WO2022170751A1 - Magnetic field enhancement apparatus - Google Patents

Abstract

A magnetic field enhancement apparatus (20): a first electrode layer (110) is arranged on a first surface (101), and a second electrode layer (120) is arranged on the first surface (101) and positioned in a first capacitor area (11), the second electrode layer (120) being spaced apart from part of the first electrode layer (110) positioned in the first capacitor area (11), a third electrode layer (130) being arranged on the first surface (101) and being positioned in a second capacitor area (12), the third electrode layer (130) being spaced apart from part of the first electrode layer (110) positioned in the second capacitor area (12), one end of a first resonant capacitor (911) being electrically connected to the second electrode layer (120), and the other end of the first resonant capacitor (911) being electrically connected to the part of the first electrode layer (110) positioned in the first capacitor area (11), the second electrode layer (120) and the part of the first electrode layer (110) positioned in the first capacitor area (11) of two adjacent magnetic field enhancement assemblies (10) being connected, one end of a second resonant capacitor (921) being electrically connected to the third electrode layer (130), and the other end of the second resonant capacitor (921) being electrically connected to the part of the first electrode layer (110) positioned in the second capacitor area (12), and the third electrode layer (120) and the part of the first electrode layer (110) positioned in the second capacitor area (12) of two adjacent magnetic field enhancement assemblies (10) being connected.

Description

Magnetic field enhancement device

Related applications

This application claims the priority of the Chinese patent application filed on February 10, 2021, with the application number of 2021101839235 and titled "A High-frequency MRI Image Enhancement Metasurface Device", which is hereby incorporated by reference in its entirety.

technical field

The present application relates to the technical field of magnetic resonance imaging, and in particular, to a magnetic field enhancement device applied to an MRI system.

Background technique

MRI (Magnetic Resonance Imaging, magnetic resonance imaging technology) is a non-invasive detection method, which is an important basic diagnostic technology in the fields of medicine, biology and neuroscience. The signal strength transmitted by the traditional MRI system mainly depends on the strength of the static magnetic field B0. The use of a high magnetic field or even an ultra-high magnetic field system can improve the signal-to-noise ratio, resolution and shorten the scanning time of the image. However, the increase of the static magnetic field strength will bring the following three problems: 1) the non-uniformity of the radio frequency (RF) field will increase, and the tuning difficulty will increase; 2) the heat generation of the human body will increase, which will bring safety hazards and patients are prone to dizziness and vomiting and other adverse reactions: 3) The purchase cost has increased significantly, which is a burden for most small-scale hospitals. Therefore, how to use as small a static magnetic field strength as possible while obtaining high imaging quality has become a crucial issue in MRI technology.

The emergence of metamaterials provides a novel and more efficient method for improving the quality and efficiency of MRI imaging. Metamaterials have special properties that many natural materials do not possess. Through the interaction between the electromagnetic wave and the metal or dielectric elements of the metamaterial and the coupling effect between the elements, the control of the electromagnetic wave propagation path and the electromagnetic field intensity distribution can be realized. Among them, the specific working principle is to use the electromagnetic resonance in the structure formed by the metamaterial to realize the adjustment of electromagnetic parameters such as anisotropy and gradient distribution. Moreover, through the design of parameters such as geometric size, shape and dielectric constant of metamaterials, resonance enhancement at different frequency points can be achieved.

A conventional magnetic field enhancement assembly includes a dielectric plate and first and second electrodes on the front and back of the dielectric plate, respectively. The orthographic projection of the second electrode on the dielectric plate is located at both ends of the orthographic projection of the first electrode on the dielectric plate, so as to form a parallel plate capacitor.

The parallel plate capacitors formed in the structure of the conventional magnetic field enhancement components are all located on the transmission line formed by the strip electrodes. After a plurality of conventional magnetic field enhancement components are connected in sequence, an enhancement device is formed. The equivalent circuit of the booster is a parallel connection of a plurality of parallel plate capacitors. The equivalent capacitance of the enhancement device formed by connecting a plurality of conventional magnetic field enhancement components is the sum of the capacitances of the plurality of parallel plate capacitors. Since the capacitance is inversely proportional to the frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency increases, and the equivalent capacitance of the enhancement device formed by connecting multiple traditional magnetic field enhancement components becomes smaller. The equivalent capacitance becomes smaller, and the capacitance that requires multiple parallel plate capacitors also becomes smaller accordingly. Since the equivalent capacitance of the enhancement device formed by connecting a plurality of conventional magnetic field enhancement components is added to the capacitances of the plurality of parallel plate capacitors, the capacitances of the plurality of parallel plate capacitors require a small capacitance value. Therefore, if the capacitance values of the plurality of parallel plate capacitors are too small, the resonance frequency of the enhancement device formed by connecting a plurality of conventional magnetic field enhancement components will fluctuate greatly, resulting in poor stability of the resonance frequency.

Application content

In view of this, the present application provides a magnetic field enhancement device.

The present application provides a magnetic field enhancement device. The magnetic field enhancement device includes a plurality of magnetic field enhancement components. Each of the magnetic field enhancement components includes a first dielectric layer, a first electrode layer, a second electrode layer, and a third electrode layer. The first dielectric layer has a first end and a second end opposite to each other. The first dielectric layer also has a first surface extending from the first end to the second end.

From the first end to the second end, the first surface includes a first capacitance region, a conduction region and a second capacitance region. The conductive region is located between the first capacitive region and the second capacitive region. The first capacitance region is close to the first end. The second capacitance region is close to the second end.

The first electrode layer is disposed on the first surface. The first electrode layer extends from the first end to the second end. Two ends of the first electrode layer extend toward the first capacitance region and the second capacitance region, respectively. The second electrode layer is disposed on the first surface. The second electrode layer is located in the first capacitance region. The second electrode layer is spaced from a portion of the first electrode layer located in the first capacitance region.

The third electrode layer is disposed on the first surface. The third electrode layer is located in the second capacitance region. The third electrode layer is spaced from a portion of the first electrode layer located in the second capacitance region.

Each of the magnetic field enhancement assemblies extends from the first end to the second end. The plurality of magnetic field enhancement components are arranged at intervals and surround to form a magnetic field enhancement space. The magnetic field enhancement space is used to place the part to be measured, so as to enhance the magnetic field of the part to be measured.

The magnetic field enhancement device further includes a plurality of first resonance capacitors. The plurality of first resonance capacitors are disposed close to the first end. One of the first resonance capacitors is arranged corresponding to one of the magnetic field enhancement components. One end of each of the first resonance capacitors is electrically connected to the second electrode layer. The other end of each of the first resonant capacitors is electrically connected to a portion of the first electrode layer located in the first capacitor region. The second electrode layers of two adjacent magnetic field enhancement components are connected to the part of the first electrode layer located in the first capacitance region. It can be understood that, in two adjacent magnetic field enhancement components, the second electrode layer of one magnetic field enhancement component and the first electrode layer of the other magnetic field enhancement component are located in the first capacitance region part of the connection. On the side of the first end, the plurality of magnetic field enhancement components are connected through the second electrode layer in each of the magnetic field enhancement components and a portion of the first electrode layer located in the first capacitance region.

When the magnetic field enhancement device is installed in a magnetic field environment, an induced current will be generated. On the side of the first end, the induced current will sequentially pass through the second electrode layer, the two ends of the first resonant capacitor, the part of the first electrode layer located in the first capacitor region, and the adjacent The second electrode layer of the magnetic field enhancement component, both ends of the first resonant capacitor, and the first electrode layer are located in the part of the first capacitor region. By analogy, when equivalent to a circuit diagram, the plurality of first resonance capacitors are sequentially connected in series one by one.

The magnetic field enhancement device further includes a plurality of second resonance capacitors. The plurality of second resonance capacitors are disposed close to the second end. One of the second resonance capacitors is arranged corresponding to one of the magnetic field enhancement components. One end of each of the second resonant capacitors is electrically connected to the third electrode layer, and the other end of each of the second resonant capacitors is electrically connected to a portion of the first electrode layer located in the second capacitor region. The third electrode layers of two adjacent magnetic field enhancement components are connected to the part of the first electrode layer located in the second capacitance region. It can be understood that, in two adjacent magnetic field enhancement components, the third electrode layer of one magnetic field enhancement component and the first electrode layer of the other magnetic field enhancement component are located in the second capacitance region part of the connection. On the side of the second end, the plurality of magnetic field enhancement components are connected through the third electrode layer in each of the magnetic field enhancement components and the portion of the first electrode layer located in the second capacitance region.

When the magnetic field enhancement device is installed in a magnetic field environment, an induced current will be generated. On the side of the second end, the induced current will sequentially pass through the third electrode layer, the two ends of the second resonant capacitor, the part of the first electrode layer located in the second capacitor region, and the adjacent The third electrode layer of the magnetic field enhancement component, both ends of the second resonant capacitor, and the first electrode layer are located in the part of the second capacitor region. By analogy, when equivalent to a circuit diagram, the plurality of second resonance capacitors are sequentially connected in series one by one.

The first electrode layer, the second electrode layer and the third electrode layer are all disposed on the first surface. The first electrode layer, the second electrode layer and the third electrode layer are arranged on the same surface, and no parallel plate capacitors are formed therebetween. The first electrode layer, the second electrode layer and the third electrode layer are arranged at intervals and are not connected to each other. In the first capacitance region, the second electrode layer and the first electrode layer are disposed on the same surface with intervals. Both ends of the first resonant capacitor are electrically connected to the second electrode layer and the first electrode layer, respectively. In the second capacitor region, two ends of the second resonant capacitor are electrically connected to the third electrode layer and the first electrode layer, respectively.

When the plurality of magnetic field enhancement components are connected and located in a magnetic field environment, the plurality of first resonance capacitors are sequentially connected in series one by one. The plurality of second resonance capacitors are sequentially connected in series one by one. When the operating frequency of the high-field or ultra-high-field MRI system (3T and above) is the same as the resonance frequency of the magnetic field enhancement device, the magnetic field enhancement device can enhance the magnetic field.

Since capacitance is inversely proportional to frequency, in high-field or ultra-high-field MRI systems (3T and above), the frequency is relatively large, and the equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components needs to be small. However, connecting the plurality of first resonant capacitors in series reduces the equivalent capacitance formed by the plurality of first resonant capacitors. Connecting the plurality of second resonant capacitors in series reduces the equivalent capacitance formed by the plurality of second resonant capacitors. The capacitance after the series connection is equivalent becomes smaller, so that the first resonant capacitor 911 and the second resonant capacitor 921 before the series connection can have a large capacitance value. When the capacitance values in the resonance frequency of the magnetic field enhancement device are allocated to the plurality of first resonance capacitances and the plurality of second resonance capacitances, the plurality of first resonance capacitances and the plurality of second resonance capacitances The capacitance value of the resonant capacitor can adopt a large capacitance value, which avoids using a capacitor with an excessively small capacitance value. Using a capacitor with a large capacitance value makes the resonance frequency of the structure formed by the magnetic field enhancement device less fluctuating, improves the stability of the resonance frequency, and is more suitable for high-field MRI.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present application. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without any creative effort.

1 is a schematic diagram of an explosion structure of a magnetic field enhancement device in an embodiment provided by the application; FIG. 2 is a schematic structural diagram of a magnetic field enhancement device in an embodiment provided by the application; A plan view of a magnetic field enhancement assembly; FIG. 4 is an equivalent circuit diagram of a magnetic field enhancement device in an embodiment provided by the application; FIG. 5 is a top view of the first magnetic field enhancement assembly in an embodiment provided by the application; FIG. 6 is the application A schematic structural diagram of a magnetic field enhancement device in an embodiment provided by the application; FIG. 7 is a top view of the first magnetic field enhancement assembly in an embodiment provided by the application; FIG. 8 is a top view of the first magnetic field enhancement assembly in an embodiment provided by the application. 9 is a top view of the second magnetic field enhancement assembly in an embodiment provided by the application; Figure 10 is a schematic structural diagram of the magnetic field enhancement device in an embodiment provided by the application; Figure 11 is a magnetic field in an embodiment provided by the application. Schematic diagram of the structure of the enhancement device; FIG. 12 is a schematic diagram of the connection structure of the second magnetic field enhancement component, the third conductive structure, the fourth conductive structure, the first resonant capacitor and the second resonant capacitor in FIG. 11 provided by the application; A top view of the second magnetic field enhancement component in an embodiment provided by the application; FIG. 14 is a side view of the third magnetic field enhancement component in an embodiment provided by the application; FIG. 15 is a third magnetic field enhancement component in an embodiment provided by the application. A side view of the first end of the assembly; FIG. 16 is a side view of the second end of the third magnetic field enhancement assembly in an embodiment provided by the application; FIG. 17 is a side view of the third magnetic field enhancement assembly in an embodiment provided by the application Figure 18 is a schematic structural diagram of a magnetic field enhancement device in an embodiment provided by the application; Figure 19 is a schematic structural diagram of a magnetic field enhancement device in an embodiment provided by the application; Figure 20 is a magnetic field in an embodiment provided by the application. A comparison diagram of the resonance frequency of the enhancement device and the traditional structure; FIG. 21 is the magnetic field distribution of the magnetic field enhancement device in an embodiment provided by the application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

Referring to FIG. 1 , the present application provides a magnetic field enhancement device 20 . The magnetic field enhancement device 20 includes a plurality of first magnetic field enhancement components 10 . Each of the first magnetic field enhancement components 10 includes a first dielectric layer 100 , a first electrode layer 110 , a second electrode layer 120 and a third electrode layer 130 . The first dielectric layer 100 has a first end 103 and a second end 104 disposed opposite to each other. The first dielectric layer 100 also has a first surface 101 extending from the first end 103 to the second end 104 .

From the first end 103 to the second end 104 , the first surface 101 includes a first capacitance region 11 , a conduction region 13 and a second capacitance region 12 . The conductive region 13 is located between the first capacitance region 11 and the second capacitance region 12 . The first capacitor region 11 is close to the first end 103 . The second capacitor region 12 is close to the second end 104 .

The first electrode layer 110 is disposed on the first surface 101 . The first electrode layer 110 extends from the first end 103 to the second end 104 . Two ends of the first electrode layer 110 extend toward the first capacitor region 11 and the second capacitor region 12 respectively. The second electrode layer 120 is disposed on the first surface 101 . The second electrode layer 120 is located in the first capacitor region 11 . The second electrode layer 120 and the portion of the first electrode layer 110 located in the first capacitor region 11 are spaced apart from each other. It can be understood that, in the first capacitor region 11 , the second electrode layer 120 and the first electrode layer 110 are spaced apart from each other.

The third electrode layer 130 is disposed on the first surface 101 . The third electrode layer 130 is located in the second capacitor region 12 . The third electrode layer 130 is spaced apart from the portion of the first electrode layer 110 located in the second capacitor region 12 . It can be understood that, in the second capacitor region 12 , the third electrode layer 130 and the first electrode layer 110 are spaced apart from each other.

Referring to FIG. 2 , each of the first magnetic field enhancement components 10 extends from the first end 103 to the second end 104 . The plurality of first magnetic field enhancement components 10 are arranged at intervals and surround to form a magnetic field enhancement space 105 . The magnetic field enhancement space 105 is used to place the part to be measured, so as to enhance the magnetic field of the part to be measured.

Referring to FIG. 3 , the magnetic field enhancement device 20 further includes a plurality of first resonance capacitors 911 . The plurality of first resonant capacitors 911 are disposed close to the first end 103 . One of the first resonant capacitors 911 is provided corresponding to one of the first magnetic field enhancement components 10 . One end of each of the first resonance capacitors 911 is electrically connected to the second electrode layer 120 . The other end of each of the first resonant capacitors 911 is electrically connected to the portion of the first electrode layer 110 located in the first capacitor region 11 . The second electrode layers 120 of the two adjacent first magnetic field enhancement components 10 are connected to the portion of the first electrode layer 110 located in the first capacitance region 11 . It can be understood that, in two adjacent first magnetic field enhancement assemblies 10 , the second electrode layer 120 of one of the first magnetic field enhancement assemblies 10 and the second electrode layer 120 of the other first magnetic field enhancement assembly 10 An electrode layer 110 is connected to a portion of the first capacitor region 11 . On the side of the first end 103 , the plurality of first magnetic field enhancement components 10 are located at the location through the second electrode layer 120 and the first electrode layer 110 in each of the first magnetic field enhancement components 10 . Part of the first capacitor region 11 is connected.

When the magnetic field enhancement device 20 is installed in a magnetic field environment, an induced current will be generated. On the side of the first end 103 , the induced current will sequentially pass through the second electrode layer 120 , both ends of the first resonant capacitor 911 , and the first electrode layer 110 is located in the first capacitor region 11 . part, the second electrode layer 120 adjacent to the first magnetic field enhancement component 10 , both ends of the first resonant capacitor 911 , the part of the first electrode layer 110 located in the first capacitor region 11 , etc. . Referring to FIG. 4 , when equivalent to a circuit diagram, the plurality of first resonant capacitors 911 are sequentially connected in series one by one.

The magnetic field enhancement device 20 further includes a plurality of second resonance capacitors 921 . The plurality of second resonance capacitors 921 are disposed close to the second end 104 . One of the second resonant capacitors 921 is disposed corresponding to one of the first magnetic field enhancement components 10 . One end of each of the second resonant capacitors 921 is electrically connected to the third electrode layer 130 , and the other end of each of the second resonant capacitors 921 is located in the second capacitor region 12 with the first electrode layer 110 . part of the electrical connection. The third electrode layers 130 of two adjacent first magnetic field enhancement components 10 are connected to the portion of the first electrode layer 110 located in the second capacitance region 12 . It can be understood that, in two adjacent first magnetic field enhancement assemblies 10 , the third electrode layer 130 of one of the first magnetic field enhancement assemblies 10 and the first magnetic field enhancement assembly 10 of the other first magnetic field enhancement assembly 10 An electrode layer 110 is connected to a portion of the second capacitor region 12 . On the side of the second end 104 , the plurality of first magnetic field enhancement components 10 are located at the location through the third electrode layer 130 and the first electrode layer 110 in each of the first magnetic field enhancement components 10 . Part of the second capacitor region 12 is connected.

When the magnetic field enhancement device 20 is installed in a magnetic field environment, an induced current will be generated. On the side of the second end 104 , the induced current will sequentially pass through the third electrode layer 130 , both ends of the second resonant capacitor 921 , and the first electrode layer 110 is located in the second capacitor region 12 . part, the third electrode layer 130 adjacent to the first magnetic field enhancement component 10 , both ends of the second resonant capacitor 921 , the part of the first electrode layer 110 located in the second capacitor region 12 , etc. . Referring to FIG. 4 , when equivalent to a circuit diagram, the plurality of second resonance capacitors 921 are sequentially connected in series one by one.

The first electrode layer 110 , the second electrode layer 120 and the third electrode layer 130 are all disposed on the first surface 101 . The first electrode layer 110 , the second electrode layer 120 and the third electrode layer 130 are disposed on the same surface, and no parallel plate capacitors are formed therebetween. The first electrode layer 110 , the second electrode layer 120 and the third electrode layer 130 are spaced apart and not connected to each other. In the first capacitor region 11 , the second electrode layer 120 and the first electrode layer 110 are disposed on the same surface at intervals. Two ends of the first resonant capacitor 911 are respectively electrically connected to the second electrode layer 120 and the first electrode layer 110 . In the second capacitor region 12 , both ends of the second resonant capacitor 921 are electrically connected to the third electrode layer 130 and the first electrode layer 110 , respectively.

When the plurality of first magnetic field enhancement components 10 are connected and located in a magnetic field environment, the plurality of first resonance capacitors 911 are connected in series one by one. The plurality of second resonance capacitors 921 are sequentially connected in series one by one. When the operating frequency of the high-field or ultra-high-field MRI system (3T and above) is the same as the resonance frequency of the magnetic field enhancement device 20, the magnetic field enhancement device 20 can enhance the magnetic field.

Since the capacitance is inversely proportional to the frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency is relatively large, so that the equivalent capacitance of the enhancement device formed by connecting multiple traditional magnetic field enhancement components needs to be small. However, the series connection of the plurality of first resonant capacitors 911 reduces the equivalent capacitance formed by the plurality of first resonant capacitors 911 . The series connection of the plurality of second resonant capacitors 921 reduces the equivalent capacitance formed by the plurality of second resonant capacitors 921 . The capacitance after the series connection is equivalent becomes smaller, so that the first resonant capacitor 911 and the second resonant capacitor 921 before the series connection can have a large capacitance value. When the capacitance values in the resonance frequency of the magnetic field enhancement device 20 are allocated to the plurality of first resonance capacitances 911 and the plurality of second resonance capacitances 921, the plurality of first resonance capacitances 911 and the plurality of second resonance capacitances 921 The capacitance values of the plurality of second resonant capacitors 921 may adopt large capacitance values, so as to avoid using capacitors with too small capacitance values. Using a capacitor with a large capacitance value makes the resonance frequency of the magnetic field enhancement device 20 less fluctuating, improves the stability of the resonance frequency, and is more suitable for use in a high-field MRI system.

The magnetic field enhancement device 20 is a high-frequency MRI image enhancement metasurface device. The high-frequency MRI image-enhancing metasurface device enables the metasurface under high-frequency operation to have a larger capacitance value, and avoids using a capacitor with an excessively small capacitance value. The high-frequency MRI image-enhancing metasurface device avoids using a capacitor with an excessively small capacitance value, thereby increasing the tunability and resonant frequency stability of the high-frequency MRI image-enhancing metasurface device under high-frequency working conditions .

The high-frequency MRI image-enhancing metasurface device adopts a capacitor with a large capacitance value so that the resonance frequency of the high-frequency MRI image-enhancing metasurface device has less fluctuation. The high-frequency MRI image enhancement metasurface device adopts a capacitor with a large capacitance value, which improves the stability of the resonance frequency of the high-frequency MRI image enhancement metasurface device, and is more suitable for high-field MRI systems.

In one embodiment, the materials of the first electrode layer 110 , the second electrode layer 120 and the third electrode layer 130 may be non-magnetic metals such as copper, silver, and gold. The material of the first dielectric layer 100 may be a material with a flame-retardant material grade of FR4, a high-temperature-resistant thermoplastic resin such as polyphenylene oxide (PPE), or a Rogers 4003C material.

In one embodiment, the materials of the first electrode layer 110 , the second electrode layer 120 and the third electrode layer 130 are the same, which are copper foils.

Referring to FIG. 5 , in one embodiment, in the first capacitor region 11 , the first resonance capacitor 911 is disposed on the first surface 101 . In the second capacitor region 12 , the second resonance capacitor 921 is disposed on the first surface 101 .

In the first capacitor region 11 , the second electrode layer 120 and the first electrode layer 110 are spaced apart from each other. A first gap is formed between the opposite ports of the second electrode layer 120 and the first electrode layer 110 , and the first surface 101 is exposed. The first resonant capacitor 911 is disposed on the first surface 101 in the first space. In the second capacitance region 12 , the third electrode 130 is spaced apart from the first electrode layer 110 . A second gap is formed between the opposite ports of the third electrode 130 and the first electrode layer 110 , and the first surface 101 is exposed. The second resonance capacitor 921 is disposed on the first surface 101 in the second space.

The first resonant capacitor 911 is disposed on the first surface 101 in the first space, and two ends of the first resonant capacitor 911 can be connected with the second electrode layer 120 and the first The electrode layer 110 is electrically connected. The second resonant capacitor 921 is disposed on the first surface 101 in the second space, and two ends of the second resonant capacitor 921 can be connected with the third electrode 130 and the first electrode using fewer leads. Layer 110 is electrically connected. Since there are fewer leads connecting the capacitors, it is possible to avoid excessive inductance introduced by the leads. The resonant frequency of the magnetic field enhancement device 20 is not affected by excessive inductance. Therefore, the resonance frequency of the magnetic field enhancement device 20 has less fluctuation, which improves the stability of the resonance frequency, and is more suitable for use in a high-field MRI system.

In one embodiment, the magnetic field formed by the first electrode layer 110 in the conduction region 13 is the main magnetic field of the magnetic field enhancement device 20 . The space surrounded by the first electrode layer 110 in the conduction region 13 is the main magnetic field enhancement space. The first resonant capacitor 911 and the second resonant capacitor 921 are symmetrical with respect to the first electrode layer 110 in the conduction region 13 . The first resonant capacitor 911 and the second resonant capacitor 921 are symmetrically disposed at the first end 103 and the second end 104, respectively. The first resonant capacitor 911 and the second resonant capacitor 921 are symmetrically arranged, so that the magnetic field formed by the magnetic field enhancement device 20 is more uniform and symmetrical, which is more conducive to the detection of the detection part and improves the image quality of the MRI system. The first resonant capacitor 911 and the second resonant capacitor 921 are symmetrically arranged at the first end 103 and the second end 104 respectively, so that the first resonant capacitor 911 and the second resonant capacitor 921 are far away The magnetic field enhances the space 105 . The first resonant capacitor 911 and the second resonant capacitor 921 are far away from the magnetic field enhancement space 105, which can prevent the electric field generated by the capacitor from causing damage to the detection part.

Referring to FIG. 6 , in one embodiment, the magnetic field enhancement device 20 further includes a plurality of first conductive structures 519 and a plurality of second conductive structures 529 . The plurality of first conductive structures 519 are disposed close to the first end 103 . Each of the first conductive structures 519 is disposed between two adjacent first magnetic field enhancement components 10 . Two ends of each of the first conductive structures 519 are located in the first capacitance region 11 with the second electrode layer 120 and the first electrode layer 110 of the two adjacent first magnetic field enhancement components 10 , respectively. part of the connection. It can be understood that one end of the first conductive structure 519 is connected to the second electrode layer 120 of the first magnetic field enhancement component 10 . The other end of one of the first conductive structures 519 is connected to a portion of the first electrode layer 110 adjacent to the first magnetic field enhancement component 10 located in the first capacitance region 11 .

On the side of the first end 103 , the plurality of first magnetic field enhancement components 10 are sequentially connected through the plurality of first conductive structures 519 . The induced current will sequentially pass through the second electrode layer 120 , both ends of the first resonant capacitor 911 , the portion of the first electrode layer 110 located in the first capacitor region 11 , the first conductive structure 519 , The second electrode layer 120 of the adjacent first magnetic field enhancement component 10, both ends of the first resonant capacitor 911, the part of the first electrode layer 110 located in the first capacitor region 11, The first conductive structure 519 is described. By analogy, when equivalent to a circuit diagram, the plurality of first resonant capacitors 911 are connected in series one by one through the plurality of first conductive structures 519 .

The plurality of second conductive structures 529 are disposed close to the second end 104 . Each of the second conductive structures 529 is disposed between two adjacent first magnetic field enhancement components 10 . Two ends of each of the second conductive structures 529 are located in the second capacitance region 12 respectively with the third electrode layer 130 and the first electrode layer 110 of the two adjacent first magnetic field enhancement components 10 . part of the connection. It can be understood that one end of the second conductive structure 529 is connected to the third electrode layer 130 of the first magnetic field enhancement component 10 . The other end of one of the first conductive structures 519 is connected to a portion of the first electrode layer 110 of the adjacent first magnetic field enhancement component 10 located in the second capacitance region 12 .

On the side of the second end 104 , the plurality of first magnetic field enhancement components 10 are sequentially connected through the plurality of second conductive structures 529 . The induced current will sequentially pass through the third electrode layer 130 , both ends of the second resonant capacitor 921 , the portion of the first electrode layer 110 located in the second capacitor region 12 , the second conductive structure 529 , The third electrode layer 130 of the adjacent first magnetic field enhancement component 10, both ends of the second resonant capacitor 921, the part of the first electrode layer 110 located in the second capacitor region 12, The second conductive structure 529 is described. By analogy, when equivalent to a circuit diagram, the plurality of second resonant capacitors 921 are connected in series one by one through the plurality of second conductive structures 529 .

In one embodiment, the first conductive structure 519 and the second conductive structure 529 have a conductive function. The materials of the first conductive structure 519 and the second conductive structure 529 may be made of metal materials such as gold, silver, and copper.

Referring to FIG. 7 , in one embodiment, the magnetic field enhancement device 20 further includes a fifth diode 461 , a sixth diode 462 and a fifth external capacitor 445 . The anode of the fifth diode 461 is electrically connected to the second electrode layer 120 . The cathode of the sixth diode 462 is electrically connected to the second electrode layer 120 . One end of the fifth external capacitor 445 is electrically connected to the first electrode layer 110 located in the first capacitor region 11 , and the other end of the fifth external capacitor 445 is respectively connected to the fifth diode 461 . The cathode is electrically connected to the anode of the sixth diode 462 .

In an MRI system, it is necessary to enhance the magnetic field strength of the feedback signal from the human body during the RF receiving stage. In the radio frequency transmitting stage of the MRI system, the magnetic field energy in the transmitting stage is more than 1000 times the magnetic field energy in the receiving stage. The induced voltage in the radio frequency transmission stage of the MRI system is between tens of volts and hundreds of volts. The induced voltage in the RF receiving stage of the MRI system is less than 1V.

The fifth diode 461 and the sixth diode 462 are connected in antiparallel. In the radio frequency transmission stage of the MRI system, the radio frequency coil transmits the radio frequency transmission signal, and the field strength of the magnetic field is relatively large. The induced voltage generated by the first magnetic field enhancement component 10 is relatively large. The positive and negative voltages applied across the fifth diode 461 and the sixth diode 462 alternate. When the loaded voltage exceeds the turn-on voltage of the fifth diode 461 and the sixth diode 462, the fifth diode 461 and the sixth diode 462 are turned on. The fifth external capacitor 445 is connected in parallel with the first resonant capacitor 911 to generate parallel resonance, so that the circuit is in a high resistance state. During the radio frequency transmission stage of the MRI system, there is almost no current flow between the two adjacent first magnetic field enhancement components 10 . The first resonant capacitors 911 are respectively disconnected from the two adjacent first magnetic field enhancement components 10, no current flows, and are in a detuned state. The magnetic field generated by the magnetic field enhancement device 20 is weakened, thereby reducing the influence of the magnetic field enhancement device 20 on the magnetic field in the radio frequency transmission stage of the MRI system, thereby reducing the artifacts of the detected image and improving the clarity of the detected image.

In the radio frequency receiving stage of the MRI system, the detection part transmits a feedback signal, and the field strength of the magnetic field is small. The induced voltage generated by the first magnetic field enhancement component 10 is relatively small. The loaded voltage cannot reach the turn-on voltages of the fifth diode 461 and the sixth diode 462, and the fifth diode 461 and the sixth diode 462 are not conducting. The first resonant capacitors 911 are electrically connected to two adjacent first magnetic field enhancement components 10 respectively, and currents pass therethrough. The magnetic field enhancement device 20 is in a resonant state and plays the role of enhancing the magnetic field.

In one embodiment, the magnetic field enhancement device 20 further includes a sixth external capacitor 4451 , a first external diode 4611 and a second external diode 4622 . The connection relationship between the sixth external capacitor 4451, the first external diode 4611 and the second external diode 4622 and the second resonance capacitor 921 is the same as that of the fifth diode 461, the sixth The diode 462 and the fifth external capacitor 445 have the same connection relationship with the first resonant capacitor 911 respectively, and the working principle is also the same, for reference to the descriptions in the above embodiments.

In the radio frequency transmission stage of the MRI system, the second resonant capacitor 921 is disconnected from the two adjacent first magnetic field enhancement components 10 respectively, no current flows, and the second resonance capacitor 921 is in a detuned state. The magnetic field generated by the magnetic field enhancement device 20 is weakened, thereby reducing the influence of the magnetic field enhancement device 20 on the magnetic field in the radio frequency emission stage, thereby reducing the artifacts of the detected image and improving the clarity of the detected image. In the radio frequency receiving stage of the MRI system, the second resonant capacitors 921 are electrically connected to two adjacent first magnetic field enhancement components 10 respectively, and current flows therethrough. The magnetic field enhancement device 20 is in a resonant state and plays the role of enhancing the magnetic field.

Referring to FIG. 8 , in one embodiment, the magnetic field enhancement device 20 further includes a first depletion MOS transistor 231 and a second depletion MOS transistor 232 . The source of the first depletion MOS transistor 231 is electrically connected to the first electrode layer 110 located in the first capacitor region 11 , and the gate and drain of the first depletion MOS transistor 231 are electrically connected. connect. The gate and drain of the second depletion MOS transistor 232 are electrically connected. The gate and drain of the second depletion MOS transistor 232 are electrically connected to the gate and drain of the first depletion MOS transistor 231 . One end of the first resonant capacitor 911 is electrically connected to the source of the second depletion MOS transistor 232 . The other end of the first resonance capacitor 911 is electrically connected to the second electrode layer 120 .

The first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 are connected in series in reverse, which can control the first electrode layer 110 and the second electrode layer 120 in the radio frequency emission stage of the MRI system Disconnected and connected during the RF receive phase. By connecting the first depletion MOS transistor 231 and the second depletion MOS transistor 232 in reverse series, it can be adapted to the AC environment in the MRI system. The first depletion MOS transistor 231 and the second depletion MOS transistor 232 are connected in reverse series to ensure that the first depletion MOS transistor 231 and the second depletion MOS transistor 231 and the second depletion are in the radio frequency emission stage. One of the MOS transistors 232 is turned off, so that the circuit where the first resonant capacitor 911 is located is disconnected, and is not electrically connected to the second electrode layer 120 and the first electrode layer 110 .

The first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 have the characteristics of low-voltage on and high-voltage off. In addition, the pinch-off voltage of the first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 at room temperature is about 1V, and the turn-off time and the recovery time are both on the order of nanoseconds. In the MRI system, there is a difference in time sequence between the radio frequency transmitting phase and the radio frequency receiving phase of several tens of milliseconds to several thousand milliseconds, which can quickly realize the connection between the first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 . on and off. The RF power in the RF transmitting stage and the RF receiving stage differs by 3 orders of magnitude. The induced voltage in the coil of the RF transmission stage is between several V and several hundreds of V, and the specific value is related to the selected sequence and flip angle.

In the radio frequency transmission stage of the MRI system, the induced voltage is relatively large, and the first depletion MOS transistor 231 and the second depletion MOS transistor 232 are in a disconnected state. The circuit where the first resonant capacitor 911 is located is in an open circuit, and is not electrically connected to the second electrode layer 120 and the first electrode layer 110 . The magnetic field enhancement device 20 is in a detuned state. There is no current in the magnetic field enhancement device 20, and no induced magnetic field that would interfere with radio frequency is generated. In the radio frequency receiving stage of the MRI system, the first depletion MOS transistor 231 and the second depletion MOS transistor 232 are turned on. The circuit where the first resonant capacitor 911 is located is in a conducting state, and the two ends thereof are respectively electrically connected to the second electrode layer 120 and the first electrode layer 110 . The magnetic field enhancement device 20 can present a resonance state, greatly enhance the signal field, and enhance the image signal-to-noise ratio.

In one embodiment, the magnetic field enhancement device 20 further includes a third depletion MOS transistor 2311 and a fourth depletion MOS transistor 2321 . The source of the third depletion MOS transistor 2311 is electrically connected to the first electrode layer 110 located in the second capacitor region 12 . The gate and drain of the third depletion MOS transistor 2311 are electrically connected. The gate and drain of the fourth depletion MOS transistor 2321 are electrically connected. The gate and drain of the fourth depletion MOS transistor 2321 are electrically connected to the gate and drain of the third depletion MOS transistor 2311 . One end of the second resonant capacitor 921 is electrically connected to the source of the fourth depletion MOS transistor 2321 . The other end of the second resonance capacitor 921 is electrically connected to the third electrode layer 130 .

The connection relationship between the third depletion MOS transistor 2311, the fourth depletion MOS transistor 2321 and the second resonant capacitor 921, and the connection between the first depletion MOS transistor 231 and the second depletion MOS transistor 231 The connection relationship between the MOSFET 232 and the first resonant capacitor 911 is the same, and the working principle thereof is also the same. For details, refer to the above embodiments.

Through the connection relationship between the third depletion MOS transistor 2311, the fourth depletion MOS transistor 2321, the second resonant capacitor 921, the first depletion MOS transistor 231, the second depletion MOS transistor 231 The MOSFET 232 and the first resonant capacitor 911 form a symmetrical structure, which can further make the magnetic field more uniform and symmetrical, which is beneficial to the imaging of the MRI system.

In one embodiment, the third electrode layer 130 and the second electrode layer 120 are not collinear. The third electrode layer 130 and the second electrode layer 120 are respectively disposed on the geometric diagonal lines of the first surface 101 .

Referring to FIG. 9 , in one embodiment, the present application provides a magnetic field enhancement device 20 . The magnetic field enhancement device 20 includes a plurality of second magnetic field enhancement components 30 . Each of the second magnetic field enhancement components 30 includes a first dielectric layer 100 and a first electrode layer 110 .

In the embodiment of FIG. 9 , the first electrode layer 110 is disposed on the first surface 101 . The first electrode layer 110 extends from the first end 103 to the second end 104 . The first electrode layer 110 covers the first surface 101 . Each of the second magnetic field enhancement components 30 extends from the first end 103 to the second end 104 . Compared with the embodiment of FIG. 1 , in the second magnetic field enhancement component 30 in the embodiment of FIG. 9 , the first electrode layer 110 covers the first surface 101 , excluding the second electrode layer 120 and the the third electrode layer 130 .

Referring to FIG. 10 , the plurality of second magnetic field enhancement components 30 are arranged at intervals. The plurality of second magnetic field enhancement components 30 are surrounded to form a magnetic field enhancement space 105 .

The magnetic field enhancement device 20 further includes a plurality of first resonant capacitors 911 and a plurality of second resonant capacitors 921 . The plurality of first resonant capacitors 911 are disposed close to the first end 103 . Each of the first resonance capacitors 911 is disposed between two adjacent second magnetic field enhancement components 30 . Two ends of the first resonant capacitor 911 are respectively electrically connected to the first electrode layers 110 located in the first capacitor region 11 of two adjacent second magnetic field enhancement components 30 . It can be understood that one end of the first resonant capacitor 911 is electrically connected to the first electrode layer 110 of the second magnetic field enhancement component 30 located in the first capacitor region 11 . The other end of the first resonant capacitor 911 is electrically connected to the first electrode layer 110 located in the second capacitance region 12 of the adjacent one of the second magnetic field enhancement components 30 .

On the side of the first end 103 , the plurality of second magnetic field enhancement components 30 are connected through the plurality of first resonance capacitors 911 . When the magnetic field enhancement device 20 is installed in a magnetic field environment, an induced current will be generated. On the side of the first end 103 , the induced current will sequentially pass through the portion of the first electrode layer 110 located in the first capacitor region 11 , the two ends of the first resonant capacitor 911 , and the adjacent first capacitor 911 . The first electrode layers 110 of the two magnetic field enhancement components 30 are located in the part of the first capacitor region 11 and at both ends of the first resonance capacitor 911 . By analogy, referring to FIG. 4 , when equivalent to a circuit diagram, the plurality of first resonant capacitors 911 are sequentially connected in series one by one.

The plurality of second resonance capacitors 921 are disposed close to the second end 104 . Each of the second resonance capacitors 921 is disposed between two adjacent second magnetic field enhancement components 30 . Two ends of the second resonant capacitor 921 are respectively electrically connected to the first electrode layers 110 located in the second capacitance region 12 of two adjacent second magnetic field enhancement components 30 . It can be understood that one end of the second resonant capacitor 921 is electrically connected to the first electrode layer 110 of the second magnetic field enhancement component 30 located in the second capacitor region 12. The other end of the second resonant capacitor 921 is electrically connected to the first electrode layer 110 located in the second capacitance region 12 of the adjacent one of the second magnetic field enhancement components 30 .

On the side of the second end 104 , the plurality of second magnetic field enhancement components 30 are connected through the plurality of second resonance capacitors 921 . When the magnetic field enhancement device 20 is installed in a magnetic field environment, an induced current will be generated. On the side of the second end 104 , the induced current will sequentially pass through the portion of the first electrode layer 110 located in the second capacitance region 12 , the two ends of the second resonant capacitor 921 , and the adjacent second The first electrode layer 110 of the magnetic field enhancement component 30 is located at the part of the second capacitance region 12 and both ends of the second resonance capacitance 921 . By analogy, referring to FIG. 4 , when equivalent to a circuit diagram, the plurality of second resonance capacitors 921 are sequentially connected in series one by one.

The first electrode layer 110 covers the first surface 101 without forming a parallel plate capacitor. When the plurality of second magnetic field enhancement components 30 are connected and located in a magnetic field environment, the plurality of first resonance capacitors 911 are connected in series one by one. The plurality of second resonance capacitors 921 are sequentially connected in series one by one.

Since the capacitance is inversely proportional to the frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency is relatively large, so that the equivalent capacitance of the enhancement device formed by connecting multiple traditional magnetic field enhancement components needs to be small. However, the series connection of the plurality of first resonant capacitors 911 reduces the equivalent capacitance formed by the plurality of first resonant capacitors 911 . The series connection of the plurality of second resonant capacitors 921 reduces the equivalent capacitance formed by the plurality of second resonant capacitors 921 . The capacitance after the series connection is equivalent becomes smaller, so that the first resonant capacitor 911 and the second resonant capacitor 921 before the series connection can have a large capacitance value. When the capacitance values in the resonance frequency of the magnetic field enhancement device 20 are allocated to the plurality of first resonance capacitances 911 and the plurality of second resonance capacitances 921, the plurality of first resonance capacitances 911 and the plurality of second resonance capacitances 921 The capacitance values of the plurality of second resonant capacitors 921 may adopt large capacitance values, so as to avoid using capacitors with too small capacitance values. Using a capacitor with a large capacitance value makes the resonance frequency of the magnetic field enhancement device 20 less fluctuating, improves the stability of the resonance frequency, and is more suitable for use in a high-field MRI system.

Referring to FIG. 11 , in one embodiment, the magnetic field enhancement device 20 further includes a plurality of third conductive structures 539 and a plurality of fourth conductive structures 549 . The plurality of third conductive structures 539 are disposed close to the first end 103 . The plurality of fourth conductive structures 549 are disposed close to the second end 104 .

In one embodiment, the third conductive structure 539 and the fourth conductive structure 549 have a conductive function. The materials of the third conductive structure 539 and the fourth conductive structure 549 may be made of metal materials such as gold, silver, and copper.

Referring to FIG. 12 , each of the third conductive structures 539 is disposed on a surface of each of the first electrode layers 110 away from the first dielectric layer 100 . One of the third conductive structures 539 is disposed corresponding to one of the second magnetic field enhancement components 30 . Two ends of each of the first resonance capacitors 911 are electrically connected to two adjacent third conductive structures 539 respectively. It can be understood that one end of one of the first resonance capacitors 911 is electrically connected to one of the third conductive structures 539 . The other end of one of the first resonance capacitors 911 is electrically connected to the adjacent one of the third conductive structures 539 . When equivalent to a circuit diagram, the plurality of first resonance capacitors 911 are sequentially connected in series through the plurality of third conductive structures 539 .

Each of the fourth conductive structures 549 is disposed on a surface of each of the first electrode layers 110 away from the first dielectric layer 100 . One of the fourth conductive structures 549 is disposed corresponding to one of the second magnetic field enhancement components 30 . Two ends of each of the second resonance capacitors 921 are electrically connected to two adjacent fourth conductive structures 549 respectively. It can be understood that one end of one of the second resonant capacitors 921 is electrically connected to one of the fourth conductive structures 549 . The other end of one of the second resonance capacitors 921 is electrically connected to the adjacent one of the fourth conductive structures 549 . When equivalent to a circuit diagram, the plurality of second resonant capacitors 921 are sequentially connected in series through the plurality of fourth conductive structures 549 .

Referring to FIG. 13 , in one embodiment, the magnetic field enhancement device 20 further includes a first inductor 241 , a third diode 213 and a fourth diode 214 . One end of the first inductor 241 is electrically connected to one end of the first resonance capacitor 911 . The anode of the third diode 213 is electrically connected to the other end of the first resonance capacitor 911 . The cathode of the third diode 213 is electrically connected to the other end of the first inductor 241 . The cathode of the fourth diode 214 is electrically connected to the other end of the first resonance capacitor 911 . The anode of the fourth diode 214 is electrically connected to the other end of the first inductor 241 .

In an MRI system, it is necessary to enhance the magnetic field strength of the feedback signal from the human body during the RF receiving stage. In the radio frequency transmitting stage of the MRI system, the magnetic field energy in the transmitting stage is more than 1000 times the magnetic field energy in the receiving stage. The induced voltage in the radio frequency transmission stage of the MRI system is between tens of volts and hundreds of volts. The induced voltage in the RF receiving stage of the MRI system is less than 1V.

The third diode 213 and the fourth diode 214 are connected in antiparallel. In the radio frequency transmission stage, the radio frequency coil transmits the radio frequency transmission signal, and the field strength of the magnetic field is relatively large. The induced voltage generated by the second magnetic field enhancement component 30 is relatively large. The positive and negative voltages applied across the third diode 213 and the fourth diode 214 alternate. When the loaded voltage exceeds the turn-on voltages of the third diode 213 and the fourth diode 214, the third diode 213 and the fourth diode 214 are turned on. The third capacitor 223 is connected in parallel with the first inductor 241 , so that the first resonant capacitor 911 , the third diode 213 , the fourth diode 214 and the first inductor 241 form a The circuit is in a high impedance state. During the radio frequency transmission stage of the MRI system, there is almost no current flow between the two adjacent second magnetic field enhancement components 30 . The first resonant capacitors 911 are respectively disconnected from the first electrode layers 110 of the two adjacent second magnetic field enhancement components 30, and almost no current flows therethrough. The magnetic field generated by the magnetic field enhancement device 20 is weakened, thereby reducing the influence of the magnetic field enhancement device 20 on the magnetic field in the radio frequency emission stage, thereby reducing the artifacts of the detected image and improving the clarity of the detected image.

In the radio frequency receiving stage of the MRI system, the detection part transmits a feedback signal, and the field strength of the magnetic field is small. The induced voltage generated by the second magnetic field enhancement component 30 is relatively small. The loaded voltage cannot reach the turn-on voltages of the third diode 213 and the fourth diode 214, and the third diode 213 and the fourth diode 214 are not conducting. The first resonant capacitors 911 are respectively electrically connected to the first electrode layers 110 of two adjacent second magnetic field enhancement components 30, and currents pass therethrough. The magnetic field enhancement device 20 is in a resonant state and plays the role of enhancing the magnetic field.

In one embodiment, the magnetic field enhancement device 20 further includes a seventh diode 2131 , an eighth diode 2141 and a second inductor 2411 . The connection relationship between the seventh diode 2131 , the eighth diode 2141 and the second inductor 2411 and the second resonant capacitor 921 is the same as that of the first inductor 241 , the third second The connection relationship between the pole tube 213 and the fourth diode 214 and the first resonant capacitor 911 is the same, and the working principle is also the same. Reference may be made to the description of the above embodiments. In the radio frequency generation stage of the MRI system, the second resonant capacitors 921 are respectively disconnected from the first electrode layers 110 of the two adjacent second magnetic field enhancement assemblies 30, no current flows, and are in a detuned state. In the radio frequency receiving stage of the MRI system, the second resonant capacitors 921 are respectively electrically connected to the first electrode layers 110 of the two adjacent second magnetic field enhancement components 30, and current flows therethrough. The magnetic field enhancement device 20 is in a resonant state and plays the role of enhancing the magnetic field.

Referring to FIG. 14 , in one embodiment, the present application provides a magnetic field enhancement device 20 . The magnetic field enhancement device 20 includes a plurality of third magnetic field enhancement components 40 . Each of the third magnetic field enhancement components 40 includes a first dielectric layer 100 , a first electrode layer 110 , a second electrode layer 120 and a fourth electrode layer 140 . The first dielectric layer 100 has a first surface 101 and a second surface 102 disposed opposite to each other.

The first electrode layer 110 is disposed on the first surface 101 , extends from the first end 103 to the second end 104 , and covers the first surface 101 .

The second electrode layer 120 is disposed on the second surface 102 . The second electrode layer 120 is located in the second capacitor region 12 . The orthographic projection of the second electrode layer 120 on the first dielectric layer 100 is located in the orthographic projection of the first electrode layer 110 on the first dielectric layer 100 to form a second structural capacitor 152 .

The fourth electrode layer 140 is disposed on the second surface 102 . The fourth electrode layer 140 is spaced apart from the second electrode layer 120 . The fourth electrode layer 140 is located in the first capacitor region 11 . The orthographic projection of the fourth electrode layer 140 on the first dielectric layer 100 is located in the orthographic projection of the first electrode layer 110 on the first dielectric layer 100 to form a first structural capacitor 151 . Compared with the embodiment of FIG. 1 , in the embodiment of FIG. 14 , the first electrode layer 110 covers the first surface 101 . The second electrode layer 120 and the fourth electrode layer 140 are disposed on the second surface 102 at intervals.

Each of the third magnetic field enhancement components 40 extends from the first end 103 to the second end 104 . The plurality of third magnetic field enhancement components 40 are arranged at intervals and surround to form a magnetic field enhancement space 105 .

Referring to FIG. 15 , in the first capacitance region 11 , the first electrode layers 110 of two adjacent third magnetic field enhancement components 40 are connected to the fourth electrode layer 140 .

When the magnetic field enhancement device 20 is installed in a magnetic field environment, an induced current will be generated. On the side of the first end 103 , the first electrode layer 110 is connected to the fourth electrode layer 140 to connect two adjacent first structure capacitors 151 . The induced current will pass through the first structure capacitors 151 one by one. When equivalent to a circuit diagram, the plurality of first structure capacitors 151 are sequentially connected in series one by one.

Referring to FIG. 16 , in the second capacitance region 12 , the first electrode layers 110 of two adjacent third magnetic field enhancement components 40 are connected to the second electrode layers 120 .

When the magnetic field enhancement device 20 is installed in a magnetic field environment, an induced current will be generated. On the side of the second end 104 , the first electrode layer 110 is connected to the second electrode layer 120 to connect two adjacent second structure capacitors 152 . The induced current will pass through the second structure capacitors 152 one by one. When equivalent to a circuit diagram, the plurality of second structural capacitors 152 are sequentially connected in series one by one.

When the plurality of third magnetic field enhancement components 40 are connected and located in a magnetic field environment, the plurality of first structural capacitors 151 are connected in series one by one. The plurality of second structure capacitors 152 are sequentially connected in series one by one. When the operating frequency of the high-field or ultra-high-field MRI system (3T and above) is the same as the resonance frequency of the magnetic field enhancement device 20, the magnetic field enhancement device 20 can enhance the magnetic field.

Since the capacitance is inversely proportional to the frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency is relatively large, so that the equivalent capacitance of the enhancement device formed by connecting multiple traditional magnetic field enhancement components needs to be small. However, the plurality of first structure capacitors 151 are connected in series one by one, so that the equivalent capacitance formed by the plurality of first structure capacitors 151 becomes smaller. The plurality of second structure capacitors 152 are sequentially connected in series one by one, so that the equivalent capacitance formed by the plurality of second structure capacitors 152 becomes smaller. The capacitance after being equivalently connected in series becomes smaller, so that the plurality of second structure capacitors 152 and the plurality of first structure capacitors 151 before being equivalently connected in series can form a structure with a larger capacitance value. Using the second structure capacitor 152 and the first structure capacitor 151 with large capacitance values makes the resonance frequency of the magnetic field enhancement device 20 less fluctuating, improves the stability of the resonance frequency, and is more suitable for high-field MRI system.

In one embodiment, the magnetic field enhancement device 20 further includes a plurality of fifth conductive structures 559 and a plurality of sixth conductive structures 569 . The plurality of first structure capacitors 151 are sequentially connected in series through the plurality of fifth conductive structures 559 . The plurality of second structure capacitors 152 are sequentially connected in series through the plurality of sixth conductive structures 569 . The plurality of fifth conductive structures 559 and the plurality of sixth conductive structures 569 have conductive functions. The materials of the plurality of fifth conductive structures 559 and the plurality of sixth conductive structures 569 may be made of metal materials such as gold, silver, and copper.

Referring to FIG. 17 , in one embodiment, the magnetic field enhancement device 20 further includes a first external capacitor 440 , a first diode 431 and a second diode 432 . Two ends of the first external capacitor 440 are respectively electrically connected to the second electrode layer 120 and the part of the first electrode layer 110 located in the second capacitor region 12 . The anode of the first diode 431 is electrically connected to the portion of the first electrode layer 110 located in the second capacitor region 12 . The cathode of the first diode 431 is electrically connected to the second electrode layer 120 . The cathode of the second diode 432 is electrically connected to the portion of the first electrode layer 110 located in the second capacitor region 12 . The anode of the second diode 432 is electrically connected to the second electrode layer 120 .

It can be understood that the turn-on voltages of the first diode 431 and the second diode 432 may be 0 volts to 1 volts. In one embodiment, the turn-on voltage of the first diode 431 and the second diode 432 may be 0.8V. In the second capacitor region 12, the first diode 431 and the second diode 432 are connected in series between the first electrode layer 110 and the second electrode layer 120, respectively. The first diode 431 and the second diode 432 are connected in reverse.

due to the RF AC characteristics of the MRI system. The induced voltages generated by the first electrode layer 110 and the second electrode layer 120 are also AC voltages. In the radio frequency transmission stage of the MRI system, since the voltage difference between the first electrode layer 110 and the second electrode layer 120 has exceeded the conductance of the first diode 431 and the second diode 432 Turn on the voltage. Therefore, no matter which of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, one of the first diode 431 and the second diode 432 is always turned on. Therefore, the first electrode layer 110 and the second electrode layer 120 are electrically connected. The second structural capacitor 302 is short-circuited. The magnetic field enhancement device 20 is in a detuned state.

In the radio frequency receiving stage of the MRI system, since the voltage difference between the first electrode layer 110 and the second electrode layer 120 is smaller than the conductance of the first diode 431 and the second diode 432 Turn on the voltage. Therefore, no matter which of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, the first diode 431 and the second diode 432 are in a non-conductive state. The magnetic field enhancement device 20 is in a resonance state.

In one embodiment, in the first capacitor region 11 , the first electrode layer 110 and the fourth electrode layer 140 may also be electrically connected to the first external capacitor 440 and the first diode, respectively. The tube 431 and the second diode 432 have the same connection relationship. The magnetic field enhancement device 20 forms a symmetrical structure at the first end 103 and the second end 104 , which is more conducive to the uniform distribution of the magnetic field and improves the imaging quality of the MRI system.

In one embodiment, the element capacitance in the foregoing embodiment may be a fixed capacitance or an adjustable capacitance. After the frequency of the radio frequency coil is determined, the element capacitance can be selected as a fixed capacitance, so that the fixed capacitance cooperates with other structural capacitances and element capacitances, so that the resonant frequency of the magnetic field enhancement device 20 is equal to the frequency of the radio frequency coil, so that the to enhance the effect of the magnetic field. When the frequency of the RF coil is uncertain, the component capacitance can be adjusted. By adjusting the adjustable capacitance, the resonant frequency is adjusted, so that the magnetic field enhancement device 20 is suitable for different working environments.

Referring to FIGS. 18 and 19 , in one embodiment, the magnetic field enhancement device 20 further includes a cylindrical support structure 50 . The cylindrical support structure 50 has two spaced opposite third ends 51 and fourth ends 53 . The cylindrical support structure 50 has an inner surface 521 and an outer surface 522 disposed opposite to each other with an interval. The inner surface 521 surrounds a detection space 509 .

In one embodiment, the plurality of first magnetic field enhancement components 10 are disposed on the outer surface 522 at intervals. The magnetic field enhancement assembly 10 extends along the third end 51 to the fourth end 53 . In one embodiment, the plurality of second magnetic field enhancement components 30 are disposed on the outer surface 522 at intervals. In one embodiment, the plurality of third magnetic field enhancement components 40 are disposed on the outer surface 522 at intervals.

The detection space 509 can be used to accommodate the detection site. The detection site may be an arm, a leg, an abdomen, or the like. The distances between the plurality of first magnetic field enhancement components 10 are equal to improve the uniformity of the local magnetic field. A plurality of the first magnetic field enhancement components 10 may be disposed on the outer surface 522 of the cylindrical support structure 50 at equal intervals.

In one embodiment, a plurality of limiting structures 550 are spaced around the outer surface 522 of the cylindrical support structure 50 . In the direction from the third end 51 to the fourth end 53 , each of the first magnetic field enhancement components 10 corresponds to the limiting structure 550 and the fourth end of the third end 51 respectively The limiting structure 550 of 53. One of the first magnetic field enhancement components 10 is fixed by the limiting structures 550 at both ends of the third end 51 and the fourth end 53 , and then the first magnetic field enhancement component 10 is fixed to the cylindrical support structure 50.

In one embodiment, the limiting structure 550 may be a through groove. The through slot can be used to insert the first magnetic field enhancement assembly 10 . The two through grooves respectively confine two ends of the first magnetic field enhancement component 10 . The first magnetic field enhancement assembly 10 can be fixed on the outer surface 522 of the cylindrical support structure 50 through the limiting structure 550 .

In one embodiment, the magnetic field enhancement device 20 may include 12 pieces of the first magnetic field enhancement components 10 , which are arranged on the outer surface 522 of the cylindrical support structure 50 at equal intervals around the axis 504 .

In one embodiment, along the direction from the first end 103 to the second end 104 , the length of the first electrode layer 110 is 100 mm, and the width of the first electrode layer 110 is 15 mm. In the direction from the first end 103 to the second end 104, the first conductive structure 519, the second conductive structure 529, the third conductive structure 539, and the fourth conductive structure 549 The width is 10mm. The diameter of the magnetic field enhancement device 20 is 100 mm.

Referring to FIG. 20 , in one embodiment, the traditional structure and the magnetic field enhancement device of the present application are applied to a 7T MRI system. It can be seen that: for a magnetic field enhancement device of the same length, in order to meet the requirements of the 7T MRI system, the traditional structure The required capacitance value is 0.6pF, which is much smaller than the capacitance value of the current commonly used capacitors. However, the capacitance value required by the magnetic field enhancement device 20 in the present application is 6 pF, which is a commonly used capacitance value in the market. Compared with the capacitance value required by the traditional structure of 0.6pF, when the capacitance value is increased by 1pF, the resonant frequency of the traditional structure is reduced by 75.5MHz. However, the resonance frequency of the magnetic field enhancement device 20 of the present application is only reduced by 22.8 MHz. Therefore, in the high frequency band, the structure of the magnetic field enhancement device 20 of the present application is more stable. The magnetic field enhancement device 20 has a relatively slow rate of change of the resonant frequency with the capacitance, which makes the tuning of the structure easier to operate and is more suitable for high-field MRI. Referring to FIG. 21 , it can be seen that the magnetic field enhancement device 20 of the present application still has a highly uniform magnetic field distribution at high frequency.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the patent of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Finally, it should also be noted that in this document, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply these entities or that there is any such actual relationship or sequence between operations. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device comprising a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element. The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. The above description of the embodiments is provided to enable those skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, this application is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features provided herein.

Claims (20)

1. A magnetic field enhancement device, comprising:

   A plurality of magnetic field enhancement assemblies (10), each of the magnetic field enhancement assemblies (10) comprising:

   The first dielectric layer (100) has a first end (103) and a second end (104) arranged oppositely, the first dielectric layer (100) also has a first surface (101), formed by the first end (103) The end (103) extends to the second end (104), the first surface (101) comprises a first capacitive region (11), a conductive region (13) and a second capacitive region (12), the conductive region (13) is located between the first capacitance region (11) and the second capacitance region (12), the first capacitance region (11) is close to the first end (103), and the second capacitance region (103) zone (12) proximate said second end (104);

   a first electrode layer (110), disposed on the first surface (101), extending from the first end (103) to the second end (104);

   The second electrode layer (120) is disposed on the first surface (101) and located in the first capacitance region (11), the second electrode layer (120) and the first electrode layer (110) Parts located in the first capacitance region (11) are arranged at intervals;

   A third electrode layer (130), disposed on the first surface (101) and located in the second capacitance region (12), the third electrode layer (130) and the first electrode layer (110) Parts located in the second capacitance region (12) are arranged at intervals;

   Each of the magnetic field enhancement components (10) extends from the first end (103) to the second end (104), the plurality of magnetic field enhancement components (10) are spaced apart and surround to form a magnetic field enhancement space (105);

   a plurality of first resonant capacitors (911), arranged close to the first end (103), one of the first resonant capacitors (911) is arranged corresponding to one of the magnetic field enhancement components (10), each of the first resonant capacitors (911) One end of the resonant capacitor (911) is electrically connected to the second electrode layer (120), and the other end of each of the first resonant capacitors (911) and the first electrode layer (110) are located in the first capacitor Parts of the region (11) are electrically connected, and the second electrode layer (120) and the first electrode layer (110) of two adjacent magnetic field enhancement components (10) are located in the first capacitance region (11). ) part of the connection;

   a plurality of second resonant capacitors (921), arranged close to the second end (104), one of the second resonant capacitors (921) is arranged corresponding to one of the magnetic field enhancement components (10), each of the second resonant capacitors (921) One end of the resonant capacitor (921) is electrically connected to the third electrode layer (130), and the other end of each of the second resonant capacitors (921) and the first electrode layer (110) are located in the second capacitor Parts of the region (12) are electrically connected, and the third electrode layer (130) and the first electrode layer (110) of two adjacent magnetic field enhancement components (10) are located in the second capacitance region (12). ) part of the connection.
2. The magnetic field enhancement device according to claim 1, characterized in that, in the first capacitor region (11), the first resonance capacitor (911) is arranged on the first surface (101);

   In the second capacitance region (12), the second resonance capacitance (921) is arranged on the first surface (101).
3. The magnetic field enhancement device of claim 1, further comprising:

   a plurality of first conductive structures (519), disposed close to the first end (103), and each of the first conductive structures (519) is disposed between two adjacent magnetic field enhancement components (10);

   Two ends of each of the first conductive structures (519) are respectively located at the second electrode layer (120) and the first electrode layer (110) of the two adjacent magnetic field enhancement components (10). Part of the first capacitive region (11) is connected;

   a plurality of second conductive structures (529), disposed close to the second end (104), and each of the second conductive structures (529) is disposed between two adjacent magnetic field enhancement components (10);

   Two ends of each of the second conductive structures (529) are respectively located at the third electrode layer (130) and the first electrode layer (110) of the two adjacent magnetic field enhancement components (10). Part of the second capacitive region (12) is connected.
4. The magnetic field enhancement device of claim 1, further comprising:

   a fifth diode (461), the anode of the fifth diode (461) is electrically connected to the second electrode layer (120);

   a sixth diode (462), the cathode of which is electrically connected to the second electrode layer (120); and

   a fifth external capacitor (445), one end of the fifth external capacitor (445) is electrically connected to the first electrode layer (110) located in the first capacitor region (11), and the fifth external capacitor ( 445) is electrically connected to the cathode of the fifth diode (461) and the anode of the sixth diode (462), respectively.
5. The magnetic field enhancement device of claim 4, further comprising:

   a first external diode (4611), the anode of the first external diode (4611) is electrically connected to the first electrode layer (110) located in the second capacitance region (12);

   a second external diode (4622), the cathode of the second external diode (4622) is electrically connected to the first electrode layer (110) located in the second capacitor region (12);

   A sixth external capacitor (4451), one end of the sixth external capacitor (4451) is electrically connected to the third electrode layer (130), and the other end of the sixth external capacitor (4451) is connected to the first external capacitor The cathode of the diode (4611) is electrically connected to the anode of the second external diode (4622).
6. The magnetic field enhancement device of claim 1, further comprising:

   a first depletion MOS transistor (231), the source of the first depletion MOS transistor (231) is electrically connected to the first electrode layer (110) located in the first capacitor region (11), The gate and drain of the first depletion-mode MOS transistor (231) are electrically connected;

   A second depletion MOS transistor (232), the gate and drain of the second depletion MOS transistor (232) are electrically connected to the gate and the drain of the first depletion MOS transistor (231). Drain electrical connection;

   One end of the first resonant capacitor (911) is electrically connected to the source of the second depletion-mode MOS transistor (232), and the other end of the first resonant capacitor (911) is electrically connected to the second electrode layer ( 120) Electrical connection.
7. The magnetic field enhancement device of claim 6, further comprising:

   A third depletion MOS transistor (2311), the source of the third depletion MOS transistor (2311) is electrically connected to the first electrode layer (110) located in the second capacitor region (12), The gate and drain of the third depletion MOS transistor (2311) are electrically connected;

   a fourth depletion MOS transistor (2321), the gate and drain of the fourth depletion MOS transistor (2321) are electrically connected to the gate and the drain of the third depletion MOS transistor (2311). Drain electrical connection;

   One end of the second resonant capacitor (921) is electrically connected to the source of the fourth depletion MOS transistor (2321), and the other end of the second resonant capacitor (921) is connected to the third electrode layer (130) Electrical connection.
8. The magnetic field enhancement device according to claim 1, characterized in that, the third electrode layer (130) and the second electrode layer (120) are respectively disposed on geometric diagonals of the first surface (101) superior.
9. The magnetic field enhancement device according to claim 1, wherein the first resonant capacitor (911) and the second resonant capacitor (921) are related to the first electrode layer in the conduction region (13) (110) Symmetrical.
10. A magnetic field enhancement device, comprising:

    A plurality of magnetic field enhancement assemblies (10), each of the magnetic field enhancement assemblies (10) comprising:

    The first dielectric layer (100) has a first end (103) and a second end (104) arranged oppositely, the first dielectric layer (100) also has a first surface (101), formed by the first end (103) The end (103) extends to the second end (104), the first surface (101) comprises a first capacitive region (11), a conductive region (13) and a second capacitive region (12), the conductive region (13) is located between the first capacitance region (11) and the second capacitance region (12), the first capacitance region (11) is close to the first end (103), and the second capacitance region (103) zone (12) proximate said second end (104);

    a first electrode layer (110), disposed on the first surface (101), extending from the first end (103) to the second end (104), and covering the first surface (101);

    Each of the magnetic field enhancement components (10) extends from the first end (103) to the second end (104), the plurality of magnetic field enhancement components (10) are spaced apart and surround to form a magnetic field enhancement space (105);

    A plurality of first resonant capacitors (911) are arranged close to the first end (103), and each of the first resonant capacitors (911) is arranged between two adjacent magnetic field enhancement components (10), so Both ends of the first resonant capacitor (911) are respectively electrically connected to the first electrode layers (110) located in the first capacitance region (11) of two adjacent magnetic field enhancement components (10);

    A plurality of second resonant capacitors (921) are arranged close to the second end (104), each of the second resonant capacitors (921) is arranged between two adjacent magnetic field enhancement components (10), so Two ends of the second resonant capacitor (921) are respectively electrically connected to the first electrode layers (110) located in the second capacitance region (12) of two adjacent magnetic field enhancement components (10).
11. The magnetic field enhancement device of claim 10, further comprising:

    A plurality of third conductive structures (539) are disposed close to the first end (103), and each of the third conductive structures (539) is disposed on each of the first electrode layers (110) away from the first end (103). a surface of a dielectric layer (100);

    Two ends of each of the first resonant capacitors (911) are respectively electrically connected to two adjacent third conductive structures (539);

    A plurality of fourth conductive structures (549) are disposed close to the second end (104), and each of the fourth conductive structures (549) is disposed on each of the first electrode layers (110) away from the first electrode layer (110). a surface of a dielectric layer (100);

    Two ends of each of the second resonance capacitors (921) are respectively electrically connected to two adjacent fourth conductive structures (549).
12. The magnetic field enhancement device of claim 10, further comprising:

    a first inductor (241), one end of the first inductor (241) is electrically connected to one end of the first resonant capacitor (911);

    A third diode (213), the anode of the third diode (213) is electrically connected to the other end of the first resonant capacitor (911), and the cathode of the third diode (213) is electrically connected to The other end of the first inductor (241) is electrically connected;

    a fourth diode (214), the cathode of the fourth diode (214) is electrically connected to the other end of the first resonant capacitor (911), and the anode of the fourth diode (214) is electrically connected to The other end of the first inductor (241) is electrically connected.
13. The magnetic field enhancement device of claim 12, further comprising:

    a second inductor (2411), one end of the second inductor (2411) is electrically connected to one end of the second resonance capacitor (921);

    A seventh diode (2131), the anode of the seventh diode (2131) is electrically connected to the other end of the second resonant capacitor (921), and the cathode of the seventh diode (2131) is electrically connected to The other end of the second inductor (2411) is electrically connected;

    The eighth diode (2141), the cathode of the eighth diode (2141) is electrically connected to one end of the second resonant capacitor (921), and the anode of the eighth diode (2141) is electrically connected to the The other end of the second inductor (2411) is electrically connected.
14. A magnetic field enhancement device, comprising:

    A plurality of magnetic field enhancement assemblies (10), each of the magnetic field enhancement assemblies (10) comprising:

    A first dielectric layer (100) having a first end (103) and a second end (104) arranged oppositely, the first dielectric layer (100) having a first surface (101) and a second surface (101) oppositely arranged 102), extending from the first end (103) to the second end (104), and the first surface (101) includes a first capacitive region (11), a conductive region (13) and a second capacitive region (12), the conduction region (13) is located between the first capacitance region (11) and the second capacitance region (12), and the first capacitance region (11) is close to the first end ( 103), the second capacitance region (12) is close to the second end (104);

    a first electrode layer (110), disposed on the first surface (101), extending from the first end (103) to the second end (104), and covering the first surface (101);

    A second electrode layer (120), disposed on the second surface (102) and located in the second capacitance region (12), the second electrode layer (120) on the first dielectric layer (100) The orthographic projection of is located in the orthographic projection of the first electrode layer (110) on the first dielectric layer (100), forming a second structural capacitor (152);

    A fourth electrode layer (140) is arranged on the second surface (102), is arranged spaced apart from the second electrode layer (120), and is located in the first capacitance region (11), the fourth electrode The orthographic projection of the layer (140) on the first dielectric layer (100) is located in the orthographic projection of the first electrode layer (110) on the first dielectric layer (100), forming a first structural capacitor (151) ;

    Each of the magnetic field enhancement components (10) extends from the first end (103) to the second end (104), the plurality of magnetic field enhancement components (10) are spaced apart and surround to form a magnetic field enhancement space (105);

    In the first capacitance region (11), the first electrode layers (110) of two adjacent magnetic field enhancement components (10) are connected to the fourth electrode layer (140);

    In the second capacitance region (12), the first electrode layers (110) of two adjacent magnetic field enhancement components (10) are connected to the second electrode layer (120).
15. The magnetic field enhancement device of claim 14, further comprising:

    a first external capacitor (440), two ends of the first external capacitor (440) are respectively located in the second capacitor region (12) with the second electrode layer (120) and the first electrode layer (110) ) part of the electrical connection;

    a first diode (431), the anode of the first diode (431) is electrically connected to the part of the first electrode layer (110) located in the second capacitance region (12), the first The cathode of the diode (431) is electrically connected to the second electrode layer (120);

    A second diode (432), the cathode of the second diode (432) is electrically connected to the part of the first electrode layer (110) located in the second capacitance region (12), the second The anode of the diode (432) is electrically connected to the second electrode layer (120).
16. The magnetic field enhancement device of claim 14, further comprising:

    a plurality of fifth conductive structures (559), the plurality of fifth conductive structures (559) sequentially connecting the plurality of first structure capacitors (151) in series;

    A plurality of sixth conductive structures (569), wherein the plurality of sixth conductive structures (569) sequentially connect the plurality of second structure capacitors (152) in series.
17. The magnetic field enhancement device of claim 14, further comprising:

    a cylindrical support structure (50) having two spaced opposite third ends (51) and fourth ends (53);

    The magnetic field enhancement assembly (10) extends along the third end (51) to the fourth end (53).
18. The magnetic field enhancement device according to claim 17, characterized in that, the cylindrical support structure (50) has an inner surface (521) and an outer surface (522) arranged opposite to each other at a distance;

    The plurality of magnetic field enhancement components (10) are arranged on the outer surface (522) at intervals.
19. The magnetic field enhancement device of claim 18, further comprising:

    a plurality of limiting structures (550), disposed on the outer surface (522), and respectively disposed on the third end (51) and the fourth end (53);

    Along the direction from the third end (51) to the fourth end (53), each of the magnetic field enhancement components (10) corresponds to the limiting structure (550) of the third end (51) respectively ) and the limiting structure (550) of the fourth end (53).
20. The magnetic field enhancement device according to claim 19, wherein the limiting structure (550) is a through groove.

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