Antenna assembly and implantable medical device

Abstract

The invention belongs to the technical field of biomedical telemetry, and provides an antenna assembly and implantable medical device.The antenna assembly comprises a first dielectric substrate, a radiation unit, a second dielectric substrate, a grounding plate, a short-circuit probe and a feed probe, the first dielectric substrate, the radiation unit, the second dielectric substrate and the grounding plate are sequentially arranged in a stacked mode, the radiation unit is in an annular shape, and the short-circuit probe is arranged on the second dielectric substrate; the feed probe is electrically connected between the radiation unit and the grounding plate, the short-circuit probe is electrically connected between the radiation unit and the grounding plate, and the grounding plate is provided with a groove body structure. The invention aims to solve the technical problem of narrow bandwidth of an implantable antenna in the prior art.

Description

Technical Field

[0001] The present application belongs to the field of biomedical telemetry technology, and in particular, relates to an antenna assembly and an implantable medical device. Background Art

[0002] Implantable antennas are key components for communication between medical devices placed inside a living body and external receivers. Antennas are essential for establishing wireless communication links inside and outside a living body. Brain-computer interface technology aims to establish a communication link between the human brain and external control devices. Currently, some brain-computer interface devices contain thousands of electrode contacts, and the density and frequency of the collected EEG signals are high, and the data density that needs to be transmitted is high.

[0003] Currently, the implantable antennas that are well known to everyone are used in pacemakers, capsule endoscopes, cochlear implants, etc. However, the frequency band of such general implantable antennas is narrow and cannot meet the needs of high data flow transmission of brain-computer interfaces. Summary of the invention

[0004] The purpose of the present application is to provide an antenna assembly and an implantable medical device, aiming to solve the technical problem of narrow bandwidth of implantable antennas in the prior art.

[0005] The first object of the present application is to provide an antenna assembly, comprising a first dielectric substrate, a radiating unit, a second dielectric substrate, a grounding plate, a short-circuit probe and a feeding probe, wherein the first dielectric substrate, the radiating unit, the second dielectric substrate and the grounding plate are stacked in sequence, the radiating unit is ring-shaped, the feeding probe is electrically connected between the radiating unit and the grounding plate, the short-circuit probe is electrically connected between the radiating unit and the grounding plate, and a slot structure is provided on the grounding plate.

[0006] In one embodiment, the slot structure includes a first slot, a second slot and a third slot, the first slot, the second slot and the third slot are connected in sequence and arranged around the central axis of the feeding probe, and the first slot and the third slot are spaced apart.

[0007] In one embodiment, the notch of the first groove extends along a first direction, the notch of the second groove extends along a second direction, and the notch of the third groove extends along a third direction, and the first direction and the third direction are both perpendicular to the second direction.

[0008] In one embodiment, the groove structure further includes a fourth groove, the fourth groove is extended along the second direction, and the fourth groove is configured at an end of the third groove away from the second groove, and the fourth groove is connected to the third groove.

[0009] In one embodiment, the slot structure further includes a fifth slot, the fifth slot is extended along the second direction, and the fifth slot is arranged on a side of the second slot away from the central axis of the feeding probe and is connected to the second slot.

[0010] In one of the embodiments, the extension length of the notch of the first groove along the first direction ranges from 2.5mm to 7mm, and the width of the notch of the first groove in the direction perpendicular to the first direction ranges from 1mm to 2mm; the extension length of the notch of the second groove along the second direction ranges from 4mm to 7mm, and the width of the notch of the second groove in the direction perpendicular to the second direction ranges from 0.5mm to 1mm; the extension length of the notch of the third groove along the third direction ranges from 5mm to 10mm, and the width of the notch of the third groove in the direction perpendicular to the third direction ranges from 1mm to 2mm; the extension length of the notch of the fourth groove along the second direction ranges from 2mm to 4mm, and the width of the notch of the fourth groove in the direction perpendicular to the second direction ranges from 1mm to 2mm; the extension length of the notch of the fifth groove along the second direction ranges from 2.5mm to 4mm, and the width of the notch of the fifth groove in the direction perpendicular to the second direction ranges from 1mm to 2mm.

[0011] In one embodiment, the radiation unit includes a ring piece structure, a microstrip line structure and a group-pair piece structure, a receiving space is formed in the middle of the ring piece structure, the group-pair piece structure is arranged in the receiving space, and the group-pair piece structure is connected to the ring piece structure through a microstrip line structure; one end of the feeding probe is connected to the group-pair piece structure, and one end of the short-circuit probe is connected to the ring piece structure.

[0012] In one embodiment, the pair of sheet structures are arranged at the center of the ring structure.

[0013] In one embodiment, the outer ring contour line of the ring piece structure is circular, the inner ring contour line of the ring piece structure is elliptical, and the ratio of the major axis to the minor axis of the ellipse is in the range of 1.0-1.5.

[0014] A second object of the present application is to provide an implantable medical device, comprising an antenna assembly as described in any one of the above items.

[0015] The beneficial effects of the antenna assembly and implantable medical device of the present application compared with the prior art are as follows: compared with the prior art, in the antenna assembly and implantable medical device, the first dielectric substrate, the radiation unit, the second dielectric substrate and the ground plate are sequentially stacked, and a short-circuit probe is arranged between the radiation unit and the ground plate, so that the number of resonance points can be increased, which is beneficial to improving the impedance matching of the antenna and reducing the resonant frequency of the antenna; in addition, by providing a slot structure on the ground plate, the impedance matching of the antenna can be improved, the impedance matching is optimized, and the bandwidth and frequency bandwidth are expanded; furthermore, the radiation unit adopts a ring structure, which is beneficial to increase the path of the effective current of the antenna, thereby reducing the size of the antenna and increasing the bandwidth of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 is a structural schematic diagram of an antenna assembly provided in an embodiment of the present application;

[0018] Figure 2 yes Figure 1 A cross-sectional view of

[0019] Figure 3 yes Figure 1 Exploded view of;

[0020] Figure 4 yes Figure 1 Schematic diagram of the structure of the middle radiation unit;

[0021] Figure 5 yes Figure 1 Schematic diagram of the structure of the middle ground plate;

[0022] Figure 6 yes Figure 5 Schematic diagram of shape parameters of the corresponding ground plate;

[0023] Figure 7 It is a simulation curve diagram of the reflection coefficient of an antenna assembly provided in an embodiment of the present application in a single layer of dura mater of head tissue changing with frequency;

[0024] Figure 8 This is a simulation curve diagram of the reflection coefficient of an antenna assembly provided in an embodiment of the present application changing with frequency in a multi-layer head tissue.

[0025] Explanation of the reference numerals: 1. first dielectric substrate; 2. radiation unit; 21. ring plate structure; 22. microstrip line structure; 23. group-pair plate structure; 24. accommodating space; 3. second dielectric substrate; 4. ground plate; 41. slot structure; 411. first groove; 412. second groove; 413. third groove; 414. fourth groove; 415. fifth groove; 5. feeding probe; 6. short-circuit probe. DETAILED DESCRIPTION

[0026] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0027] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "upward", "vertical", "horizontal", "bottom", "inside", "outside", "inner side", "outer side" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0028] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0031] See also Figure 1 and Figure 2 and Figure 3As shown, an embodiment of the present application provides an antenna assembly, which includes a first dielectric substrate 1, a radiation unit 2, a second dielectric substrate 3, a grounding plate 4, a short-circuit probe 6 and a feeding probe 5. The first dielectric substrate 1, the radiation unit 2, the second dielectric substrate 3 and the grounding plate 4 are stacked in sequence, the radiation unit 2 is ring-shaped, the feeding probe 5 is electrically connected between the radiation unit 2 and the grounding plate 4, the short-circuit probe 6 is electrically connected between the radiation unit 2 and the grounding plate 4, and a slot structure 41 is opened on the grounding plate 4.

[0032] For the convenience of description, refer to Figure 1 The positional relationship of the antenna components in the figure defines the thickness direction or stacking direction of the antenna components as the up and down direction or the vertical direction. Therefore, it can be seen that the first dielectric substrate 1, the radiation unit 2, the second dielectric substrate 3 and the ground plate 4 are stacked in sequence from top to bottom. Of course, it can also be from bottom to top.

[0033] Specifically, the antenna assembly includes two dielectric substrate structures, namely a first dielectric substrate 1 and a second dielectric substrate 3 ; the first dielectric substrate 1 is located above the second dielectric substrate 3 , and the radiation unit 2 is sandwiched between the first dielectric substrate 1 and the second dielectric substrate 3 .

[0034] The shapes and sizes of the first dielectric substrate 1 and the second dielectric substrate 3 can be matched consistently, and the outer contours of the first dielectric substrate 1 and the second dielectric substrate 3 can be circular or rectangular; the preparation materials of the first dielectric substrate 1 and the second dielectric substrate 3 are both biocompatible Kapton Polymide (polyimide film), and the relative dielectric constant can be selected to be 3.5, so as to achieve the purpose of isolating the radiation unit 2 from the tissue and improving biosafety.

[0035] The radiation unit 2 is made of metal material and is used to carry current. The radiation unit 2 is in a ring shape, which increases the path of the effective current of the antenna, is beneficial to reducing the size of the antenna, and is beneficial to increasing the bandwidth of the antenna; in addition, a plurality of curved slits can be opened or etched on the radiation unit 2 to form a winding structure, thereby further extending the effective current and further reducing the size of the antenna. By adjusting the position and size of the slits, the two resonance points can be brought close to each other, which is beneficial to increasing the bandwidth of the antenna.

[0036] The grounding plate 4 is also made of metal material. The grounding plate 4 is connected to the side of the second dielectric substrate 3 facing away from the radiation unit 2. A slot structure 41 is opened on the grounding plate 4. The slot structure 41 may include multiple independent or multiple interconnected grooves. By opening the grooves, the capacitance (or capacitive impedance) of the antenna impedance can be improved, thereby optimizing the impedance matching, expanding the bandwidth of the high-frequency resonance point position, and a new resonance point appears at the low-frequency position, thereby achieving the purpose of expanding the bandwidth and frequency width.

[0037] The short-circuit probe 6 is electrically connected between the radiation unit 2 and the ground plate 4. The radiation unit 2 and the ground plate 4 are short-circuited by the short-circuit probe 6. The installation position of the short-circuit probe 6 is located at the position of the current zero point. The short-circuit probe 6 runs through the second dielectric substrate 3. The setting of the short-circuit probe 6 increases the capacitive value of the antenna impedance, improves the impedance matching of the antenna, can reduce the resonant frequency of the antenna, and make the antenna have a new resonance point at 1.4GHz, which is conducive to reducing the size of the antenna.

[0038] The feeding probe 5 is electrically connected between the radiation unit 2 and the ground plate 4 . The radiation unit 2 and the ground plate 4 are connected via the feeding probe 5 . The short-circuit probe 6 runs through the second dielectric substrate 3 .

[0039] In this embodiment, the first dielectric substrate 1, the radiation unit 2, the second dielectric substrate 3 and the grounding plate 4 are stacked in sequence, and a short-circuit probe 6 is arranged between the radiation unit 2 and the grounding plate 4, so that the number of resonance points can be increased, which is beneficial to improving the impedance matching of the antenna and reducing the resonant frequency of the antenna; in addition, by providing a slot structure 41 on the grounding plate 4, the impedance matching of the antenna can be improved, the impedance matching can be optimized, and the bandwidth and frequency bandwidth can be expanded; furthermore, the radiation unit 2 adopts a ring structure, which is beneficial to increase the path of the effective current of the antenna, thereby reducing the size of the antenna and increasing the bandwidth of the antenna.

[0040] In one embodiment, referring to Figure 3 and Figure 5 As shown, the slot structure 41 includes a first slot 411 , a second slot 412 and a third slot 413 . The first slot 411 , the second slot 412 and the third slot 413 are connected in sequence and arranged around the central axis of the feeding probe 5 . The first slot 411 and the third slot 413 are spaced apart.

[0041] Specifically, the first groove 411 , the second groove 412 and the third groove 413 may be through grooves, and the first groove 411 , the second groove 412 and the third groove 413 penetrate the thickness direction of the grounding plate 4 or penetrate to the upper and lower surfaces of the grounding plate 4 .

[0042] The notch of the first groove 411, the notch of the second groove 412 and the notch of the third groove 413 can all be extended in a linear shape, an extended end of the notch of the first groove 411 is connected to an extended end of the notch of the second groove 412, and the other extended end of the notch of the second groove 412 is connected to an extended end of the notch of the third groove 413; the extension direction of the notch of the first groove 411 is set at an angle with the extension direction of the notch of the second groove 412, and the range of the angle is 0°-180°, but does not include 0° and 180°; the extension direction of the notch of the third groove 413 is set at an angle with the extension direction of the notch of the second groove 412 The angle setting ranges from 0° to 180°, but does not include 0° and 180°. The bending direction of the third groove 413 relative to the second groove 412 is consistent with the bending direction of the first groove 411 relative to the second groove 412. The first groove 411 and the third groove 413 are located on the same side of the extension direction of the second groove 412. Therefore, it can be seen that the first groove 411, the second groove 412 and the third groove 413 are arranged in a ring shape with an opening, and the other extending end of the first groove 411 and the other extending end of the third groove 413 are spaced apart and not connected.

[0043] In this embodiment, the central axis of the first groove 411, the second groove 412 and the third groove 413 is the central axis of the feeding probe 5, so that the groove structure 41 is arranged in a circumferential direction of the feeding probe 5. The uniformity and symmetry of the groove length and the groove area of ​​the groove structure 41 are more conducive to improving the capacitive impedance of the antenna, thereby optimizing the impedance matching, increasing the number of resonance points, expanding the bandwidth of the high-frequency resonance point position, and a new resonance point appears at the low-frequency position, thereby achieving the purpose of expanding the bandwidth and frequency width.

[0044] In one embodiment, referring to Figure 3 and Figure 5 As shown, the notch of the first groove 411 extends along the first direction X, the notch of the second groove 412 extends along the second direction Y, and the notch of the third groove 413 extends along the third direction Z. The first direction X and the third direction Z are both perpendicular to the second direction Y.

[0045] Specifically, the first direction X is perpendicular to the second direction Y. It can be seen that the extension direction of the notch of the first groove 411 is perpendicular to the extension direction of the notch of the second groove 412. The third direction Z is perpendicular to the second direction Y. It can be seen that the extension direction of the notch of the third groove 413 is perpendicular to the extension direction of the notch of the second groove 412. The third groove 413 and the first groove 411 are symmetrically arranged at both ends of the second groove 412. Therefore, it can be understood that the first groove 411, the second groove 412 and the third groove 413 are connected and surrounded to form a "U" shape, and the groove body structure 41 can also be called a U-shaped groove structure.

[0046] Among them, combined Figure 6 As shown, the extension length of the notch of the first groove 411 along the first direction X ranges from 2.5 mm to 7 mm, and the width of the notch of the first groove 411 perpendicular to the first direction X ranges from 1 mm to 2 mm. For example, the extension length L1 of the notch of the first groove 411 is 7 mm, and the width W1 of the notch of the first groove 411 is 1.5 mm.

[0047] Combination Figure 6 As shown, the extension length range of the notch of the second groove 412 along the second direction Y is 4mm to 7mm, and the width range of the notch of the second groove 412 perpendicular to the second direction Y is 0.5mm to 1mm. For example, the extension length L2 of the notch of the second groove 412 is 5mm, and the width W2 of the notch of the second groove 412 is 0.7mm.

[0048] Combination Figure 6 As shown, the extension length range of the notch of the third groove 413 along the third direction Z is 5mm to 10mm, and the width range of the notch of the third groove 413 perpendicular to the third direction Z is 1mm to 2mm. For example, the extension length L2 of the notch of the third groove 413 is 9mm, and the width W3 of the notch of the third groove 413 is 1.5mm.

[0049] In this embodiment, the symmetry of the circumferential distribution of the first groove 411, the second groove 412 and the third groove 413 in the feeding probe 5 is enhanced. By controlling the extended length and width dimensions of the first groove 411, the second groove 412 and the third groove 413, the capacitive impedance of the antenna is further improved, the impedance matching is optimized, the number of resonance points is increased, the bandwidth of the high-frequency resonance point position is extended, and more resonance points appear at the low-frequency position, thereby achieving the purpose of extending the bandwidth and frequency width.

[0050] In one embodiment, referring to Figure 3 and Figure 5 As shown, the groove body structure 41 also includes a fourth groove 414, the groove opening of the fourth groove 414 is extended along the second direction Y, and the fourth groove 414 is arranged at an end of the third groove 413 away from the second groove 412, the fourth groove 414 is connected with the third groove 413, and the fourth groove 414 can also be a through groove, which passes through the upper surface and the lower surface of the grounding plate 4.

[0051] Specifically, the fourth groove 414 is arranged opposite to the second groove 412, the notch extension direction of the fourth groove 414 is perpendicular to the notch extension direction of the third groove 413, and the fourth groove 414 is arranged opposite to and parallel to the second groove 412. Figure 6As shown, the extension length range of the notch of the fourth groove 414 along the second direction Y is 2mm to 4mm, and the width range of the notch of the fourth groove 414 perpendicular to the second direction Y is 1mm to 2mm. For example, the extension length L4 of the fourth groove 414 is 3.5mm, and the width W4 of the notch of the fourth groove is 1.8mm.

[0052] In this embodiment, the first groove 411, the second groove 412, the third groove 413 and the fourth groove 414 are connected end to end in sequence, and are arranged around the central axis of the feeding probe 5 to form an annular through space with an opening, thereby changing the shape and size of the groove structure 41. By adding the fourth groove 414, the quality factor Q value of the antenna is reduced, and two adjacent resonance points can be merged into a wide bandwidth. The capacitive impedance of the antenna is further improved, the impedance matching is improved, and the number of resonance points is increased, thereby achieving the purpose of expanding the bandwidth and frequency bandwidth.

[0053] In one embodiment, referring to Figure 3 and Figure 5 As shown, the slot structure 41 further includes a fifth slot 415 , the slot opening of the fifth slot 415 extends along the second direction Y, and the fifth slot 415 is disposed on a side of the second slot 412 away from the central axis of the feeding probe 5 , and is connected to the second slot 412 .

[0054] Specifically, the slot extension direction of the fifth groove 415 is parallel to the slot extension direction of the second groove 412, the fifth groove 415 is located beside the slot extension direction of the second groove 412, and the fifth groove 415 is located outside the second groove 412, the outside refers to the side of the second groove 412 away from the feeding probe 5, and the slot wall of the fifth groove 415 is connected with the slot wall of the second groove 412; Figure 6 As shown, the extension length range of the notch of the fifth groove 415 along the second direction Y is 2.5mm~4mm, and the width range of the notch of the fifth groove 415 perpendicular to the second direction Y is 1mm~2mm; for example, the extension length L5 of the fifth groove 415 is 3mm, and the width W5 of the notch of the fifth groove 415 is 1mm.

[0055] In this embodiment, by adding the fifth groove 415, the quality factor Q value of the antenna is further reduced, the capacitive impedance of the antenna is further improved, the impedance matching degree is improved, and the number of resonance points is increased, thereby achieving the purpose of expanding the bandwidth and frequency bandwidth; the design of the overall groove structure 41 can enable the antenna to excite new resonance points at low frequencies, and by adjusting the sizes of the first groove 411, the second groove 412, the third groove 413, the fourth groove 414 and the fifth groove 415 on the surface of the ground plate 4, the impedance matching within the bandwidth is improved, thereby expanding the bandwidth of the antenna.

[0056] In one embodiment, referring to Figure 3 and Figure 4 As shown, the radiation unit 2 includes a ring sheet structure 21, a microstrip line structure 22 and a group-pair sheet structure 23. A receiving space 24 is formed in the middle of the ring sheet structure 21. The group-pair sheet structure 23 is arranged in the receiving space 24, and the group-pair sheet structure 23 is connected to the ring sheet structure 21 through the microstrip line structure 22; one end of the feeding probe 5 is connected to the group-pair sheet structure 23, and one end of the short-circuit probe 6 is connected to the ring sheet structure 21.

[0057] Specifically, the first dielectric substrate 1, the radiation unit 2, the second dielectric substrate 3 and the ground plane 4 are all sheet-like or layered structures, wherein the radiation unit 2 includes a ring-shaped ring sheet structure 21, a strip-shaped microstrip line structure 22 and a sheet-like group-pair sheet structure 23.

[0058] Among them, the ring-piece structure 21 is in a circular ring shape or a rectangular ring shape, that is, the middle area of ​​the ring-piece structure 21 forms a accommodating space 24, and the accommodating space 24 is a through-hole structure. The outer ring contour line of the ring-piece structure 21 is in a circular, elliptical or rectangular shape, and the inner ring contour line of the ring-piece structure 21 is in a circular, elliptical or rectangular shape.

[0059] In a possible embodiment, the outer ring contour line of the ring-piece structure 21 is circular, and the radius of the circle is R=6mm. The inner ring contour line of the ring-piece structure 21 is elliptical, and the major axis radius of the ellipse is R=5mm~5.5mm. The ratio of the major axis to the minor axis of the ellipse is 1.0-1.5. For example, the major axis radius of the ellipse can be selected to be R=5.2mm, and the ratio of the major axis to the minor axis of the ellipse is 1.2.

[0060] The paired sheet structure 23 is located in the accommodating space 24 . The paired sheet structure 23 is spaced apart from the inner ring of the ring sheet structure 21 . The paired sheet structure 23 is connected to the upper end of the feeding probe 5 . The paired sheet structure 23 may be in the shape of a disc.

[0061] The microstrip line structure 22 is used to connect the ring sheet structure 21 and the group-pair sheet structure 23 , and plays a bridge role between the ring sheet structure 21 and the group-pair sheet structure 23 . By adding the microstrip line structure 22 , the current path can be increased.

[0062] In this embodiment, by designing the radiation unit 2 into a circular ring shape and providing an accommodating space 24, the feeding probe 5 can be connected to the ring structure 21 through the microstrip line structure 22 from the middle area of ​​the radiation unit 2, which is beneficial to increasing the effective current path, while maintaining a small size while increasing multiple resonance points, thereby widening the impedance bandwidth of the antenna, and being able to generate multiple resonance points to improve impedance matching.

[0063] In one embodiment, the antenna assembly further includes a third dielectric substrate and a rectifier circuit. The third dielectric substrate is located on a side of the grounding plate 4 facing away from the second dielectric substrate 3 . The rectifier circuit is connected to a side of the third substrate facing away from the grounding plate 4 .

[0064] In this embodiment, the rectifier circuit is integrated on the back of the antenna assembly and is designed to be integrated with the antenna as a whole, which reduces the volume of the rectifier antenna and helps to reduce the overall space occupied by the antenna assembly.

[0065] The above antenna assembly is implanted into human tissue for simulation. The simulation conditions and contents are as follows: In order to be close to the human body environment, the implantable antenna needs to be simulated in an environment simulating human tissue. Generally, a single-layer head or multi-layer head tissue model is used to simulate the implantable antenna. The dielectric constant and conductivity of the human tissue are set to change with the frequency. The simulation environment size of the simulated head tissue is 60mm×60mm×60mm.

[0066] Reference Figure 7 As shown, Figure 7 This is a simulation curve chart of the reflection coefficient of the antenna assembly in the single-layer dura mater (Dura) of the head tissue varying with frequency. The size of Dura is set to 60mm×60mm×60mm, and the antenna assembly is placed in the center of the cubic human body phantom. The horizontal axis is the frequency in GHz, and the vertical axis is the value of the reflection coefficient S11 in dB. It can be seen from the figure that the -10dB operating bandwidth of the antenna in the single-layer head tissue is 3460MHz (800MHz~4260MHz), covering the ISM band and WMTM band.

[0067] Reference Figure 8 As shown, Figure 8 This is a simulation curve diagram of the reflection coefficient of the antenna component changing with frequency in the multi-layer head tissue. The cross-sectional size of the human head phantom is 60mm×60mm. The thickness of each layer of tissue from the outside to the inside is: skin (Skin) 0.5mm, fat (Fat) 0.5mm, skull (Bone) 3mm, dura (Dura) 0.5mm, cerebrospinal fluid (CSF) 0.5mm, brain (Brain) 30mm. The antenna is placed between the skull (Bone) and the dura (Dura), and the implantation depth is 4mm. Figure 8 The horizontal axis is frequency in GHz, and the vertical axis is the value of the reflection coefficient S11 in dB. It can be seen from the figure that the antenna assembly operates at four frequency points, namely 900 MHz, 1.5 GHz, 2.15 GHz and 4 GHz. Its -10dB working bandwidth covers 760 MHz to 4570 MHz, and the relative bandwidth is 142.96%.

[0068] An embodiment of the present application further provides an implantable medical device, which includes the antenna assembly in the above embodiment; the diameter of the implantable medical device is between 10 mm and 20 mm.

[0069] In this embodiment, the antenna component in the implantable medical device is stacked in sequence by a first dielectric substrate 1, a radiation unit 2, a second dielectric substrate 3 and a grounding plate 4, and a short-circuit probe 6 is arranged between the radiation unit 2 and the grounding plate 4, so that the number of resonance points can be increased, which is beneficial to improving the impedance matching of the antenna and reducing the resonant frequency of the antenna; in addition, by providing a slot structure 41 on the grounding plate 4, the impedance matching of the antenna can be improved, the impedance matching can be optimized, and the bandwidth and frequency bandwidth can be expanded; furthermore, the radiation unit 2 adopts a ring structure, which is beneficial to increase the path of the effective current of the antenna, thereby reducing the size of the antenna and increasing the bandwidth of the antenna.

[0070] Implantable medical devices are widely used in monitoring body temperature, intracranial pressure, heart rate and blood sugar levels. The antenna assembly in the implantable medical device is a key device for communication between the medical device placed in the body and the external receiver, and is crucial to establishing wireless communication links inside and outside the body. Brain-computer interface technology aims to establish a communication link between the human brain and external control devices. The brain-computer interface device contains thousands of electrode contacts. The density of the collected EEG signals is high, the frequency is high, and the data density that needs to be transmitted is high. The antenna assembly has a wide bandwidth and a small size. It is a miniaturized implantable antenna and an important device for realizing brain-computer wireless communication. The implantable antenna assembly can be used in fields such as cardiac pacemakers, capsule endoscopes and cochlear implants. The frequency band of the implantable antenna assembly is increased, which can meet the needs of high data flow transmission of the brain-computer interface. At the same time, in the complex environment of the human body, it is not easy to produce frequency deviation and it is not easy to affect the performance of the antenna.

[0071] In summary, the application scenario of this solution is brain-computer interface, and the antenna assembly has the characteristics of small size, wide bandwidth and biocompatibility. The size of this antenna assembly is φ=12mm, and the thickness is only 0.25mm. By engraving the groove structure 41 on the ground plate 4 and introducing the short-circuit probe 6, the capacitive value of the load is increased, the impedance matching is improved, and the bandwidth of the antenna is expanded. The -10dB working bandwidth covers 760MHz~4570MHz, which meets the requirements of brain-computer interface applications for wide bandwidth of wireless transmission links and solves the problem of frequency offset in the complex tissue environment of the human body.

[0072] Compared with the existing technology, this solution has the following advantages:

[0073] The radiation unit 2, ground plate 4, first dielectric substrate 1 and second dielectric substrate 3 in the antenna assembly are all circular. The elliptical storage space 24 on the surface of the radiation unit 2 and the groove structure 41 composed of multiple grooves on the ground plate 4 effectively reduce the size of the antenna assembly. The structural size of the antenna assembly is π×62mm×0.25mm, which realizes miniaturization and is convenient for integration with miniaturized head equipment and implantation in the head.

[0074] The antenna assembly adopts the method of cutting grooves and adding short-circuit probes 6 to increase the resonance points, thereby improving the impedance matching of the antenna assembly; a U-shaped groove structure 41 is opened or carved on the ground plate 4, and a fourth groove 414 and a fifth groove 415 are further opened, so that the groove structure 41 can excite a new resonance point at a low frequency. By adjusting the size of the groove structure 41 on the surface of the ground plate 4, the impedance matching within the bandwidth is improved, thereby expanding the bandwidth of the antenna.

[0075] The first dielectric substrate 1 and the second dielectric substrate 3 used in this solution are both biocompatible Kapton Polymide with a dielectric constant of 3.5. Without affecting the performance of the low-frequency resonance point and keeping the antenna small, the bandwidth of the antenna is further expanded. The -10dB working bandwidth of the antenna is 3810MHz, covering 760MHz~4570MHz, and the relative bandwidth is 142.96%. The wide frequency band obtained by this antenna assembly meets the needs of brain-computer interface applications for transmitting high-speed and large amounts of data streams, and solves the problem of frequency deviation of the antenna assembly in the complex environment of the human body.

[0076] The above are only preferred embodiments of the present application, and only specifically describe the technical principles of the present application. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanation here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application, and other specific implementation methods of the present application that can be associated with the technicians in this field without creative work, should be included in the scope of protection of the present application.

Claims

1. An antenna assembly, characterized in that: The invention comprises a first dielectric substrate, a radiation unit, a second dielectric substrate, a grounding plate, a short-circuit probe and a feeding probe. The first dielectric substrate, the radiation unit, the second dielectric substrate and the grounding plate are sequentially stacked. The radiation unit is ring-shaped. The feeding probe is electrically connected between the radiation unit and the grounding plate. The short-circuit probe is electrically connected between the radiation unit and the grounding plate. A slot structure is provided on the grounding plate.

2. The antenna assembly according to claim 1, wherein: The slot structure includes a first slot, a second slot and a third slot. The first slot, the second slot and the third slot are connected in sequence and arranged around the central axis of the feeding probe. The first slot and the third slot are spaced apart.

3. The antenna assembly according to claim 2, wherein: The notch of the first groove extends along a first direction, the notch of the second groove extends along a second direction, and the notch of the third groove extends along a third direction. Both the first direction and the third direction are perpendicular to the second direction.

4. The antenna assembly according to claim 3, characterized in that The groove structure further includes a fourth groove, which is extended along the second direction and is disposed at an end of the third groove away from the second groove, and the fourth groove is connected to the third groove.

5. The antenna assembly according to claim 4, characterized in that The slot structure further includes a fifth slot, which is extended along the second direction and is disposed on a side of the second slot away from the central axis of the feeding probe, and is connected to the second slot.

6. The antenna assembly according to claim 5, characterized in that The extension length range of the notch of the first groove along the first direction is 2.5mm~7mm, and the width range of the notch of the first groove perpendicular to the first direction is 1mm~2mm; the extension length range of the notch of the second groove along the second direction is 4mm~7mm, and the width range of the notch of the second groove perpendicular to the second direction is 0.5mm~1mm; the extension length range of the notch of the third groove along the third direction is 5mm~10mm, and the width range of the notch of the third groove perpendicular to the third direction is 1mm~2mm; the extension length range of the notch of the fourth groove along the second direction is 2mm~4mm, and the width range of the notch of the fourth groove perpendicular to the second direction is 1mm~2mm; the extension length range of the notch of the fifth groove along the second direction is 2.5mm~4mm, and the width range of the notch of the fifth groove perpendicular to the second direction is 1mm~2mm.

7. The antenna assembly according to any one of claims 1 to 6, characterized in that: The radiation unit includes a ring piece structure, a microstrip line structure and a group-pair piece structure. The middle of the ring piece structure forms an accommodating space. The group-pair piece structure is arranged in the accommodating space, and the group-pair piece structure is connected to the ring piece structure through a microstrip line structure; one end of the feeding probe is connected to the group-pair piece structure, and one end of the short-circuit probe is connected to the ring piece structure.

8. The antenna assembly according to claim 7, wherein: The pair of sheet structures are arranged at the ring center of the ring sheet structure.

9. The antenna assembly according to claim 7, wherein: The outer ring contour line of the ring piece structure is circular, the inner ring contour line of the ring piece structure is elliptical, and the ratio of the major axis to the minor axis of the ellipse is in the range of 1.0-1.

5.

10. An implantable medical device, characterized in that: Comprising the antenna assembly as described in any one of claims 1-9.

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