CN106898874B

CN106898874B - Watch watchband antenna for wearable wireless system

Info

Publication number: CN106898874B
Application number: CN201710243686.0A
Authority: CN
Inventors: 李高升; 高贵; 刘培国; 陈雨微; 卢中昊; 刘伟
Original assignee: National University of Defense Technology
Current assignee: National University of Defense Technology
Priority date: 2017-04-14
Filing date: 2017-04-14
Publication date: 2023-03-31
Anticipated expiration: 2037-04-14
Also published as: CN106898874A

Abstract

The invention provides a watch watchband antenna for a wearable wireless system, which comprises a watch watchband and a feed device arranged on the watch watchband, wherein the watch watchband is made of metal and is provided with at least one gap; the feed device comprises a micro-strip medium substrate, a metal ground arranged on the micro-strip medium substrate and a feed probe, wherein the feed probe penetrates through the metal ground and the micro-strip medium substrate and is inserted and connected into a gap of the watch band. The watch watchband antenna is convenient to install, firm in structure, low in price, light in weight and small in size, and the using burden of a user is relieved. The invention realizes the radiation of the antenna by means of the watch watchband structure, and increases the selection range of the wearable wireless system antenna.

Description

Watch watchband antenna for wearable wireless system

Technical Field

The invention relates to the technical field of wireless communication, in particular to a watch watchband antenna for a wearable wireless system.

Background

In the prior art, common antenna systems widely exist in radar, communication, navigation and other systems, and the antennas are usually made of metal materials or a mixed structure of metal and solid media. In the wearable field, the realization approaches of related antennas at home and abroad in recent years mainly comprise the following aspects:

1. a miniaturized planar antenna containing silver nanowires is characterized in that the silver nanowires are arranged into a specific pattern by using a template, then a layer of liquid polymer is laid on the silver nanowires, after the polymer is solidified, an elastic material containing an expected pattern is formed, the pattern material can form a radiating component with a patch antenna, and the working frequency of the antenna is controlled by adjusting the shape of the radiating component.

2. The metal button or metal belt buckle antenna has small size and certain radiation capability, and has advantages in electrical size for systems with longer wavelength and higher frequency.

3. Tag antennas of cloth art materials, there has been recently a paper to study tags (logo) on bags and clothes as an antenna for wearable system radiation and receiving tools, such as louiside wilford LV shaped antenna published in korea 2015, using a material with certain conductivity instead of original cloth art materials, keeping the shape and size of the trademark unchanged. It has also been investigated to use a notched Apple of Apple (Apple) corporation as an antenna, and to use a fibrous material to achieve a certain radiation and reception capability.

4. The size of the metal material deformation oscillator antenna, the loop antenna and the like is small, and the deformation oscillator antenna, the loop antenna and the like are similar to the current mainstream mobile phone antenna and are usually smaller than the mobile phone antenna in the system.

5. Microstrip antenna, metal plane fractal antenna etc. use principles and methods such as buckling, self-similar, compress microstrip base plate thickness as far as possible, reduce antenna size and weight.

In the aspect of informatization of sports shoes, related technologies that have appeared and are being studied in recent years include: the automatic shoelace tying function of Nike corporation, a motion sensor and an automatic control system are installed to assist users in using. The company Lining (LiNing) collaborated with the company Setaria to develop a sole embedded chip and a small-sized micro electronic system. Adida (Adidas) and others implant a chip in the sole of a shoe to monitor the daily movement of the user. In addition, a plurality of companies have research on wearable informatization and intellectualization, but all the companies relate to electromagnetic radiation and receiving application of watch watchbands.

In the field of smart watch watchband antennas, a bent oscillator antenna form is generally adopted, and the antenna is installed in a watch dial by bending a straight line to reduce the size. Or, a part of the watch band is replaced by an antenna structure and materials, so that the design of the antenna outside the watch dial is realized, but a technical scheme that a feeding device is arranged in a gap of the watch band does not exist.

The antennas applied in the prior art have the following defects, which are specifically shown as follows: the fabric antenna has weak radiation capability, low radiation gain, low overall efficiency and large energy loss due to weak conductivity; the common defects of the deformed oscillator antenna, the loop antenna, the button antenna, the belt buckle antenna and the like are small physical size, limited electrical size, weak emission direction and insufficient concentration of radiated and received radio energy; compared with the user requirement, the microstrip antenna, the fractal antenna and the like are still not small enough, the installation is not very convenient, and the fixing firmness is limited and the volume occupation is inevitable due to the adoption of the externally-arranged protruding structure. The information system developed by the sports clothing manufacturer at present only carries out monitoring and display and does not have a wireless transmission function; or the performance index needs to be improved by using the micro antenna. The conventional antenna usually needs to be additionally provided with a radiation and feed structure, is an extra part for users, and has defects of convenience and simplicity in use.

Disclosure of Invention

The invention aims to provide a watch watchband antenna for a wearable wireless system, and aims to solve the problems of weak radiation capability, low gain and poor directivity of an antenna in the wearable wireless system or a human body center network system in the prior art.

In order to achieve the above object, the present invention provides a wristwatch band antenna for a wearable wireless system, comprising a wristwatch band as an antenna main body and a feeding device disposed on the wristwatch band, wherein the wristwatch band is made of a metal material, and the wristwatch band is provided with at least one gap; the feed device comprises a micro-strip medium substrate, a metal ground arranged on the micro-strip medium substrate and a feed probe, wherein the feed probe penetrates through the metal ground and the micro-strip medium substrate and is inserted and connected into a gap of the watch band.

Preferably, a plurality of gaps are arranged in parallel on two sides of the watch band in the width direction.

Preferably, a plurality of slits are provided in the middle of the watch band in the width direction.

Preferably, the width of the watch band is 10 to 20mm.

Preferably, the area of the gap of the watch strap accounts for 1/4-1/2 of the area of the watch strap.

Preferably, the size of the microstrip dielectric substrate is 10mm × 10mm × 1.2mm, and the dielectric constant of the microstrip dielectric substrate is 2.2.

Preferably, the feeding probe is welded in any one of the gaps on the watch band.

Compared with the prior art, the invention has the following beneficial effects:

the watch watchband antenna for the wearable wireless system comprises a watch watchband and a feed device, wherein the watch watchband is made of a metal material, and a plurality of gaps are formed in the watch watchband; the feed device comprises a micro-strip medium substrate, a metal ground and a feed probe, wherein the feed probe penetrates through the metal ground and the micro-strip medium substrate to be connected with the watch watchband. The watch watchband antenna is convenient to install, firm in structure, low in price, light in weight and small in size, and reduces the using burden of a user. The radiation of the antenna is realized by adopting a watch strap structure, so that the selection range of the wearable wireless system antenna is enlarged; the watch watchband is used as the antenna main body, so that the size of the antenna is remarkably increased, the electrical length of the antenna is changed, the radiation capability is strong, the radiation gain is high, and the energy loss is small.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. In the drawings:

FIG. 1a is a schematic diagram of a watch wristband antenna for a wearable wireless system according to the present invention;

FIG. 1b is a schematic view of a metal-grating wristband with a plurality of parallel slits;

FIG. 1c is a graph of the reflection coefficient of the antenna with the feed point of the feed device placed at different positions in FIGS. 1a and 1 b;

FIG. 2 is a graph of the reflection coefficient of a watchband antenna for different configurations of the watchband antenna and a human body;

FIG. 3 is an antenna radiation pattern for a watch band antenna for 10mm, 15mm and 20mm wide bands;

FIG. 4a is a view of the radiation direction of three watch wristband antennas with different air gaps at 2.46GHz (Phi =0 ° & Theta0 ° -360 °);

FIG. 4b shows the radiation direction of three watch wristband antennas with different air gaps at 2.46GHz (Phi =90 ° & Theta0 ° -360 °);

FIG. 4c is a view of the radiation direction of three watch wristband antennas with different air gaps at 2.46GHz (Theta =90 ° & Phi0 ° -360 °);

FIG. 5a is the pattern achieved by three different shaped watchband antennas;

FIG. 5b is a schematic structural view of a short slit wristband;

FIG. 5c is a schematic view of the construction of a long slit watch band;

fig. 6a is a two-dimensional pattern with the wristband in full contact with the skin, partial contact and away from the body (Phi =0 ° & Theta0 ° -360 °);

fig. 6b is the far field pattern with the wristband in full contact with the skin, partial contact and away from the human body (Phi =90 °);

fig. 6c is a two-dimensional pattern of the wristband in full contact with the skin, partial contact and exit from the body (Theta =90 ° & Phi0 ° -360 °);

FIG. 7 is a graph of measured and simulated reflection coefficients of the antenna with the feed point placed in front of the right side of the dial and at the middle position of the right side of the dial;

FIG. 8a is a measured and simulated two-dimensional radiation pattern (Phi =0 ° & Theta0 ° -360 °) at 2.46GHz for a watch wristband antenna;

FIG. 8b is a measured and simulated far field radiation pattern (Phi =90 ° & Theta0 ° -360 °) at 2.46GHz for a watch wristband antenna;

FIG. 8c is a measured and simulated pattern (Theta =90 ° & Phi0 ° -360 °) at 2.46GHz for a watch wristband antenna;

the watch comprises a watch band 1, a watch band 11, a gap 01, a sky shuttle watch band 02, a grid watch band 03, a short gap watch band 04, a long gap watch band 2, a feeding device 21, a microstrip medium substrate 22, a metal ground 23, a feeding probe 3 and a dial.

Detailed Description

Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered by the claims.

The invention relates to a watch watchband antenna for a wearable wireless system, which comprises a watch watchband 1 serving as an antenna main body and a feed device 2 arranged on the watch watchband, wherein the watch watchband is made of metal and is provided with at least one gap 11; the power feeding device 2 comprises a microstrip medium substrate 21, a metal ground 22 arranged on the microstrip medium substrate, and a power feeding probe 23, wherein the power feeding probe 23 penetrates through the metal ground 22 and the microstrip medium substrate 21, is inserted and connected in a gap 11 of the watch band.

In a specific embodiment, a plurality of slits 11 are provided in parallel on both sides of the watch band 1 in the width direction.

In a specific embodiment, a plurality of slits 11 are provided in the middle of the wristwatch band 1 in the width direction.

In a particular embodiment, the width of the watch band 1 is between 10 and 20mm.

In a specific embodiment, the area of the gap 11 of the watch band 1 occupies 1/4 to 1/2 of the area of the watch band.

In a specific embodiment, the size of the microstrip dielectric substrate is 10mm × 10mm × 1.2mm, and the dielectric constant of the microstrip dielectric substrate is 2.2.

In a particular embodiment, the feed probe 23 is welded in any one of the slots 11 in the watch strap.

In the present invention, fig. 1a is a schematic structural diagram of a watch band antenna for a wearable wireless system. The watch band 1 is a sky shuttle watch band 01, a feeding point of a feeding device can be arranged at different positions of the watch band, and the specific feeding point is positioned at a point P1 behind the middle position of the right side of the sky shuttle watch band, or the feeding point is positioned at a point P2 in front of the middle position of the right side of the sky shuttle watch band, or the feeding point is positioned at a point P3 in the middle of the right side of the watch dial 3. Fig. 1b is a schematic structural diagram of a metal-grating wristband with a plurality of parallel slits, wherein the feeding point is located at the right middle point P4 of the grating wristband 02. Fig. 1c is a reflection coefficient curve of the antenna with the feeding point of the feeding means placed at different positions in fig. 1a and 1 b. As can be seen from the figure: when the feed point is located at a point P1 behind the middle position on the right of the band, a point P2 in front of the middle position on the right of the band, and a point P3 in the middle position on the right of the dial, the resonant frequencies of the antennas are 2.11GHz, 1.60GHz, and 2.46GHz, respectively. For the feed point at point P4, there are three resonant frequencies, 0.66GHz, 1.17GHz, and 2.66GHz, respectively. The reflection coefficient of the antenna changes along with the change of the feeding position, and the resonant frequency meets the requirements of the wearable wireless system. The feed point may be located elsewhere on the wristband if the system has particular requirements for frequency or other parameters. Furthermore, if the watchband is shaped differently, the feeding can be implemented in a similar manner.

Table 1 gives the frequency matching characteristics for different positions of the feed point. Wherein the relative bandwidth at 2.46GHz is 77.8%, which is located in the industrial, scientific and medical (ISM band) public common band.

TABLE 1 frequency matching characteristics of a watchband antenna at different feed positions

FIG. 2 is a graph of the reflection coefficient of the watchband antenna for different configurations of the body, the watchband of the watchband antenna being in full contact with the wrist, partially in contact with the wrist, and the watch being removed from the arm and wrist. As can be seen from fig. 2, the resonant frequency of the watchband antenna in three cases is increased from 1.69GHz to 2.46GHz and 4.09GHz in turn, and the watchband antenna for the wearable wireless system of the invention can obtain different resonant frequencies by adjusting the position relationship between the antenna and the human body, thereby being applied to different fields.

FIG. 3 is an antenna radiation pattern for a watch band antenna with a band width of 10mm, 15mm and 20mm. As can be seen from fig. 3, the antenna radiation directions in the three cases are slightly different from each other, and therefore, the wristwatch band antenna of the present invention can satisfy the use requirements even when the band width is 10 to 20mm.

Further, the number of slots on the wristband will affect the radiation pattern of the antenna of the present invention, and based on the structure of the wristband shown in fig. 1b, the slot area is the antenna radiation pattern corresponding to the structure of 1/2 and 1/4 of the watch wristband area, respectively, without changing the circumference of the wristband. In consideration of the fact that the forearm of a person may be in a posture perpendicular to the ground (for example, standing) or in a posture parallel to the ground (lying on a table) in real life, fig. 4a, 4b and 4c provide three sectional views of a two-dimensional radiation pattern, which reflects the radiation condition of the antenna in the whole space. FIG. 4a is a view of the radiation direction of three watch wristband antennas with different air gaps at 2.46GHz (Phi =0 ° & Theta0 ° -360 °); FIG. 4b shows the radiation direction of three watch wristband antennas with different air gaps at 2.46GHz (Phi =90 ° & Theta0 ° -360 °); fig. 4c shows the radiation direction of three watch wristband antennas with different air gaps at 2.46GHz (Theta =90 ° & Phi0 ° -360 °). As can be seen from the figure, the antenna has a wider main lobe above the back of the hand, and can meet the requirement of large-range coverage required by the arm in a frequently active state.

Fig. 5a is a directional diagram implemented by three different shapes of watchband antennas, where two watchband structures are structural schematic diagrams of the short-gap watchband and the long-gap watchband shown in fig. 5b and fig. 5c, respectively, where the widths of the short-gap watchband 03 and the long-gap watchband 04 are both 20mm, the widths of the gaps are both 1mm, the distance between two adjacent gaps is 6mm, the length of the gap of the short-gap watchband 03 is 5mm, and the length of the gap of the long-gap watchband 04 is 8.5mm; the other type of watchband is a lattice watchband 02, and the lattice watchband 02 has a larger gap amount than the short-gap watchband 03 and the long-gap watchband 04. As can be seen from fig. 5a, the band antenna using the short-gap band 03 and the long-gap band 04 has a slightly higher gain than the band antenna using the lattice band 02, but the difference in current distribution due to the difference in the structure of the lattice band 02 causes the difference in the main lobe directivity of the directional pattern by about 45 °.

Fig. 6a is a two-dimensional pattern with the wristband in full contact with the skin, partial contact and away from the body (Phi =0 ° & Theta0 ° -360 °); fig. 6b is the far field pattern with the wristband in full contact with the skin, partial contact and away from the human body (Phi =90 °); fig. 6c is a two-dimensional pattern with the wristband in full contact with the skin, partial contact and off the body (Theta =90 ° & Phi0 ° -360 °). As shown in fig. 6a, 6b and 6c, the gain of the radiation pattern in the frequency range of 2.4GHz-2.5GHz is approximately about 5dBi, and covers the 2.4GHz-2.5GHz frequency band for industrial, scientific and medical use, so that the antenna can be applied to the fields of wireless navigation and positioning, space electromagnetic energy collection and charging, human body center network and digital multimedia, internet of things, smart city, smart home, sports, medical and health data acquisition and real-time transmission, and the like.

In this example, a band antenna produced by using a shuttle band as a prototype was tested in a microwave anechoic chamber. A small microstrip dielectric substrate with the thickness of 10mm multiplied by 1.2mm is used as a basic feed structure, and ArlonDi880 with the dielectric constant of 2.2 is used as a material. The main instrument used is an Anritsu37369A Vector Network Analyzer (VNA), the watch watchband antenna is tested under the condition of being naturally worn, and the test bandwidth is 40MHz-6.0GHz. As shown in fig. 7, the curve of the measured and simulated reflection coefficients of the antenna is obtained when the feeding point is placed at the middle position of the right front side and the right side of the dial.

The radiation pattern test of the watch watchband antenna in the microwave darkroom uses the equivalent of a human hand model and an arm model, and the horizontal medium rotary table is matched with the vector network analyzer to obtain the radiation characteristic. An ultra-wideband and ridged horn antenna is used as an auxiliary transmission tool. FIG. 8a is a measured and simulated two-dimensional radiation pattern (Phi =0 ° & Theta0 ° -360 °) at 2.46GHz for a watch wristband antenna; FIG. 8b is a measured and simulated far field radiation pattern (Phi =90 ° & Theta0 ° -360 °) at 2.46GHz for a watch wristband antenna; fig. 8c is the measured and simulated pattern (Theta =90 ° & Phi0 ° -360 °) at 2.46GHz for a watch wristband antenna. The actual measurement and simulation radiation pattern of the watch watchband antenna at 2.46GHz are given in the above fig. 8a, fig. 8b and fig. 8c, the test data is well matched with the simulation result, and the effectiveness of the watch watchband antenna of the invention is verified.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The watch watchband antenna for the wearable wireless system is characterized by comprising a watch watchband (1) serving as an antenna main body and a feed device (2) arranged on the watch watchband, wherein the watch watchband is made of a metal material, a plurality of gaps (11) are arranged on two sides of the watch watchband (1) in the width direction in parallel, and a plurality of gaps (11) are arranged in the middle of the watch watchband (1) in the width direction; the feed device (2) comprises a micro-strip dielectric substrate (21), a metal ground (22) arranged on the micro-strip dielectric substrate and a feed probe (23), wherein the feed probe (23) penetrates through the metal ground (22) and the micro-strip dielectric substrate (21) and is inserted and connected into a gap (11) of the watch strap.

2. The watch wristband antenna according to claim 1, characterized in that the width of the watch wristband (1) is 10-20 mm.

3. The watch wristband antenna according to claim 1, wherein the slot (11) area of the watch wristband (1) is between 1/4 and 1/2 of the watch wristband area.

4. The watch wristband antenna of claim 1, wherein the microstrip dielectric substrate has dimensions of 10mm x 1.2mm, and the microstrip dielectric substrate has a dielectric constant of 2.2.

5. The watch wristband antenna according to claim 1, characterized in that the feed probe (23) is welded in any one of the slots (11) on the watch wristband.