A miniaturized ultra-wideband implantable antenna for large mammal health monitoring

Abstract

The application discloses a miniaturized ultra-wideband implantable antenna for large mammal health monitoring, and relates to the technical field of implantable biomedical antenna, and the antenna comprises a dielectric substrate, a radiation surface arranged on the upper surface of the dielectric substrate and a ground plane arranged on the lower surface of the dielectric substrate. The radiation surface adopts a closed rectangular radiation patch structure and is etched with symmetric U-shaped grooves and arc-shaped grooves, the inner side of the radiation surface extends a matching branch and is connected with a coaxial feeding center probe; the center probe vertically penetrates the dielectric substrate and forms a stable radio frequency loop with the ground plane. The antenna realizes double-frequency ultra-wideband operation through loading of a short-circuit probe, optimization of groove structure size and the ground plane topology, and has excellent impedance matching and tissue adaptability in a 1.86-3.52 GHz frequency band. The antenna has the characteristics of miniaturization, wideband and compact structure, and is suitable for wireless power supply and data communication applications of in-vivo implantable devices such as dairy cow health monitoring.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a miniaturized ultrawide bandwidth implantable antenna for health monitoring of large mammals, used for the acquisition and monitoring of physiological parameters in dairy cows. Background Technology

[0002] With the rapid development of smart animal husbandry and biomedical telemetry technologies, implantable medical devices have been widely used for real-time monitoring of body temperature and physiological parameters in dairy cows. In recent years, implantable antenna technology has been widely applied in the field of intelligent animal health management, especially in dairy farming—early detection of chronic diseases caused by body temperature imbalances (such as heat stress / heatstroke) is crucial. Abnormal body temperatures in dairy cows occur repeatedly in both summer and winter, potentially leading to respiratory distress, heat stress, or heatstroke, and in severe cases, even endangering the lives of the cattle.

[0003] In smart animal husbandry systems, implanted devices are used to collect physiological parameters such as body temperature, heart rate, and muscle activity in ruminants like cattle in real time, and the data is uploaded via low-power wireless communication modules. This is a crucial support for future smart animal husbandry. The implanted antenna, as a core component of the communication system, must possess characteristics such as miniaturization, wideband response, high stability, and biocompatibility.

[0004] Currently, implantable antennas used for livestock monitoring generally suffer from problems such as large size, narrow bandwidth, dual-frequency characteristics being easily affected by biological tissue environment, and poor impedance matching stability, making it difficult to simultaneously meet the dual needs of wireless power transmission and wireless data communication.

[0005] Antennas are prone to detuning under different implantation depths and different tissue dielectric properties, limiting their long-term stable operation in actual ranching scenarios. Especially when antennas are implanted in the muscle tissue of large animals such as cattle, it is possible to continuously monitor information such as body temperature, physiological electrical signals, and activity behavior, and transmit it wirelessly to external devices, thereby enabling health management, location tracking, and precision farming.

[0006] Therefore, developing an implantable antenna with a compact structure, dual-frequency ultra-wide bandwidth, and strong tissue adaptability is of great significance for promoting the practical application of dairy cow health monitoring equipment. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides a miniaturized ultra-wideband implantable antenna for health monitoring of large mammals. It solves the problems commonly found in existing implantable patch antennas used in animal applications, such as difficulty in achieving both miniaturization and structural stability, insufficient matching of dielectric properties to biological tissues, narrow bandwidth, insufficient dual-band ultra-wideband coverage, and inadequate biocompatibility and long-term reliability.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A miniaturized ultrawideband implantable antenna for health monitoring of large mammals includes a dielectric substrate, a radiating surface disposed on the upper surface of the dielectric substrate, and a grounding plane disposed on the lower surface of the dielectric substrate.

[0010] The radiating surface adopts a closed rectangular radiating patch structure, and the surface of the radiating patch is etched with symmetrical U-shaped grooves and arc-shaped grooves; the surface current distribution is controlled by the groove structure, and the equivalent current path is extended to achieve miniaturization and dual-frequency resonance.

[0011] The grounding plane has a composite groove structure;

[0012] A coaxial feed solder joint is provided on the radiating surface, and a corresponding ground plane coaxial feed grounding port is provided on the grounding plane. The coaxial feed solder joint and the ground plane coaxial feed grounding port are connected by a central probe to form a feed structure.

[0013] The central probe passes vertically through the dielectric substrate.

[0014] Furthermore, a coaxial feed solder joint is provided at the center of the radiating patch for connecting with the center probe to realize radio frequency signal feeding and dual-frequency response, and short-circuit probes are provided on both sides.

[0015] Furthermore, the composite groove structure of the grounding plane is symmetrically distributed along the edge and the central region.

[0016] Furthermore, a short-circuit probe is loaded between the radiating patch and the ground plane, and the short-circuit probe passes vertically through the dielectric substrate and maintains an electrical connection with the radiating patch and the ground plane.

[0017] Furthermore, the dielectric substrate is made of Rogers RO4350 material, which has a relative permittivity of 3.66, a loss tangent of 0.0037, and a thickness of 0.254 mm.

[0018] Furthermore, both the radiating patch and the grounding plane are made of copper.

[0019] Furthermore, the central probe is a metal column coated with chlorinated polyethylene.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0021] This invention provides a miniaturized, compact, dual-band wideband implantable patch antenna, comprising: a coaxial feed solder joint at the center of the radiating surface; a ground plane coaxial feed grounding port on the ground plane; and a central probe connecting the coaxial feed solder joint and the ground plane coaxial feed grounding port to form a feed structure; the central probe perpendicularly passes through the dielectric substrate. This invention achieves coverage of two operating frequency bands, 1.9 GHz and 2.45 GHz, for long-distance high-frequency telemetry and high-frequency local communication, respectively; strong polarization stability: the antenna's main polarization direction remains consistent under animal movement conditions, avoiding signal loss caused by polarization mismatch; robust mechanical structure: optimized probe soldering position, reliable electrical connection, adaptable to the muscle movement environment in cattle; wide adaptability: suitable for health monitoring modules in medium to large animals such as cattle, sheep, and horses; easy integration: compact size (6mm × 6mm × 0.254mm), can be packaged and used with implantable sensor chips and batteries; excellent biocompatibility: the selected dielectric and conductor materials are stable and suitable for long-term operation in bovine muscle tissue. The antenna structure of this invention is particularly well-suited for livestock and poultry health monitoring and remote communication systems in smart agriculture scenarios, improving the intelligence and precision of livestock management, and has significant industrial value and promotion potential.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] 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.

[0024] Figure 1 This is a schematic diagram of the radiation surface structure according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the ground plane structure according to an embodiment of the present invention;

[0026] Figure 3 This is a cross-sectional structural diagram of an embodiment of the present invention;

[0027] Figure 4 The diagram shows the return loss (S11) curve of the antenna in the simulation software for the working frequency in bovine muscle tissue according to an embodiment of the present invention.

[0028] Figure 5 This is a comparison curve of the return loss (S11) of the antenna in the embodiment of the present invention at the operating frequency in simulation software and actual measured bovine muscle tissue.

[0029] Figure 6 The radiation patterns of the antenna in bovine muscle tissue at frequencies of 1.9 GHz and 2.45 GHz, according to an embodiment of the present invention. Detailed Implementation

[0030] 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. All equivalent substitutions, parameter adjustments, or structural modifications made based on the concept of the present invention should fall within the scope of protection of the present invention.

[0031] This embodiment provides a compact dual-band ultra-wideband implantable antenna suitable for dairy cow health monitoring. Through reactive loading and geometry optimization based on slots, dual-band ultra-wideband characteristics are achieved: symmetrical U-shaped and curved slots are processed on both the radiating surface and the ground, and short-circuit probes are loaded to improve impedance matching at 1.9 GHz and 2.45 GHz, thereby achieving miniaturization.

[0032] 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.

[0033] like Figure 1 , Figure 2 and Figure 3 The diagram shows the front, back, side, and exploded views of the designed dual-band implanted antenna. The antenna includes a dielectric substrate, a radiating surface on the upper surface of the dielectric substrate, and a grounding plane on the lower surface of the dielectric substrate.

[0034] The radiating surface adopts a closed rectangular radiating patch structure, and the surface of the radiating patch is etched with symmetrical U-shaped grooves and arc-shaped grooves; the surface current distribution is controlled by the groove structure, and the equivalent current path is extended to achieve miniaturization and dual-frequency resonance.

[0035] The grounding plane has a composite groove structure;

[0036] A coaxial feed solder joint is provided on the radiating surface, and a corresponding ground plane coaxial feed grounding port is provided on the grounding plane. The coaxial feed solder joint and the ground plane coaxial feed grounding port are connected by a central probe to form a feed structure.

[0037] The central probe passes vertically through the dielectric substrate.

[0038] Specifically, the dielectric substrate and cladding are made of Rogers RO4350 material with a relative permittivity of [missing information]. =3.66, loss tangent With a density of 0.0037 mm and a thickness of 0.254 mm, this radiating patch features low dielectric loss, high mechanical stability, and good biocompatibility, meeting the requirements for miniaturization and long-term operation of implantable devices. Both the radiating patch and the ground plane are made of copper, exhibiting excellent conductivity suitable for use in the biological environment. A coaxial feed solder joint is located at the center of the radiating patch, with short-circuit probes on both sides. A corresponding coaxial feed ground port is located on the ground plane. The central probe connects the coaxial feed solder joint to the ground port to form a complete RF feed structure. The central probe passes perpendicularly through the dielectric substrate, enabling signal transmission between the radiating surface and the ground plane.

[0039] Specifically, such as Figure 1 As shown, the radiating patch is a rectangular metal patch structure with symmetrical U-shaped and arc-shaped grooves etched on its surface. The grooves are uniform in width and optimized in size to control the surface current distribution and extend the equivalent current path, thereby achieving antenna miniaturization and dual-frequency resonant characteristics. The overall size of the radiating patch is 6.0 mm × 6.0 mm, which is compact and easy to implant subcutaneously.

[0040] Specifically, such as Figure 2 As shown, the grounding plane is a complete metal plane with a composite slot structure. The slot shape and the radiating surface slot structure form electromagnetic coupling, further expanding the operating bandwidth and improving impedance matching. The slot structure of the grounding plane is symmetrically distributed along the edge and center region, which can effectively constrain the current flow and improve the radiation stability and dual-frequency operation capability of the antenna in the biological tissue environment. The overall size of the radiating patch is 6.0 mm × 5.8 mm, with a compact structure, making it easy to implement subcutaneously.

[0041] Specifically, such as Figure 3 As shown, a short-circuit probe is loaded between the radiating patch and the ground plane. The short-circuit probe passes perpendicularly through the dielectric substrate and maintains a good electrical connection with the radiating patch and the ground plane. By adjusting the position and size of the short-circuit probe, the impedance matching state of the 1.9 GHz and 2.45 GHz frequency bands can be precisely controlled, enabling the antenna to achieve excellent impedance matching in the target frequency band. 11 | Response.

[0042] Furthermore, the overall size of the antenna is 6.0 mm × 6.0 mm × 0.254 mm. At the free space wavelength corresponding to the lowest operating frequency, the electrical size is only 0.0371λ0 × 0.0371λ0 × 0.0016λ0, achieving a highly miniaturized design that is easy to integrate into implantable monitoring devices.

[0043] like Figure 4 The diagram shows the simulation and testing platform for the antenna of this invention in a bovine tissue model. The antenna is encapsulated in a 0.2 mm thick biocompatible alumina layer, implanted at a depth of 3 mm, and placed inside a three-layer bovine tissue model. This model can realistically simulate the subcutaneous tissue environment of dairy cows, ensuring a high degree of consistency between simulation results and actual application scenarios. The antenna of this invention underwent a significant evolution in its design process. 11 | Curve graph. As shown in the graph, with the introduction of the U-shaped slot, arc-shaped slot, short-circuit probe, and ground plane composite slot, the antenna extends to dual-band ultra-wideband operation, ultimately achieving | S in the 1.86–3.52 GHz range. 11 |≤−10dB, achieving ultra-wideband impedance matching, which can simultaneously cover the wireless power supply and data communication frequency bands commonly used in implantable devices, providing a good port matching foundation for stable system operation.

[0044] like Figure 5 As shown, the antenna of this invention is simulated and measured in bovine muscle tissue. 11 | Comparison Curves. The two curves show a high degree of agreement. The simulated curves cover the 1.86–3.52 GHz band and exhibit a significant resonance dip near 1.9 GHz. They also maintain excellent matching in the 2.45 GHz band, proving the accuracy and reliability of the simulation model and demonstrating that the antenna possesses stable dual-band impedance characteristics. Both curves satisfy | S ... 11 The impedance matching requirement of ≤ -10 dB and the small resonant point deviation verify the accuracy of the antenna model and the feasibility of its performance, providing a reliable impedance matching basis for stable communication of implantable devices.

[0045] like Figure 6 The figure shows a comparison of the simulated and measured radiation patterns of the antenna of the present invention at two center frequencies: 1.9 GHz and 2.45 GHz. The simulation and measured results are in good agreement. The antenna exhibits a multi-lobed radiation pattern, with the main radiation direction concentrated in the vertical direction, which can effectively transmit energy to the outside, meeting the radiation requirements of wireless communication for implantable devices. Furthermore, it has good cross-polarization suppression, and the overall radiation performance meets the wireless communication requirements for dairy cow health monitoring.

[0046] Table 1 shows the key dimensional parameters of the antenna, all in mm;

[0047] Table 1 Dimensional Parameters

[0048] parameter Value / mm parameter Value / mm parameter Value / mm parameter Value / mm l 6.0 e 5.8 n 1.4 r1 0.28 w 5.8 f 4.9 o 1.2 r2 0.4 h 0.35 g 5.6 p 0.8 r3 0.48 a 0.6 i 3.2 q 5.6 s 2.4 b 2.2 j 2.8 t 0.5 c 0.6 k 5.0 v 3.0 d 0.4 m 0.4 z 2.8

[0049] This antenna exhibits excellent reflection parameters (|S) in both the 1.9 GHz and 2.45 GHz frequency bands. 11(|< -10 dB), covering the dual-band application needs of animal health monitoring in the 1.9 GHz band (for high-speed wireless communication) and the 2.45 GHz band (for physiological parameter monitoring).

[0050] In summary, the miniaturized high-gain dual-band broadband implantable patch antenna provided by this invention effectively achieves dual-band broadband performance within a limited volume through a carefully designed slotted structure and probe feeding method. It is suitable for implantation in animal bodies (such as bovine muscle tissue) and has broad application prospects in the field of smart agriculture, such as animal health monitoring, behavior tracking, and remote communication.

[0051] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0052] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this 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 this invention.

Claims

1. A miniaturized ultra-wideband implantable antenna for large mammal health monitoring, characterized in that, The antenna includes a dielectric substrate, a radiating surface disposed on the upper surface of the dielectric substrate, and a grounding plane disposed on the lower surface of the dielectric substrate; The radiating surface adopts a closed rectangular radiating patch structure, and the surface of the radiating patch is etched with symmetrical U-shaped grooves and arc-shaped grooves; The grounding plane has a composite groove structure; A coaxial feed solder joint is provided on the radiating surface, and a corresponding ground plane coaxial feed grounding port is provided on the grounding plane. The coaxial feed solder joint and the ground plane coaxial feed grounding port are connected by a central probe to form a feed structure. The central probe passes vertically through the dielectric substrate.

2. The miniaturized ultra-widebandwidth implantable antenna for health monitoring of large mammals according to claim 1, characterized in that, The radiating patch has a coaxial power supply solder joint at its center and short-circuit probes on both sides.

3. The miniaturized ultra-widebandwidth implantable antenna for health monitoring of large mammals according to claim 1, characterized in that, The composite trench structure of the grounding plane is symmetrically distributed along the edge and the central region.

4. The miniaturized ultra-widebandwidth implantable antenna for health monitoring of large mammals according to claim 1, characterized in that, The short-circuit probe is loaded between the radiating patch and the ground plane. The short-circuit probe passes vertically through the dielectric substrate and maintains an electrical connection with the radiating patch and the ground plane.

5. The miniaturized ultra-widebandwidth implantable antenna for health monitoring of large mammals according to claim 1, characterized in that, The dielectric substrate is made of Rogers RO4350 material, with a relative permittivity of 3.66, a loss tangent of 0.0037, and a thickness of 0.254 mm.

6. The miniaturized ultrawide bandwidth implantable antenna for health monitoring of large mammals according to claim 1, characterized in that, Both the radiating patch and the grounding plane are made of copper.

7. The miniaturized ultra-widebandwidth implantable antenna for health monitoring of large mammals according to claim 1, characterized in that, The central probe is a metal column coated with chlorinated polyethylene.

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