CN110544824B - Square annular circularly polarized implantable antenna for wireless biomedical treatment - Google Patents
Square annular circularly polarized implantable antenna for wireless biomedical treatment Download PDFInfo
- Publication number
- CN110544824B CN110544824B CN201910960059.8A CN201910960059A CN110544824B CN 110544824 B CN110544824 B CN 110544824B CN 201910960059 A CN201910960059 A CN 201910960059A CN 110544824 B CN110544824 B CN 110544824B
- Authority
- CN
- China
- Prior art keywords
- loading unit
- antenna
- triangular
- triangular loading
- short
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000005855 radiation Effects 0.000 claims abstract description 49
- 230000010287 polarization Effects 0.000 claims abstract description 35
- 230000002035 prolonged effect Effects 0.000 claims abstract description 6
- 239000000523 sample Substances 0.000 claims description 58
- 239000000758 substrate Substances 0.000 claims description 38
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 4
- 239000000560 biocompatible material Substances 0.000 claims description 4
- 230000002093 peripheral effect Effects 0.000 claims description 4
- 239000013307 optical fiber Substances 0.000 abstract description 2
- 238000002513 implantation Methods 0.000 description 8
- 238000004088 simulation Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000032683 aging Effects 0.000 description 1
- WYTGDNHDOZPMIW-RCBQFDQVSA-N alstonine Natural products C1=CC2=C3C=CC=CC3=NC2=C2N1C[C@H]1[C@H](C)OC=C(C(=O)OC)[C@H]1C2 WYTGDNHDOZPMIW-RCBQFDQVSA-N 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000002775 capsule Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000004060 metabolic process Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000035790 physiological processes and functions Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000001356 surgical procedure Methods 0.000 description 1
- 230000009747 swallowing Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/27—Adaptation for use in or on movable bodies
- H01Q1/273—Adaptation for carrying or wearing by persons or animals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
- H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/48—Earthing means; Earth screens; Counterpoises
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/50—Structural association of antennas with earthing switches, lead-in devices or lightning protectors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
- H01Q13/10—Resonant slot antennas
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q23/00—Antennas with active circuits or circuit elements integrated within them or attached to them
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
- H01Q3/30—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
Abstract
The invention discloses a square annular circularly polarized implantable antenna for wireless biomedical treatment, which is characterized in that rectangular grooves with the same size are formed on four sides of a square ring to form a meandering structure, so that the surface current path of a radiation unit can be prolonged, and the size of the antenna can be reduced. Eight triangular loading units are loaded in the middle of the square annular radiation patch, so that effective capacitance and inductance distribution of unit length can be effectively increased, and propagation constant is increased, and the resonant frequency of the antenna is shifted to the low-frequency direction. The two groups of triangular loading units are connected by a rectangular conduction band at the center position of the two groups of triangular loading units to generate geometric disturbance and circular polarization characteristics. The volume of the antenna is only 10×10×0.635mm 3 The novel optical fiber antenna has the characteristics of miniaturization, circular polarization, wide frequency band, interference resistance, good biocompatibility and the like, is suitable for the WMTS1.43GHz frequency band, and can meet the working requirements after being implanted into human tissues.
Description
Technical Field
The invention relates to the technical field of implanted antennas, in particular to a square annular circularly polarized implanted antenna for wireless biomedical treatment, which is applicable to a circularly polarized implanted wireless biomedical device in a WMTS1.43GHz frequency band.
Background
At present, the population is aging and sub-health population is increasing, 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 biomedical technology can provide more efficient and convenient medical care service, and has wide development prospect. The wireless biomedical device is implanted into a human body device by adopting methods such as swallowing or surgery, and the like, 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 doctors, 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 changes, the designed implanted antenna needs to have a small size, interference resistance, low power consumption, and biocompatibility. The implanted antenna is moved or rotated by the movement of the human body, which makes the external antenna unable to complete communication because of the inability to align with the implanted antenna. If the external antenna is a linear polarized antenna, the implanted antenna and the external antenna can cause polarization mismatch due to angle change, thereby reducing communication quality. The circular polarized antenna can reduce the polarization characteristic requirement of the external linear polarized antenna, can effectively solve the problem of polarization mismatch, and simultaneously has the characteristics of reducing error rate, reducing multipath interference and the like. However, designing a circularly polarized implantable antenna needs to satisfy various requirements such as circular polarization, miniaturization, electromagnetic interference and compatibility, operating bandwidth and frequency, and biocompatibility, 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 to increase 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 wideband endoscope circular polarized antenna is disclosed, which reduces the design size of the antenna by opening a groove which forms a certain angle with a long arm and has different length on a radiation unit, adding a pair of open-circuit grooves on the floor, further reducing the size of the antenna, conforming the antenna with the outer wall of a capsule, generating circular polarization characteristics, and the antenna has good polarization characteristics and impedance matching in a frequency range. Non-patent document 2: the invention discloses a miniaturized implanted circular antenna, which consists of a middle circular radiation patch and an outer circular ring, wherein rectangular grooves are added on two sides of the circular ring to prolong the current path of the surface of the antenna, the size of the antenna is reduced, two branches are added on the inner side of the antenna circular radiation patch to generate geometric perturbation so as to produce circular polarization characteristics, and a Z-shaped groove is formed in the middle of the middle circular radiation patch to improve the impedance matching of the antenna and the circular polarization purity. The same dielectric substrate is added at the top of the radiation unit to prevent the radiation patch from being in direct contact with a human body, and meanwhile, the dielectric substrate can also be used as a buffer between human tissues and the radiation patch.
List of citations
Non-patent document 1: das R. Yoo H. Awideband circularlypolarized conformal endoscopic antenna system for high-speed datatransfer [ J ]. IEEEAntennas andWireless Propagation Letters,2017,65 (6): 2816-2826.
Non-patent document 2: li R., guo Y.X., zhang B., et al A miniaturized circularly polarized implantable annular-ring antinna [ J ]. IEEE Antennas and Wireless Propagation Letters,2017,16:2566-2569.
Disclosure of Invention
The invention aims to provide a square annular circularly polarized implantable 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 implantable wireless biomedical device, is suitable for a WMTS1.43GHz frequency band, and can meet the working requirements after being implanted into human tissues.
The technical scheme of the invention is as follows: a square annular circular polarization implantable antenna for wireless biomedical treatment comprises dielectric substrate 1, square annular radiation paster 2, first short-circuit probe 3, second short-circuit probe 4, coaxial connector 5, floor 6, its characterized in that:
a. the square ring-shaped radiation patch 2 consists of a square ring 2-1, a first triangular loading unit 2-2, a second triangular loading unit 2-3, a third triangular loading unit 2-4, a fourth triangular loading unit 2-5, a fifth triangular loading unit 2-6, a sixth triangular loading unit 2-7, a seventh triangular loading unit 2-8 and an eighth triangular loading unit 2-9, wherein the square ring 2-1 is positioned at the outer side edge of the square ring-shaped radiation patch 2, rectangular grooves with the same size are formed on four edges of the square ring 2-1 to form a meandering structure, the surface current path of the radiation unit can be prolonged, the size of the antenna is reduced, the first triangular loading unit 2-2, the second triangular loading unit 2-3, the third triangular loading unit 2-4, the fourth triangular loading unit 2-5, the fifth triangular loading unit 2-6, the sixth triangular loading unit 2-7, the seventh triangular loading unit 2-8 and the eighth triangular loading unit 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 annular 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, and the third triangular loading unit 2-4, the fourth triangular loading unit 2-5 and the seventh triangular loading unit 2-8 are connected with each other through high-impedance rectangular conduction bands parallel to the diagonal direction of the dielectric substrate 1, the gaps among the eighth triangular loading units 2-9 extend to the edges of the square ring 2-1 to form an open-circuit structure, the third triangular loading unit 2-4, the fourth triangular loading unit 2-5, the seventh triangular loading unit 2-8 and the eighth triangular loading unit 2-9 are connected by rectangular conduction bands at the central positions to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference values are formed in space to generate circular polarization characteristics, and the circular polarization purity can be further optimized by adjusting the size of the connected rectangles;
b. the first short-circuit probe 3 and the second short-circuit probe 4 are arranged on a third triangular loading unit 2-4 and a seventh triangular loading unit 2-8 in the square annular radiation patch 2, the first short-circuit probe 3 and the second short-circuit probe 4 are symmetrical with respect to the center of the antenna dielectric substrate 1, and new resonance points can be introduced by adding the first short-circuit probe 3 and the second short-circuit probe 4, so that the axial ratio bandwidth of the implanted antenna is widened;
c. the coaxial connector 5 is positioned on a fifth 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 an antenna on other electronic elements of the implanted wireless biomedical device is reduced, and 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.
Distance W between square ring 2-1 of square ring-shaped radiation patch 2 and edge of dielectric substrate 2 The peripheral width L of the square ring 2-1 is 0.2 mm-0.4 mm 4 The length L of the rectangular groove around the square ring 2-1 is 0.9 mm-1.2 mm 6 Is 0.7 mm-0.9 mm wide W 3 Width L of the meandering structure is 0.1 mm-0.3 mm 5 The eight triangle loading units at the center position of the inner side of the square annular radiation patch 2 are isosceles right triangles, and the length W of the right angle side is 0.1 mm-0.3 mm 1 The gap width L between the eight triangular loading units is 2.8 mm-3.1 mm 3 The high-impedance rectangular conduction bandwidth L is 0.1 mm-0.3 mm and is formed by connecting eight triangular loading units with the square ring 2-1 2 The length L of rectangular conduction band of the third connecting triangle loading unit 2-4, the fourth triangle loading unit 2-5, the seventh triangle loading unit 2-8 and the eighth triangle loading unit 2-9 is 0.2 mm-0.4 mm 1 Is 0.4mm to 0.6mm.
The distance R between the first short-circuit probe 3 and the second short-circuit probe 4 and the center of the dielectric substrate 1 1 The included angle a between the center positions of the first short-circuit probe 3 and the second short-circuit probe 4 and the longitudinal symmetry axis of the dielectric substrate 1 is 2.6 mm-3.1 mm 1 The radius R of the first short-circuit probe 3 and the second short-circuit probe 4 is 6-14 DEG 2 The radius of the first short-circuit probe 3 and the second short-circuit probe 4 is equal to the radius of the inner core of the coaxial connector 5 and is 0.2 mm-0.4 mm.
The distance L between the coaxial connector 5 and the transverse symmetry axis of the dielectric substrate 1 0 Is 0.8 mm-1.2 mm away from the medium substrate1 distance W of longitudinal symmetry axis 0 Is 1.8mm to 2.2mm.
The external surface of the square annular circularly polarized implantable antenna is plated with a layer of biocompatible material alumina, the thickness is 0.03mm, and the dielectric constant epsilon is 0.03mm r The loss tangent tan delta is 0.008, which is 9.2, separates human tissues from the circularly polarized implantable antenna, and reduces the influence of human tissues on the antenna performance.
The invention has the following effects: the invention designs a square annular circularly polarized implantable antenna for wireless biomedical treatment, rectangular grooves with the same size are formed on four sides of a square ring to form a tortuous 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 effective capacitance and inductance distribution of unit length can be effectively increased, and propagation constant is increased, and the resonant frequency of the antenna is shifted to the low-frequency direction. The two groups of triangular loading units are connected by a rectangular conduction band at the center position to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference are formed in space to generate circular polarization characteristics, and the polarization purity can be further optimized by adjusting the size of the connecting rectangle. The floor adopts a complete square structure, a shielding layer can be formed in the implanted wireless biomedical device, the 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. Adding two shorting probes can introduce new resonance points, thereby widening the axial ratio bandwidth of the implanted antenna. The circularly polarized implanted antenna has a planar structure, and the volume of the antenna is only 10 multiplied by 0.635mm 3 The novel optical fiber antenna has the characteristics of miniaturization, circular polarization, wide frequency band, interference resistance, good biocompatibility and the like, is suitable for the WMTS1.43GHz frequency band, and can meet the working requirements after being implanted into human tissues.
Drawings
Fig. 1 is a schematic diagram of the front structure 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 view of the back structure of an embodiment of the present invention.
FIG. 4 shows a rectangular groove length L around a square ring according to an embodiment of the present invention 6 Width W 3 Effects on antenna impedance bandwidth and axial ratio bandwidth.
FIG. 5 is a schematic diagram of the length W of the right-angle sides of eight triangle loading units according to an embodiment of the present invention 1 Effects on antenna impedance bandwidth and axial ratio bandwidth.
FIG. 6 is a diagram of a connecting rectangular conduction band length L of two sets of triangle loading units according to an embodiment of the invention 1 Effects on antenna impedance bandwidth and axial ratio bandwidth.
Fig. 7 is a schematic view of the depth of layer of implanted skin according to an embodiment of the present invention.
Fig. 8 is a graph showing the effect of different implant depths H on antenna impedance bandwidth and axial ratio bandwidth in an embodiment of the present invention.
FIG. 9 is a graph of simulated and measured impedance bandwidth for an embodiment of the present invention.
Fig. 10 is an E-plane radiation pattern at a frequency of 1.43GHz for an embodiment of the invention.
Fig. 11 is an H-plane radiation pattern at a frequency of 1.43GHz for an embodiment of the invention.
Detailed Description
The specific embodiments of the invention are: as shown in fig. 1, a square annular circularly polarized implantable antenna for wireless biomedical treatment is composed of a dielectric substrate 1, a square annular radiation patch 2, a first short-circuit probe 3, a second short-circuit probe 4, a coaxial connector 5 and a floor 6, and is characterized in that: the square ring-shaped radiation patch 2 consists of a square ring 2-1, a first triangular loading unit 2-2, a second triangular loading unit 2-3, a third triangular loading unit 2-4, a fourth triangular loading unit 2-5, a fifth triangular loading unit 2-6, a sixth triangular loading unit 2-7, a seventh triangular loading unit 2-8 and an eighth triangular loading unit 2-9, wherein the square ring 2-1 is positioned at the outer side edge of the square ring-shaped radiation patch 2, rectangular grooves with the same size are formed on four edges of the square ring 2-1 to form a meandering structure, the surface current path of the radiation unit can be prolonged, the size of the antenna is reduced, the first triangular loading unit 2-2, the second triangular loading unit 2-3, the third triangular loading unit 2-4, the fourth triangular loading unit 2-5, the fifth triangular loading unit 2-6, the sixth triangular loading unit 2-7, the seventh triangular loading unit 2-8 and the eighth triangular loading unit 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 annular 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, and the third triangular loading unit 2-4, the fourth triangular loading unit 2-5 and the seventh triangular loading unit 2-8 are connected with each other through high-impedance rectangular conduction bands parallel to the diagonal direction of the dielectric substrate 1, the gaps among the eighth triangular loading units 2-9 extend to the edges of the square ring 2-1 to form an open-circuit structure, the third triangular loading unit 2-4, the fourth triangular loading unit 2-5, the seventh triangular loading unit 2-8 and the eighth triangular loading unit 2-9 are connected by rectangular conduction bands at the central positions to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference values are formed in space to generate circular polarization characteristics, and the circular polarization purity can be further optimized by adjusting the size of the connected rectangles; the first short-circuit probe 3 and the second short-circuit probe 4 are arranged on a third triangular loading unit 2-4 and a seventh triangular loading unit 2-8 in the square annular radiation patch 2, the first short-circuit probe 3 and the second short-circuit probe 4 are symmetrical with respect to the center of the antenna dielectric substrate 1, and new resonance points can be introduced by adding the first short-circuit probe 3 and the second short-circuit probe 4, so that the axial ratio bandwidth of the implanted antenna is widened; the coaxial connector 5 is positioned on a fifth 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; the floor 6 is of a complete square structure, a shielding layer can be formed in the implanted wireless biomedical device, interference of an antenna on other electronic elements of the implanted wireless biomedical device is reduced, and 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.
The square ring 2-1 of the square ring-shaped radiation patch 2 is away from the edge of the medium substrateDistance W 2 The peripheral width L of the square ring 2-1 is 0.2 mm-0.4 mm 4 The length L of the rectangular groove around the square ring 2-1 is 0.9 mm-1.2 mm 6 Is 0.7 mm-0.9 mm wide W 3 Width L of the meandering structure is 0.1 mm-0.3 mm 5 The eight triangle loading units at the center position of the inner side of the square annular radiation patch 2 are isosceles right triangles, and the length W of the right angle side is 0.1 mm-0.3 mm 1 The gap width L between the eight triangular loading units is 2.8 mm-3.1 mm 3 The high-impedance rectangular conduction bandwidth L is 0.1 mm-0.3 mm and is formed by connecting eight triangular loading units with the square ring 2-1 2 The rectangular conduction band length L of the third triangular loading unit 2-4, the fourth triangular loading unit 2-5, the seventh triangular loading unit 2-8 and the eighth triangular loading unit 2-9 is 0.2 mm-0.4 mm 1 Is 0.4mm to 0.6mm.
The distance R between the first short-circuit probe 3 and the second short-circuit probe 4 and the center of the dielectric substrate 1 1 The included angle a between the center positions of the first short-circuit probe 3 and the second short-circuit probe 4 and the longitudinal symmetry axis of the dielectric substrate 1 is 2.6 mm-3.1 mm 1 The radius R of the first short-circuit probe 3 and the second short-circuit probe 4 is 6-14 DEG 2 The radius of the first short-circuit probe 3 and the second short-circuit probe 4 is equal to the radius of the inner core of the coaxial connector 5 and is 0.2 mm-0.4 mm.
The distance L between the coaxial connector 5 and the transverse symmetry axis of the dielectric substrate 1 0 Is 0.8 mm-1.2 mm, and is a distance W from the longitudinal symmetry axis of the medium substrate 1 0 Is 1.8mm to 2.2mm.
The external surface of the square annular circularly polarized implantable antenna is plated with a layer of biocompatible material alumina, the thickness is 0.03mm, and the dielectric constant epsilon is 0.03mm r The loss tangent tan delta is 0.008, which is 9.2, separates human tissues from the circularly polarized implantable antenna, and reduces the influence of human tissues on the antenna performance.
Examples: the specific manufacturing process is as described in the embodiment mode. A Rogers RO3210 dielectric substrate is selected, and dielectric constant epsilon r =10.2, loss tangent tan δ=0.003, thickness h=0.635 mm, and standard SMA joints are used for coaxial joints. The length L of the dielectric substrate 1 was 10mm, and the width W was 10mm. The square ring is provided with the same size on four sidesThe rectangular groove forms a meandering structure, which can prolong the current path on the surface of the radiating unit and reduce the size of the antenna. Distance W of square ring 2-1 of square ring radiation patch 2 from edge of dielectric substrate 2 The peripheral width L of the square ring 2-1 is 0.2mm 4 Rectangular groove length L around square ring 2-1 is 1.05mm 6 0.81mm wide W 3 Width L of the serpentine structure of 0.24mm 5 The eight triangular loading units at the center of the inner side of the square annular radiation patch 2 are isosceles right triangles, and the length W of the right angle side is 0.24mm 1 Width L of gap between eight triangular loading units of 2.9mm 3 High-impedance rectangular conduction band width L of 0.2mm and connecting eight triangular loading units with square ring 2-1 2 Rectangular conduction band length L of 0.35mm connecting third triangle loading unit 2-4, fourth triangle loading unit 2-5, seventh triangle loading unit 2-8, eighth triangle loading unit 2-9 1 Is 0.5mm. Eight triangular loading units are loaded in the middle of the square annular radiation patch, so that effective capacitance and inductance distribution of unit length can be effectively increased, and propagation constant is increased, and the resonant frequency of the antenna is shifted to the low-frequency direction. The two groups of triangular loading units are connected by a rectangular conduction band at the center position to generate geometric disturbance, so that orthogonal components with equal amplitude and 90-degree phase difference are formed in space to generate circular polarization characteristics, and the circular polarization purity can be further optimized by adjusting the size of the connecting rectangle. The floor adopts a complete square structure, a shielding layer can be formed in the implanted wireless biomedical device, the 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. Distance R between first shorting probe 3 and second shorting probe 4 and center of dielectric substrate 1 1 The included angle a between the center positions of the first short-circuit probe 3 and the second short-circuit probe 4 and the longitudinal symmetry axis of the dielectric substrate 1 is 2.8mm 1 Radius R of the first shorting probe 3 and the second shorting probe 4 is 10 degrees 2 The radius of the first shorting probe 3 and the second shorting probe 4 is equal to the radius of the inner core of the coaxial connector 5, which is 0.3 mm. Two are addedThe shorting probe can introduce a new resonance point, thereby widening the axial ratio bandwidth of the implanted antenna. Distance L of coaxial connector 5 from transverse symmetry axis of dielectric substrate 1 0 Is 1mm, a distance W from the longitudinal symmetry axis of the medium substrate 1 0 Is 2mm. The outer surface of the square annular circularly polarized implanted antenna is plated with a layer of biocompatible material alumina with the thickness of 0.03mm and the dielectric constant epsilon r The loss tangent tan delta is 0.008, which is 9.2, separates human tissues from the circularly polarized implantable antenna, and reduces the influence of human tissues on the antenna performance.
Selecting rectangular groove length L around square ring 6 Width W 3 Analysis of the influence on the antenna impedance bandwidth and the axial ratio bandwidth as shown in FIG. 4, L is selected respectively 6 ＝0.7mm、W 3 ＝0.1mm、L 6 ＝0.81mm、W 3 =0.24 mm and L 6 ＝0.9mm、W 3 As shown in fig. 4, as the size of the rectangular slot increases, the resonance point of the circularly polarized implanted antenna shifts to a low frequency, and the frequency point with the optimal axial ratio performance shifts to a low frequency, which indicates that the miniaturization degree of the antenna is improved, because rectangular slots with the same size are formed on four sides of the square ring, a meandering structure is formed, the surface current path of the radiating element can be prolonged, and the size of the antenna is reduced. When L 6 ＝0.81mm、W 3 When the wave length is=0.24 mm, the circularly polarized implantable antenna can obtain better performance, and the impedance bandwidth and the axial ratio bandwidth cover the required WMTS1.43GHz frequency band.
Selecting the length W of the right-angle sides of eight triangular loading units 1 Analysis of the influence on the antenna impedance bandwidth and the axial ratio bandwidth As shown in FIG. 5, W is selected respectively 1 ＝2.8mm、W 1 =2.9 mm and W 1 As can be seen from fig. 5, as the length of the right-angle side of the triangular loading unit increases, the resonant frequency of the circularly polarized implanted antenna shifts to the low frequency direction, the optimal frequency point of the axial ratio performance shifts to the low frequency, the resonant degree increases and decreases, and the optimal frequency point of the axial ratio performance shifts to the low frequency, because eight triangular loading units are loaded in the middle of the square annular radiation patch, the antenna performance is improvedThe effective capacitance and inductance distribution of unit length can be effectively increased, and the propagation constant is increased, so that the resonant frequency of the antenna is shifted towards the low frequency direction. When W is 1 When the wave length is=2.9mm, the circularly polarized implantable antenna can obtain better performance, and the impedance bandwidth and the axial ratio bandwidth cover the required WMTS1.43GHz frequency band.
The influence of the connection rectangular conduction band length L1 analysis of the two groups of triangular loading units on the antenna impedance bandwidth and the axial ratio bandwidth is selected, and as shown in FIG. 6, L is selected respectively 1 ＝0.4mm、L 1 =0.5 mm and L 1 As can be seen from fig. 6, the resonance degree of the circularly polarized implanted antenna is slightly shifted toward low frequency, the axial ratio performance minimum value is firstly reduced and then increased, which indicates that the length of the rectangular conduction band has a larger influence on the impedance matching and the polarization purity of the antenna, because the two groups of triangular loading units are connected by the rectangular conduction band near the center position to generate geometric disturbance, thereby forming orthogonal components with equal amplitude and 90 degrees of phase difference in space to generate circular polarization characteristics, and the circular polarization purity can be further optimized by adjusting the size of the connecting rectangle.
The circularly polarized implanted antenna designed by the invention is mainly applied to a skin layer, in the actual implantation process, the implantation precision cannot be accurate, so that the influence of the implantation depth on the antenna performance is analyzed, the distance between the upper layer of a skin model and the upper surface of the antenna is H, the schematic diagram of the implantation skin layer depth is shown in fig. 7, the influence of different implantation depths H on the impedance bandwidth and the axial ratio bandwidth of the antenna is shown in fig. 8, along with the increase of the implantation depth, the resonance point of the circularly polarized implanted antenna slightly shifts to a low frequency, the resonance degree is gradually increased, the required WMTS1.43GHz frequency band can still be well covered, the minimum value of the axial ratio performance is gradually increased, and the three implantation depths can still cover the required WMTS1.43GHz frequency band.
The method is characterized in that an implanted circularly polarized antenna is placed in an environment simulating human tissues, a vector network analyzer is used for testing the impedance bandwidth of the antenna, the axial ratio bandwidth of the antenna is tested in an indirect mode of matching the external antenna, the simulation results and the test results of the impedance bandwidth and the axial ratio bandwidth are shown in fig. 9, the simulation impedance bandwidth of the implanted antenna is 1.34 GHz-1.49 GHz, the resonance frequency is 1.43GHz, the simulation axial ratio bandwidth is 1.35 GHz-1.47 GHz, the actual measured impedance bandwidth is 1.33 GHz-1.45 GHz, the resonance frequency is 1.42GHz, the resonance degree is increased, the actual measured axial ratio bandwidth is 1.34 GHz-1.46 GHz, the axial ratio bandwidth can cover the working frequency, the consistency between the actual measurement and the simulation results is good, the working bandwidth of the circularly polarized implanted antenna is wide, the impedance characteristic and the axial ratio characteristic in the working frequency band are good, the resonance frequency and the axial ratio bandwidth center slightly deviate to the position of the simulated human tissues, and the offset is mainly caused by the existence of bubbles, the processing test errors, the influence of the coaxial cable on the antenna test environment and the simulation environment and the difference of the simulated dielectric constant.
The radiation patterns of the E face and the H face of the antenna at the frequency point of 1.43GHz are tested, the radiation characteristics of the antenna are checked, and the actual measured patterns are shown in fig. 10 and 11. As can be seen from the directional diagram, the main polarization of the implanted circular polarized antenna is right-hand circular polarization, the right-hand maximum gain value is-23 dBic, and the two groups of triangular loading units are connected by a rectangular conduction band near the center position to generate geometric disturbance, so that the right-hand circular polarization characteristic is generated, the antenna has good radiation characteristic in the working frequency band, has a wider axial ratio beam, is suitable for the WMTS1.43GHz working frequency band, and can meet the requirement of a complex implantation environment.
The safety of the circular polarization implanted antenna is comprehensively analyzed, 1W of input signals are provided for the circular polarization implanted antenna, the average SAR value is utilized to evaluate the safety range of the human body model for absorbing energy, the simulation calculation shows that the maximum 1-/10-gSAR value 259.2/28.4W/kg of the circular polarization implanted antenna at 1.43GHz is calculated, and in order to meet the safety standards of FCC and IEEE on SAR values, the maximum allowable input power of the circular polarization implanted antenna is 5.18mW and 41.5mW, and the circular polarization implanted antenna meets the conditions that electromagnetic radiation is safe and harmless to human body tissues.
Claims (5)
1. A square annular circular polarization implantable antenna for wireless biomedical treatment comprises dielectric substrate (1), square annular radiation paster (2), first short circuit probe (3), second short circuit probe (4), coaxial connector (5), floor (6), its characterized in that:
a. the square annular radiation patch (2) consists of a square ring (2-1), a first triangular loading unit (2-2), a second triangular loading unit (2-3), a third triangular loading unit (2-4), a fourth triangular loading unit (2-5), a fifth triangular loading unit (2-6), a sixth triangular loading unit (2-7), a seventh triangular loading unit (2-8) and an eighth triangular loading unit (2-9), wherein the square ring (2-1) is positioned at the outer side edge of the square annular radiation patch (2), rectangular grooves with the same size are formed on four sides of the square ring (2-1) to form a meandering structure, the surface current path of the radiation unit can be prolonged, the size of the antenna is reduced, the first triangular loading unit (2-2), the second triangular loading unit (2-3), the third triangular loading unit (2-4), the fourth triangular loading unit (2-5), the fifth triangular loading unit (2-6), the sixth triangular loading unit (2-7), the seventh triangular loading unit (2-8) and the eighth triangular loading unit (2-9) are positioned at the inner side of the 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 the dielectric substrate (1), effective capacitance and inductance distribution of unit length can be effectively increased, propagation constant is increased, resonance frequency of an antenna is offset towards a low-frequency direction, gaps among a third triangular loading unit (2-4), a fourth triangular loading unit (2-5), a seventh triangular loading unit (2-8) and an eighth triangular loading unit (2-9) extend to the edge of the square ring (2-1) to form an open-circuit structure, the third triangular loading unit (2-4), the fourth triangular loading unit (2-5) and the seventh triangular loading unit (2-8) are connected by the rectangular conduction band near the center position, geometric disturbance is generated, orthogonal components with equal amplitude and 90-degree phase difference are formed in space, circular polarization characteristics are generated, and circular polarization purity can be further optimized by adjusting the size of the connecting rectangles;
b. the first short-circuit probe (3) and the second short-circuit probe (4) are arranged on a third triangular loading unit (2-4) and a seventh triangular loading unit (2-8) in the square annular radiation patch (2), the first short-circuit probe (3) and the second short-circuit probe (4) are symmetrical with respect to the center of the antenna dielectric substrate (1), and new resonance points can be introduced by adding the first short-circuit probe (3) and the second short-circuit probe (4), so that the axial ratio bandwidth of the implanted antenna is widened;
c. the coaxial connector (5) is positioned on a fifth 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 an antenna on other electronic elements of the implanted wireless biomedical device is reduced, and electromagnetic compatibility of the implanted antenna is improved;
the distance L between the coaxial connector (5) and the transverse symmetry axis of the dielectric substrate (1) 0 Is 0.8 mm-1.2 mm, and is a distance W from the longitudinal symmetry axis of the medium substrate (1) 0 Is 1.8mm to 2.2mm.
2. The square ring shaped circularly polarized implantable antenna for wireless biomedical treatment according to claim 1, wherein 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.
3. The square ring shaped circularly polarized implantable antenna for wireless biomedical treatment according to claim 1, characterized in that the square ring (2-1) of the square ring shaped radiating patch (2) is at a distance W from the edge of the dielectric substrate 2 The peripheral width L of the square ring (2-1) is 0.2 mm-0.4 mm 4 The length L of the rectangular groove around the square ring (2-1) is 0.9 mm-1.2 mm 6 Is 0.7 mm-0.9 mm wide W 3 Width L of the meandering structure is 0.1 mm-0.3 mm 5 The eight triangular loading units at the center position of the inner side of the square annular radiation patch (2) are isosceles right triangles, and the length W of the right angle side is 0.1 mm-0.3 mm 1 The gap width L between the eight triangular loading units is 2.8 mm-3.1 mm 3 Eight triangular loading units and square rings are arranged at the length of 0.1 mm-0.3 mm(2-1) connected high impedance rectangular conduction band width L 2 The length L of rectangular conduction band of the third connecting triangle loading unit (2-4), the fourth triangle loading unit (2-5), the seventh triangle loading unit (2-8) and the eighth triangle loading unit (2-9) is 0.2 mm-0.4 mm 1 Is 0.4mm to 0.6mm.
4. The square ring shaped circularly polarized implantable antenna for wireless biomedical treatment according to claim 1, characterized in that the distance R between the first short circuit probe (3) and the second short circuit probe (4) and the center of the dielectric substrate (1) 1 The included angle a between the center positions of the first short-circuit probe (3) and the second short-circuit probe (4) and the longitudinal symmetry axis of the dielectric substrate (1) is 2.6 mm-3.1 mm 1 The radius R of the first short-circuit probe (3) and the second short-circuit probe (4) is 6-14 DEG 2 The radius of the first short-circuit probe (3) and the radius of the second short-circuit probe (4) are equal to the radius of the inner core of the coaxial connector (5) and are 0.2 mm-0.4 mm.
5. The square ring shaped circularly polarized implanted antenna for wireless biomedical treatment according to claim 1, wherein the external surface of the square ring shaped circularly polarized implanted antenna is plated with a layer of biocompatible material alumina, the thickness is 0.03mm, the dielectric constant epsilon r The loss tangent tan delta is 0.008, which is 9.2, separates human tissues from the circularly polarized implantable antenna, and reduces the influence of human tissues on the antenna performance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910960059.8A CN110544824B (en) | 2019-10-10 | 2019-10-10 | Square annular circularly polarized implantable antenna for wireless biomedical treatment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910960059.8A CN110544824B (en) | 2019-10-10 | 2019-10-10 | Square annular circularly polarized implantable antenna for wireless biomedical treatment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110544824A CN110544824A (en) | 2019-12-06 |
| CN110544824B true CN110544824B (en) | 2024-02-20 |
Family
ID=68715579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910960059.8A Active CN110544824B (en) | 2019-10-10 | 2019-10-10 | Square annular circularly polarized implantable antenna for wireless biomedical treatment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110544824B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1665461A1 (en) * | 2003-09-08 | 2006-06-07 | Samsung Electronics Co., Ltd. | Electromagnetically coupled small broadband monopole antenna |
| CN102832451A (en) * | 2012-09-18 | 2012-12-19 | 陕西海创中盈信息技术有限公司 | Wide-band miniaturized gain-controllable directional antenna and manufacturing method thereof |
| CN105846072A (en) * | 2016-05-05 | 2016-08-10 | 华南理工大学 | Broad axial ratio beam circularly polarized antenna used for biomedical telemetry |
| CN107732442A (en) * | 2017-09-13 | 2018-02-23 | 华南理工大学 | A kind of implanted circular polarized antenna applied to Wireless Medical Telemetry |
| JP2018207346A (en) * | 2017-06-06 | 2018-12-27 | 株式会社Ｓｏｋｅｎ | Antenna device |
| CN109473766A (en) * | 2018-12-26 | 2019-03-15 | 吉林医药学院 | Wireless broadband circle polarized implanted antenna of the biologic medical equipment based on graphene |
| CN209298336U (en) * | 2019-03-12 | 2019-08-23 | 吉林医药学院 | The double frequency implanted antenna based on graphene for rehabilitation nursing device |
| CN210576441U (en) * | 2019-10-10 | 2020-05-19 | 吉林医药学院 | Square ring-shaped circularly polarized implanted antenna for wireless biomedical treatment |
-
2019
- 2019-10-10 CN CN201910960059.8A patent/CN110544824B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1665461A1 (en) * | 2003-09-08 | 2006-06-07 | Samsung Electronics Co., Ltd. | Electromagnetically coupled small broadband monopole antenna |
| CN102832451A (en) * | 2012-09-18 | 2012-12-19 | 陕西海创中盈信息技术有限公司 | Wide-band miniaturized gain-controllable directional antenna and manufacturing method thereof |
| CN105846072A (en) * | 2016-05-05 | 2016-08-10 | 华南理工大学 | Broad axial ratio beam circularly polarized antenna used for biomedical telemetry |
| JP2018207346A (en) * | 2017-06-06 | 2018-12-27 | 株式会社Ｓｏｋｅｎ | Antenna device |
| CN107732442A (en) * | 2017-09-13 | 2018-02-23 | 华南理工大学 | A kind of implanted circular polarized antenna applied to Wireless Medical Telemetry |
| CN109473766A (en) * | 2018-12-26 | 2019-03-15 | 吉林医药学院 | Wireless broadband circle polarized implanted antenna of the biologic medical equipment based on graphene |
| CN209298336U (en) * | 2019-03-12 | 2019-08-23 | 吉林医药学院 | The double frequency implanted antenna based on graphene for rehabilitation nursing device |
| CN210576441U (en) * | 2019-10-10 | 2020-05-19 | 吉林医药学院 | Square ring-shaped circularly polarized implanted antenna for wireless biomedical treatment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110544824A (en) | 2019-12-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Hayat et al. | Miniaturized dual-band circularly polarized implantable antenna for capsule endoscopic system | |
| CN110854522A (en) | Implanted small circularly polarized antenna loaded with octagonal complementary split resonant ring | |
| Shang et al. | An ultrawideband capsule antenna for biomedical applications | |
| CN110350299A (en) | The implanted circular polarized antenna of loop checking installation sector load patch based on graphene | |
| CN210984938U (en) | Square resonant ring loaded implanted circularly polarized antenna for wireless biomedical | |
| CN110890625A (en) | Square-ring-shaped capacitive loading implantation type circularly polarized antenna with double-bending resonant ring | |
| Abbas et al. | Miniaturized antenna for high data rate implantable brain-machine interfaces | |
| CN210576441U (en) | Square ring-shaped circularly polarized implanted antenna for wireless biomedical treatment | |
| Saleeb et al. | Detection of kidney cancer using circularly polarized patch antenna array | |
| CN110544824B (en) | Square annular circularly polarized implantable antenna for wireless biomedical treatment | |
| CN210576431U (en) | Implanted small circularly polarized antenna loaded with octagonal complementary split resonant ring | |
| CN209133683U (en) | Wireless broadband circle polarized implanted antenna of the biologic medical equipment based on graphene | |
| Aoyagi et al. | Development of an implantable WBAN path-loss model for capsule endoscopy | |
| CN211088504U (en) | Square-ring-shaped capacitive loading implantation type circularly polarized antenna with double-bending resonant ring | |
| CN110808451A (en) | Square resonant ring loaded implanted circularly polarized antenna for wireless biomedical | |
| CN109768371A (en) | The double frequency implanted antenna based on graphene for rehabilitation nursing device | |
| CN210182566U (en) | Implanted circularly polarized antenna of annular loop sector loading patch based on graphene | |
| CN210576443U (en) | Implanted circularly polarized antenna with loading gradient structure for wireless biomedical treatment | |
| CN205790392U (en) | Microstrip antenna and apply the implantable medical devices of this microstrip antenna | |
| Leib et al. | Design and characterization of a UWB slot antenna optimized for radiation in human tissue | |
| Patil et al. | Microwave antennas suggested for Biomedical Implantation | |
| Li et al. | An implantable stripline-fed slot antenna for biomedical applications | |
| CN209298336U (en) | The double frequency implanted antenna based on graphene for rehabilitation nursing device | |
| Li et al. | An E-field probe based near-field measurement system for on-and in-body antennas | |
| CN107611595B (en) | Implantable MIMO antenna applied to biomedical telemetry |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |