CN105846053A - Portable device - Google Patents

Abstract

The invention discloses a portable device, which comprises a grounding element and an antenna structure. The antenna structure includes: a grounding branch, a feeding-in branch, a low-frequency radiation branch, and a high-frequency radiation branch. The feeding branch is coupled to the grounding element through the grounding branch. The low-frequency radiation branch is coupled to the feed-in branch. The high-frequency radiation branch is coupled to the feed-in branch. The low-frequency radiation branch has a winding structure to reduce the specific absorption rate of the antenna structure. The meandering structure extends towards the interior of the portable device, which may keep the hot spot current away from the edge of the portable device, i.e. away from the human body at the point of current maximum on the low frequency radiating branch. Therefore, a specific absorption rate of the antenna structure in a high frequency band can be effectively reduced by the meandering structure, so that the portable device and the antenna structure of the present invention can meet the legal specification.

Description

portable device

technical field

The present invention relates to a portable device, in particular to a portable device comprising an antenna structure.

Background technique

With the development of mobile communication technology, portable devices have become more and more common in recent years, such as portable computers, mobile phones, multimedia players and other portable electronic devices with mixed functions. In order to meet people's needs, portable devices usually have a wireless communication function. Some cover long-distance wireless communication ranges, for example: portable phones use 2G, 3G, LTE (Long Term Evolution) systems and their frequency bands of 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz and 2500MHz for communication, while some It covers the short-distance wireless communication range, for example: Wi-Fi and Bluetooth systems use 2.4GHz, 5.2GHz and 5.8GHz frequency bands for communication.

Antennas are indispensable components in portable devices supporting wireless communication functions. In order to prevent the electromagnetic waves emitted by the antenna from having adverse effects on the human body, current laws and regulations have strict regulations on the Specific Absorption Rate (SAR) of portable devices. How to design antenna elements that take into account communication quality and compliance with regulations has become a major challenge for designers today.

Contents of the invention

In order to solve the above technical problems, in a preferred embodiment, the present invention provides a portable device, including: a grounding element; and an antenna structure, including: a grounding branch; a feeding branch, with a feeding point , wherein the feeding branch is coupled to the ground element via the grounding branch; a low-frequency radiation branch is coupled to the feeding branch; and a high-frequency radiation branch is coupled to the feeding branch ; wherein the low-frequency radiation branch has a meandering structure.

In some embodiments, the meander structure is used to reduce a specific absorption rate of the antenna structure.

In some embodiments, a current maximum point of the low-frequency radiation branch is located on the meandering structure.

In some embodiments, the antenna structure is adjacent to an edge of the portable device, and the meander structure extends away from the edge of the portable device.

In some embodiments, the meandering structure extends toward the direction close to the ground branch.

In some embodiments, the meandering structure is any one or a combination of a U-shape, a W-shape, an N-shape, an S-shape or a Z-shape.

In some embodiments, a first end of the feeding branch is coupled to the ground element via the grounding branch, and a first end of the low-frequency radiation branch is coupled to a second end of the feeding branch. end, a second end of the low-frequency radiation branch is an open-circuit end, a first end of the high-frequency radiation branch is coupled to the second end of the feed-in branch, and the high-frequency radiation branch A second end of is an open circuit end.

In some embodiments, the second end of the low frequency radiation branch and the second end of the high frequency radiation branch extend in opposite directions.

In some embodiments, the portable device further includes: a display, wherein the antenna structure is interposed between the display and an edge of the portable device.

In some embodiments, the feed branch and the low frequency radiation branch excite a low frequency band, the feed branch and the high frequency radiation branch excite a high frequency band, the low frequency band is between 2400MHz and 2484MHz Between, and the high frequency band is between 5150MHz and 5850MHz.

The portable device in the present invention has a meandering structure in its low-frequency radiation branch to reduce the specific absorption rate of the antenna structure. The meandering structure extends toward the interior of the portable device, which can keep the hot spot current away from the edge of the portable device, that is, make the point of the maximum current on the low-frequency radiation branch farther away from the human body. Therefore, the specific absorption rate of the antenna structure in the high frequency band can be effectively reduced through the meander structure, so that the portable device and the antenna structure of the present invention can comply with legal regulations.

Description of drawings

FIG. 1 is a schematic diagram showing a portable device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram showing an antenna structure according to an embodiment of the present invention;

FIG. 3 is a schematic diagram showing an antenna structure according to another embodiment of the present invention;

FIG. 4 is a schematic diagram showing SAR measurement of the antenna structure according to an embodiment of the invention.

Explanation of reference signs:

100～portable device;

101, 102, 103 ~ the edge of the portable device;

110～grounding element;

120～monitor;

200, 300～antenna structure

220～grounding branch;

221～the first end of the grounding branch;

222～the second end of the grounding branch;

230～feeding branch;

231～the first end of the feeding branch;

232～the second end of the feeding branch;

240, 340 ~ low frequency radiation branch;

241, 341～the first end of the low-frequency radiation branch;

242, 342～the second end of the low-frequency radiation branch;

250～high-frequency radiation branch;

251～the first end of the high-frequency radiation branch;

252～the second end of the high-frequency radiation branch;

260, 360 ~ winding structure;

290～signal source;

FP ~ feed point.

detailed description

In order to make the purpose, features and advantages of the present invention more comprehensible, the specific embodiments of the present invention are specifically listed below, together with the accompanying drawings and descriptions, and are described in detail as follows.

FIG. 1 is a schematic diagram showing a portable device 100 according to an embodiment of the invention. The portable device 100 can be a smart phone (Smart Phone), a tablet computer (Tablet Computer), or a notebook computer (Notebook Computer). As shown in FIG. 1 , the portable device 100 includes a ground element 110 , an antenna structure 200 , and a display 120 . The ground element 110 may be a metal plane, which may be disposed on a printed circuit board (PCB). The antenna structure 200 can be made of metal, such as copper, silver, aluminum, iron, or alloys thereof. The antenna structure 200 is interposed between the display 120 and an edge 101 of the portable device 100 . The display 120 may be any kind of electronic display device, such as a liquid crystal display (Liquid Crystal Display) or an organic electroluminescence display (Organic Electroluminescence Display, OLED). In the embodiment of FIG. 1, the antenna structure 200 is located on the top of the portable device 100, but the present invention is not limited thereto. In other embodiments, the antenna structure 200 may instead be located on the side of the portable device 100 , for example, may be between the display 120 and the other edge 102 (or edge 103 ) of the portable device 100 . It must be understood that the portable device 100 may also include other components, such as a processor, a speaker, a battery, a touch module, an audio control module, or a casing (not shown).

FIG. 2 is a schematic diagram showing an antenna structure 200 according to an embodiment of the invention. FIG. 2 is used to illustrate the detailed features of the antenna structure 200 of FIG. 1 . As shown in FIG. 2 , the antenna structure 200 includes: a grounding branch 220 , a feeding branch 230 , a low-frequency radiation branch 240 , and a high-frequency radiation branch 250 . The above branches are all made of metal, such as copper, silver, aluminum, iron, or their alloys. The feed branch 230 has a feed point FP, and the feed branch 230 is coupled to the ground element 110 via the ground branch 220 . Both the low frequency radiation branch 240 and the high frequency radiation branch 250 are coupled to the feeding branch 230 , and the length of the low frequency radiation branch 240 is longer than that of the high frequency radiation branch 250 .

The ground branch 220 may be roughly L-shaped. The feeding branch 230 may be substantially straight. The low frequency radiation branch 240 may have a meandering structure 260 . The high-frequency radiation branch 250 may be substantially straight. The feed point FP is located on a first end 231 of the feed branch 230 . The feeding point FP can be coupled to a signal source 290 via a coaxial cable (not shown). The signal source 290 may be a radio frequency (Radio Frequency, RF) module, which is used to excite the antenna structure 200 . The first end 231 of the feeding branch 230 is coupled to a first end 221 of the grounding branch 220 , and a second end 222 of the grounding branch 220 is coupled to the grounding element 110 . A first end 241 of the low frequency radiation branch 240 is coupled to a second end 232 of the feeding branch 230 , and a second end 242 of the low frequency radiation branch 240 is an open end (Open End). A first end 251 of the high frequency radiation branch 250 is coupled to the second end 232 of the feeding branch 230 , and a second end 252 of the high frequency radiation branch 250 is an open circuit end. The second end 242 of the low frequency radiation branch 240 and the second end 252 of the high frequency radiation branch 250 may extend in opposite directions.

The antenna structure 200 is adjacent to the edge 101 of the portable device 100 . In the antenna structure 200 , the meander structure 260 of the low frequency radiation branch 240 extends away from the edge 101 of the portable device 100 . In other words, the meander structure 260 extends toward the direction close to the ground branch 220 . The meandering structure 260 is roughly U-shaped. In other embodiments, the meander structure 260 may also have other shapes, such as an N shape, an S shape, or a Z shape.

Please refer to Figures 1 and 2 together. The principle of operation of the antenna structure 200 may be as follows. The feed-in branch 230 and the low-frequency radiation branch 240 can jointly excite to generate a low-frequency band, while the feed-in branch 230 and the high-frequency radiation branch 250 can jointly excite to generate a high-frequency band. The total length of the feed branch 230 and the low frequency radiation branch 240 may be approximately equal to a quarter wavelength of the low frequency band. The total length of the feed branch 230 and the high frequency radiation branch 250 may be approximately equal to a quarter wavelength of the high frequency band. For example, the aforementioned low frequency band may be between 2400MHz and 2484MHz, and the aforementioned high frequency band may be between 5150MHz and 5850MHz. Therefore, the portable device 100 and the antenna structure 200 can at least support the operating frequency bands of mobile communications such as Wi-Fi and Bluetooth.

It must be noted that due to the frequency doubling effect, the feeding branch 230 and the low-frequency radiation branch 240 will excite another high-order resonance mode located in the aforementioned high-frequency band (eg, 5 GHz band). This high-order resonance mode is the main reason why the Specific Absorption Rate (SAR) of the traditional Planar Inverted F Antenna (PIFA) in the high frequency band cannot meet the legal requirements. In the present invention, the design of adding a meander structure 260 to the low-frequency radiation branch 240 is used to overcome the problems faced by the prior art. In a preferred embodiment, a current maximum point (Current Maximum Point) of the low-frequency radiation branch 240 is just located on the meander structure 260, and the multiplied frequency of the current falls near 5G. In more detail, the length of a resonant path between the feeding point FP and the meandering structure 260 of the low-frequency radiation branch 240 may be approximately equal to one-eighth of the wavelength of the aforementioned low-frequency band, or the length of the aforementioned high-frequency band. a quarter wavelength of the frequency band. Because the meandering structure 260 will reverse the current direction and cancel each other, reduce the current intensity and radiation field intensity, thus reducing the negative impact of the above-mentioned high-order resonance mode on the specific absorption rate. On the other hand, the meandering structure 260 extends toward the interior of the portable device 100 , which can also keep the hot spot current away from the edge 101 of the portable device 100 , that is, make the maximum current point on the low-frequency radiation branch 240 farther away from the human body. Therefore, the meander structure 260 can effectively reduce a specific absorption rate of the antenna structure 200 in the high frequency band, so the portable device 100 and the antenna structure 200 of the present invention can comply with legal regulations.

The meandering structure is any one or a combination of a U-shape, a W-shape, an N-shape, an S-shape or a Z-shape. FIG. 3 is a schematic diagram showing an antenna structure 300 according to another embodiment of the present invention. FIG. 3 is similar to FIG. 2 , the difference between them is that a low-frequency radiation branch 340 of the antenna structure 300 has a meandering structure 360 , which is roughly a W-shape. The distance between any two adjacent parallel branches of the meandering structure 360 may be approximately equal to 0.5 mm. In addition, in order to save design space, the width of the serpentine structure 360 may be thinner than that of the rest of the lower frequency radiation branch 340 . The remaining features of the antenna structure 300 in FIG. 3 are the same as those of the antenna structure 200 in FIG. 2 , so both embodiments can achieve similar operational effects.

FIG. 4 is a schematic diagram showing SAR measurement of the antenna structure 300 according to an embodiment of the invention. FIG. 4 is used to illustrate the actual measurement results of the specific absorption rate from the top and bottom of the portable device 100 . Please refer to Figure 4 and Table 1 below.

specific absorption rate above Specific Absorption Rate of the Bottom Traditional Planar Inverted-F Antenna 2.38 2.52 Antenna system of the present invention 1.51 2.79

Table 1: Actual measured specific absorption rate (when the antenna gain is the same as -2.95dBi)

Table 1 is a comparison table of the actual measured specific absorption rate. According to the measurement results, compared with the traditional planar inverted-F antenna, under the same antenna gain (for example: the same as -2.95dBi), the specific absorption rate measured by the present invention can be significantly reduced, especially the upper The specific absorption rate can reach about 60% of the conventional design, therefore, the antenna system of the present invention will more easily comply with the statutory specific absorption rate specification.

It should be noted that the above-mentioned element sizes, element shapes, and frequency ranges are not limitations of the present invention. Antenna designers can adjust these settings according to different needs. The structure of the portable device and antenna of the present invention is not limited to the states shown in FIGS. 1-4. The invention may comprise only any one or more features of any one or more of the embodiments of Figures 1-4. In other words, not all the illustrated features must be implemented in the portable device and the antenna structure of the present invention at the same time.

The ordinal numbers in this specification and claims, such as "first", "second", "third", etc., have no sequential relationship with each other, and are only used to mark and distinguish two terms with the same name. of different components.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The protection scope of the invention should be defined by the claims.

Claims (10)

1. a portable unit, it is characterised in that including:

One earth element；And

One antenna structure, including:

One ground connection branch road；

One feed-in branch road, has a load point, and wherein this feed-in branch road is via this ground connection branch road coupling It is connected to this earth element；

One low frequency radiation branch road, is coupled to this feed-in branch road；And

One high frequency radiation branch road, is coupled to this feed-in branch road；

Wherein this low frequency radiation branch road has a serpentine structure.

2. portable unit as claimed in claim 1, wherein this serpentine structure is used for reducing this antenna knot One specific absorption rate of structure.

3. portable unit as claimed in claim 1, wherein an electric current of this low frequency radiation branch road is maximum Value point is positioned in this serpentine structure.

4. portable unit as claimed in claim 1, wherein this antenna structure is adjacent to this portable unit An edge, and this serpentine structure is made to extend towards the direction at this edge away from this portable unit.

5. portable unit as claimed in claim 1, wherein this serpentine structure is towards near this ground connection branch road Direction make extend.

6. portable unit as claimed in claim 1, wherein this serpentine structure is a U-shaped, a W Any one or a few combination in font, a N font, a S font or a zigzag.

7. portable unit as claimed in claim 1, wherein one first end of this feed-in branch road is via this Ground connection branch road is coupled to this earth element, and one first end of this low frequency radiation branch road is coupled to this feed-in and props up One second end on road, one second end of this low frequency radiation branch road is an open end, this high frequency radiation branch road One first end be coupled to this second end of this feed-in branch road, and one second end of this high frequency radiation branch road It it is an open end.

8. portable unit as claimed in claim 7, wherein this second end of this low frequency radiation branch road and This second end of this high frequency radiation branch road is made to extend in the opposite direction.

9. portable unit as claimed in claim 1, also includes:

One display, wherein this antenna structure is between this display and an edge of this portable unit.

10. portable unit as claimed in claim 1, wherein this feed-in branch road and this low frequency radiation branch road Exciting generation one low-frequency band, this feed-in branch road and this high frequency radiation branch road excite generation one high frequency band, This low-frequency band is between 2400MHz to 2484MHz, and this high frequency band is between 5150MHz Between 5850MHz.