CN108448233A - A kind of multipolarization conformal antenna for capsule endoscope - Google Patents

Abstract

The invention discloses a kind of multipolarization conformal antennas for capsule endoscope, including aerial radiation chip unit, metal floor, medium substrate, coaxial feed and capsule shell, the antenna radiation unit is located at the upper surface of medium substrate, the metal floor patch is located at the lower surface of the medium substrate, the entire conformal bending of antenna is nested in capsule, forms hollow structure inside.The aerial radiation chip unit generally parallelogram sturcutre connects rectangle patch vertically above-mentioned notching construction near distributing point about symmetrical two notching constructions of the longitudinal axis, inside high impedance line.The antenna is by 50 Ω coaxial cables to radiation patch unit into row energization.The present invention has many advantages, such as that flexible is conformal, occupies small capsule spatial volume, multipolarization, has electromagnetism interference performance, broadband, suitable for capsule endoscope system, the radiation-curable or arbitrary polarized wave of reception.

Description

A Multi-polarization Conformal Antenna for Capsule Endoscopy

technical field

The invention relates to the communication field, in particular to a multi-polarization conformal antenna for a capsule endoscope.

Background technique

To establish a reliable communication between the body and the body of a wireless capsule endoscope system depends to a large extent on the performance of the antenna inside the capsule. The position and direction of the capsule in the human body are uncertain, and the space inside the capsule is limited, and other electronic components need to be accommodated: transceivers, batteries, LED lights, cameras, etc. Therefore, antenna design needs to consider many of the above factors: lossy dispersion characteristics of human tissue, electromagnetic compatibility issues, miniaturization, etc.

Most of the antenna technologies currently used in capsule endoscopes are designed as built-in helical antennas or planar antennas, which have the disadvantages of large size and easy polarization mismatch. Many shortcomings make it difficult for current capsule endoscope antennas to adapt to the human body. And the complex and changeable application environment requirements inside the capsule.

Contents of the invention

In order to overcome the shortcomings and deficiencies of the prior art, the present invention provides a multi-polarization conformal antenna for capsule endoscope.

The present invention adopts following technical scheme:

A multi-polarization conformal antenna for capsule endoscope, comprising a capsule shell, an antenna radiation unit, a metal floor, a dielectric substrate and coaxial feed, the antenna radiation unit is located on the upper surface of the dielectric substrate, the metal The floor is located on the lower surface of the dielectric substrate, and the entire antenna is conformally bent and nested in the capsule shell to form an internal hollow structure.

The entire antenna is conformally bent and nested in the capsule shell to form an internal hollow structure, specifically: the antenna radiation unit forms a cylindrical surface structure on the outside, and the metal floor forms a closed cylindrical surface structure on the inside as an electromagnetic shielding layer.

The antenna radiation unit, the dielectric substrate and the metal floor are all parallelogram structures.

The antenna radiating unit is composed of two slots and two embedded rectangular patches, and the two rectangular patches and the two slots are symmetrical about the longitudinal axis of the dielectric substrate.

The two embedded rectangular patches are respectively connected to the antenna radiation unit through a high-impedance line, the high-impedance line is perpendicular to the slot, and after conformal bending, polarization in the Y direction and the Z direction is formed.

The coaxial feed is composed of a feed port and a coaxial cable. The feed port is located on the longitudinal axis of the dielectric substrate. The two slots are located on both sides of the feed port. direction of polarization.

The radius of the inner core of the coaxial cable is 0.35 mm, and the radius of the outer core of the coaxial cable is 0.805 mm.

The shell of the capsule has a thickness of 0.1 mm, a diameter of 11 mm and a height of 26 mm.

The width of the slot is 0.5mm and the length is 6.6mm.

Beneficial effects of the present invention:

(1) The present invention has the characteristics of being flexible and conformable, occupying a small volume inside the capsule, radiating or receiving arbitrary polarized waves, and having anti-electromagnetic interference performance;

(2) The present invention changes the current path by changing the structure of the radiation patch, and there are obvious current paths in the three directions of X, Y, and Z, which can effectively solve the problem of the contact between the capsule and the external receiving device during the continuous movement in the body. polarization mismatch problem.

Description of drawings

Fig. 1 is an overall structural diagram of a multi-polarization conformal antenna for a capsule endoscope according to the present invention;

Fig. 2 (a) is a plane unfolded top view of a multi-polarization conformal antenna for a capsule endoscope according to the present invention;

Fig. 2 (b) is a plane unfolded side view of a multi-polarized conformal antenna for a capsule endoscope according to the present invention;

Fig. 3 is a parameter diagram of a multi-polarization conformal antenna used in a capsule endoscope according to the present invention;

Fig. 4 is the S-parameter curve of the planar and three-dimensional conformal structures of a multi-polarized conformal antenna for capsule endoscopes in the present invention when the center frequency is 2.45 GHz;

Fig. 5(a) is a three-dimensional current path diagram of a multi-polarization conformal antenna used in a capsule endoscope according to the present invention when the center frequency is 2.45 GHz.

Fig. 5(b) is a current path diagram on the XOY plane when the center frequency is 2.45 GHz for a multi-polarization conformal antenna used in a capsule endoscope according to the present invention.

Fig. 5(c) is a current path diagram on the XOZ plane when the center frequency is 2.45 GHz for a multi-polarization conformal antenna used in a capsule endoscope according to the present invention.

Fig. 6 is a gain pattern diagram of a multi-polarization conformal antenna used in a capsule endoscope according to the present invention when the center frequency is 2.45 GHz.

Fig. 7 is a schematic diagram of a working environment of a multi-polarization conformal antenna used in a capsule endoscope according to the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

As shown in FIG. 1 , a multi-polarization conformal antenna for a capsule endoscope, the antenna 2 is conformally nested inside the capsule shell 1 by bending to form an internal hollow structure. The shell of the capsule has a thickness of 0.1 mm, a height of 26 mm, and a diameter of 11 mm, so that the antenna is compatible with human body radiation, biocompatible, has the effect of isolating and insulating human tissue, and serves as a protective layer for the antenna.

As shown in Figure 2(a) and Figure 2(b), a multi-polarization conformal antenna for capsule endoscopes includes a dielectric substrate 3, an antenna radiation unit 4, a metal floor 9 and a coaxial feed 6 . The dielectric substrate is a single-layer structure, the antenna radiation unit 4 is printed on the upper surface, and the metal floor 9 is printed on the lower surface of the dielectric substrate. The antenna radiating unit is bent conformally to form a cylindrical surface structure on the outside, and the metal floor patch is bent to form a complete closed cylindrical surface structure on the inside to serve as an electromagnetic shielding layer.

The antenna radiating unit 4 has a parallelogram structure and is composed of slots 7A, 7B symmetrical to the longitudinal axis and two embedded rectangular patches 5A, 5B.

Each of the embedded rectangular patches is connected to the antenna radiation unit through an embedded high-impedance line 8A, 8B. The two high-impedance lines are symmetrical about the longitudinal axis, and the width of the high-impedance line is 0.5 mm.

The coaxial feed includes a feed port and a coaxial cable, the coaxial feed is located on the longitudinal axis of the antenna radiation unit, the feed port is located on the longitudinal axis of the dielectric substrate, and the two slots are located Both sides of the feed port are conformally bent to form polarization along the X direction.

The slots symmetrical about the longitudinal axis are located on both sides of the coaxial port, and have the functions of adjusting impedance matching and optimizing, and form polarization along the X direction after conformal bending.

The metal floor 9 has a parallelogram structure and is printed on the lower surface of the dielectric substrate.

The dielectric substrate 3, the antenna radiation unit 4, and the metal floor 9 are all parallelograms, which are bent and conformally nested inside the capsule shell to form a hollow structure.

In this embodiment, the dielectric substrate 3 is made of flexible material Polyimide with a relative permittivity of 3.5, an electrical loss tangent of 0.0035, and a thickness of 0.2 mm. The dielectric substrate is a parallelogram structure with a length of 33 mm, a width of 8 mm, and a height of 0.2 mm. The overall contours of the antenna radiation unit and the metal floor are both a parallelogram. During the conformal bending process, the short sides on both sides form a coupling, and finally form a hollow cylindrical structure with a height of 8mm, an outer diameter of 5.4mm, and an inner diameter of 5.2mm. The coaxial excitation is to excite the antenna radiation unit through the coaxial port, and the feeding point is located on the longitudinal symmetry axis of the radiation patch.

As shown in Figure 3, the specific parameters are the length of the radiation patch: L1=32mm, width: W1=7mm, the length of the inner rectangular patch: L2=8mm, width: W2=5mm, and the parallelogram radiation patch The distances are all S1=0.5mm, the length of the slot symmetrical about the longitudinal axis: W3=6.6mm, the width: L3=0.5mm, and the radius of the coaxial inner core is 0.35mm.

As shown in Fig. 4, Fig. 5(a), Fig. 5(b), Fig. 5(c) and Fig. 6, the present invention adopts a parallelogram structure to form a coupling in a curved conformal shape, and realizes a thinner dielectric substrate Impedance matching on the surface to achieve the purpose of miniaturization; through the directional modification of the current path, a current path along the X direction 10 and a bending direction 11 is generated, wherein the current path in the bending direction 11 can be decomposed into 13 along the Y direction and 12 along the Z direction The current path realizes multi-polarization in three directions. The invention can overcome the polarization mismatch problem caused between the capsule endoscope and the external receiving device during the continuous movement. The antenna impedance bandwidth is 13.9%, covering the ISM frequency band of 2.45GHz.

As shown in Figure 7, the working environment of the antenna is a human muscle cube with a side length of 100mm, and the implantation depth is 50mm. The relative permittivity ε _r and conductivity σ of human muscle tissue at a frequency of 2.45 GHz are given in the figure.

The antenna has the advantages of being flexible, bendable and conformal, occupying a small volume inside the capsule, having anti-electromagnetic interference performance, and multi-polarization.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the embodiment, and any other changes, modifications, substitutions and combinations made without departing from the spirit and principle of the present invention , simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present invention.

Claims (9)

1. a kind of multipolarization conformal antenna for capsule endoscope, including capsule shell, which is characterized in that further include antenna spoke Unit, metal floor, medium substrate and coaxial feed are penetrated, the antenna radiation unit is located at the upper surface of medium substrate, described Metal floor is located at the lower surface of medium substrate, and the entire conformal bending of antenna is nested in capsule shell, forms inner hollow knot Structure.

2. multipolarization conformal antenna according to claim 1, which is characterized in that the entire conformal bending of antenna is nested in In capsule shell, hollow structure inside is formed, specially：Antenna radiation unit forms Cylinder Surface structure on the outside, metal Plate forms closed Cylinder Surface structure in inside, as electro-magnetic screen layer.

3. multipolarization conformal antenna according to claim 1, which is characterized in that the antenna radiation unit, medium substrate And metal floor is parallelogram sturcutre.

4. multipolarization conformal antenna according to claim 1, which is characterized in that the antenna radiation unit is slotted by two And two embedded rectangle patches are constituted, described two rectangle patches and two flutings are symmetrical about the medium substrate longitudinal axis.

5. multipolarization conformal antenna according to claim 4, which is characterized in that described two embedded rectangle patches point Antenna radiation unit is not connected by high impedance line, high impedance line is perpendicular to fluting, after conformal bending, forms Y-direction and the side Z To polarization.

6. multipolarization conformal antenna according to claim 4, which is characterized in that the coaxial feed is by feed port and together Shaft cable is constituted, and the feed port is located on the longitudinal axis of medium substrate, and two flutings are positioned at the both sides of feed port, altogether Polarization in X direction is formed after shape bending.

7. multipolarization conformal antenna according to claim 6, which is characterized in that coaxial cable inner core radius is 0.35mm, The outer core radius of coaxial cable is 0.805mm.

8. multipolarization conformal antenna according to claim 1, which is characterized in that the capsule shell thickness is 0.1mm, directly Diameter is 11mm, is highly 26mm.

9. multipolarization conformal antenna according to claim 5, which is characterized in that the width of fluting is 0.5mm, a length of 6.6mm。