Flexible wearable liquid metal antenna and wearable electronic equipment

Abstract

The utility model relates to a flexible wearable liquid metal antenna and wearable electronic equipment, and belongs to the technical field of wearable antennas. Comprising a dielectric substrate, a grounding metal sheet, a feed port metal sheet, a metal floor and an inverted F-shaped groove, according to the dual-band wrist type PIFA antenna, a flexible material PDMS is used as a dielectric substrate, liquid metal EGaIn is used as a radiation material, and the EGaIn is wrapped in a microfluidic channel formed by the PDMS, so that the wearable antenna working at two frequency bands of 2.4 GHz and 5.8 GHz is realized. Compared with a traditional solid metal wearable antenna, the wearable antenna designed on the basis of liquid metal can well receive signals, material fatigue or cracking cannot be caused by repeated bending, and the wearable antenna has high self-repairing capacity and has more advantages in the wearable aspect.

Description

Technical Field

[0001] The present invention belongs to the technical field of wearable antennas, and in particular relates to a flexible wearable liquid metal antenna and a wearable electronic device. Background Art

[0002] In the past decade, research interest in wearable antennas has grown significantly due to their potential for widespread application in wireless body-centric systems. Wearable antennas are usually required to have low profile, high flexibility, and excellent ductility to conform to the body to which they are attached, such as conformal or wearable electronic devices.

[0003] Wearable antennas play an important role in wireless data transmission, but the design of wearable antennas is very different from that of conventional antennas. First, the human body has a very large scattering effect on antenna radiation. The antenna will experience reduced gain, poor matching, and deteriorated radiation patterns near the human body. Secondly, flexible wearable antennas need to maintain performance stability under various physical deformations, temperature, and humidity changes. In addition, the safety risks of the human body in a long-term electromagnetic radiation environment must also be considered when designing the antenna. All these issues pose huge challenges to the design of wearable antennas.

[0004] Therefore, flexible materials such as PDMS as substrate materials and liquid metal EGaIn as radiation patches can be developed into reconfigurable antenna structures for wearable electronic devices. Summary of the invention

[0005] The technical problems to be solved by the present invention are:

[0006] In order to avoid the shortcomings of the prior art, the present invention provides a flexible wearable liquid metal antenna and a wearable electronic device. The wearable antenna and the liquid metal antenna are combined to make the antenna have strong self-repairing ability and good conformality, so as to solve the problems of insufficient flexibility and difficulty in reconstruction of traditional solid metal.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A flexible wearable liquid metal antenna, characterized in that it comprises: a dielectric substrate, a feeding part, a radiation part, a metal floor, and a grounding part;

[0009] The dielectric substrate is made of flexible material and can be bent to fit the shape of the wrist;

[0010] The radiation part is located on the front side of the dielectric substrate and uses liquid metal to achieve antenna radiation;

[0011] The feeding part is used to feed the radiating part;

[0012] The metal floor is located on the back side of the dielectric substrate;

[0013] The grounding portion is used to connect the radiation portion and the metal floor.

[0014] A further technical solution of the present invention is that the radiation part is an inverted F structure, specifically, an inverted F groove is opened on the front side of the dielectric substrate, and the inverted F groove is filled with liquid metal.

[0015] A further technical solution of the present invention: the liquid metal is EGaIn.

[0016] A further technical solution of the present invention is as follows: the inverted F structure comprises a long branch, a short branch and a short-circuit branch; the long branch and the short branch share a feeding port, corresponding to two frequency bands respectively, thereby realizing a dual-band radiating antenna.

[0017] A further technical solution of the present invention is that the feeding part is a feeding metal sheet, which vertically penetrates the dielectric substrate along the Z direction and is connected to the feeding ports of the two branches.

[0018] A further technical solution of the present invention is that the width of the metal floor is smaller than the width of the dielectric substrate.

[0019] A further technical solution of the present invention is that the grounding part is a grounding metal sheet, which vertically penetrates the dielectric substrate along the Z direction and is connected to the port of the short-circuit branch.

[0020] A further technical solution of the present invention is as follows: the material of the dielectric substrate is PDMS, the relative dielectric constant is 2.67, and the tangent loss is 0.0375.

[0021] A wearable electronic device, characterized by comprising the above-mentioned flexible wearable liquid metal antenna, for receiving signals.

[0022] The beneficial effects of the present invention are:

[0023] The present invention provides a flexible wearable liquid metal antenna and a wearable electronic device, which designs a dual-band wrist-type PIFA antenna with a flexible material PDMS as a dielectric substrate and liquid metal EGaIn as a radiation material, wherein EGaIn is wrapped in a microfluidic channel formed by PDMS. This allows the antenna to have a smaller three-dimensional structural area, operate in the 2.4GHz and 5.8GHz frequency bands, achieve continuous tuning, have high isolation and linear characteristics, and do not require additional bias circuits or excitation means.

[0024] For PIFA antenna to achieve multi-band operation, it can be achieved by using dual feed points or by using slots on the PIFA antenna radiation metal sheet. When dual feed points are used, the tuning frequency and tuning range are often subject to certain restrictions. Therefore, in the actual design of PIFA antenna, slots are often used to achieve multi-band operation. Compared with the prior art, the antenna of the present invention has the following advantages:

[0025] 1. The wearable antenna proposed in the present invention uses PDMS as the substrate material. Since PDMS is a soft material, the wire can easily adapt to the bending and twisting movements of the wrist, thereby providing better comfort and wearability.

[0026] 2. The wearable antenna proposed in the present invention can work in the frequency range of 2.4GHz and 5.8GHz at the same time, which makes it very suitable for WLAN communication applications. It can provide a more stable and reliable wireless connection, allowing users to more easily perform high-speed data transmission on mobile devices.

[0027] 3. Liquid metal combines the excellent properties of traditional rigid and flexible materials. Compared with traditional solid metal wearable antennas, the wearable antenna designed based on liquid metal in this invention can not only receive signals well, but also will not cause material fatigue or cracking after repeated bending. It has strong self-repairing ability and has more advantages in realizing wearability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0029] Figure 1 This is a schematic diagram of a plane model of a flexible wearable liquid metal antenna shown in the present invention. (including a left view, a top view, and a front view);

[0030] Figure 2 Long branch road labeling diagram;

[0031] Figure 3 Short branch marking diagram;

[0032] Figure 4 A schematic diagram of a conformal model of an antenna shown in the present invention (main view);

[0033] Figure 5 Graphs showing reflection coefficients of the antenna of the present invention in a plane model and a conformal model respectively;

[0034] FIG. 6 is a radiation gain pattern of the antenna conformal model shown in the present invention on the xoz plane and the yoz plane ( Fig. 6A is the gain pattern at the operating frequency of 2.4 GHz, Figure 6Bis the plane gain pattern at the operating frequency of 5.8 GHz);

[0035] FIG. 7 is a SAR distribution diagram obtained by simulating the antenna conformal model shown in the present invention and the human arm model ( Fig. 7A This is the SAR distribution diagram when the operating frequency is 2.4GHz. Figure 7B This is the SAR distribution diagram when the operating frequency is 5.8GHz).

[0036] The accompanying drawings are marked as follows:

[0037] 1- dielectric substrate, 2- grounding metal sheet, 3- feeding port metal sheet, 4- metal floor, 5- inverted F groove. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] The present invention proposes a flexible wearable liquid metal antenna, a dual-band wrist-type PIFA antenna (Planar Inverted F-shaped Antenna, also known as a planar inverted F antenna) with a flexible material PDMS as a dielectric substrate and liquid metal EGaIn as a radiation material, wherein EGaIn is wrapped in a microfluidic channel formed by PDMS, thereby realizing a wearable antenna operating in two frequency bands of 2.4 GHz and 5.8 GHz.

[0040] The technical solution adopted by the present invention is: a flexible microstrip patch antenna combining EGaIn and PDMS, including a dielectric substrate, a grounded metal sheet, a feed port metal sheet, a metal floor, and an inverted F groove; the typical structure of the PIFA antenna consists of four parts: metal grounding, a radiation patch, a short-circuit wall, and a feed port. The structure of the antenna proposed by the present invention is to conform the traditional inverted F antenna to the wrist, wherein the L-shaped part is for receiving the 2.4GHz frequency band, and its bifurcation is for receiving the 5.8GHz frequency band. PDMS material is filled between the radiation patch and the metal floor. A thin groove in the shape of an antenna is etched on the upper surface of the PDMS model for EGaIn filling.

[0041] like Figure 1 As shown, Figure 1 The left view, top view and front view of a flexible wearable liquid metal antenna plane model. Figure 1 The present invention will be further described:

[0042] A dual-frequency flexible wearable liquid metal antenna comprises a dielectric substrate 1, a grounding metal sheet 2, a feeding port metal sheet 3, a metal floor 4, and an inverted F groove 5; the inverted F groove 5 is etched on the upper surface of the dielectric substrate 1, and the inverted F groove 5 is filled with liquid metal; the metal floor 4 is pasted to a part of the lower surface of the dielectric substrate 1, and the width of the metal floor 4 is smaller than the width of the dielectric substrate 1; the grounding metal sheet 2 and the feeding port metal sheet 3 vertically penetrate the dielectric substrate 1 along the Z direction, wherein the grounding metal sheet 2 is connected to the short-circuit branch at the rightmost end of the inverted F groove, and the feeding port metal sheet 3 is connected to the feeding port in the middle of the inverted F groove.

[0043] The material of the dielectric substrate is PDMS, with a relative dielectric constant of 2.67, a tangent loss of 0.0375, a length SX and a width SY of 50.68 mm and 15 mm respectively, and a thickness SH of 2 mm; the width W of the grounding metal sheet 2 and the feeding port metal sheet 3 is 1 mm, and the spacing distance D thereof is 5 mm; the thickness h of the thin groove on the dielectric substrate 1 is 0.1 mm, and the distance AX between the right end of the groove and the right boundary of the dielectric substrate 1 is 14.34 mm; the inverted F groove 5 is filled with liquid metal to form an antenna, wherein the length L1 of the long branch in the x direction is 16.41 mm, as shown in FIG. Figure 2 The red part in the middle is the long branch; the length L2 of the left part of the short branch in the y direction is 5.72mm, and the length Ld of the short branch in the x direction is 3.17mm. Figure 3 The red part in the middle is the short branch; the length of the long branch and the antenna "short-circuit branch" in the x direction is H 5.7mm, and the width of the inverted F groove 5 is W; the length SX of the metal floor 4 is 50.68mm, and the width GY is 6.25mm.

[0044] Liquid metal 5 is filled into the groove on the upper surface of dielectric substrate 1 to form an inverted F-shaped antenna. It is connected to metal floor 4 through grounding metal sheet 2, and the antenna is fed through feeding port metal sheet 3; the two branches of the antenna, one long and one short, form two resonance points, one low and one high in frequency, respectively, to achieve dual-frequency operation.

[0045] The metal floor 4 is adhered to the lower surface of the dielectric substrate 1. The length of the metal floor 4 is the same as that of the dielectric substrate 1 but the width is different: one end in the negative Y direction is aligned with the edge of the dielectric substrate 1, and the other end in the positive Y direction is vertically connected to the grounding metal sheet 2 and the feeding port metal sheet 3.

[0046] The present invention also provides a wearable electronic device, comprising the above-mentioned flexible wearable liquid metal antenna, for receiving signals.

[0047] Figure 4This is the front view of the conformal model formed after the antenna is conformally formed into a circular ring. The inner radius R1 of the conformal ring of the dielectric substrate 1 is 30 mm, and the outer radius R2 is 32 mm, which are similar to the radius of the human forearm. The Z-direction height CSZ of the negative X-space part of the dielectric substrate 1 is 17 mm, and the X-direction length CSX of the positive X-space part is 18.82 mm.

[0048] Figure 5 The reflection coefficient curves of the antenna in the plane model and the conformal model are shown in Figure 2. The black curve represents the reflection coefficient of the plane model, and the red curve represents the reflection coefficient of the conformal model. Each curve has two resonance points at 2.4 GHz and 5.8 GHz. The resonance depth of the plane model is slightly lower than that of the conformal model, and the resonance depth of all resonance points is lower than -15 dB.

[0049] Fig. 6A and Figure 6B They are the two radiation gain patterns of the 2.4 GHz resonance point and 5.8 GHz resonance point of the antenna conformal model. The red curve represents the xoz plane gain pattern, and the light green curve represents the yoz plane gain pattern. The pattern has a certain symmetry about the xoy plane, but the symmetry is reduced due to the conformality of the model, and the direction with the strongest gain tends to rise toward the positive Z direction. The 2.4 GHz curve is relatively smoother.

[0050] Fig. 7A and Figure 7B The SAR distribution diagrams obtained by simulating the antenna conformal model and the human arm model at operating frequencies of 2.4 GHz and 5.8 GHz respectively, both meet the radiation peak standard, among which the radiation peak at the operating frequency of 5.8 GHz is slightly higher than that at 2.4 GHz.

[0051] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A flexible wearable liquid metal antenna, characterized in that: include: Dielectric substrate, feeding part, radiating part, metal floor, grounding part; The dielectric substrate is made of flexible material and can be bent to fit the shape of the wrist; The radiation part is located on the front side of the dielectric substrate and uses liquid metal to achieve antenna radiation; The feeding part is used to feed the radiating part; The metal floor is located on the back side of the dielectric substrate; The grounding portion is used to connect the radiation portion and the metal floor.

2. A flexible wearable liquid metal antenna according to claim 1, characterized in that: The radiation part is an inverted F structure, specifically, an inverted F groove is opened on the front surface of the dielectric substrate, and the inverted F groove is filled with liquid metal.

3. A flexible wearable liquid metal antenna according to claim 2, characterized in that: The liquid metal is EGaIn.

4. A flexible wearable liquid metal antenna according to claim 2, characterized in that: The inverted F structure includes a long branch, a short branch and a short-circuit branch. The long branch and the short branch share a feeding port, which correspond to two frequency bands respectively, thereby realizing a dual-band radiating antenna.

5. A flexible wearable liquid metal antenna according to claim 4, characterized in that: The feeding part is a feeding metal sheet, which vertically penetrates the dielectric substrate along the Z direction and is connected with the feeding ports of the two branches.

6. A flexible wearable liquid metal antenna according to claim 1, characterized in that: The width of the metal floor is smaller than the width of the dielectric substrate.

7. A flexible wearable liquid metal antenna according to claim 4, characterized in that: The grounding part is a grounding metal sheet, which vertically penetrates the dielectric substrate along the Z direction and is connected to the port of the short-circuit branch.

8. The flexible wearable liquid metal antenna according to claim 1, characterized in that: The material of the dielectric substrate is PDMS, with a relative dielectric constant of 2.67 and a tangent loss of 0.0375.

9. A wearable electronic device, characterized in that A flexible wearable liquid metal antenna comprising any one of claims 1 to 8, for receiving signals.

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