阅读说明：本技术 用于无线生物医疗的方环形圆极化植入式天线 (Square ring-shaped circularly polarized implanted antenna for wireless biomedical treatment ) 是由 欧仁侠 张华磊 鲍捷 张光雷 李莹 杨春哲 于 2019-10-10 设计创作，主要内容包括：本发明公开了用于无线生物医疗的方环形圆极化植入式天线,在方形环四个边上开相同尺寸的矩形槽,形成蜿蜒曲折结构,能够延长辐射单元表面电流路径,缩小天线的尺寸。在方环形辐射贴片中间加载八个三角形加载单元,能够有效增加单位长度的有效电容和电感分布,增大传播常数,从而使天线的谐振频率向低频方向偏移。将两组三角形加载单元缝隙延伸至方形环边缘形成开路结构,在两组三角形加载单元靠中心位置通过矩形导带连接,产生几何扰动,产生圆极化特性。天线的体积仅为10×10×0.635mm<Sup>3</Sup>,具有小型化、圆极化、频带宽、抗干扰、生物兼容性好等特性,适用于WMTS 1.43GHz频段,能满足植入人体组织后的工作需求。(3 The invention discloses a square annular circularly polarized implanted antenna for wireless biomedical treatment, wherein rectangular grooves with the same size are formed on four sides of a square ring to form a winding structure, so that the surface current path of a radiation unit can be prolonged, and the size of the antenna is reduced. Eight triangular loading units are loaded in the middle of the square annular radiation patch, so that the effective capacitance and inductance distribution of unit length can be effectively increased, the propagation constant is increased, and the resonant frequency of the antenna is shifted to the low-frequency direction. And the gaps of the two groups of triangular loading units extend to the edges of the square rings to form an open circuit structure, and the two groups of triangular loading units are connected by a rectangular conduction band near the center position to generate geometric disturbance and generate circular polarization characteristics. The volume of the antenna is only 10 multiplied by 0.635mm3, the antenna has the characteristics of miniaturization, circular polarization, wide frequency band, interference resistance, good biological compatibility and the like, is suitable for WMTS 1.43GHz frequency band, and can meet the working requirement after being implanted into human tissues.)

1. a square ring circular polarization implanted antenna for wireless bio-medical treatment comprises medium base plate (1), square ring radiation paster (2), short circuit probe (3), short circuit probe (4), coaxial joint (5), floor (6), its characterized in that:

a. The square annular radiation patch (2) consists of a square ring (2-1), a triangular loading unit (2-2), a triangular loading unit (2-3), a triangular loading unit (2-4), a triangular loading unit (2-5), a triangular loading unit (2-6), a triangular loading unit (2-7), a triangular loading unit (2-8) and a triangular loading unit (2-9), wherein the square ring (2-1) is positioned at the outer edge of the square annular radiation patch (2), rectangular grooves with the same size are formed in four edges of the square ring (2-1) to form a zigzag structure, the surface current path of the radiation unit can be prolonged, the size of the antenna is reduced, and the triangular loading unit (2-2), the triangular loading unit (2-3) are arranged, The antenna comprises triangular loading units (2-4), triangular loading units (2-5), triangular loading units (2-6), triangular loading units (2-7), triangular loading units (2-8) and triangular loading units (2-9) which are located at the center of the inner side of a square annular radiation patch (2), each triangular loading unit is connected with a square ring (2-1) through a high-impedance rectangular conduction band parallel to the diagonal direction of a dielectric substrate (1), effective capacitance and inductance distribution of unit length can be effectively increased, propagation constants are increased, the resonant frequency of the antenna is shifted to the low-frequency direction, and gaps among the triangular loading units (2-4), the triangular loading units (2-5), the triangular loading units (2-8) and the triangular loading units (2-9) extend to the edge of the square ring (2-1) to form an open-circuit structure The triangular loading units (2-4), the triangular loading units (2-5), the triangular loading units (2-8) and the triangular loading units (2-9) are connected close to the center positions through rectangular conduction bands to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference are formed in space to generate a circular polarization characteristic, and the circular polarization purity can be further optimized by adjusting the size of a connecting rectangle;

b. The short-circuit probe (3) and the short-circuit probe (4) are arranged on a triangular loading unit (2-4) and a triangular loading unit (2-8) in the square annular radiation patch (2), the short-circuit probe (3) and the short-circuit probe (4) are centrosymmetric with respect to the antenna dielectric substrate (1), new resonance points can be introduced by adding the short-circuit probe (3) and the short-circuit probe (4), and the axial ratio bandwidth of the implanted antenna is further widened;

c. The coaxial connector (5) is positioned on the triangular loading unit (2-6) in the square annular radiation patch (2), an inner core of the coaxial connector (5) is connected with the square annular radiation patch (2), and an outer core of the coaxial connector (5) is connected with the floor (6);

d. The floor (6) is of a complete square structure, a shielding layer can be formed in the implanted wireless biomedical device, interference of the antenna on other electronic elements of the implanted wireless biomedical device is reduced, and the electromagnetic compatibility of the implanted antenna is improved.

2. The square-ring circular polarized implantable antenna for wireless biomedical applications according to claim 1, wherein the dielectric substrate (1) has a length L of 9.5mm to 10.5mm and a width W of 9.5mm to 10.5 mm.

3. The square-ring circularly polarized implantable antenna for wireless biomedical applications according to claim 1, wherein the square ring (2-1) of the square-ring shaped radiation patch (2) has a distance W2 of 0.2mm to 0.4mm from the edge of the dielectric substrate, a width L4 of 0.9mm to 1.2mm around the square ring (2-1), a rectangular slot length L6 of 0.7mm to 0.9mm around the square ring (2-1), a width W3 of 0.1mm to 0.3mm, a width L5 of the meander structure of 0.1mm to 0.3mm, eight triangular loading units at the central position of the inner side of the square-ring shaped radiation patch (2) are isosceles right triangles, a length W1 of 2.8mm to 3.1mm at right angles, a gap width L3 between the eight triangular loading units of 0.1mm to 0.3mm, a high impedance of L2 mm to 0.3mm connecting the eight triangular loading units with the square ring (2-1), the length L1 of the rectangular guide belt connecting the triangular loading unit (2-4), the triangular loading unit (2-5), the triangular loading unit (2-8) and the triangular loading unit (2-9) is 0.4 mm-0.6 mm.

4. The square-ring circularly polarized implantable antenna for wireless biomedical treatment according to claim 1, wherein the distance R1 between the short-circuit probe (3) and the short-circuit probe (4) and the center of the dielectric substrate (1) is 2.6mm to 3.1mm, the included angle a1 between the circle center positions of the short-circuit probe (3) and the short-circuit probe (4) and the longitudinal symmetry axis of the dielectric substrate (1) is 6 degrees to 14 degrees, the radius R2 of the short-circuit probe (3) and the short-circuit probe (4) is 0.2mm to 0.4mm, and the radius of the short-circuit probe (3) and the short-circuit probe (4) is equal to the inner core radius of the coaxial connector (5).

5. The square-ring type circularly polarized implantable antenna for wireless biomedical applications according to claim 1, wherein the distance L0 between the coaxial connector (5) and the transverse symmetry axis of the dielectric substrate (1) is 0.8 mm-1.2 mm, and the distance W0 between the coaxial connector and the longitudinal symmetry axis of the dielectric substrate (1) is 1.8 mm-2.2 mm.

6. The square-ring circular polarization implantable antenna for wireless biomedical treatment according to claim 1, wherein a layer of biocompatible material aluminum oxide is plated on the outer surface of the square-ring circular polarization implantable antenna, the thickness is 0.03mm, the dielectric constant epsilonr is 9.2, and the loss tangent tan delta is 0.008, so that human tissues and the circular polarization implantable antenna are isolated, and the influence of the human tissues on the performance of the antenna is reduced.

Technical Field

The invention relates to the technical field of implanted antennas, in particular to a square-ring circularly polarized implanted antenna for wireless biomedical treatment, which is suitable for a WMTS (wireless transmit receive set) 1.43GHz circularly polarized implanted wireless biomedical device.

Background

At present, the population aging and sub-health population are continuously increased, and the population needs to be nursed through daily examination, surgical operation and state monitoring, but the cost of medical care is higher, and the wireless biological medical treatment technology can provide more efficient and convenient medical care service and has wide development prospect. The wireless biological medical treatment device is implanted into a human body by adopting methods such as swallowing or operation, can continuously monitor the metabolism level of the human body without considering the physiological state of a patient, provides accurate diagnosis and treatment information for a doctor, and can greatly reduce the pain of the patient. The wireless biomedical device is generally composed of a sensor, an antenna, a battery and the like, wherein the antenna is a core device of the implanted wireless biomedical device and is a bridge for transmitting human body state information. Since the electrical characteristics and structure of human tissue may vary with time and individual, the designed implanted antenna needs to have a small size, interference resistance, low power consumption, and biocompatibility. After the implanted antenna is implanted into a human body, the implanted antenna can move or rotate due to the movement of the human body, so that the external antenna cannot be aligned with the implanted antenna to finish communication. If the antenna is a linearly polarized antenna outside the body, the polarization mismatch between the implanted antenna and the antenna outside the body is caused by the change of the angle, thereby reducing the communication quality. The circularly polarized antenna can reduce the polarization characteristic requirement on the in-vitro linearly polarized antenna, can effectively solve the problem of polarization mismatch, and has the characteristics of reducing the error rate, reducing multipath interference and the like. However, designing an implantable circularly polarized antenna needs to meet various requirements of circular polarization, miniaturization, electromagnetic interference and compatibility, working bandwidth and frequency, biocompatibility, and the like, and designing an implantable circularly polarized antenna with excellent performance has certain challenges. The miniaturization method of the implanted antenna mainly comprises the steps of prolonging a current path, increasing the electric size, changing the structure of a dielectric substrate, adopting a high-dielectric-constant dielectric substrate, adopting a loading technology to increase an active network and the like. Non-patent document 1: a radiation unit is provided with grooves which form a certain angle with a long arm and are different in length, the design size of the antenna is reduced, a pair of open-circuit grooves are additionally arranged on a floor, the size of the antenna is further reduced, the antenna is conformal with the outer wall of a capsule, the circular polarization characteristic is generated, and the antenna has good polarization characteristic and impedance matching in a frequency range. Non-patent document 2: the utility model discloses a miniaturized implanted ring shape antenna comprises the ring in the middle of circular radiation paster and the outside, increases the rectangular channel in ring both sides and prolongs antenna surface current path, reduces the size of antenna, increases two minor matters in the inboard of antenna ring radiation paster, thereby produces the circular polarization characteristic of how much perturbation, opens a Z-shaped groove in the middle of the circular radiation paster of middle, improves the impedance matching of antenna and promotes circular polarization purity. The same medium substrate is added on the top of the radiation unit to prevent the radiation patch from directly contacting with the human body, and meanwhile, the medium substrate can also be used as a buffer between human body tissues and the radiation patch.

List of cited documents

Non-patent document 1: das R, Yoo H. A Wireless and cyclic poled systematic antenna system for high-speed data transfer [ J ]. IEEE Antennas and Wireless Propagation Letters,2017,65(6): 2816) 2826.

non-patent document 2: li R, Guo Y.X., Zhang B, et al.A. finely polarized implantable annular-ring antenna [ J ]. IEEE Antennas and Wireless deployment Letters,2017,16: 2566-.

Disclosure of Invention

The invention aims to provide a square-ring circularly polarized implanted antenna for wireless biomedical treatment, which has the characteristics of circular polarization, wide frequency band, interference resistance, miniaturization, excellent biocompatibility and the like, is easy to integrate into an implanted wireless biomedical device, is suitable for WMTS (Wireless Telecommunications System) 1.43GHz frequency band, and can meet the working requirement after being implanted into human tissues.

The technical scheme of the invention is as follows: a square ring circular polarization implanted antenna for wireless bio-medical treatment comprises medium base plate 1, square ring radiation paster 2, short circuit probe 3, short circuit probe 4, coaxial joint 5, floor 6, its characterized in that:

a. The square annular radiation patch 2 consists of a square ring 2-1, a triangular loading unit 2-2, a triangular loading unit 2-3, a triangular loading unit 2-4, a triangular loading unit 2-5, a triangular loading unit 2-6, a triangular loading unit 2-7, a triangular loading unit 2-8 and a triangular loading unit 2-9, wherein the square ring 2-1 is positioned at the outer edge of the square annular radiation patch 2, rectangular grooves with the same size are formed on four edges of the square ring 2-1 to form a zigzag structure, the surface current path of the radiation unit can be prolonged, the size of an antenna is reduced, and the triangular loading unit 2-2, the triangular loading unit 2-3, the triangular loading unit 2-4, the triangular loading unit 2-5, The triangular loading units 2-6, the triangular loading units 2-7, the triangular loading units 2-8 and the triangular loading units 2-9 are positioned at the center of the inner side of the square annular radiation patch 2, each triangular loading unit is connected with the square ring 2-1 through a high-impedance rectangular conduction band parallel to the diagonal direction of the dielectric substrate 1, the effective capacitance and inductance distribution of unit length can be effectively increased, the propagation constant is increased, the resonant frequency of the antenna is shifted to the low-frequency direction, gaps among the triangular loading units 2-4, the triangular loading units 2-5, the triangular loading units 2-8 and the triangular loading units 2-9 are extended to the edge of the square ring 2-1 to form an open circuit structure, and the triangular loading units 2-4, the triangular loading units 2-5, the triangular loading units 2-8, The triangular loading units 2-9 are connected close to the central position through rectangular conduction bands to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference are formed in space, the circular polarization characteristic is generated, and the circular polarization purity can be further optimized by adjusting the size of a connecting rectangle;

b. The short-circuit probe 3 and the short-circuit probe 4 are arranged on the triangular loading unit 2-4 and the triangular loading unit 2-8 in the square annular radiation patch 2, the short-circuit probe 3 and the short-circuit probe 4 are symmetrical with respect to the center of the antenna dielectric substrate 1, new resonance points can be introduced by adding the short-circuit probe 3 and the short-circuit probe 4, and the axial ratio bandwidth of the implanted antenna is further widened;

c. The coaxial connector 5 is positioned on the triangular loading units 2-6 in the square annular radiation patch 2, the inner core of the coaxial connector 5 is connected with the square annular radiation patch 2, and the outer core of the coaxial connector 5 is connected with the floor 6;

d. The floor 6 is of a complete square structure, a shielding layer can be formed in the implanted wireless biomedical device, interference of the antenna on other electronic elements of the implanted wireless biomedical device is reduced, and the electromagnetic compatibility of the implanted antenna is improved.

The length L of the dielectric substrate 1 is 9.5 mm-10.5 mm, and the width W is 9.5 mm-10.5 mm.

_{2 4 6 3 5 1 3 2 1}the distance W2 between a square ring 2-1 of the square ring-shaped radiation patch 2 and the edge of the dielectric substrate is 0.2 mm-0.4 mm, the width L4 of the square ring 2-1 is 0.9 mm-1.2 mm, the length L6 of a rectangular groove around the square ring 2-1 is 0.7 mm-0.9 mm, the width W3 is 0.1 mm-0.3 mm, the width L5 of the zigzag structure is 0.1 mm-0.3 mm, eight triangle loading units at the center position of the inner side of the square ring-shaped radiation patch 2 are isosceles right-angled triangles, the length W1 of the right-angled sides is 2.8 mm-3.1 mm, the gap width L3 between the eight triangle loading units is 0.1 mm-0.3 mm, the high-resistance rectangular guide bandwidth L2 connecting the eight triangle loading units with the square ring 2-1 is 0.2 mm-0.4 mm, the triangle loading units are connected with the triangle loading units 2-5 and the triangle loading units 2-8 mm, The rectangular guide belt length L1 of the triangular loading units 2-9 is 0.4 mm-0.6 mm.

_{1 1 2}The distance R1 between the short circuit probe 3 and the short circuit probe 4 and the center of the medium substrate 1 is 2.6 mm-3.1 mm, the included angle a1 between the circle center positions of the short circuit probe 3 and the short circuit probe 4 and the longitudinal symmetry axis of the medium substrate 1 is 6-14 degrees, the radius R2 of the short circuit probe 3 and the short circuit probe 4 is 0.2 mm-0.4 mm, and the radius of the short circuit probe 3 and the short circuit probe 4 is equal to the radius of an inner core of the coaxial connector 5.

_{0 0}The distance L0 between the coaxial connector 5 and the transverse symmetry axis of the dielectric substrate 1 is 0.8 mm-1.2 mm, and the distance W0 between the coaxial connector 5 and the longitudinal symmetry axis of the dielectric substrate 1 is 1.8 mm-2.2 mm.

_rthe outer surface of the square-ring-shaped circularly polarized implanted antenna is plated with a layer of biocompatible material aluminum oxide, the thickness is 0.03mm, the dielectric constant epsilon r is 9.2, the loss tangent tan delta is 0.008, human tissues are isolated from the circularly polarized implanted antenna, and the influence of the human tissues on the performance of the antenna is reduced.

³The invention has the following effects: the invention designs a square annular circularly polarized implanted antenna for wireless biomedical treatment, rectangular grooves with the same size are formed on four sides of a square ring to form a winding structure, a current path on the surface of a radiation unit can be prolonged, and the size of the antenna is reduced. Eight triangular loading units are loaded in the middle of the square annular radiation patch, so that the effective capacitance and inductance distribution of unit length can be effectively increased, the propagation constant is increased, and the resonant frequency of the antenna is shifted to the low-frequency direction. The gaps of the two groups of triangular loading units extend to the edges of the square rings to form an open-circuit structure, the two groups of triangular loading units are connected by the rectangular conduction band near the center position to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference are formed in space, the circular polarization characteristic is generated, and the polarization purity can be further optimized by adjusting the size of the connecting rectangle. The floor adopts complete square structure, can form the shielding layer in implanted wireless biomedical device, reduces the antenna to the interference of other electronic components of implanted wireless biomedical device, promotes the electromagnetic compatibility ability of implanted antenna. Two short-circuit probes are added, so that a new resonance point can be introduced, and the axial ratio bandwidth of the implanted antenna is further widened. The circularly polarized implanted antenna is of a planar structure, the volume of the antenna is only 10 multiplied by 0.635mm3, the circularly polarized implanted antenna has the characteristics of miniaturization, circular polarization, wide frequency band, interference resistance, good biocompatibility and the like, is suitable for WMTS 1.43GHz frequency band, and can meet the working requirement after being implanted into human tissues.

drawings

Fig. 1 is a schematic front view of an embodiment of the present invention.

Fig. 2 is a schematic side view of an embodiment of the present invention.

Fig. 3 is a schematic diagram of a back structure according to an embodiment of the invention.

_{6 3}Fig. 4 shows the effect of the length L6 and the width W3 of the rectangular slot around the square ring on the impedance bandwidth and the axial ratio bandwidth of the antenna according to the embodiment of the present invention.

₁fig. 5 shows the effect of the length W1 of the legs of the eight triangular loading units on the impedance bandwidth and the axial ratio bandwidth of the antenna according to the embodiment of the present invention.

₁Fig. 6 shows the effect of the connecting rectangular conductor strip length L1 of two groups of triangular loading units on the impedance bandwidth and the axial ratio bandwidth of the antenna according to the embodiment of the present invention.

FIG. 7 is a schematic illustration of the depth of implantation into a skin layer in accordance with an embodiment of the present invention.

Fig. 8 is a graph showing the effect of different implant depths H on the antenna impedance bandwidth and axial ratio bandwidth according to an embodiment of the present invention.

Fig. 9 is a plot of simulated and measured impedance bandwidth for an embodiment of the present invention.

FIG. 10 is an E-plane radiation pattern for an embodiment of the present invention at a frequency of 1.43 GHz.

FIG. 11 is an H-plane radiation pattern at a frequency of 1.43GHz according to an embodiment of the invention.

Detailed Description

The specific implementation mode of the invention is as follows: as shown in fig. 1, the square-ring circularly polarized implantable antenna for wireless biomedical use is composed of a dielectric substrate 1, a square-ring radiation patch 2, a short-circuit probe 3, a short-circuit probe 4, a coaxial connector 5, and a floor 6, and is characterized in that: the square annular radiation patch 2 consists of a square ring 2-1, a triangular loading unit 2-2, a triangular loading unit 2-3, a triangular loading unit 2-4, a triangular loading unit 2-5, a triangular loading unit 2-6, a triangular loading unit 2-7, a triangular loading unit 2-8 and a triangular loading unit 2-9, wherein the square ring 2-1 is positioned at the outer edge of the square annular radiation patch 2, rectangular grooves with the same size are formed on four edges of the square ring 2-1 to form a zigzag structure, the surface current path of the radiation unit can be prolonged, the size of an antenna is reduced, and the triangular loading unit 2-2, the triangular loading unit 2-3, the triangular loading unit 2-4, the triangular loading unit 2-5, The triangular loading units 2-6, the triangular loading units 2-7, the triangular loading units 2-8 and the triangular loading units 2-9 are positioned at the center of the inner side of the square annular radiation patch 2, each triangular loading unit is connected with the square ring 2-1 through a high-impedance rectangular conduction band parallel to the diagonal direction of the dielectric substrate 1, the effective capacitance and inductance distribution of unit length can be effectively increased, the propagation constant is increased, the resonant frequency of the antenna is shifted to the low-frequency direction, gaps among the triangular loading units 2-4, the triangular loading units 2-5, the triangular loading units 2-8 and the triangular loading units 2-9 are extended to the edge of the square ring 2-1 to form an open circuit structure, and the triangular loading units 2-4, the triangular loading units 2-5, the triangular loading units 2-8, The triangular loading units 2-9 are connected close to the central position through rectangular conduction bands to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference are formed in space, the circular polarization characteristic is generated, and the circular polarization purity can be further optimized by adjusting the size of a connecting rectangle; the short-circuit probe 3 and the short-circuit probe 4 are arranged on the triangular loading unit 2-4 and the triangular loading unit 2-8 in the square annular radiation patch 2, the short-circuit probe 3 and the short-circuit probe 4 are symmetrical with respect to the center of the antenna dielectric substrate 1, new resonance points can be introduced by adding the short-circuit probe 3 and the short-circuit probe 4, and the axial ratio bandwidth of the implanted antenna is further widened; the coaxial connector 5 is positioned on the triangular loading units 2-6 in the square annular radiation patch 2, the inner core of the coaxial connector 5 is connected with the square annular radiation patch 2, and the outer core of the coaxial connector 5 is connected with the floor 6; the floor 6 is of a complete square structure, a shielding layer can be formed in the implanted wireless biomedical device, interference of the antenna on other electronic elements of the implanted wireless biomedical device is reduced, and the electromagnetic compatibility of the implanted antenna is improved.

The length L of the dielectric substrate 1 is 9.5 mm-10.5 mm, and the width W is 9.5 mm-10.5 mm.

_{2 4 6 3 5 1 3 2 1}The distance W2 between a square ring 2-1 of the square ring-shaped radiation patch 2 and the edge of the dielectric substrate is 0.2 mm-0.4 mm, the width L4 of the square ring 2-1 is 0.9 mm-1.2 mm, the length L6 of a rectangular groove around the square ring 2-1 is 0.7 mm-0.9 mm, the width W3 is 0.1 mm-0.3 mm, the width L5 of the zigzag structure is 0.1 mm-0.3 mm, eight triangle loading units at the center position of the inner side of the square ring-shaped radiation patch 2 are isosceles right-angled triangles, the length W1 of the right-angled sides is 2.8 mm-3.1 mm, the gap width L3 between the eight triangle loading units is 0.1 mm-0.3 mm, the high-resistance rectangular guide bandwidth L2 connecting the eight triangle loading units with the square ring 2-1 is 0.2 mm-0.4 mm, the triangle loading units are connected with the triangle loading units 2-5 and the triangle loading units 2-8 mm, The rectangular guide belt length L1 of the triangular loading units 2-9 is 0.4 mm-0.6 mm.

_{1 1 2}the distance R1 between the short circuit probe 3 and the short circuit probe 4 and the center of the medium substrate 1 is 2.6 mm-3.1 mm, the included angle a1 between the circle center positions of the short circuit probe 3 and the short circuit probe 4 and the longitudinal symmetry axis of the medium substrate 1 is 6-14 degrees, the radius R2 of the short circuit probe 3 and the short circuit probe 4 is 0.2 mm-0.4 mm, and the radius of the short circuit probe 3 and the short circuit probe 4 is equal to the radius of an inner core of the coaxial connector 5.

_{0 0}The distance L0 between the coaxial connector 5 and the transverse symmetry axis of the dielectric substrate 1 is 0.8 mm-1.2 mm, and the distance W0 between the coaxial connector 5 and the longitudinal symmetry axis of the dielectric substrate 1 is 1.8 mm-2.2 mm.

_rThe outer surface of the square-ring-shaped circularly polarized implanted antenna is plated with a layer of biocompatible material aluminum oxide, the thickness is 0.03mm, the dielectric constant epsilon r is 9.2, the loss tangent tan delta is 0.008, human tissues are isolated from the circularly polarized implanted antenna, and the influence of the human tissues on the performance of the antenna is reduced.