Miniaturized self-duplexing implantable antenna

Abstract

The application provides a miniaturized self-duplex implantable antenna, comprising a dielectric substrate, a cover layer on top of the dielectric substrate, a radiation surface printed on top of the dielectric substrate, a ground plane printed on the bottom of the dielectric substrate, the radiation surface and the ground plane being communicated through a first rectangular spiral patch short-circuit probe and a second rectangular spiral patch short-circuit probe, the radiation surface being connected with the center lines of a first rectangular spiral patch coaxial feeding probe and a second rectangular spiral patch coaxial feeding probe; the radiation surface comprises the first rectangular spiral patch and the second rectangular spiral patch, the first rectangular spiral patch and the second rectangular spiral patch are arranged in a bending rectangular spiral structure through a bending rectangular gap and are different in structure, and the first rectangular spiral patch and the second rectangular spiral patch are different by 180 degrees in self-rotation angle. The miniaturized self-duplex implantable antenna provided by the application is simple in structure, small in size, low in profile, low in coupling, circularly polarized and self-duplex.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a miniaturized self-duplex implantable antenna for use in bio-telemetry and wireless power transmission. Background Technology

[0002] The rapid development of biomedical engineering and personalized healthcare has spurred research into implantable medical devices by scholars worldwide. Implantable medical devices replace traditional wired connections by being implanted into the human body, significantly improving patient comfort and real-time health data monitoring. These devices can transmit patients' pathological data to external medical receivers, providing reliable data support for doctors to develop treatment plans. Currently, as front-end devices for data transmission and reception, implantable antennas are widely used in implantable medical devices such as capsule endoscopes, pacemakers, and brain pacemakers, and are also extensively used in implantable biosensors for detecting and recording blood pressure, blood sugar, heart rate, and intracranial pressure.

[0003] Implantable medical devices and implantable biosensors often require a stable power supply. However, traditional implantable medical devices and implantable biosensors rely on internal chemical batteries for power. Due to limitations in battery energy storage and lifespan, the batteries of implantable devices need to be replaced periodically via surgery. This significantly increases the treatment risks and costs for patients.

[0004] Therefore, the more practical and effective method of powering implantable medical devices via wireless power transmission has gradually become a research hotspot. For implantable antennas designed for bio-telemetry and wireless power transmission, scholars from various countries have proposed several different solutions. In the paper "Radiative Near-Field Wireless Power Transfer to Scalp-Implantable Biotelemetric Device," the authors designed a dual-band antenna capable of biotelemetry at 915 MHz and power transfer at 1.9 GHz, but the duplex operation problem was not solved. In "Wireless Powering and Telemetry of Deep-Body Ingestible Bioelectronic Capsule," the authors proposed a self-duplex dual-band implantable antenna that can simultaneously perform biotelemetry at 915 MHz and power transfer at 1.3 GHz, achieving duplex operation. However, its dielectric substrate thickness of only 0.13 mm and the excessive number of short-circuit probes increased the difficulty of subsequent antenna fabrication. In "Biotelemetry and Wireless Powering of Biomedical Implants Using a Rectifier Integrated Self-Diplexing Implantable Antenna," the authors also proposed a self-duplex dual-band implantable antenna that can simultaneously perform biotelemetry at 915 MHz and power transfer at 1.47 GHz, but the biotelemetry band did not achieve circular polarization. Therefore, designing a dual-frequency implantable power transmission antenna with simple structure, small size, low profile, low coupling, circular polarization, and self-duplex has high application value. Summary of the Invention

[0005] The purpose of this invention is to provide a miniaturized self-duplex implantable antenna with simple structure, small size, low profile, low coupling, circular polarization, and self-duplex capability.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A miniaturized self-duplex implantable antenna includes: a dielectric substrate and a cover layer, wherein the cover layer is located on top of the dielectric substrate;

[0008] The top of the dielectric substrate is printed with a radiating surface, and the bottom of the dielectric substrate is printed with a ground plane. The radiating surface and the ground plane are connected by a first rectangular spiral patch short-circuit probe and a second rectangular spiral patch short-circuit probe. The radiating surface is connected to the center line of the first rectangular spiral patch coaxial feed probe and the center line of the second rectangular spiral patch coaxial feed probe.

[0009] The radiating surface includes a first rectangular spiral patch and a second rectangular spiral patch. The first rectangular spiral patch and the second rectangular spiral patch are arranged along the y-axis and do not contact each other. The first rectangular spiral patch and the second rectangular spiral patch form a bent rectangular spiral structure by setting a curved rectangular gap, and the two structures are different. The spin angles of the first rectangular spiral patch and the second rectangular spiral patch differ by 180°.

[0010] Optionally, the first rectangular spiral patch is provided with a first rectangular spiral patch coaxial feed center line solder joint and a first rectangular spiral patch short-circuit via solder joint; the second rectangular spiral patch is provided with a second rectangular spiral patch coaxial feed center line solder joint and a second rectangular spiral patch short-circuit via solder joint; the first rectangular spiral patch coaxial feed center line solder joint is connected to the center line of the first rectangular spiral patch coaxial feed probe; the first rectangular spiral patch short-circuit via solder joint is connected to the first rectangular spiral patch short-circuit probe; the second rectangular spiral patch coaxial feed center line solder joint is connected to the center line of the second rectangular spiral patch coaxial feed probe; and the second rectangular spiral patch short-circuit via solder joint is connected to the second rectangular spiral patch short-circuit probe.

[0011] The ground plane is provided with a short-circuit via solder joint on the right half of the ground plane, a coaxial power supply grounding port on the right half of the ground plane, a short-circuit via solder joint on the left half of the ground plane, and a coaxial power supply grounding port on the left half of the ground plane. The short-circuit via solder joint on the right half of the ground plane is connected to the second rectangular spiral patch short-circuit probe. The coaxial power supply grounding port on the right half of the ground plane is connected to the center line of the second rectangular spiral patch coaxial power supply probe. The short-circuit via solder joint on the left half of the ground plane is connected to the first rectangular spiral patch short-circuit probe. The coaxial power supply grounding port on the left half of the ground plane is connected to the center line of the first rectangular spiral patch coaxial power supply probe.

[0012] Optionally, the radiating surface includes a first rectangular spiral patch and a second rectangular spiral patch. The first rectangular spiral patch and the second rectangular spiral patch are arranged along the y-axis and do not contact each other. The first rectangular spiral patch and the second rectangular spiral patch form a bent rectangular spiral structure by setting a curved rectangular gap, and the two structures are different. The spin angles of the first rectangular spiral patch and the second rectangular spiral patch differ by 180°.

[0013] Optionally, the ground plane is provided with a rectangular groove that runs through the ground plane along the x-axis and has a width of 0.2 mm.

[0014] Optionally, the radius of the first rectangular spiral patch coaxial feed center probe and the second rectangular spiral patch coaxial feed center probe are both 0.2 mm, and the radius of the first rectangular spiral patch short-circuit probe and the second rectangular spiral patch short-circuit probe are both 0.2 mm.

[0015] Optionally, the first rectangular spiral patch is provided with three rectangular slots 25, 26, and 27 along the negative y-axis, with a width ratio of 3:2:4. The second rectangular spiral patch is provided with three rectangular slots 22, 23, and 24 along the positive y-axis, with a width of 0.2 mm for each slot.

[0016] Optionally, a first impedance matching stub is connected along the negative x-axis at the junction of the center line of the first rectangular spiral patch and the coaxial feed probe of the first rectangular spiral patch, to improve the impedance matching of the antenna. The width of the first impedance matching stub is 0.4 mm.

[0017] A second impedance matching stub is connected along the negative y-axis at the junction of the centerline of the second rectangular spiral patch and the coaxial feed probe of the second rectangular spiral patch. This stub is used to improve the impedance matching of the antenna. The impedance matching stub is 0.4 mm wide and forms a 90° angle with the second rectangular spiral patch.

[0018] Optionally, the connection point of the first rectangular spiral patch and the coaxial feed center line solder joint of the first rectangular spiral patch is located at the connection point of the first impedance matching stub and the first rectangular spiral patch, and the connection point of the second rectangular spiral patch and the coaxial feed center line solder joint of the second rectangular spiral patch is located at the connection point of the second impedance matching stub and the second rectangular spiral patch.

[0019] Optionally, the dielectric substrate and the capping layer are made of Rogers 6010 material with a relative permittivity of 10.2.

[0020] Optionally, both the radiating surface and the ground plane are made of metallic copper.

[0021] According to specific embodiments provided by the present invention, the following technical effects are disclosed: The miniaturized self-duplex implantable antenna provided by the present invention introduces a second feed port and adopts a dual-feed port feeding method. By increasing the isolation of the two radiating elements through slotting in the ground plane, the bio-telemetry function and the wireless power transmission function can work simultaneously and in parallel, avoiding the situation where the bio-telemetry function is unavailable due to the operation of the wireless power transmission function; the rectangular spiral structure is beneficial to extending the effective current path, and the main frequency can be controlled by adjusting the size of the slot; the present invention has a small size, with a volume of only 9.774 mm. 3 It has advantages such as wide bandwidth, circular polarization, and full duplex in the biological telemetry frequency band. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a cross-sectional structural diagram of an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the radiation surface structure according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the ground plane structure according to an embodiment of the present invention;

[0026] Figure 4 This is a return loss curve of the antenna in skin tissue at a frequency of 1.47 GHz, as shown in this embodiment of the invention.

[0027] Figure 5 This is a return loss curve of the antenna in skin tissue at a frequency of 2.45 GHz, as shown in this embodiment of the invention.

[0028] Figure 6 This is a 3 dB axial ratio diagram of the antenna in skin tissue at a frequency of 2.45 GHz, according to an embodiment of the present invention.

[0029] Figure 7 This is a graph showing the isolation degree of the antenna in skin tissue in an embodiment of the present invention;

[0030] Figure 8 This is a current amplitude distribution diagram of the antenna at a center frequency of 1.47 GHz in an embodiment of the present invention;

[0031] Figure 9This is a current amplitude distribution diagram of the antenna at a center frequency of 2.45 GHz in an embodiment of the present invention;

[0032] Figure 10 This is a radiation pattern of the antenna in skin tissue at a frequency of 1.47 GHz, as shown in an embodiment of the present invention.

[0033] Figure 11 This is a radiation pattern of the antenna in skin tissue at a frequency of 2.45 GHz, as shown in an embodiment of the present invention.

[0034] Reference numerals: 1. Cover layer; 2. Radiation surface; 3. Dielectric substrate; 4. Ground plane; 5. Second rectangular spiral patch short-circuit probe; 6. Center line of the second rectangular spiral patch coaxial feed probe; 7. First rectangular spiral patch short-circuit probe; 8. Center line of the first rectangular spiral patch coaxial feed probe; 9. Short-circuit via solder joint on the right half of the ground plane; 10. Coaxial feed grounding port on the right half of the ground plane; 11. Short-circuit via solder joint on the left half of the ground plane; 12. Coaxial feed grounding port on the left half of the ground plane; 13. Solder joint on the center line of the first rectangular spiral patch coaxial feed; 14. Short-circuit via on the first rectangular spiral patch. Solder joints; 15. Second rectangular spiral patch coaxial feed centerline solder joint; 16. Second rectangular spiral patch short-circuit via solder joint; 17. First rectangular spiral patch; 18. Second rectangular spiral patch; 19. Ground plane rectangular slot; 20. First impedance matching stub; 21. Second impedance matching stub; 22. Second rectangular spiral patch first rectangular slot; 23. Second rectangular spiral patch second rectangular slot; 24. Second rectangular spiral patch third rectangular slot; 25. First rectangular spiral patch first rectangular slot; 26. First rectangular spiral patch second rectangular slot; 27. First rectangular spiral patch third rectangular slot; Detailed Implementation

[0035] The purpose of this invention is to provide a miniaturized self-duplex implantable antenna with simple structure, small size, low profile, low coupling, circular polarization, and self-duplex capability.

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 1-3 As shown, in this embodiment of the invention, the origin of the spatial rectangular coordinate system is set at the geometric center of the ground plane 4, the z-axis is set vertically upward, the x-axis is set horizontally forward, and the y-axis is set horizontally to the right.

[0038] like Figure 1 As shown, a miniaturized self-duplex implantable antenna is characterized by comprising: a dielectric substrate 3 and a cover layer 1, wherein the cover layer 1 is located on top of the dielectric substrate 3.

[0039] The top of the dielectric substrate 3 is printed with a radiating surface 2, and the bottom of the dielectric substrate 3 is printed with a ground plane 4. The radiating surface 2 and the ground plane 4 are connected by a first rectangular spiral patch short-circuit probe 7 and a second rectangular spiral patch short-circuit probe 5. The radiating surface 2 is connected to the center line of the first rectangular spiral patch coaxial feed probe and the center line of the second rectangular spiral patch coaxial feed probe 6.

[0040] like Figure 2 As shown, the radiating surface 2 includes a first rectangular spiral patch 17 and a second rectangular spiral patch 18. The first rectangular spiral patch 17 and the second rectangular spiral patch 18 are arranged horizontally along the y-axis. The first rectangular spiral patch 17 is located to the left of the second rectangular spiral patch 18, and the two do not contact each other. The first rectangular spiral patch 17 and the second rectangular spiral patch 18 form a bent rectangular spiral structure by setting a curved rectangular gap, and the structures are different. The spin angles of the first rectangular spiral patch 17 and the second rectangular spiral patch 18 differ by 180°.

[0041] The first rectangular spiral patch 17 is provided with a first rectangular spiral patch coaxial feed center line solder joint 13 and a first rectangular spiral patch short-circuit via solder joint 14. The second rectangular spiral patch 18 is provided with a second rectangular spiral patch coaxial feed center line solder joint 15 and a second rectangular spiral patch short-circuit via solder joint 16. The first rectangular spiral patch coaxial feed center line solder joint 13 is connected to the first rectangular spiral patch coaxial feed probe center line 8. The first rectangular spiral patch short-circuit via solder joint 14 is connected to the first rectangular spiral patch short-circuit probe 7. The second rectangular spiral patch coaxial feed center line solder joint 15 is connected to the second rectangular spiral patch coaxial feed probe center line 6. The second rectangular spiral patch short-circuit via solder joint 16 is connected to the second rectangular spiral patch short-circuit probe 5.

[0042] The ground plane 4 is provided with a short-circuit via solder joint 8 on the right half of the ground plane, a coaxial power supply grounding port 10 on the right half of the ground plane, a short-circuit via solder joint 11 on the left half of the ground plane, and a coaxial power supply grounding port 12 on the left half of the ground plane. The short-circuit via solder joint 8 on the right half of the ground plane is connected to the second rectangular spiral patch short-circuit probe 5. The coaxial power supply grounding port 10 on the right half of the ground plane is connected to the center line 6 of the second rectangular spiral patch coaxial power supply probe. The short-circuit via solder joint 11 on the left half of the ground plane is connected to the first rectangular spiral patch short-circuit probe 7. The coaxial power supply grounding port 12 on the left half of the ground plane is connected to the center line 8 of the first rectangular spiral patch coaxial power supply probe.

[0043] like Figure 3As shown, a rectangular groove 19 is provided on the ground plane 4. The rectangular groove penetrates the ground plane 4 along the x-axis. The dimensions of the rectangular groove 19 are 5.6 mm × 0.2 mm, and the center line along the x-axis is 0.2 mm away from the x-axis.

[0044] The coaxial feed center probes of the first rectangular spiral patch 17 and the second rectangular spiral patch 18 both have a radius of 0.2 mm, and the short-circuit probes of the first rectangular spiral patch 7 and the second rectangular spiral patch 5 both have a radius of 0.2 mm.

[0045] like Figure 2 As shown, the first rectangular spiral patch is provided with first rectangular spiral patch first rectangular slit 25, first rectangular spiral patch second rectangular slit 26, and first rectangular spiral patch third rectangular slit 27 in sequence along the negative y-axis. The width ratio of the first rectangular spiral patch first rectangular slit 25, first rectangular spiral patch second rectangular slit 26, and first rectangular spiral patch third rectangular slit 27 is 3:2:4. The second rectangular spiral patch is provided with second rectangular spiral patch first rectangular slit 22, second rectangular spiral patch second rectangular slit 23, and second rectangular spiral patch third rectangular slit 24 in sequence along the positive y-axis. The width of the second rectangular spiral patch first rectangular slit 22, second rectangular spiral patch second rectangular slit 23, and second rectangular spiral patch third rectangular slit 24 is 0.2 mm.

[0046] A first impedance matching stub 20 is connected along the negative x-axis at the junction of the first rectangular spiral patch 17 and the center line of the coaxial feed probe of the first rectangular spiral patch, which is used to improve the impedance matching of the antenna. The width of the first impedance matching stub 20 is 0.4 mm.

[0047] A second impedance matching stub 21 is connected along the negative y-axis at the junction of the second rectangular spiral patch 18 and the center line 6 of the coaxial feed probe of the second rectangular spiral patch, which is used to improve the impedance matching of the antenna; the impedance matching stub is 0.4 mm wide, and the length direction of the second impedance matching stub 21 forms a 90° angle with the length direction of the second rectangular spiral patch 18.

[0048] The connection point of the first rectangular spiral patch 17 and the coaxial feed center line solder joint 13 is located at the connection point of the first impedance matching stub 20 and the first rectangular spiral patch 17. The connection point of the second rectangular spiral patch 18 and the coaxial feed center line solder joint 15 is located at the connection point of the second impedance matching stub 21 and the second rectangular spiral patch 18.

[0049] The dielectric substrate 3 and the capping layer 1 are made of Rogers 6010 material with a relative permittivity of 10.2.

[0050] Both the radiating surface and the ground plane 4 are made of metallic copper. The first rectangular spiral patch 17, the coaxial power supply center probe, the second rectangular spiral patch 18, the first rectangular spiral patch short-circuit probe 7, and the second rectangular spiral patch short-circuit probe 5 are all metallic cylinders.

[0051] like Figure 1-3 As shown, the specific dimensional parameters of each component are shown in Table 1:

[0052] Table 1 Dimensional parameters of each component

[0053]

[0054] Figure 4 This is the return loss curve of the antenna in skin tissue at a frequency of 1.47 GHz in this embodiment. Figure 4 As can be seen, the antenna has a return loss of less than -10 dB in the 1.42-1.51 GHz frequency band, achieving the power transmission frequency band.

[0055] Figure 5 and Figure 6 The return loss curve and axial ratio curve of the antenna in skin tissue at a frequency of 2.45 GHz in this embodiment are obtained from... Figure 5 It can be seen that the antenna's return loss is less than -10 dB in the 2.35-2.52 GHz frequency band, achieving the biological telemetry frequency band: From Figure 6 It can be seen that the antenna has an axial ratio of less than 3 dB in the 2.36-2.52 GHz frequency band, realizing dual polarization in the biological telemetry frequency band.

[0056] Figure 7 The antenna isolation curve in this embodiment is from... Figure 7 As can be seen, the antenna isolation in the 1.42-1.51 GHz band and the 2.35-2.52 GHz band is less than -25 dB, ensuring the normal operation of port 1 and port 2.

[0057] Figure 8 This is a diagram showing the electric field distribution of the centerline 6 of the second rectangular spiral patch coaxial feed probe of the antenna in this embodiment at 1.47 GHz. Figure 8 As can be seen, at 1.47 GHz, the maximum electric field occurs at the central rectangular patch of the second rectangular spiral patch 18, and the electric field distribution on the ground plane 4 below the excitation patch is greater than that on the other side of the excitation patch. When the second rectangular spiral patch 18 is excited, the electric field hardly couples to the first rectangular spiral patch 17.

[0058] Figure 9This is an electric field distribution diagram of the centerline of the first rectangular spiral patch coaxial feed probe of the antenna in this embodiment at 2.45 GHz. Figure 9 As can be seen, at 2.45 GHz, the electric field is uniformly distributed on the first rectangular spiral patch 17, with the maximum value appearing on the x- and y-coordinates. The electric field distribution on the ground plane 4 below the excitation patch is greater than that on the other side of the excitation patch. When the first rectangular spiral patch 17 is excited, the electric field hardly couples to the second rectangular spiral patch 18. This confirms the high isolation of the radiator.

[0059] Figure 10 This is the radiation pattern of the antenna in skin tissue at a frequency of 1.47 GHz in this embodiment. In the figure, E represents the electric field and H represents the magnetic field. It can be seen from the figure that the maximum radiation gain of the antenna in this embodiment is -43.7 dB.

[0060] Figure 11 This is the radiation pattern of the antenna in skin tissue at a frequency of 2.45 GHz. In the figure, E represents the electric field and H represents the magnetic field. It can be seen from the figure that the maximum radiation gain of the antenna in this embodiment is -33.1 dB.

[0061] This invention provides a miniaturized self-duplex implantable antenna. It introduces a second feed port and employs a dual-feed port feeding method. By increasing the isolation between the two radiating elements through a slot in the ground plane, the bio-telemetry function and the wireless power transfer function can operate simultaneously and in parallel, avoiding the situation where the bio-telemetry function becomes unavailable due to the operation of the wireless power transfer function. The rectangular spiral structure helps to extend the effective current path, and the main frequency can be controlled by adjusting the size of the slot. This invention has a small size, with a volume of only 9.774 mm². 3 It has advantages such as wide bandwidth, circular polarization, and full duplex in the biological telemetry frequency band.

[0062] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A miniaturized self-duplex implantable antenna, characterized in that, include: A dielectric substrate and a cover layer, wherein the cover layer is located on top of the dielectric substrate; The top of the dielectric substrate is printed with a radiating surface, and the bottom of the dielectric substrate is printed with a ground plane. The radiating surface and the ground plane are connected by a first rectangular spiral patch short-circuit probe and a second rectangular spiral patch short-circuit probe. The radiating surface is connected to the center line of the first rectangular spiral patch coaxial feed probe and the center line of the second rectangular spiral patch coaxial feed probe. The radiating surface includes a first rectangular spiral patch and a second rectangular spiral patch. The first rectangular spiral patch and the second rectangular spiral patch are arranged along the y-axis and do not contact each other. The first rectangular spiral patch and the second rectangular spiral patch form a bent rectangular spiral structure by setting a bent rectangular gap, and the two structures are different. The spin angles of the first rectangular spiral patch and the second rectangular spiral patch differ by 180°. A rectangular groove is provided on the ground plane, which penetrates the ground plane along the x-axis and has a width of 0.2 mm. The first rectangular spiral patch is provided with first rectangular spiral patch No. 1 rectangular slot (25), first rectangular spiral patch No. 2 rectangular slot (26), and first rectangular spiral patch No. 3 rectangular slot (27) in sequence along the negative y-axis. The width ratio of the first rectangular spiral patch No. 1 rectangular slot (25), first rectangular spiral patch No. 2 rectangular slot (26), and first rectangular spiral patch No. 3 rectangular slot (27) is 3:2:

4. The second rectangular spiral patch is provided with second rectangular spiral patch No. 1 rectangular slot (22), second rectangular spiral patch No. 2 rectangular slot (23), and second rectangular spiral patch No. 3 rectangular slot (24) in sequence along the positive y-axis. The width of the second rectangular spiral patch No. 1 rectangular slot (22), second rectangular spiral patch No. 2 rectangular slot (23), and second rectangular spiral patch No. 3 rectangular slot (24) is 0.2 mm. The connection point of the first rectangular spiral patch and the coaxial feed center line of the first rectangular spiral patch is located at the connection point of the first impedance matching stub and the first rectangular spiral patch. The connection point of the second rectangular spiral patch and the coaxial feed center line of the second rectangular spiral patch is located at the connection point of the second impedance matching stub and the second rectangular spiral patch.

2. The miniaturized self-duplex implantable antenna according to claim 1, characterized in that, The first rectangular spiral patch is provided with a first rectangular spiral patch coaxial feed center line solder joint and a first rectangular spiral patch short-circuit via solder joint. The second rectangular spiral patch is provided with a second rectangular spiral patch coaxial feed center line solder joint and a second rectangular spiral patch short-circuit via solder joint. The first rectangular spiral patch coaxial feed center line solder joint is connected to the center line of the first rectangular spiral patch coaxial feed probe. The first rectangular spiral patch short-circuit via solder joint is connected to the first rectangular spiral patch short-circuit probe. The second rectangular spiral patch coaxial feed center line solder joint is connected to the center line of the second rectangular spiral patch coaxial feed probe. The second rectangular spiral patch short-circuit via solder joint is connected to the second rectangular spiral patch short-circuit probe. The ground plane is provided with a short-circuit via solder joint on the right half of the ground plane, a coaxial power supply grounding port on the right half of the ground plane, a short-circuit via solder joint on the left half of the ground plane, and a coaxial power supply grounding port on the left half of the ground plane. The short-circuit via solder joint on the right half of the ground plane is connected to the second rectangular spiral patch short-circuit probe. The coaxial power supply grounding port on the right half of the ground plane is connected to the center line of the second rectangular spiral patch coaxial power supply probe. The short-circuit via solder joint on the left half of the ground plane is connected to the first rectangular spiral patch short-circuit probe. The coaxial power supply grounding port on the left half of the ground plane is connected to the center line of the first rectangular spiral patch coaxial power supply probe.

3. The miniaturized self-duplex implantable antenna according to claim 2, characterized in that, The radius of the first rectangular spiral patch coaxial feed center probe and the second rectangular spiral patch coaxial feed center probe are both 0.2 mm, and the radius of the first rectangular spiral patch short-circuit probe and the second rectangular spiral patch short-circuit probe are both 0.2 mm.

4. The miniaturized self-duplex implantable antenna according to claim 1, characterized in that, A first impedance matching stub is connected along the negative x-axis at the junction of the center line of the first rectangular spiral patch and the coaxial feed probe of the first rectangular spiral patch, which is used to improve the impedance matching of the antenna. The width of the first impedance matching stub is 0.4 mm. A second impedance matching stub is connected along the negative y-axis at the junction of the center line of the second rectangular spiral patch and the coaxial feed probe of the second rectangular spiral patch, which is used to improve the impedance matching of the antenna; the impedance matching stub is 0.4 mm wide, and the length direction of the second impedance matching stub forms a 90° angle with the length direction of the second rectangular spiral patch.

5. The miniaturized self-duplex implantable antenna according to claim 1, characterized in that, The dielectric substrate and the capping layer are made of Rogers 6010 material with a relative permittivity of 10.

2.

6. The miniaturized self-duplex implantable antenna according to claim 1, characterized in that, Both the radiating surface and the ground plane are made of metallic copper.

Images