High gain capsule antenna applying dielectric resonator for wireless capsule endoscope

Abstract

The invention belongs to the technical field of wireless medical equipment, and provides a high-gain capsule antenna used for a wireless capsule endoscope and applying a dielectric resonator, which is used for solving the problem that stable and high-quality communication between the wireless capsule endoscope in a human body and external receiving equipment is difficult to maintain by the existing wireless capsule endoscope. The antenna comprises a capsule shell 1, an antenna body 2 and a dielectric resonator 3, the antenna body and the dielectric resonator are both arranged in the capsule shell, the capsule shell is composed of a cylindrical tubular shell and hemispherical shells connected with the two ends of the cylindrical tubular shell, and the antenna body is arranged in parallel along the circular end face of the cylindrical tubular shell. The dielectric resonator is arranged above the antenna body and located in the hemispherical shell on the same side, a preset distance is kept between the dielectric resonator and the antenna body, and electromagnetic waves emitted by the dielectric resonator to the antenna body are converged. In conclusion, through the design of the dielectric resonator, the antenna gain can be greatly improved, so that the communication quality is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless medical equipment, and specifically designs a high-gain capsule antenna using a dielectric resonator for a wireless capsule endoscope. Background Art

[0002] Wireless Capsule Endoscopy (WCE) is an endoscope in the shape of a capsule. As a wireless implantable device, it has been widely used in medical diagnosis and treatment. The wireless capsule endoscopy system includes: capsule shell, battery, imaging system, sensor, signal transmission device, antenna, etc. Among them, the antenna is used to transmit the human body related data, images and other information collected by the capsule from the human body to the receiving device outside the human body. Its performance will greatly affect the quality of information transmission.

[0003] In modern medicine, the commonly used means of inspection of the digestive tract is a wired endoscope system, but the wired endoscope system is complicated to operate and involves medical problems such as cross infection, which brings pain to patients and cannot achieve the inspection of the entire digestive tract. A wireless capsule endoscope can enter the human body through oral administration, move in the body and be discharged through gastrointestinal peristalsis, and has the ability to inspect the entire digestive tract of parts such as the small intestine, and avoids causing pain to patients, overcoming the defect that traditional endoscopes are not suitable for the elderly, the weak and those with serious illnesses. However, the human digestive tract environment is complex, and the electrical properties of various organs vary greatly. When a wireless capsule endoscope using a traditional low-gain capsule antenna travels in the digestive tract, changes in the surrounding environment will make its information transmission with the outside world unstable, affecting the normal operation of the wireless endoscope system; in short, it is difficult for the current wireless capsule endoscope to maintain stable and high-quality communication between the wireless capsule endoscope in the human body and an external receiving device. Therefore, the present invention provides a high-gain capsule antenna using a dielectric resonator for a wireless capsule endoscope. Summary of the invention

[0004] The purpose of the present invention is to provide a high-gain capsule antenna using a dielectric resonator for a wireless capsule endoscope, so as to solve the problem that the existing wireless capsule endoscope is difficult to maintain stable and high-quality communication between the wireless capsule endoscope in the human body and an external receiving device.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A high-gain capsule antenna using a dielectric resonator for a wireless capsule endoscope comprises: a capsule shell 1, an antenna body 2 and a dielectric resonator 3; characterized in that the antenna body and the dielectric resonator are both arranged inside the capsule shell, the capsule shell is composed of a cylindrical tubular shell and a hemispherical shell connected at both ends, the antenna body is arranged parallel to the circular end surface of the cylindrical tubular shell, the dielectric resonator is arranged above the antenna body and located in the hemispherical shell on the same side, the dielectric resonator maintains a preset distance from the antenna body, and the dielectric resonator converges the electromagnetic waves emitted by the antenna body.

[0007] Furthermore, the dielectric resonator comprises a central dielectric cylinder and a plurality of dielectric cylinders, wherein the central dielectric cylinder is arranged along the central axis of the capsule shell, and the plurality of dielectric cylinders are nested in sequence outside the central dielectric cylinder.

[0008] Furthermore, in the dielectric resonator, the dielectric constants of the dielectric layers increase or decrease in sequence from the central dielectric cylinder outward, and the heights of the dielectric layers decrease in sequence.

[0009] Furthermore, the dielectric resonator is in a semi-spherical or spherical shape.

[0010] Furthermore, the antenna body includes: a dielectric substrate 2-1, a radiating metal layer 2-2 and a grounding metal layer 2-3; the radiating metal layer is arranged on the front side of the dielectric substrate and faces the dielectric resonator, the grounding metal layer is arranged on the back side of the dielectric substrate, and the dielectric substrate is arranged parallel to the circular end face of the cylindrical tubular shell.

[0011] Furthermore, the radiating metal layer includes: a metal strip 2-2-1 and a feeding microstrip line 2-2-2, the radiating metal layer presents a 180° rotationally symmetrical structure along the center point of the front side of the dielectric substrate, the metal strip presents a planar Hilbert fractal structure, the planar Hilbert fractal structure is composed of four second-order Hilbert fractal units connected, and the two free ends are respectively connected to the feeding microstrip lines.

[0012] Furthermore, the metal strips are arranged in double layers.

[0013] Based on the above technical solution, the beneficial effects of the present invention are:

[0014] The invention provides a high-gain capsule antenna using a dielectric resonator for a wireless capsule endoscope. The dielectric resonator is added to improve the gain of the antenna, and the antenna has the advantage of high gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1This is a schematic structural diagram of a high-gain capsule antenna using a dielectric resonator for a wireless capsule endoscope provided by the present invention, wherein 1 is a capsule shell, 2 is an antenna body, and 3 is a dielectric resonator.

[0016] Figure 2 for Figure 1 The schematic diagram of the structure of the antenna body in the high-gain capsule antenna using a dielectric resonator is shown, wherein 2-1 is a dielectric substrate 2-1, 2-2 is a radiation metal layer, and 2-3 is a grounding metal layer 2-3.

[0017] Figure 3 for Figure 2 The schematic diagram of the structure of the radiating metal layer in the antenna body is shown, wherein 2-2-1 is a metal strip and 2-2-2 is a feeding microstrip line.

[0018] Figure 4 for Figure 1 The schematic diagram of the structure of the dielectric resonator in the high-gain capsule antenna using the dielectric resonator is shown, wherein 3-1 is a central dielectric cylinder, 3-2 is a first dielectric cylinder, and 3-3 is a second dielectric cylinder.

[0019] Figure 5 Schematic diagram of the structure of a spherical dielectric resonator in an embodiment of the present invention.

[0020] Figure 6 This is a schematic diagram of the structure of the capsule antenna in the comparative example provided by the present invention.

[0021] Figure 7 This is a diagram of S-parameter simulation results of a high-gain capsule antenna using a dielectric resonator in an embodiment of the present invention.

[0022] Figure 8 This is a graph showing the gain simulation results of a high-gain capsule antenna using a dielectric resonator in an embodiment of the present invention. Fig. 9 This is the gain simulation result diagram of the capsule antenna in the comparative example. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0024] This embodiment provides a high-gain capsule antenna using a dielectric resonator for wireless capsule endoscope, and its structure is as follows: Figure 1 As shown, it includes: a capsule shell 1, an antenna body 2 and a dielectric resonator 3;

[0025] The capsule shell 1 is composed of a cylindrical tubular shell and hemispherical shells connected at both ends thereof, and the axis where the central axis of the cylindrical tubular shell is located is defined as the central axis of the capsule shell;

[0026] The antenna body 2 and the dielectric resonator 3 are both arranged inside the capsule shell, the antenna body 2 is arranged parallel to the circular end surface of the cylindrical tubular shell, the dielectric resonator 3 is arranged above the antenna body 2 and in the hemispherical shell on the same side, the dielectric resonator 3 and the antenna body 2 maintain a preset distance, and the dielectric resonator converges the electromagnetic waves emitted by the antenna body;

[0027] The antenna body is as follows Figure 2 As shown, it includes: a dielectric substrate 2-1, a radiation metal layer 2-2 and a grounding metal layer 2-3; the radiation metal layer 2-2 is arranged on the front side of the dielectric substrate and faces the dielectric resonator 3, the grounding metal layer 2-3 is arranged on the back side of the dielectric substrate, and the dielectric substrate 2-1 is arranged parallel to the circular end surface of the cylindrical tubular shell;

[0028] The radiation metal layer 2-2 is as follows Figure 3 As shown, it includes: a metal strip 2-2-1 and a feeding microstrip line 2-2-2, the radiation metal layer is in a 180° rotational symmetric structure along the center point of the front side of the dielectric substrate, the metal strip 2-2-1 is in a planar Hilbert fractal structure, the planar Hilbert fractal structure is composed of four second-order Hilbert fractal units connected, and the two free ends are respectively connected to the feeding microstrip line 2-2-2; further, the metal strip 2-2-1 adopts a double-layer arrangement to more effectively utilize the arrangement space, thereby realizing the miniaturization of the antenna;

[0029] The dielectric resonator 3 is as follows Figure 4 As shown, it includes: a central dielectric cylinder 3-1 and several dielectric cylinders, in which the first dielectric cylinder 3-2 and the second dielectric cylinder 3-3 are specifically used in this embodiment; the central dielectric cylinder 3-1 is arranged along the central axis of the capsule shell, and the first dielectric cylinder 3-2 and the second dielectric cylinder 3-3 are nested in sequence on the outside of the central dielectric cylinder 3-1, and from the central dielectric cylinder 3-1 to the outside, the dielectric constant of the dielectric layer increases or decreases in sequence, and the height of the dielectric layer decreases in sequence; through the structural design of the above-mentioned dielectric resonator 3, a convergence path along the axial direction (the central axis of the capsule shell) is provided for the electromagnetic waves emitted by the antenna body, which produces a convergence effect on the electromagnetic waves, thereby improving the gain of the antenna, and then improving the quality of information transmission.

[0030] Based on the above high-gain capsule antenna, it is also necessary to explain:

[0031] First, the wireless capsule endoscope also includes components such as a light source, an imaging element, a sensor, a battery, a transceiver module, etc. located in the capsule shell. As the prior art known in the art, the present invention will not be described in detail. Figure 1 and Figure 5Also, the present invention arranges the antenna body 2 and the dielectric resonator 3 conformally in a hemispherical shell on one side of the capsule shell. This arrangement significantly reduces the space occupied by the antenna inside the capsule, so that the capsule has a larger internal space for placing other components.

[0032] Secondly, the present invention makes the outer contour of the dielectric resonator 3 present a spherical shape through the structural design of the dielectric resonator 3, thereby achieving a conformal design with the capsule shell; according to the actual use environment and assembly space design, the dielectric resonator 3 in this embodiment is generally hemispherical, such as Figure 4 As shown, in other use environments and assembly space designs, the dielectric resonator 3 as a whole can also present a spherical shape, such as Figure 5 As shown;

[0033] Third, according to the task index requirements in the actual application scenario, the total length of the metal strip 2-2-1 of the radiating metal layer 2-2 of the antenna body 2 is determined by the working wavelength, and the layout of the metal strip can be adaptively designed; and the length of the feeding microstrip line at both ends can be matched and adjusted, one end is fed through the microstrip line, and the other end is connected to a matching load to reduce the reflection of electromagnetic waves; at the same time, according to the task index requirements in the actual application scenario, the spacing between the dielectric resonator and the antenna body can be simulated and optimized to obtain a suitable gain; based on this, the working frequency band of the antenna is determined by the total length of the metal strip 2-2-1, and the electromagnetic waves emitted by the antenna body are converged by the dielectric resonator to obtain a higher gain, thereby achieving the purpose of higher communication quality.

[0034] The beneficial effects of the present invention are described in detail below in conjunction with simulation tests. In order to more intuitively illustrate the core creativity of the present invention, the present invention also provides a comparative example, whose structure is as follows: Figure 6 As shown, the only difference between the capsule antenna in the comparative example and the present embodiment is that no dielectric resonator is included; specifically, the high-gain capsule antenna based on the dielectric resonant cavity in the present embodiment operates in the industrial, scientific and medical (ISM) frequency band (2.4 GHz), wherein the dielectric substrate adopts Rogers5880, the relative dielectric constant is 2.2, the long side dimension is 8.05 mm, and the short side dimension is 6.65 mm; the height of the central dielectric cylinder of the dielectric resonator is 5.12 mm, the radius is 2 mm, and the relative dielectric constant is 5; the height of the first dielectric cylinder in the dielectric resonant cavity is 3.77 mm, the outer radius is 4 mm, the inner radius is 2 mm, and the relative dielectric constant is 25; the height of the second dielectric cylinder in the dielectric resonant cavity is 2.29 mm, the outer radius is 5 mm, the inner radius is 4 mm, and the relative dielectric constant is 50; the interval between the dielectric resonator and the antenna body is 0.473 mm; the capsule antenna in the embodiment and the comparative example is simulated and tested, and the results are as follows:

[0035] like Figure 7 The figure shows the S parameter diagram of the high-gain capsule antenna based on the dielectric resonator in this embodiment. It can be seen from the figure that S11 reaches -44.75dB at 2.4GHz; Figure 8 FIG. 1 is a gain diagram (φ=90°) of a high-gain capsule antenna based on a dielectric resonator in this embodiment. Fig. 9 The figure shows the gain diagram of the capsule antenna in the comparative example (φ=90°). It can be seen from the figure that the maximum gain of the high-gain capsule antenna based on the dielectric resonator in this embodiment increases from -21.98dB to -14.7dB. It can be seen that the dielectric resonator can greatly improve the antenna gain.

[0036] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A high-gain capsule antenna using a dielectric resonator for a wireless capsule endoscope, comprising: A capsule shell (1), an antenna body (2) and a dielectric resonator (3); characterized in that the antenna body and the dielectric resonator are both arranged inside the capsule shell, the capsule shell is composed of a cylindrical tubular shell and hemispherical shells connected at both ends, the antenna body is arranged parallel to the circular end surface of the cylindrical tubular shell, the dielectric resonator is arranged above the antenna body and located in the hemispherical shell on the same side, the dielectric resonator and the antenna body maintain a preset distance, and the dielectric resonator converges the electromagnetic waves emitted by the antenna body.

2. The high-gain capsule antenna using a dielectric resonator for wireless capsule endoscope according to claim 1, characterized in that: The dielectric resonator comprises a central dielectric cylinder and a plurality of dielectric cylinders. The central dielectric cylinder is arranged along the central axis of the capsule shell, and the plurality of dielectric cylinders are nested in sequence outside the central dielectric cylinder.

3. The high-gain capsule antenna using a dielectric resonator for wireless capsule endoscope according to claim 2, characterized in that: In the dielectric resonator, the dielectric constants of the dielectric layers increase or decrease in sequence from the central dielectric cylinder outward, and the heights of the dielectric layers decrease in sequence.

4. The high-gain capsule antenna using a dielectric resonator for wireless capsule endoscope according to claim 2, characterized in that: The dielectric resonator is in a semi-spherical or spherical shape.

5. The high-gain capsule antenna using a dielectric resonator for wireless capsule endoscope according to claim 1, characterized in that: The antenna body comprises: a dielectric substrate (2-1), a radiating metal layer (2-2) and a grounding metal layer (2-3); the radiating metal layer is arranged on the front side of the dielectric substrate and faces the dielectric resonator, the grounding metal layer is arranged on the back side of the dielectric substrate, and the dielectric substrate is arranged parallel to the circular end face of the cylindrical tubular shell.

6. The high-gain capsule antenna using a dielectric resonator for wireless capsule endoscope according to claim 5, characterized in that: The radiation metal layer comprises: a metal strip (2-2-1) and a feeding microstrip line (2-2-2); the radiation metal layer presents a 180° rotationally symmetrical structure along the center point of the front side of the dielectric substrate; the metal strip presents a planar Hilbert fractal structure; the planar Hilbert fractal structure is composed of four second-order Hilbert fractal units connected together, and two free ends are respectively connected to the feeding microstrip line.

7. The high-gain capsule antenna using a dielectric resonator for wireless capsule endoscope according to claim 6, characterized in that: The metal strips are arranged in double layers.

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