An implantable antenna device for a medical device and a method of manufacturing

Abstract

This invention discloses an implantable antenna device and its manufacturing method for medical devices, comprising a first metal layer, a first dielectric substrate, a second metal layer, a second dielectric substrate, a third metal layer, a third dielectric substrate, and a fourth metal layer stacked together. The first and second metal layers are electrically coupled through the first dielectric substrate. The third metal layer is electrically connected to both the second and fourth metal layers, such that the second, third, and fourth metal layers together form a loop current circuit. Furthermore, a portion of the structure of the third metal layer and a portion of the structure of the fourth metal layer have a predetermined geometric overlap region on a projection plane perpendicular to the thickness direction, forming a parallel capacitor to adjust the imaginary part of the antenna's input impedance. This invention's antenna achieves high radiation efficiency, 50-ohm self-impedance matching, and standard PCB manufacturing feasibility within an extremely compact size, making it particularly suitable for space-constrained implantable medical devices.

Description

Technical Field

[0001] This invention relates to the field of implantable antenna devices, and in particular to an implantable antenna device for medical devices and a manufacturing method thereof. Background Technology

[0002] With the rapid development of Wireless Body Area Network (WBAN) technology, implantable medical devices (such as pacemakers and sensors) have become important medical tools. Implantable wireless pacemakers (LCPs) monitor and transmit cardiac health data wirelessly, replacing traditional leaded pacemakers. While wireless pacemakers offer significant advantages in reducing infection risks and improving patient comfort, existing wireless communication links still face many challenges. In particular, traditional implantable antennas have low radiation efficiency and are susceptible to the effects of high water content and conductivity in human tissue, thus reducing communication quality and reliability. At the same time, due to the limited space in implantable devices, excessively large antennas can also affect the overall performance and comfort of the device.

[0003] Traditional implantable antennas often employ an electrically coupled loop antenna structure. While this type of antenna has a simple operating principle and is easy to integrate, its manufacturing process is complex, its size is large, and its radiation efficiency is relatively low. To overcome these problems, designing a miniaturized antenna with high radiation efficiency that is easy to integrate with implantable devices is particularly important. Existing solutions mostly rely on high-precision micromachining technology, which not only increases costs but also limits production scale and application scope.

[0004] Therefore, the objective of this invention is to provide an implantable antenna with four stacked metal layers, manufactured using traditional PCB technology, which has higher radiation efficiency, smaller size and easier integration, thus overcoming the shortcomings of the prior art. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art. To achieve the above objective, an implantable antenna device for medical devices and a manufacturing method are provided to solve the problems mentioned in the background art.

[0006] An implantable antenna device for use in a medical device, comprising: A first metal layer, a first dielectric substrate, a second metal layer, a second dielectric substrate, a third metal layer, a third dielectric substrate, and a fourth metal layer are sequentially stacked along the thickness direction. The first metal layer is configured as an open-circuit low-impedance transmission line, and the fourth metal layer is configured as a ground layer. The first metal layer and the second metal layer are electrically coupled through the first dielectric substrate to transmit radio frequency signals and increase the real part of the input impedance of the antenna; The third metal layer is electrically connected to the second metal layer and the fourth metal layer respectively, so that the second metal layer, the third metal layer and the fourth metal layer together form a ring current loop; Furthermore, a portion of the structure of the third metal layer and a portion of the structure of the fourth metal layer have a predetermined geometric overlap area on a projection plane perpendicular to the thickness direction, which forms a parallel capacitor for adjusting the imaginary part of the antenna input impedance.

[0007] As a further aspect of the present invention: the first dielectric substrate has a first dielectric constant and a first thickness, and the second dielectric substrate and the third dielectric substrate both have a second dielectric constant and a second thickness; The first dielectric constant is lower than the second dielectric constant, and the first thickness is greater than the second thickness.

[0008] As a further aspect of the present invention: the dielectric constant of the first dielectric substrate is in the range of 2.0 to 4.0, and the thickness is in the range of 0.2 mm to 0.4 mm; The dielectric constants of the second dielectric substrate and the third dielectric substrate are in the range of 9.0 to 11.0, and the thicknesses are in the range of 0.1 mm to 0.2 mm.

[0009] As a further aspect of the present invention: the first dielectric substrate is made of Rogers 3003 material, and the second and third dielectric substrates are made of Rogers 6010 material.

[0010] As a further aspect of the invention: at least one of the second metal layer and the third metal layer has a bent or meandering planar geometry to extend the current path from the second metal layer to the fourth metal layer.

[0011] As a further aspect of the present invention: the first metal layer and the second metal layer have a first preset overlap area, the first preset overlap area being configured to adjust the real part of the input impedance of the antenna to a preset range of 50 ohms.

[0012] As a further aspect of the present invention: the geometric overlap region between the third metal layer and the fourth metal layer has a second preset overlap area, the second preset overlap area being configured to adjust the imaginary part of the input impedance of the antenna to a preset range close to zero.

[0013] As a further aspect of the present invention: the resonant operating frequency of the antenna is in the MICS band range of 402MHz to 405MHz, or in the ISM band range of 2400MHz to 2500MHz.

[0014] As a further embodiment of the present invention: the first metal layer, the second metal layer, the third metal layer and the fourth metal layer are all copper layers, and are respectively formed on the corresponding dielectric substrate by printed circuit board process, and are formed into an integrated multilayer board structure by lamination process.

[0015] The second aspect provides a technical solution: a method for manufacturing an implantable antenna device for a medical device as described in any of the above claims, comprising the following steps: Fabricate and obtain a first dielectric substrate, a second dielectric substrate, and a third dielectric substrate; A first metal layer and a second metal layer are respectively patterned and formed on the first surface and the second surface of the first dielectric substrate; A third metal layer is patterned and formed on the second surface of the second dielectric substrate; A fourth metal layer is patterned and formed on the first surface of the third dielectric substrate; The dielectric substrates are laminated together in the order of the first metal layer, the first dielectric substrate, the second metal layer, the second dielectric substrate, the third metal layer, the third dielectric substrate, and the fourth metal layer to form a multilayer board structure. Among them, after lamination: The first metal layer is configured as an open-circuit low-impedance transmission line and is electrically coupled to the second metal layer through the first dielectric substrate to transmit radio frequency signals and increase the real part of the antenna's input impedance. The third metal layer is electrically connected to the second metal layer and the fourth metal layer respectively through a conductive path that penetrates the second dielectric substrate and the third dielectric substrate, thereby forming a ring current loop together. Furthermore, a portion of the third metal layer and at least a portion of the fourth metal layer form a predetermined geometric overlap region on a projection plane perpendicular to the lamination direction, thereby constituting a parallel capacitor for adjusting the imaginary part of the antenna input impedance.

[0016] Compared with the prior art, the present invention has the following technical advantages: The above technical solution employs a first metal layer (top layer), a first dielectric substrate, a second metal layer (intermediate layer one), a second dielectric substrate, a third metal layer (intermediate layer two), a third dielectric substrate, and a fourth metal layer (bottom layer) stacked sequentially from top to bottom along the thickness direction. The top layer is configured as an open-circuit low-impedance transmission line, and the bottom layer is configured as a ground layer. The top layer and intermediate layer one are coupled non-contactly via the first dielectric substrate, transmitting the radio frequency signal to intermediate layer one and increasing the real part of the antenna's input impedance in the process. Intermediate layer two is electrically connected to intermediate layer one and the bottom layer via conductive paths, forming a complete loop current circuit, which serves as the core radiating structure of the antenna. Furthermore, a portion of the structure of intermediate layer two and a portion of the structure of the bottom layer have a predetermined geometric overlap region in the vertical projection direction. This overlap region forms a distributed parallel capacitor for finely compensating and adjusting the imaginary part of the antenna's input impedance.

[0017] First, through the electric field coupling mechanism between the top layer and the first intermediate layer, and the capacitance compensation mechanism between the second intermediate layer and the bottom layer, the antenna can adjust its input impedance to around 50 ohms without any external matching network, achieving self-impedance matching and reducing system losses and circuit complexity. Second, the combination of a low-dielectric-constant thick substrate and a high-dielectric-constant thin substrate ensures efficient coupling of energy from the top layer to the first intermediate layer while shortening the effective wavelength of the lower loop, achieving the required low-frequency resonance within a very small physical volume, thus simultaneously achieving high radiation efficiency and miniaturization. Third, the overall four-layer structure is fully compatible with standard printed circuit board manufacturing processes, eliminating the need for high-precision micromachining technology, significantly reducing manufacturing costs and improving mass production feasibility. Therefore, the antenna of this invention is particularly suitable for implantable medical devices such as wireless pacemakers that have stringent requirements for size, efficiency, and power consumption, providing a stable and reliable wireless communication link in the high-loss tissue environment of the human body, effectively extending the service life of the device. Attached Figure Description

[0018] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of an implantable antenna device according to an embodiment of this application; Figure 2 This is a schematic diagram of the reflection coefficient and input impedance curves of an analog antenna in the MICS band, as measured in heart tissue according to an embodiment of this application. Figure 3 The following are schematic diagrams of the simulation model of the antenna according to the embodiments disclosed in this application, namely, top view, bottom view, and side view; Figure 4 This is a schematic diagram of a simulated antenna implanted in a human anatomical model, according to an embodiment of this application.

[0019] In the figure: 10, first metal layer; 11, first dielectric substrate; 20, second metal layer; 21, second dielectric substrate; 30, third metal layer; 31, third dielectric substrate; 40, fourth metal layer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please refer to Figure 1 In this embodiment of the invention, an implantable antenna device for medical devices employs a structure of alternating layers of four metal layers and three dielectric substrates, achieving high radiation efficiency and self-impedance matching within an extremely compact size. It includes: like Figure 1 As shown, the antenna includes the following layers stacked sequentially from top to bottom along the thickness direction: a first metal layer 10, a first dielectric substrate 11, a second metal layer 20, a second dielectric substrate 21, a third metal layer 30, a third dielectric substrate 31, and a fourth metal layer 40.

[0022] Specifically, the first metal layer 10 is the top layer of the antenna and is configured as an open-circuit low-impedance transmission line for receiving or transmitting radio frequency (RF) signals. The fourth metal layer 40 is the bottom layer of the antenna and is configured as a ground layer, providing a potential reference plane. The first dielectric substrate 11 is specifically disposed between the top layer and the first intermediate layer. The first metal layer 10 and the second metal layer 20 are electrically coupled through the first dielectric substrate 11, rather than in direct physical contact. The second metal layer 20 is specifically the first intermediate layer of the antenna. This coupling method enables the RF signal to be transmitted from the first metal layer 10 to the second metal layer 20, and in the process, increases the real part of the input impedance of the entire antenna, making it closer to the standard 50 ohms.

[0023] The third metal layer 30 is specifically the second intermediate layer of the antenna, and it forms electrical connections with the second metal layer 20 and the fourth metal layer 40, respectively. Specifically, in this embodiment, this electrical connection is achieved through metallized vias penetrating the second dielectric substrate 21 and the third dielectric substrate 31. The second dielectric substrate 21 is specifically a dielectric substrate disposed between the first intermediate layer and the second intermediate layer, and the third dielectric substrate 31 is specifically a dielectric substrate disposed between the second intermediate layer and the bottom layer. Thus, the second metal layer 20, the third metal layer 30, and the fourth metal layer 40, which serves as a ground layer, together constitute a continuous loop current circuit, namely, a loop formed from the first intermediate layer to the second intermediate layer to the bottom layer. This loop is the core structure for the antenna to radiate electromagnetic energy outward.

[0024] Furthermore, to finely adjust the imaginary part of the antenna's input impedance, a portion of the third metal layer 30 is spatially designed to have a predetermined geometric overlap region with at least a portion of the fourth metal layer 40 on a projection plane perpendicular to the thickness direction. Specifically, this geometric overlap region is a parallel capacitor formed at the overlap between the intermediate layer and the bottom layer, which generates a capacitive effect, thereby adjusting the imaginary part of the antenna's input impedance to near zero and achieving good resonance matching.

[0025] The antenna has a very small overall thickness and can be manufactured using standard PCB processes, making it ideal for integration into space-constrained implantable medical devices.

[0026] Example 2 Based on Example 1, the material and thickness parameters of each dielectric substrate were further optimized to achieve the best balance between miniaturization and high radiation efficiency.

[0027] In this embodiment, the first dielectric substrate 11 is made of a material having a first dielectric constant and a first thickness, while the second dielectric substrate 21 and the third dielectric substrate 31 are both made of materials having a second dielectric constant and a second thickness. A key design principle is that the first dielectric constant is lower than the second dielectric constant, and the first thickness is greater than the second thickness.

[0028] Preferably, the dielectric constant of the first dielectric substrate 11 is in the range of 2.0 to 4.0, and the thickness is in the range of 0.2 mm to 0.4 mm; the dielectric constants of the second dielectric substrate 21 and the third dielectric substrate 31 are in the range of 9.0 to 11.0, and the thickness is in the range of 0.1 mm to 0.2 mm.

[0029] As a specific material selection option, the first dielectric substrate 11 can be made of Rogers 3003 material (dielectric constant approximately 3.0) with a thickness of 0.254 mm. The second dielectric substrate 21 and the third dielectric substrate 31 can be made of Rogers 6010 material (dielectric constant approximately 10.2) with a thickness of 0.127 mm. This is a preferred embodiment in which Rogers 3003 (0.254 mm thick) is used between the top layer and the first intermediate layer, Rogers 6010 (0.127 mm thick) is used between the first intermediate layer and the second intermediate layer, and between the second intermediate layer and the bottom layer.

[0030] This combination of a "low dielectric constant, thick substrate" and a "high dielectric constant, thin substrate" produces a synergistic effect. The top low dielectric constant thick substrate reduces the electric field energy bound between the first metal layer 10 and the second metal layer 20, thus lowering the quality factor of this coupling region. This allows more energy to be effectively coupled to the lower second metal layer 20, improving energy transfer efficiency. Simultaneously, the lower high dielectric constant thin substrate significantly increases the effective dielectric constant of the environment surrounding the loop current circuit formed by the second metal layer 20, the third metal layer 30, and the fourth metal layer 40, shortening the effective operating wavelength. This means that, within the same physical size, the electrical path of the current is relatively lengthened, enabling the antenna to resonate at lower target frequencies (such as the 402-405MHz MICS band) within a very small volume.

[0031] like Figure 2 As shown, the diagram illustrates the reflection coefficient and input impedance curves of a simulated antenna placed in heart tissue in the MICS band. The two mechanisms work together to achieve a balance between high antenna radiation efficiency and physical miniaturization.

[0032] Example 3 This embodiment optimizes the geometry of the metal layer to further achieve extreme compression of the antenna size.

[0033] like Figure 3 As shown, the diagrams depict the simulation model of the antenna, including top view, bottom view, and side view.

[0034] In this embodiment, at least one of the second metal layer 20 (i.e., intermediate layer one) or the third metal layer 30 (i.e., intermediate layer two) is designed to have a bent or meandering pattern, rather than a simple straight line or arc segment.

[0035] This bent or meandering design substantially extends the current transmission path from the second metal layer 20, through the third metal layer 30, and finally to the fourth metal layer 40, which serves as the ground layer. Since the electrical length of the current path determines the antenna's resonant frequency, this design allows for a smaller projected antenna area compared to a straight-lined antenna, while maintaining the same operating frequency. This is particularly critical for devices with extremely stringent lateral dimension requirements, such as leadless pacemakers.

[0036] like Figure 4 As shown, the diagram illustrates a simulated antenna implanted in a human anatomical model. Example 4 This embodiment details a method for achieving precise antenna input impedance matching by controlling the interlayer overlap area.

[0037] The core of this invention's 50-ohm self-matching lies in two independent adjustment mechanisms. First, the mechanism for adjusting the real part of the input impedance relies on a first preset overlap area between the first metal layer 10 and the second metal layer 20. This overlap area is specifically the overlapping region between the top layer and the middle layer. The signal undergoes electric field coupling through this overlap area. The size of this overlap area significantly affects the coupling strength, and thus changes the real part of the input impedance as seen from the first metal layer 10. Designers can use electromagnetic simulation software to optimize the size, spacing, and relative position of the first metal layer 10 and the second metal layer 20, targeting 50 ohms, thereby determining an optimal first preset overlap area so that the real part of the antenna's input impedance is adjusted to within a preset range of 50 ohms (e.g., 45-55 ohms).

[0038] Secondly, the mechanism for adjusting the imaginary part of the input impedance relies on the geometric overlap region described in Embodiment 1. Specifically, this geometric overlap region is the capacitor formed at the overlap between the second intermediate layer and the bottom layer. This overlap region consists of a portion of the third metal layer 30 and a portion of the fourth metal layer 40, forming a parallel capacitor. When the first preset overlap area matches the real part of the impedance to 50 ohms, the imaginary part of the impedance is usually not zero due to the parasitic reactance of the loop itself. At this time, by independently adjusting the area of ​​this geometric overlap region (i.e., the second preset overlap area), the value of the parallel capacitor can be changed, thereby precisely introducing a reactance component with the opposite sign and equal magnitude to the original reactance, compensating the imaginary part of the antenna's input impedance at the target operating frequency to a preset range close to zero (e.g., an absolute value less than 5 ohms).

[0039] By independently adjusting the above two steps, the antenna input port can achieve optimal impedance matching with the standard 50-ohm RF front-end circuit without the need for any external lumped element matching network, thus minimizing energy reflection and mismatch loss.

[0040] Example 5 This embodiment demonstrates the frequency scalability of the antenna structure described in this invention.

[0041] By proportionally scaling the overall physical dimensions of the antenna, including the planar dimensions of each metal layer and the thickness of each dielectric substrate, and accordingly fine-tuning the feed position and the size of the interlayer overlap area, the four-layer antenna structure of the present invention can be tuned to different operating frequency bands.

[0042] In a preferred embodiment of the invention, the antenna size is optimized so that its resonant operating frequency falls within the 402MHz to 405MHz MICS (Medical Implantable Communication Service) band, one of the most commonly used communication bands for implantable medical devices. In another alternative embodiment, by proportionally reducing the antenna size, its resonant operating frequency can be tuned to the 2400MHz to 2500MHz ISM band. Antennas operating in the ISM band are more compact and suitable for applications requiring higher data transmission rates. Both operating modes share the exact same four-layer topology, differing only in geometric parameters.

[0043] Example 6 This embodiment limits the materials and processes used to manufacture the antenna in order to support its advantages of low cost and mass production.

[0044] In this embodiment, all metal layers, including the first metal layer 10, the second metal layer 20, the third metal layer 30, and the fourth metal layer 40, are copper layers. These copper layers are patterned on the surface of their respective dielectric substrates using standard printed circuit board (PCB) processing techniques, such as pattern plating or etching. Subsequently, according to a predetermined stacking order, the dielectric substrates with copper layer patterns are aligned using prepreg or other adhesive materials and subjected to high temperature and pressure. They are then cured into an inseparable, integrated multilayer board structure through a lamination process.

[0045] Manufactured using standard PCB processes, it avoids the high-cost, high-precision micromachining technology commonly used in existing technologies. While ensuring the accuracy of the antenna structure, it greatly reduces manufacturing costs and improves production yield and scale.

[0046] Example 7 This embodiment describes a method for manufacturing an implantable antenna device for a medical device as described in any of the above embodiments, including the following steps: Step S1: Substrate preparation. A first dielectric substrate 11, a second dielectric substrate 21, and a third dielectric substrate 31 are provided. The materials and thicknesses of these substrates can be selected according to design requirements, such as the combination in Example 2.

[0047] Step S2: First patterning. On the first surface (upper surface) and the second surface (lower surface) of the first dielectric substrate 11, the first metal layer 10 and the second metal layer 20 are respectively patterned and formed by PCB processes such as photolithography and etching.

[0048] Step S3: Secondary patterning. On the second surface (lower surface) of the second dielectric substrate 21, a first portion (e.g., upper layer connection pad and partial trace) and a second portion (e.g., lower layer connection pad and trace constituting the overlapping area) of the third metal layer 30 are patterned and formed. Step S4: Third patterning. A fourth metal layer 40 is patterned on the first surface (upper surface) of the third dielectric substrate 31, which will serve as a ground layer.

[0049] Step S5: Interlayer Conduction and Lamination. Before or during lamination, conductive pathways, such as metallized vias, are formed at predetermined positions on the second dielectric substrate 21 and the third dielectric substrate 31 through processes such as laser drilling and hole metallization. Then, the boards are aligned and stacked in the following order: first metal layer 10 on top, first dielectric substrate 11, second metal layer 20, second dielectric substrate 21, third metal layer 30, third dielectric substrate 31, and fourth metal layer 40 on the bottom, and laminated into a whole by high temperature and high pressure.

[0050] After lamination, the structure formed by the above steps S2-S5 naturally achieves the following functions: the first metal layer 10 is specifically the top layer, configured as an open-circuit low-impedance transmission line, and forms an electric field coupling with the second metal layer 20 through the first dielectric substrate 11; the third metal layer 30 is specifically the second intermediate layer, which electrically connects the second metal layer 20 and the fourth metal layer 40 through a pre-fabricated conductive path, forming a ring current loop from the first intermediate layer to the second intermediate layer to the bottom layer; at the same time, a preset overlapping area is formed on the third metal layer 30 and the fourth metal layer 40 on the vertical projection plane, specifically the parallel capacitor at the overlap between the second intermediate layer and the bottom layer, which serves as a parallel capacitor for adjusting the imaginary part of the input impedance.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents, all of which should be included within the scope of protection of the invention.

Claims

1. An implantable antenna device for medical devices, characterized in that, include: A first metal layer (10), a first dielectric substrate (11), a second metal layer (20), a second dielectric substrate (21), a third metal layer (30), a third dielectric substrate (31), and a fourth metal layer (40) are sequentially stacked along the thickness direction. The first metal layer is configured as an open-circuit low-impedance transmission line, and the fourth metal layer is configured as a ground layer. The first metal layer and the second metal layer are electrically coupled through the first dielectric substrate to transmit radio frequency signals and increase the real part of the input impedance of the antenna; The third metal layer is electrically connected to the second metal layer and the fourth metal layer respectively, so that the second metal layer, the third metal layer and the fourth metal layer together form a ring current loop; Furthermore, a portion of the structure of the third metal layer and a portion of the structure of the fourth metal layer have a predetermined geometric overlap area on a projection plane perpendicular to the thickness direction, which forms a parallel capacitor for adjusting the imaginary part of the antenna input impedance.

2. The implantable antenna device for medical devices according to claim 1, characterized in that, The first dielectric substrate has a first dielectric constant and a first thickness, and the second dielectric substrate and the third dielectric substrate both have a second dielectric constant and a second thickness; The first dielectric constant is lower than the second dielectric constant, and the first thickness is greater than the second thickness.

3. An implantable antenna device for medical devices according to claim 2, characterized in that, The dielectric constant of the first dielectric substrate is in the range of 2.0 to 4.0, and the thickness is in the range of 0.2 mm to 0.4 mm; The dielectric constants of the second dielectric substrate and the third dielectric substrate are in the range of 9.0 to 11.0, and the thicknesses are in the range of 0.1 mm to 0.2 mm.

4. An implantable antenna device for medical devices according to claim 2, characterized in that, The first dielectric substrate is made of Rogers 3003 material, and the second and third dielectric substrates are made of Rogers 6010 material.

5. An implantable antenna device for a medical device according to any one of claims 1 to 4, characterized in that, At least one of the second metal layer and the third metal layer has a bent or meandering planar geometry to extend the current path from the second metal layer to the fourth metal layer.

6. An implantable antenna device for a medical device according to any one of claims 1 to 4, characterized in that, The first metal layer and the second metal layer have a first preset overlap area, which is configured to adjust the real part of the input impedance of the antenna to a preset range of 50 ohms.

7. An implantable antenna device for medical devices according to claim 6, characterized in that, The geometric overlap region between the third metal layer and the fourth metal layer has a second preset overlap area, which is configured to adjust the imaginary part of the input impedance of the antenna to a preset range close to zero.

8. An implantable antenna device for a medical device according to any one of claims 1 to 4, characterized in that, The resonant operating frequency of the antenna is in the MICS band range of 402MHz to 405MHz, or in the ISM band range of 2400MHz to 2500MHz.

9. An implantable antenna device for a medical device according to any one of claims 1 to 4, characterized in that, The first metal layer, the second metal layer, the third metal layer, and the fourth metal layer are all copper layers, and are formed on their respective dielectric substrates by printed circuit board technology, and are integrated into a multilayer board structure by lamination process.

10. A method for manufacturing an implantable antenna device for a medical device as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Fabricate and obtain a first dielectric substrate, a second dielectric substrate, and a third dielectric substrate; A first metal layer and a second metal layer are respectively patterned and formed on the first surface and the second surface of the first dielectric substrate; A third metal layer is patterned and formed on the second surface of the second dielectric substrate; A fourth metal layer is patterned and formed on the first surface of the third dielectric substrate; The dielectric substrates are laminated together in the order of the first metal layer, the first dielectric substrate, the second metal layer, the second dielectric substrate, the third metal layer, the third dielectric substrate, and the fourth metal layer to form a multilayer board structure. Among them, after lamination: The first metal layer is configured as an open-circuit low-impedance transmission line and is electrically coupled to the second metal layer through the first dielectric substrate to transmit radio frequency signals and increase the real part of the antenna's input impedance. The third metal layer is electrically connected to the second metal layer and the fourth metal layer respectively through a conductive path that penetrates the second dielectric substrate and the third dielectric substrate, thereby forming a ring current loop together. Furthermore, a portion of the third metal layer and at least a portion of the fourth metal layer form a predetermined geometric overlap region on a projection plane perpendicular to the lamination direction, thereby constituting a parallel capacitor for adjusting the imaginary part of the antenna input impedance.

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