In (b) of , the first unit antenna 4100 and the second unit antenna 4200 may not be connected in series with each other. Specifically, when the first connection section 4110 of the first unit antenna 4100 is electrically connected to the RF generator 1000, the second connection section 4150 of the first unit antenna 4100 may be connected to the unit antenna of another layer through a capacitive element, or may be electrically connected to the RF generator 1000. Similarly, the third connection section 4250 of the second unit antenna 4200 may be connected to the unit antenna of another layer through a capacitive element, or may be electrically connected to the RF generator 1000.

[0337] The first unit antenna 4100 and the second unit antenna 4200 may be connected in parallel to the RF generator 1000. Alternatively, the first unit antenna 4100 and the second unit antenna 4200 may be connected to different RF generators 1000.

[0338] Hereinafter, with reference to Figure 17 and Figure 18 , another method of constructing the antenna structure 2000 having 3 turns using three unit antennas is described. Hereinafter, it is assumed that the antenna structure 2000 is composed of three turns, and each turn has a shape including three antenna segments, as shown in Figure 13 Therefore, Figure 13 The content described in can be applied to the connection relationship between the antenna segments.

[0339] Figure 17 FIG. is a view showing a unit antenna according to an exemplary embodiment, Figure 18 FIG. is a view showing the antenna structure 2000 composed of unit antennas according to an exemplary embodiment.

[0340] It can be understood that Figure 17 The first unit antenna 4100 shown in further includes Figure 14 The first additional arc section 4170 and the first additional arc connection section 4160 in the first unit antenna 4100 shown in . Therefore, although the content described in Figure 14 can be applied, the connection relationship between the parts of the unit antenna may be changed.

[0341] Specifically, the first unit antenna 4100 may include a first connection section 4110, a first arc section 4120, a first arc connection section 4130, a second arc section 4140, a first additional arc connection section 4160, a first additional arc section 4170, and a second connection section 4150.

[0342] The first arcuate section 4120 may form part of an internal antenna, the second arcuate section 4140 may form part of an intermediate antenna, and the first additional arcuate section 4170 may form part of an external antenna. In other words, the first additional arcuate section 4170 may have a third radius of curvature greater than a first radius of curvature of the first arcuate section 4120 or a second radius of curvature of the second arcuate section 4140.

[0343] In addition, different from that shown in Figure 14 , the second arcuate section 4140 may be connected to the first arc connection section 4130 and the first additional arc connection section 4160. In addition, different from that shown in Figure 14 , the second connection section 4150 may be connected to the first additional arcuate section 4170.

[0344] Referring to Figure 18 , the antenna structure 2000 may be composed of three unit antennas. In this case, Figure 17 the description of the first unit antenna 4100 described in Figure 13 may be applied to each unit antenna as it is. Additionally, Figure 18 the content described in

[0345] [Capacitor Module]

[0346] Hereinafter, a capacitor module 5000 serving as a capacitive element will be described, and in addition, a method of connecting the capacitor module 5000 to a unit antenna will be described with reference to Figures 19 to 20 .

[0347] Figure 19 is a view showing a capacitor module 5000 according to an exemplary embodiment.

[0348] Referring to Figure 19 , the capacitor module 5000 may include at least one capacitor bank 5100, a main body 5200, a heat dissipation part 5300, and a bus bar 5400.

[0349] The capacitor module 5000 is intended to be used as the above-mentioned inter-turn capacitor or inter-layer capacitor, and may be understood as a device for voltage rise or voltage drop by being disposed between antenna segments in the antenna structure 2000.

[0350] The capacitor module 5000 may be implemented in a form in which at least one capacitor bank 5100 is mounted on the main body 5200 and assembled with the heat dissipation part 5300 and the bus bar 5400.

[0351] The capacitor bank 5100 may include at least one capacitor, and the capacitor may be an element that accumulates electrical energy, and various types of capacitors may be used (e.g., electrolytic capacitors, tantalum capacitors, high dielectric capacitors, polyester capacitors, ceramic capacitors, multilayer ceramic capacitors, etc.).

[0352] The main body 5200 may include a substrate on which the capacitor bank 5100 is mounted.

[0353] The main body 5200 may be designed to have a structure in which the heat dissipation part 5300 and the bus bar 5400 are joined.

[0354] The heat dissipation part 5300 may dissipate the heat generated in the capacitor module 5000 to the outside. The heat dissipation part 5300 may include a plurality of heat dissipation fins.

[0355] The bus bar 5400 may be a member for electrically connecting the capacitor module 5000 and the unit antennas of the antenna structure 2000 to each other.

[0356] Meanwhile, the capacitor bank 5100 of the capacitor module 5000 should be electrically inserted between the unit antennas, and the size of the capacitor bank 5100 may not be small enough to be physically positioned between the unit antennas. Therefore, the capacitor bank 5100 should be positioned and spaced from the unit antennas by up to a certain distance, and the bus bar 5400 may need to have the following shape so that the capacitor bank 5100 and the unit antenna 4000 are electrically connected to each other.

[0357] Reference Figure 19 to (b) of, the bus bar 5400 may be divided into a first section 5410, a second section 5420, a third section 5430, and a fourth section 5440.

[0358] The first section 5410 may refer to the section of the bus bar 5400 connected to the capacitor bank 5100. The first section 5410 may include a first fixing hole fixed to the capacitor bank 5100, and may be joined to the main body 5200 through the first fixing hole and a first fixing pin (or a first fixing screw).

[0359] The fourth section 5440 may represent a part of the bus bar 5400 connected to the unit antenna 4000. The fourth section 5440 may include a second fixing hole to be fixed to the unit antenna 4000, and may be joined to any one of the unit antennas through the second fixing hole and a second fixing pin (or a second fixing screw).

[0360] The second section 5420 and the third section 5430 can be understood as sections for connecting the first section 5410 and the fourth section 5440. For example, the second section 5420 can extend from the first section 5410, the third section 5430 can extend from the fourth section 5440, and the second section 5420 and the third section 5430 can be joined such that the capacitor bank 5100 can be electrically connected to the unit antenna 4000 through the bus bar 5400.

[0361] The first section 5410 and the second section 5420 can be integrally formed as one body. The second section 5420 can be bent from the first section 5410 such that the angle between the first section 5410 and the second section 5420 becomes a preset angle (e.g., 90°). Here, the preset angle can be changed as needed.

[0362] The third section 5430 and the fourth section 5440 can be integrally formed as one body. The fourth section 5440 can be bent from the third section 5430 such that the angle between the third section 5430 and the fourth section 5440 becomes a preset angle (e.g., 90°). Here, the preset angle can be changed as needed.

[0363] Each of the second section 5420 and the third section 5430 can include fixing holes and can be joined by fixing pins (or fixing screws). Here, a separate fixing member can be used, and the fixing member can be used as a device for supporting the capacitor module 5000.

[0364] [Engaging with the Capacitor Module and the Unit Antenna]

[0365] Figure 20 is a view showing a capacitor module inserted between unit antennas according to an exemplary embodiment.

[0366] Reference Figure 20 , the antenna structure 2000 can include first to third unit antennas 4100, 4200, and 4300, and can also include first to third capacitor modules 5001, 5002, and 5003.

[0367] The first capacitor module 5001 can be electrically inserted between the first unit antenna 4100 and the second unit antenna 4200. Specifically, the first bus bar of the first capacitor module 5001 can be connected to the second connection section 4150 of the first unit antenna 4100, and the second bus bar of the first capacitor module 5001 can be connected to the third connection section 4210 of the second unit antenna 4200.

[0368] The second capacitor module 5002 can be electrically inserted between the second unit antenna 4200 and the third unit antenna 4300. Specifically, the first bus bar of the second capacitor module 5002 can be connected to the fourth connection section 4250 of the second unit antenna 4200, and the second bus bar of the second capacitor module 5002 can be connected to the fifth connection section 4310 of the third unit antenna 4300.

[0369] The third capacitor module 5003 can be electrically inserted between the third unit antenna 4300 and the unit antenna of another layer. Specifically, the first bus bar of the third capacitor module 5003 can be connected to the sixth connection section 4350 of the third unit antenna 4300, and the second bus bar of the third capacitor module 5003 can be connected to the connection section of the unit antenna of another layer.

[0370] Meanwhile, when the antenna structure 2000 is formed as a single layer, the third capacitor module 5003 can be omitted.

[0371] [Gas reforming system]

[0372] Hereinafter, reference will be made to Figure 21 describe the gas reforming system 10 using the plasma induction system 100.

[0373] Figure 21 is a block diagram of the gas reforming system 10 according to an exemplary embodiment. Referring to Figure 21 , the gas reforming system 10 may include a pre-processor 200, a plasma induction system 100, and a post-processor 300.

[0374] Meanwhile, although Figure 21 not shown in, the gas reforming system 10 may further include a central controller for controlling the pre-processor 200, the plasma induction system 100, and the post-processor 300. The central controller may control a first controller for controlling the pre-processor 200, a second controller for controlling the plasma induction system 100, and a third controller for controlling the post-processor 300.

[0375] Gas reforming may mean converting an existing gas into another type of gas, and can be performed in various ways, such as catalyst-based reforming, heat-based reforming, and plasma-based reforming. The gas reforming described in the present disclosure is described as a process of converting a supplied gas into another type of gas using plasma, but the technical idea of the present disclosure is not limited thereto.

[0376] The feed gas to be reformed may mean the gas to be processed at the location where the gas reforming system 10 is required. Alternatively, the feed gas may refer to a certain amount of gas collected by a specific method.

[0377] Depending on the generation cause, the feed gas can be classified as biogas, landfill gas (LFG), natural gas, or methane gas. Depending on the type, the gas to be reformed can include methane (CH4), carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), etc. Hereinafter, for ease of explanation, the case where the feed gas includes at least methane and carbon dioxide will be described, but the technical idea of the present disclosure is not limited thereto.

[0378] When the feed gas is reformed, syngas can be produced. The syngas can be a mixed gas of hydrogen and carbon monoxide, and can be not only a raw material for various chemical products but also an energy source such as power generation. More specifically, the final product finally produced can vary depending on what post-treatment is performed on the syngas.

[0379] In the present disclosure, the final product obtained through the gas reforming system 10 can mean high-purity hydrogen, methanol, aviation oil, base oil, bio-naphtha, biodiesel, carbon black, graphene, carbon nanotubes, ammonia, or carbon monoxide, but is not limited thereto.

[0380] The gas reforming system 10 described in the present disclosure can perform pre-treatment, reforming process, and post-treatment, and each process can be respectively performed in the pre-processor 200, plasma induction system 100, and post-processor 300. The mentioned configurations and each process will be described below.

[0381] First, the pre-processor 200 can perform pre-treatment on the feed gas before gas reforming.

[0382] The pre-treatment is a process for more effectively performing gas reforming, and can be considered in terms of the yield of syngas generated through gas reforming, the composition ratio of the syngas, energy conversion efficiency, etc.

[0383] For example, a desulfurization process and a gas separation process can be performed on the feed gas in the pre-processor 200.

[0384] Hereinafter, with reference to Figure 22 the structure and function of the pre-processor 200 will be described.

[0385] Figure 22 is a block diagram of the pre-processor 200 according to an exemplary embodiment. Referring to Figure 22 the pre-processor 200 can include a desulfurization module 210, a pre-treatment gas separation module 220, a first gas separation tube 231, and a second gas separation tube 232.

[0386] The desulfurization module 210 can perform a desulfurization process on the feed gas. The desulfurization process can be understood as one of the processes for filtering out unnecessary components before injecting the feed gas into the discharge tube 3000 of the plasma induction system 100.

[0387] Specifically, when the feed gas is biogas, it may include components such as hydrogen sulfide, halides, and silicon-containing compounds. These components may need to be removed from the feed gas because they may form corrosive acids during the reforming process and damage the durability of the discharge tube 3000 or the post-processor 300.

[0388] The desulfurization module 210 can be supplied with the feed gas and remove hydrogen sulfide. The process of removing hydrogen sulfide in the desulfurization module 210 can be classified into dry, wet, and biological processes. For example, the desulfurization module 210 can perform a dry desulfurization process that uses metal oxides such as iron, zinc, and copper and adsorbents such as activated carbon to remove hydrogen sulfide through physical / chemical adsorption. Another example is that the desulfurization module 210 can perform a wet desulfurization process in which hydrogen sulfide is dissolved by contacting the feed gas with a liquid at a specific temperature and specific pressure. Another example is that the desulfurization module 210 can perform a biological desulfurization process that oxidizes and decomposes hydrogen sulfide and removes it using microbial metabolism.

[0389] The desulfurization module 210 can be fluidly connected to the pre-treatment gas separation module 220. Specifically, the outlet of the desulfurization module 210 can be fluidly connected to the inlet of the pre-treatment gas separation module 220 so that the gas passing through the desulfurization process in the desulfurization module 210 can be transferred into the pre-treatment gas separation module 220.

[0390] In addition to the desulfurization module 210, the pre-processor 200 can also include a module for removing specific components. For example, when the feed gas is landfill gas, the pre-processor 200 can also include a dehumidification module for removing moisture.

[0391] The pre-treatment gas separation module 220 can separate the supplied gas into multiple sub-feed streams. For example, the pre-treatment gas separation module 220 can separate the supplied feed stream into a first sub-feed stream and a second sub-feed stream.

[0392] The pre-treatment gas separation module 220 can be connected to multiple gas separation tubes. For example, the outlet of the pre-treatment gas separation module 220 can be connected to the first gas separation tube 231 and the second gas separation tube 232. The first sub-feed stream separated by the pre-treatment gas separation module 220 can be transferred to the first gas separation tube 231, and the second sub-feed stream can be transferred to the second gas separation tube 232.

[0393] Multiple gas separation tubes can be understood as a configuration that fluidly connects the pretreatment gas separation module 220 and the discharge tube 3000. Here, the multiple gas separation tubes can perform the function of supplying a gas with a specific composition ratio to a specific location of the discharge tube 3000. For example, as described below, the first gas separation tube 231 can be connected to an inlet located at the top of the discharge tube 3000 such that a CO2-rich gas is supplied to the top of the plasma induction region of the discharge tube 3000. Additionally, as described later, the second gas separation tube 232 can be connected to a second inlet located at the bottom of the discharge tube 3000 such that a methane-rich gas (e.g., a CH4-rich gas) is supplied to the bottom of the plasma induction region of the discharge tube 3000.

[0394] When separating gases from the pretreatment gas separation module 220, a separation membrane including a porous structure can be used. For example, the pretreatment gas separation module 220 can include a membrane that includes pores having a size within a certain range inside thereof.

[0395] The separation membrane can be disposed between the inlet of the pretreatment gas separation module 220 and the first gas separation tube 231. Alternatively, the separation membrane can be disposed between the inlet of the pretreatment gas separation module 220 and the second gas separation tube 232.

[0396] The separation membrane can separate a gas having particles of a certain size from the gases in the feed stream supplied to the pretreatment gas separation module 220. For example, when the feed stream is supplied into the pretreatment gas separation module 220, a hydraulic pressure is formed, and some of the feed stream can pass through the separation membrane through the formed hydraulic pressure.

[0397] In the present disclosure, the pretreatment gas separation module 220 can be designed to separate the supplied feed stream into a first sub-feed stream having a high carbon dioxide molar ratio and a second sub-feed stream having a high methane molar ratio. For example, the molar ratio of carbon dioxide to methane in the first sub-feed stream can be about 10:0 to 7:3, and the molar ratio of carbon dioxide to methane in the second sub-feed stream can be about 0:10 to 2:8.

[0398] The molar ratio of carbon dioxide in the first sub-feed stream can be greater than the molar ratio of carbon dioxide in the second sub-feed stream. Additionally, the molar ratio of methane in the first sub-feed stream can be less than the molar ratio of methane in the second sub-feed stream.

[0399] Meanwhile, the molar ratio of carbon dioxide in the first sub-feed stream and the molar ratio of methane in the second sub-feed stream can vary according to the design method of the pretreatment gas separation module 220. For example, the molar ratio of carbon dioxide in the first sub-feed stream and the molar ratio of methane in the second sub-feed stream can be determined according to the pressure in the pretreatment gas separation module 220 and the pore diameter of the separation membrane.

[0400] The reasons for separating the gases in this way can be: i) it is necessary to inject the gases involved in the endothermic reaction (such as methane) into the rear end of the plasma induction region to maintain plasma discharge; and ii) the composition ratio of the gases flowing into the discharge tube 3000 should be controlled within a certain range so that the ratio of hydrogen and carbon monoxide in the reformed synthesis gas passing through the plasma induction system 100 can be a specific value as described later. Considering this, it may be necessary to appropriately select the specifications of the separation membrane to separate the feed stream supplied from the pretreatment gas separation module 220 into multiple sub-feed streams with a preferred gas composition ratio.

[0401] For example, when the ratio of carbon dioxide in the feed stream supplied to the pretreatment gas separation module 220 is about 34%, the ratio of methane is about 44%, the ratio of nitrogen is about 20%, and the ratio of oxygen is about 2%, the ratio of carbon dioxide in the first sub-feed stream is about 60%, the ratio of methane is about 25%, the ratio of nitrogen is about 12%, the ratio of oxygen is about 3%, and in the second sub-feed stream, the ratio of carbon dioxide is about 10%, the ratio of methane is about 58%, the ratio of nitrogen is about 29%, and the ratio of oxygen is about 3%.

[0402] Hereinafter, reference will be made to Figure 23 describe the plasma induction system 100 for gas reforming.

[0403] Figure 23 is a view showing the plasma induction system 100 for gas reforming according to an exemplary embodiment.

[0404] The plasma induction system 100 can be understood as a system that uses plasma reforming of the gas supplied from the pre-processor 200 to produce synthesis gas and then supplies the produced synthesis gas to the post-processor 300.

[0405] The plasma induction system 100 can perform gas reforming by generating plasma via plasma induction, by receiving the pre-treated feed gas and passing it through the plasma region.

[0406] For example, when reforming a feed gas containing methane and carbon dioxide, the following reactions can occur in the discharge tube 3000.

[0407] CH4+H2O→CO+3H2

[0408] CO+H2O→CO2+H2

[0409] CH4+CO2→2CO+2H2

[0410] The above reaction can be carried out in the process of decomposing and resynthesizing the gas supplied by the thermal energy of the plasma. Therefore, synthesis gas containing hydrogen and carbon monoxide can be produced by reforming methane and carbon dioxide in the feed gas by the plasma.

[0411] Reference Figure 23 , the plasma induction system 100 may include an RF generator 1000, an ignition antenna structure 2800, a main antenna structure 2900, a discharge tube 3000, an auxiliary gas supply module 4100, a steam supply module 6200, an upper swirl generator 7100, lower swirl generators 7200 and 7300, and a guiding structure 8000.

[0412] First, the antenna structure 2000 can be divided into an ignition antenna structure 2800 and a main antenna structure 2900.

[0413] The ignition antenna structure 2800 is configured to excite plasma generation and can be arranged to surround the outer surface of the discharge tube 3000. The ignition antenna structure 2800 can have a layered structure, and for example, as Figure 3 and Figure 23 shown, it can have a 2-layer - 2-turn structure including two layers of antennas, where each layer of antenna consists of two turns. However, the number of layers and the number of turns per layer of the ignition antenna structure 2800 are not limited to 2 layers - 2 turns and can be appropriately determined as needed.

[0414] Different from the main antenna structure 2900, a capacitive element may not be provided between the layer antennas in the ignition antenna structure 2800. That is, it is necessary to apply a high voltage to the ignition antenna structure 2800 as described above, so when a capacitive element is provided between the layer antennas (or unit antennas), it is necessary to avoid reducing the amplitude of the voltage.

[0415] Compared with the main antenna structure 2900, the ignition antenna structure 2800 can excite plasma by forming a relatively strong electric field in the discharge tube 3000, and then cause the particles to collide with each other at high speed.

[0416] The main antenna structure 2900 is configured to maintain plasma and can be arranged to surround the outer surface of the discharge tube 3000. The main antenna structure 2900 can be arranged in a direction parallel to the central axis of the discharge tube 3000 and spaced apart from the ignition antenna structure 2800 by up to a certain distance.

[0417] The main antenna structure 2900 can be understood to have any one of the shapes of the antenna structure 1000 described in Figures 7 to 18 . Hereinafter, for the convenience of explanation, the main antenna structure 2900 can have Figure 11 , Figure 16the shape described in, and includes a first main antenna module 2901 and a second main antenna module 2902 connected to different RF generators, but the technical idea of the present disclosure is not limited thereto.

[0418] The plasma induction region (PIR) in the discharge tube 3000 can be defined by the ignition antenna structure 2800 and the main antenna structure 2900. When electric power is applied to the ignition antenna structure 2800 in the case of injecting auxiliary gas, plasma can be excited in a region corresponding to the ignition antenna structure 2800 in the plasma induction region (PIR). Then, when electric power is applied to the main antenna structure 2900, the plasma can be transferred to and maintained in a region corresponding to the main antenna structure 2900 in the plasma induction region (PIR). While maintaining the plasma, the gas to be reformed can be injected into the interior of the discharge tube 3000, and gas reforming can be performed.

[0419] The RF generator 1000 can be a device that applies electric power to the antenna structure 2000, and as described above, the structure and method of applying electric power will be omitted.

[0420] The number of RF generators 1000 can vary according to the structure of the main antenna structure 2900.

[0421] For example, when the main antenna structure 2900 can be composed of unit antennas in which layer antennas are not connected in series with each other as described in Figure 11 and Figure 16 and the unit antennas of each layer can be connected in series with the unit antennas of other layers, the main antenna structure 2900 can be composed of a first main antenna module 2901 and a second main antenna module 2902 that are not connected to each other through a conductor. In this case, the RF generator 1000 can be divided into a first RF generator 1001 for applying electric power to the ignition antenna structure 2800, a second RF generator 1002 for applying electric power to the first main antenna module 2201, and a third RF generator 1003 for applying electric power to the second main antenna module 2902. However, even in this case, the first main antenna module 2901 and the second main antenna module 2902 can be powered by one RF generator.

[0422] As another example, as described in Figure 9 when, in the main antenna structure 2900, the antenna segments within the layer antennas are connected in series with each other and the layer antennas are also connected in series with each other, the RF generator 1000 can be divided into a first RF generator 1001 for applying electric power to the ignition antenna structure 2800 and a second RF generator 1002 for applying electric power to the main antenna structure 2900.

[0423] The auxiliary gas supply module 6100 can supply auxiliary gas into the discharge tube 3000. Here, the auxiliary gas can be understood as the gas used to release plasma, such as argon or helium.

[0424] The auxiliary gas supply module 6100 can supply auxiliary gas to the top of the discharge tube 3000 through the auxiliary gas supply pipe 4110, and the amount of the supplied auxiliary gas can be controlled by a mass flow controller (MFC).

[0425] The auxiliary gas can be transferred to the upper eddy current generator 7100 through the auxiliary gas supply pipe 4110, and then transferred into the discharge tube 3000 in a state with a specific shape (e.g., straight forward, clockwise eddy current or counterclockwise eddy current) in the upper eddy current generator 7100.

[0426] The steam supply module 6200 can supply water vapor into the discharge tube 3000. The steam supply module 6200 can be fluidly connected to the discharge tube 3000 to adjust the ratio of water vapor in the air flow supplied to the discharge tube 3000 within a preset range.

[0427] The above-mentioned first sub-feed stream can flow into the discharge tube 3000 through the upper swirl generator 5100. The second sub-feed stream can flow into the discharge tube 3000 through the first lower swirl generator 7200. The water vapor supplied from the steam supply module 6200 can flow into the discharge tube 3000 through the second lower swirl generator 7300.

[0428] In this way, the first sub-feed stream, the second sub-feed stream and the water vapor can be supplied into the discharge tube 3000 while respectively having specific shapes (e.g., clockwise swirl or counterclockwise swirl). In this case, the swirl directions of the first sub-feed stream, the second sub-feed stream and the water vapor can be determined to improve the energy conversion efficiency. The method for determining the swirl direction of each stream will be described later.

[0429] The guiding structure 8000 can be a structure for supplying gas to the rear end of the plasma induction region (PIR) inside the discharge tube 3000. For example, referring to Figure 23 , the guiding structure 8000 can extend from the lower end of the discharge tube 3000 to the rear end of the plasma induction region (PIR), and the gas supplied to the lower end of the discharge tube 3000 can move along the outer wall of the guiding structure 8000 and reach the rear end of the plasma induction region (PIR).

[0430] The guiding structure 8000 can be inserted into the discharge tube 3000. For example, the discharge tube 3000 can be divided into a first part and a second part with different widths. The ignition antenna structure 2800 and the main antenna structure 2900 can be arranged in the first part, and the guiding structure 8000 can be inserted inside the second part.

[0431] Meanwhile, the plasma induction system 100 can also include an electrode attached to the outside of the discharge tube 3000 for plasma ignition, the ignition antenna structure 2800, and a pulse generator for applying a high-voltage pulse to the electrode. When the high-voltage pulse is applied to the electrode, the end of the auxiliary gas supply tube 6110 located inside the discharge tube 3000 can be used as a different electrode, so that a strong electric field is formed between the electrode and the auxiliary gas supply tube 6110 and plasma ignition is achieved.

[0432] The plasma induction system 100 can operate in the following manner.

[0433] First, the plasma ignition operation can be performed. Specifically, when the auxiliary gas is supplied to the discharge tube 3000, electric power can be applied to the ignition antenna structure 2800 through the first RF generator 1001, and the plasma in the discharge tube 3000 can be ignited.

[0434] After that, the plasma maintenance operation can be performed. Specifically, the electric power of the second RF generator 1002 can be applied to the first main antenna module 2201, and the electric power of the third RF generator 1003 can be applied to the second main antenna module 2902, so that the plasma ignited near the ignition antenna structure 2800 in the discharge tube 3000 can be transferred to the main antenna structure 2900 and maintained near the main antenna structure 2900.

[0435] The gas to be reformed can be supplied in the state of maintaining the plasma. Specifically, the first sub-feed stream (gas rich in CO2) can flow into the upper end of the discharge tube 3000, and the second sub-feed stream (gas rich in CH4) and water vapor can flow into the back end of the plasma induction region (PIR) in the discharge tube 3000.

[0436] When the first sub-feed stream, the second sub-feed stream, and water vapor can flow into the discharge tube 3000, the above-mentioned chemical reaction of the plasma can occur, thereby generating synthesis gas.

[0437] The synthesis gas generated in the plasma induction system 100 can be post-processed to generate the final product.

[0438] Post-treatment can be largely understood as a gas conversion process and a gas separation process, and the post-treatment unit 300 can include a gas conversion module and a post-treatment gas separation module for each process.

[0439] First, the synthesis gas generated in the discharge tube 3000 can be transferred to the gas conversion module, and hydrogen or carbon monoxide in the synthesis gas can be converted into a specific gas. At this time, the gas conversion module can have different compositions or structures depending on the type of the final product to be produced in the gas reforming system 10, and the types of reactions that occur can also be different.

[0440] For example, the gas conversion module can be a water gas shift (WGS) module. The water gas shift module can perform a process of converting carbon monoxide in the synthesis gas into hydrogen using a catalytic reaction. Specifically, the synthesis gas and steam can be supplied to the water gas shift module, and then the reaction CO + H2O -> CO2 + H2 occurs.

[0441] When the final product to be produced in the gas reforming system 10 is high-purity hydrogen, the water gas shift module can be selected as the gas conversion module. Alternatively, in the process of collecting carbon dioxide through the gas reforming system 10, the water gas shift module can be selected as the gas conversion module.

[0442] As another example, the gas conversion module can be a Fischer-Tropsch process module. The Fischer-Tropsch process module can perform a process of synthesizing liquid hydrocarbons from the synthesis gas using a catalytic reaction. Specifically, the Fischer-Tropsch process module can be supplied with the synthesis gas and the following reaction occurs: (2n + 1)H2 + (n)CO -> C(n)H(2n + 2) + (n)H2O.

[0443] When the final product to be produced in the gas reforming system 100 is aviation fuel, the Fischer-Tropsch process module can be selected as the gas conversion module.

[0444] As another example, the gas conversion module can be a methanol synthesis module. The methanol synthesis module can be implemented as a fixed-bed reactor or a fluidized-bed reactor, and can perform a process of synthesizing methanol from the synthesis gas using a catalytic reaction.

[0445] The gas discharged from the gas conversion module can be supplied to the post-treatment gas separation module. Hereinafter, for the sake of explanation, the gas discharged from the gas conversion module can be referred to as an intermediate product (IP).

[0446] The post-treatment gas separation module can perform a gas separation process. The gas separation process performed in the post-treatment gas separation module can be understood as a process of improving the efficiency of obtaining the final product.

[0447] The post-treatment gas separation module can be implemented as a pressure swing adsorption (PSA) method. The pressure swing adsorption method can separate gases by using an adsorbent to first adsorb the components with high selectivity among the passing gases and by first discharging the components with low selectivity.

[0448] The post-treatment gas separation module can be implemented in the form of a separation membrane including the separation membrane of the pre-treatment gas separation module as described above.

[0449] The gas discharged from the post-treatment gas separation module can be the final product and can be collected in a collector. There can be additional configurations, such as changing the pressure or temperature between the post-treatment gas separation module and the collector.

[0450] Meanwhile, during the process of reforming gas using the gas reforming system 10, there are situations as follows: depending on the type of the final product of the gas reforming process, it is necessary to avoid using auxiliary gas to greatly assist plasma excitation and maintenance.

[0451] For example, when the final product of the gas reforming process is high-purity hydrogen, hydrogen can be collected from the syngas generated by plasma reforming through post-treatment. However, in this case, when an auxiliary gas such as argon is mixed with the syngas, it is relatively difficult to separate hydrogen and argon in the syngas, resulting in a significant reduction in the production of high-purity hydrogen or the need for additional equipment, leading to a significant decrease in process efficiency.

[0452] Considering the above situation, even if an auxiliary gas is used in the plasma ignition stage, it can be considered that no auxiliary gas is used in the plasma maintenance stage of actively generating syngas.

[0453] When no auxiliary gas is used, plasma maintenance may weaken and the plasma may become unstable. To compensate for this, the driving frequency of the electric power applied to the main antenna structure 2900 should be increased. However, as the driving frequency increases, the maximum voltage applied to the main antenna structure 2900 may also increase, increasing the risk of arc discharge between the layer antennas and thus increasing the risk of structural damage.

[0454] To solve the above problems, an antenna structure that may not cause an arc in the case of not using an auxiliary gas in the plasma maintenance stage has been studied and developed.

[0455] As a result, a plasma induction system 100 using the antenna structure 2000 described in the present disclosure has been constructed, a gas reforming system 10 using the constructed plasma induction system 100 has been designed, and it has been experimentally confirmed that even when no auxiliary gas is used, the production of synthesis gas can be maintained at a certain level by maintaining the plasma.

[0456] Hereinafter, it will be described in detail using experimental data.

[0457] First, the designed gas reforming system 10 has been described previously in Figures 21 to 23 , so the details will be omitted. In the experiment, by keeping the flow rate of methane gas in the first sub-feed stream, the flow rate of carbon dioxide gas in the second sub-feed stream, and the supply amount of water vapor at constant values, and by adjusting the injection amount of argon, the production of synthesis gas and the energy conversion efficiency (ECE) were examined, and whether an arc occurred was examined during this process.

[0458] Table 1

[0459]

[0460] In each experiment shown in Table 1 above, the main antenna structure 2900 can use the forms described in Figure 11 and Figure 16 (hereinafter, the shape of two partitions). The quartz disk and the air gap in "Settings" can indicate the adjustment of the dielectric constant between the layer antennas in the main antenna structure 2900, and the method of adjusting the dielectric constant between the layer antennas will be described later. The lower nozzle direction in "Settings" can indicate the swirling direction of methane gas when viewed from the upper part of the discharge tube 3000, and can be related to the swirling direction of water vapor, and the method of determining the swirling direction of methane gas will be described later. In addition, in all experiments, argon can be injected into the discharge tube 3000 during plasma ignition, and the amount of argon described in Table 1 can indicate the amount of argon flowing into the discharge tube 3000 during the plasma maintenance stage after plasma ignition is detected.

[0461] Referring to Table 1, it was confirmed that even when argon could not be injected during the stage where the main antenna structure 2900 maintained the plasma, the production of synthesis gas and the energy conversion efficiency were maintained above a certain level. Specifically, when argon was not injected in each setting, the production of synthesis gas increased compared to when argon was injected, and the energy conversion efficiency decreased slightly.

[0462] Meanwhile, in the experiments where argon could not be injected, no arc discharge or damage caused by arc discharge was confirmed.

[0463] In other words, as a result of experimenting with various types of settings using the main antenna structure 2900 with a two-zone shape, it was confirmed that the plasma could be maintained during the plasma maintenance phase without injecting argon, and the production of the synthesis gas and the energy conversion efficiency exceeded specific standards.

[0464] As described above, when an auxiliary gas such as argon is not used to maintain the plasma, a plasma reforming method that minimizes the use of the auxiliary gas can be obtained.

[0465] Hereinafter, reference will be made to Figure 24 describe a plasma reforming method that minimizes the use of the auxiliary gas.

[0466] Figure 24 is a flowchart showing a plasma reforming method according to an exemplary embodiment.

[0467] Reference Figure 24 , the plasma reforming method may include a step S1100 of injecting an auxiliary gas, a step S1200 of applying electric power to the ignition antenna structure 2800, a step S1300 of checking whether the plasma is ignited, a step S1400 of applying electric power to the main antenna structure, a step S1500 of injecting a gas to be reformed, and a step S1600 of stopping the injection of the auxiliary gas.

[0468] Hereinafter, each step will be described in detail.

[0469] First, an auxiliary gas can be injected into the discharge tube 3000. This is one of the steps for plasma ignition and can be understood as an operation to create an environment favorable for igniting the plasma.

[0470] At the same time, in order to create a more favorable plasma ignition environment, the internal pressure of the discharge tube 3000 can be reduced. To reduce the internal pressure, the discharge tube 3000 can be connected to a pressure pump, and the pressure pump can adjust the internal pressure of the discharge tube 3000. When only the main antenna structure 2900 is used to ignite the plasma without using the ignition antenna structure 2800, a preferred environment for plasma ignition can be created. However, even when the ignition antenna structure 2800 is used, a favorable environment for plasma ignition can be created by reducing the internal pressure. In the case where the internal pressure of the discharge tube 3000 is reduced, a step of increasing the internal pressure of the discharge tube 3000 can be additionally performed after the plasma is ignited.

[0471] In addition, the plasma induction system 100 may further include an exhaust system for exhausting the gas in the discharge tube 3000, and the auxiliary gas injected into the interior of the discharge tube 3000 can be exhausted through the exhaust system, thereby preventing the auxiliary gas from moving to the post-processor 300. More specifically, the plasma induction system 100 may further include an exhaust port and an exhaust pump that are fluidly connected to the discharge tube 3000 and the exhaust system, and by operating the exhaust pump, the gas in the discharge tube 3000 can be discharged into the exhaust system. This is to prevent an adverse effect on the generation of the target gas in the post-treatment in the case where the auxiliary gas can be transferred to the post-processor 300 as described above.

[0472] After injecting the auxiliary gas, electric power can be applied to the ignition antenna structure 2800 for plasma ignition S1200. For example, an RF voltage can be applied to the ignition antenna structure 2800 through the first RF generator 1001. The ignition antenna structure 2800 receiving the RF voltage can form an electric field inside the discharge tube 3000, and the formed electric field can cause argon gas to collide with each other, thereby igniting the plasma.

[0473] Step S1100 and step S1200 can be executed simultaneously. Alternatively, step S1200 can be first executed before step S1100.

[0474] It can be confirmed whether the plasma is ignited S1300. It can be determined whether the plasma is ignited based on the degree of change in the electric power applied to the ignition antenna structure 2800. For example, when the voltage or current measured with respect to the ignition antenna structure 2800 falls outside the threshold range, it can be determined that the plasma is ignited. Another example is that when the amount of change in the voltage or current measured with respect to the ignition antenna structure 2800 falls outside the threshold range, it can be determined that the plasma is ignited. At the same time, whether the plasma is ignited can be automatically detected by the plasma induction system 100, or can be detected by the input of the user (for example, the user can visually check whether the plasma is ignited and can input the inspection result into the plasma induction system 100).

[0475] When plasma ignition is detected, electric power can be applied to the main antenna structure 2900 for main discharge S1400. For example, the second RF generator 1002 and / or the third RF generator 1003 can apply electric power to the main antenna structure 2900, and the main antenna structure 2900 can form an electric field and a magnetic field in the discharge tube 3000 to maintain the plasma.

[0476] The main discharge may refer to the phenomenon that the plasma ignited by the ignition antenna structure 2800 moves to and is maintained on the main antenna structure 2900. Specifically, when electric power is applied to the main antenna structure 2900, the plasma generated in the region corresponding to the ignition antenna structure 2800 in the plasma induction region (PIR) within the discharge tube 3000 can move to the region corresponding to the main antenna structure 2900 in the plasma induction region (PIR), and the plasma can be maintained while the particles in the discharge tube 3000 can collide with each other through the electromagnetic field that the main antenna structure 2900 can form.

[0477] In the state of maintaining the plasma, the gas to be reformed can be injected in step S1500. For example, a gas rich in carbon dioxide, a gas rich in methane, and water vapor can be injected into the discharge tube 3000.

[0478] The time for injecting the gas to be reformed can be selected from: the time after a certain period has elapsed since the plasma induction system 100 starts operating, the time after a certain period has elapsed since electric power is applied to the ignition antenna structure 2800, the time when it is confirmed that the plasma is ignited, the time after a certain period has elapsed since it is confirmed that the plasma is ignited, the previous time after a certain period has elapsed since the injection of the auxiliary gas is stopped, the time when the injection of the auxiliary gas is stopped, and the time after a certain period has elapsed since the injection of the auxiliary gas is stopped. Meanwhile, the gas to be reformed can be injected according to the user's input.

[0479] In other words, step S1500 does not necessarily need to be executed after step S1400, and step S1500 can also be executed even when step S1100 or step S1400 is being executed. However, the timing for injecting the gas to be reformed should be determined considering the performance of the plasma induction system 100 or the gas reforming system 10 and the energy conversion efficiency, because the plasma can be ignited solely with the auxiliary gas, and depending on the final product to be generated, all the gas in the discharge tube 3000 can be discharged so as to discharge the auxiliary gas before reaching the normal state after injecting the gas to be reformed, as will be described later, and in this case, the syngas generated by reforming the gas to be reformed may be consumed unnecessarily.

[0480] In step S1600, the injection of the auxiliary gas can be stopped after the gas to be reformed has been injected.

[0481] The stop timing of injecting the auxiliary gas can be selected as any one of the following: the time when the plasma is ignited, the time after a certain time has elapsed since the plasma is ignited, the previous time based on the time when the gas to be reformed is injected, the time when the gas to be reformed is injected, and the time after a certain time has elapsed since the gas to be reformed is injected. In other words, step S1600 does not have to be executed after step S1500, and can be executed during step S1300 or step S1500.

[0482] Meanwhile, when the plasma is maintained by the main discharge and reaches the normal state, the plasma induction system 100 can block the flow path connecting the discharge tube 3000 and the exhaust system to each other or stop the operation of the exhaust pump, so that the synthesis gas generated in the discharge tube 3000 can be transmitted to the post-processor 300. Alternatively, when a certain time may elapse after the injection of the auxiliary gas is stopped, the plasma induction system 100 can block the flow path connecting the discharge tube 3000 and the exhaust system to each other or stop the operation of the exhaust pump. This can be understood as for discharging the synthesis gas containing the auxiliary gas and for providing the post-processor 300 with the synthesis gas that does not contain the auxiliary gas or has an auxiliary gas ratio lower than a certain level as described above.

[0483] The use of the auxiliary gas can be minimized (only used in the plasma ignition stage) by the above-described plasma reforming method, thereby maximizing the production of the synthesis gas without mixing the auxiliary gas.

[0484] Hereinafter, reference will be made to Figure 25 Describe the design method of the plasma induction system 100 for improving the performance of plasma reforming.

[0485] First, in order to increase the production of the synthesis gas or the energy conversion efficiency in the plasma induction system 100, it is necessary to improve the performance of the antenna structure 2000 (especially the main antenna structure 2900).

[0486] As a way to improve the performance of the main antenna structure 2900, there is a method of reducing the magnitude of the parasitic capacitance between the layer antennas when designing the main antenna structure 2900. This is to reduce the electric power consumed by the parasitic capacitance between the layer antennas, so that all the electric power applied to the main antenna structure 2900 can be supplied to the plasma without unnecessary power consumption.

[0487] In other words, even when the same voltage (or electric power) is applied to the main antenna structure 2900, as the parasitic capacitance in the main antenna structure 2900 becomes smaller, the electric power consumed by the main antenna structure 2900 can be reduced, and the electric power supplied to the plasma can be increased, thereby increasing the production of the synthesis gas.

[0488] Meanwhile, when a relatively high voltage is applied to the main antenna structure 2900, arc discharge may occur between the layer antennas in the main antenna structure 2900. To prevent such arc discharge from occurring, it is inevitable to insert a dielectric such as quartz between the layer antennas. The insertion of the dielectric may cause an increase in parasitic capacitance, which becomes a factor degrading the performance of the plasma induction system 100.

[0489] Experiments have been conducted in which the main antenna structure 2900 having a two-division shape is used, and the parasitic capacitance is reduced, but arc discharge does not occur. Therefore, it is confirmed that when a gas gap of a certain size is provided between the layer antennas in the main antenna structure 2900, the production amount of the synthesis gas and the energy conversion efficiency are improved.

[0490] The experimental data are as follows.

[0491] Table 2

[0492]

[0493] The dielectric adjustment form of the main antenna structure 2900 performed in the experiment is as Figure 25 shown. Figure 25 is a view showing the main antenna structure 2900 in which the parasitic capacitance is differently adjusted according to an exemplary embodiment. Refer to Figure 25 (a) of. The dielectric 3100 can be provided between the layer antennas in the main antenna structure 2900 without a gas gap, and the settings of Experiment 1 and Experiment 2 in Table 2 correspond to this. Refer to Figure 25 (b) of. A gas gap having a first thickness T1 and a dielectric 3100 having a second thickness T2 can be provided between the layer antennas in the main antenna structure 2900, and the setting of Experiment 3 in Table 2 corresponds to this (the first thickness T1 in Experiment 3 is 1 mm, and the second thickness T2 is 2 mm). Refer to Figure 25 (c) of. The layer antennas in the main antenna structure 2900 are spaced apart by up to a first thickness T1, and the dielectric 3100 is not inserted, and the settings of Experiment 4 and Experiment 5 in Table 2 correspond to this (the first thickness T1 in Experiment 4 and Experiment 5 is 3 mm).

[0494] When comparing Experiment 1&2 and Experiment 3 in Table 2, when the quartz disk is provided and spaced up to 1 mm, the production amount of the synthesis gas increases and the energy conversion efficiency is higher than when only the quartz disk can be provided between the main antenna structures 2900.

[0495] When comparing Experiment 1&2 and Experiment 4&5 in Table 2, when the main antenna structure is spaced up to 3 mm without providing the quartz disk, the production amount of the synthesis gas increases and the energy conversion efficiency is higher than when only the quartz disk is provided between the main antenna structures 2900.

[0496] When comparing Experiment 3 with Experiments 4&5 in Table 2, when a quartz disk is disposed between the main antenna structures 2900 and spaced up to 1 mm apart, compared with when the quartz disk is not provided and the main antenna structures are spaced up to 3 mm apart, the yield of the synthesis gas increases, but the energy conversion efficiency is lower.

[0497] When comparing Experiments 6&7 with Experiments 8&9 in Table 2, when the main antenna structures are spaced up to 3 mm apart and the quartz disk is not provided, compared with when the quartz disk is disposed between the main antenna structures 2900 and spaced up to 1 mm apart, the gas yield increases and the energy conversion efficiency is higher.

[0498] Considering the above experimental results, it may be preferable that the layer antennas in the main antenna structure 2900 are spaced apart by a gap of up to a certain size and the dielectric 3100 is not provided in order to improve the performance of the plasma induction system 100.

[0499] The size of the gap can be determined based on at least one selected from the following: the diameter of the discharge tube 3000, the length of the discharge tube 3000, the length of the ignition antenna structure 2800 in a direction parallel to the central axis of the discharge tube 3000, and the length of the main antenna structure 2900 in a direction parallel to the central axis of the discharge tube 3000. For example, when the diameter of the discharge tube 3000 is about 80 mm and the length of the discharge tube 3000 is about 250 mm, the size of the gap can be about 3 mm.

[0500] Hereinafter, a method for determining the swirling direction of the gas injected into the discharge tube 3000 to improve the performance of plasma reforming will be described.

[0501] In the plasma induction system 100, the flowing gas injected into the discharge tube 3000 substantially has swirl, and when viewed from the top of the discharge tube 3000 toward the inside of the discharge tube 3000, the swirling direction can be divided into a clockwise (CW) direction or a counterclockwise (CCW) direction.

[0502] The gas flows into the discharge tube 3000 through a vortex generator, and the swirling direction of the gas in the discharge tube 3000 can be determined according to the structure of the vortex generator.

[0503] Meanwhile, in the gas reforming system 10 described in the present disclosure, the feed gas can be divided into a first sub-feed stream and a second sub-feed stream in the pre-processor 200, and the first sub-feed stream, the second sub-feed stream, and water vapor can be respectively injected into the discharge tube 3000 of the plasma induction system 100 through different flow paths.

[0504] Reference Figure 23, the first sub-feed stream can form a clockwise or counterclockwise swirl through the upper swirl generator 7100 and can flow into the discharge tube 3000. The second sub-feed stream can form a clockwise or counterclockwise swirl through the first lower swirl generator 7200 and can flow into the discharge tube 3000. Water vapor can form a clockwise or counterclockwise swirl through the second lower swirl generator 7300 and can flow into the discharge tube 3000.

[0505] At this time, not only the design of the antenna structure 2000 but also the swirl direction of the gas injected into the discharge tube 3000 can be an important factor in improving the performance of the plasma induction system 100. In particular, when the second sub-feed stream and water vapor flow into the rear end of the plasma induction region (PIR), the degree of chemical reaction varies depending on whether the swirl directions of each gas are the same or opposite, thereby affecting the yield of the synthesis gas and the energy conversion efficiency.

[0506] The influence of the swirl direction of the gas in the discharge tube 3000 on the yield of the synthesis gas and the energy conversion efficiency has been studied, and through experiments, it has been confirmed that when the swirl directions of the second sub-feed stream and water vapor are opposite to each other, the yield of the synthesis gas and the energy conversion efficiency can be increased.

[0507] The experimental data are shown below.

[0508] Table 3

[0509]

[0510]

[0511] In the above experiments, the lower nozzle direction can represent the swirl direction of the second sub-feed stream, and in all experiments, the swirl direction of water vapor is counterclockwise (CCW), and the swirl direction of the first sub-feed stream is clockwise (CW). When comparing Experiment 1 and Experiments 2&3 in Table 3, when the swirl directions of the second sub-feed stream and water vapor are designed to be opposite to each other rather than the same counterclockwise direction, the yield of the synthesis gas increases and the energy conversion efficiency is higher.

[0512] Similarly, when comparing Experiments 4&5 and Experiments 6&7 in Table 3, when the swirl directions of the second sub-feed stream and water vapor are designed to be opposite to each other rather than the same counterclockwise direction, the yield of the synthesis gas increases and the energy conversion efficiency is higher.

[0513] In view of the above experimental results, the first lower swirl generator 7200 and the second lower swirl generator 7300 need to be designed such that the swirl directions of the second sub-feed stream and the water vapor are opposite to each other in order to improve the performance of the plasma induction system 100.

[0514] Hereinafter, reference will be made to Figure 26 describe the structures of the first lower swirl generator 7200 and the second lower swirl generator 7300.

[0515] Figure 26 is a view showing the lower swirl generators 7200 and 7300 according to an exemplary embodiment. Figure 26 (a) of shows the first lower swirl generator 7200, and Figure 26 (b) of shows the second lower swirl generator 7300 positioned at the upper end of the first lower swirl generator 7200.

[0516] The first lower swirl generator 7200 can be supplied with the second sub-feed stream and transfer the second sub-feed stream into the discharge tube 3000. The first lower swirl generator 7200 can include a first inlet tube 7210, a second inlet tube 7220, and a nozzle portion 7230.

[0517] The first inlet tube 7210 and the second inlet tube 7220 can be tubes connected to a gas supplier to be supplied with gas. For example, the first inlet tube 7210 and the second inlet tube 7220 can be connected to the second gas separation tube 232 to which the second sub-feed stream is supplied.

[0518] The nozzle portion 7230 can transfer the gas flowing into the first inlet tube 7210 or the second inlet tube 7220 into the discharge tube 3000 and can form a swirl during this process. For example, the nozzle portion 7230 can include a plurality of nozzle tubes arranged in a spiral shape based on the center of the first lower swirl generator 7200.

[0519] According to the direction of the nozzle tubes of the nozzle portion 7230, the gas passing through the nozzle portion 7230 can have a clockwise or counterclockwise swirl shape. Referring to Figure 26 , the gas supplied to the discharge tube 3000 through the first lower swirl generator 7200 can have a clockwise swirl shape.

[0520] The second lower swirl generator 7300 can be supplied with water vapor and transfer it into the interior of the discharge tube 3000.

[0521] The second lower swirl generator 7300 can include a third inlet tube 7310 and a fourth inlet tube 7320.

[0522] The third inlet pipe 7310 and the fourth inlet pipe 7320 may be pipes connected to another gas supplier to be supplied with gas. For example, the third inlet pipe 7310 and the fourth inlet pipe 7320 may be connected to the steam supply module 6200 and be supplied with water vapor.

[0523] The third inlet pipe 7310 and the fourth inlet pipe 7320 may be arranged such that the supplied gas has a swirl in a specific direction. For example, as Figure 26 shown, the third inlet pipe 7310 and the fourth inlet pipe 7320 may be arranged in a manner that they contact the discharge tube 3000, and the gas flowing from the third inlet pipe 7310 and the fourth inlet pipe 7320 may rotate along the edge or the inner surface of the discharge tube 3000. In this case, depending on the arrangement direction of the third inlet pipe 7310 and the fourth inlet pipe 7320, the swirl direction of the gas passing through the second lower swirl generator 7300 may be set to the clockwise or counterclockwise direction.

[0524] It can be designed that each of the gases passing through the first lower swirl generator 7200 and the second lower swirl generator 7300 may have swirls in opposite directions. For example, referring to Figure 26 (b) of, the swirl direction of the methane-rich gas passing through the first lower swirl generator 7200 may be the clockwise direction, and the swirl direction of the water vapor passing through the second lower swirl generator 7300 may be the counterclockwise direction.

[0525] The gas passing through each of the first lower swirl generator 7200 and the second lower swirl generator 7300 may move between the discharge tube 3000 and the guiding structure 8000, and then reach the rear end of the plasma induction region (PIR), as Figure 23 shown.

[0526] In this way, the different gases flowing into the rear end of the plasma induction region (PIR) in the discharge tube 3000 through the lower swirl generators 7200 and 7300 may have different swirl directions, so that the chemical reaction can be more active and the gas reforming efficiency can be improved.

[0527] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present disclosure, but are not necessarily limited to one embodiment. In addition, the features, structures, effects, etc. illustrated in each embodiment may also be combined or modified by those skilled in the art related to the embodiment in other embodiments. Therefore, the configurations related to the combination and modification should be interpreted as being included within the scope of the present disclosure.

[0528] Although the present disclosure has been described above with reference to the embodiments, the embodiments are merely examples and do not limit the present disclosure, and those skilled in the art will know that the present disclosure can be changed and modified in various ways not illustrated above without departing from the scope of the present disclosure. That is, the components described in detail in the embodiments of the present disclosure can be modified. In addition, the differences related to the changes and modifications should be construed as being included within the scope of the present disclosure determined by the claims.

Claims

1. An antenna structure is provided which is disposed around the side periphery of a discharge tube that provides a space in which plasma is generated. The antenna structure includes: n unit antennas, where the n unit antennas include a first unit antenna to an nth unit antenna, and n is a natural number greater than or equal to 2. Among them, each of the n unit antennas includes: A first arc section, which has a first radius of curvature and includes a first end and a second end; A second arc section, which has a second radius of curvature and includes a third end and a fourth end; and An arc connection section that connects the second end of the first arc section and the third end of the second arc section. Among them, the mth unit antenna and the (m + 1)th unit antenna are arranged such that the angle formed by the first virtual line and the second virtual line is 360 / n degrees. Among them, the first virtual line connects the center of the discharge tube and the arc connection section of the mth unit antenna. Among them, the second virtual line connects the center of the discharge tube and the arc connection section of the (m + 1)th unit antenna. Among them, the mth unit antenna and the (m + 1)th unit antenna are adjacent, and m is a natural number less than n. Among them, the first radius of curvature is different from the second radius of curvature.

2. The antenna structure according to claim 1, wherein The first radius of curvature corresponds to the side perimeter of the discharge tube. Among them, the second radius of curvature has a value greater than the first radius of curvature.

3. The antenna structure according to claim 1, wherein The first arc section has a first central angle, and the first central angle is equal to or less than 360 / n degrees.

4. The antenna structure according to claim 3, wherein The second arc section has a second central angle, and the second central angle is less than the first central angle.

5. The antenna structure according to claim 1, wherein n is a natural number greater than or equal to 3, and m is a natural number less than (n - 1). Among them, when the (m + 2)th unit antenna and the (m + 1)th unit antenna are adjacent, the fourth end of the second arc section of the mth unit antenna and the first end of the first arc section of the (m + 2)th unit antenna are electrically connected.

6. The antenna structure according to claim 5, wherein An inter-turn capacitor is electrically inserted between the fourth end of the second arc section of the mth unit antenna and the first end of the first arc section of the (m + 2)th unit antenna.

7. The antenna structure according to claim 1, wherein The n unit antennas are arranged in a first plane to form a first-layer antenna.

8. The antenna structure according to claim 7, wherein The first radius of curvature is less than the second radius of curvature. Among them, the first arc sections of the first to nth unit antennas constitute the inner turn of the first-layer antenna to surround the discharge tube. Among them, the second arc sections of the first to nth unit antennas constitute the outer turn of the first-layer antenna to surround the inner turn.

9. The antenna structure according to claim 7, wherein The n unit antennas are arranged clockwise or counterclockwise in the first plane. Among them, the second arc section of the mth unit antenna is arranged to surround at least a part of the first arc section of the (m + 1)th unit antenna.

10. The antenna structure according to claim 7, the antenna structure further includes: A second-layer antenna, which is composed of p unit antennas different from the n unit antennas. Among them, p is a natural number greater than or equal to 2. Among them, the second-layer antenna is arranged in a second plane spaced apart from the first plane by a predetermined distance. Among them, one unit antenna among the n unit antennas is electrically connected to one unit antenna among the p unit antennas through an inter-layer capacitor.

11. The antenna structure according to claim 1, wherein n is 3. Wherein, the fourth end of the second arc section of the first unit antenna is connected to the first end of the first arc section of the third unit antenna through a first inter-turn capacitor, and wherein, the fourth end of the second arc section of the third unit antenna is connected to the first end of the first arc section of the second unit antenna through a second inter-turn capacitor.

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