TWI763523B - Mobile device for eliminating nulls of radiation pattern - Google Patents

Abstract

A mobile device for eliminating nulls of its radiation pattern includes a ground element, a first radiation element, a second radiation element, and a dielectric substrate. The first radiation element has a feeding point. The second radiation element is adjacent to the first radiation element. The second radiation element is floating and substantially has a relatively long L-shape. The dielectric substrate is adjacent to the ground element. The first radiation element and the second radiation element are disposed on the dielectric substrate. An antenna structure is formed by the ground element, the first radiation element, the second radiation element, and the dielectric substrate.

Description

Mobile device for eliminating radiation field zero

The present invention relates to a mobile device, in particular to a mobile device and an antenna structure thereof.

With the development of mobile communication technology, mobile devices have become more and more common in recent years, such as laptop computers, mobile phones, multimedia players and other portable electronic devices with mixed functions. In order to meet people's needs, mobile devices usually have the function of wireless communication. Some cover long-distance wireless communication range, for example: mobile 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 cover short-range wireless communication range, for example: Wi-Fi, Bluetooth systems use the 2.4GHz, 5.2GHz and 5.8GHz frequency bands for communication.

Antenna is an indispensable element in the field of wireless communication. If the antenna used for receiving or transmitting signals has a null radiation field, it is easy to cause the communication quality of the mobile device to be degraded. Therefore, how to design an approximately omnidirectional antenna element is an important issue for antenna designers.

In a preferred embodiment, the present invention provides a mobile device for eliminating the zero point of a radiation field, comprising: a grounding element; a first radiation part with a feeding point; a second radiation part adjacent to the first radiation part, wherein the second radiating part is in a floating state and presents a long L-shape; and a dielectric substrate adjacent to the grounding element, wherein the first radiating part and the second radiating part are both disposed on the dielectric substrate ; wherein the ground element, the first radiation portion, the second radiation portion, and the dielectric substrate together form an antenna structure.

In some embodiments, the first radiation portion has a short L-shape.

In some embodiments, the first radiation portion includes a first portion and a second portion coupled to each other, and the second portion is substantially perpendicular to the first portion.

In some embodiments, the second radiation portion includes a third portion and a fourth portion coupled to each other, and the fourth portion is substantially perpendicular to the third portion.

In some embodiments, a coupling gap is formed between the second radiation part and the first radiation part.

In some embodiments, the dielectric substrate has an equal-width L-shape.

In some embodiments, the antenna structure covers a first frequency band and a second frequency band, the first frequency band is between 2400MHz and 2500MHz, and the second frequency band is between 5150MHz and 5850MHz.

In some embodiments, the total length of the first radiation portion is approximately equal to 0.25 times the wavelength of the second frequency band.

In some embodiments, the total length of the second radiation portion is approximately equal to one wavelength of the first frequency band.

In some embodiments, the maximum current density of the first frequency band is distributed at the turns and ends of the second radiating portion.

In order to make the objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are given in the following, and are described in detail as follows in conjunction with the accompanying drawings.

Certain terms are used throughout the specification and claims to refer to particular elements. It should be understood by those skilled in the art that hardware manufacturers may refer to the same element by different nouns. This specification and the scope of the patent application do not use the difference in name as a way to distinguish elements, but use the difference in function of the elements as a criterion for distinguishing. The words "including" and "including" mentioned in the entire specification and the scope of the patent application are open-ended terms, so they should be interpreted as "including but not limited to". The word "substantially" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. Furthermore, the word "coupled" in this specification includes any direct and indirect electrical connection means. Therefore, if a first device is described as being coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device through other devices or connecting means. Second device.

The following disclosure provides many different embodiments or examples for implementing different features of the present invention. The following disclosure describes specific examples of various components and their arrangements to simplify the description. Of course, these specific examples are not intended to be limiting. For example, if the disclosure describes that a first feature is formed on or over a second feature, it may include embodiments in which the first feature and the second feature are in direct contact, and may also include additional Embodiments in which the feature is formed between the first feature and the second feature, such that the first feature and the second feature may not be in direct contact. In addition, different examples of the following disclosure may reuse the same reference symbols or (and) signs. These repetitions are for the purpose of simplicity and clarity and are not intended to limit the particular relationship between the different embodiments or/and structures discussed.

FIG. 1 is a schematic diagram of a mobile device 100 according to an embodiment of the present invention. The mobile device 100 can be a smart phone, a tablet computer, or a notebook computer. As shown in FIG. 1 , the mobile device 100 includes: a ground element 110 , a first radiation element 120 , a second radiation element 130 , and a dielectric substrate 170 , wherein The grounding element 110 , the first radiating part 120 and the second radiating part 130 can all be made of metal materials, such as copper, silver, aluminum, iron, or alloys thereof. It must be understood that, although not shown in FIG. 1, the mobile device 100 may further include other components, such as a processor, a touch panel, a speaker, a battery module, and a casing.

The grounding element 110 may be approximately a square or a rectangle. The ground element 110 can be used to provide a ground voltage. For example, the ground element 110 can be implemented by a ground copper foil, which can be further coupled to a System Ground Plane (not shown) of the mobile device 100 .

The first radiating portion 120 may approximately have a short L-shape. In detail, the first radiation part 120 has a first end 121 and a second end 122 , wherein a feeding point FP is located at the first end 121 of the first radiation part 120 , and the first radiation The second end 122 of the portion 120 is an open end. The feeding point FP can further be coupled to a signal source (Signal Source) 190 . For example, the signal source 190 may be a radio frequency (RF) module. In some embodiments, the first radiation portion 120 includes a first portion 124 and a second portion 125 coupled to each other. Each of the first portion 124 and the second portion 125 may be substantially in the shape of a straight bar, wherein the second portion 125 may be substantially perpendicular to the first portion 124 . In addition, the length L2 of the second portion 125 may be greater than or equal to the length L1 of the first portion 124 .

The second radiating portion 130 may generally have a long L-shape (compared to the first radiating portion 120 ). In detail, the second radiating portion 130 has a first end 131 and a second end 132, each of which is an open end. The first end 131 of the second radiating portion 130 and the second end 122 of the first radiating portion 120 may extend substantially in opposite directions and away from each other. It must be noted that the second radiating portion 130 is in a floating state and does not directly contact any other metal element. In some embodiments, the second radiation portion 130 includes a third portion 134 and a fourth portion 135 coupled to each other. The third portion 134 and the fourth portion 135 may each be substantially in a straight bar shape, wherein the fourth portion 135 may be substantially perpendicular to the third portion 134 . In addition, the length L4 of the fourth portion 135 may be approximately equal to the length L3 of the third portion 134 . In some embodiments, the second radiating part 130 is adjacent to the first radiating part 120 , so that a coupling can be formed between the third part 134 of the second radiating part 130 and the second part 125 of the first radiating part 120 Coupling Gap GC1. It must be understood that the term "adjacent" or "adjacent" in this specification may mean that the distance between two corresponding elements is less than a predetermined distance (for example: 5mm or less), but usually does not include that the two corresponding elements are in direct contact with each other. (that is, the aforementioned pitch is shortened to 0). In some embodiments, the second end 122 of the first radiating portion 120 is adjacent to a turning point 136 of the second radiating portion 130 (which is coupled between the third portion 134 and the fourth portion 135 ).

The dielectric substrate 170 may have an equal-width L-shape, which may be adjacent to the ground element 110 . For example, the dielectric substrate 170 can be a FR4 (Flame Retardant 4) substrate, a printed circuit board (Printed Circuit Board, PCB), or a flexible printed circuit board (Flexible Printed Circuit Board, FPC). Both the first radiation part 120 and the second radiation part 130 may be disposed on the same surface of the dielectric substrate 170 . In a preferred embodiment, the ground element 110 , the first radiating portion 120 , the second radiating portion 130 , and the dielectric substrate 170 can jointly form a planar antenna structure (Antenna Structure). In other embodiments, the dielectric substrate 170 can also be changed into a rectangle, wherein the grounding element 110 is disposed on the same surface of the dielectric substrate 170 .

FIG. 2 shows a return loss diagram of the antenna structure of the mobile device 100 according to an embodiment of the present invention, wherein the horizontal axis represents the operating frequency (MHz), and the vertical axis represents the return loss (dB). According to the measurement results in FIG. 2 , when excited by the signal source 190 , the antenna structure of the mobile device 100 can cover a first frequency band FB1 and a second frequency band FB2 . For example, the first frequency band FB1 may be between 2400MHz and 2500MHz, and the second frequency band FB2 may be between 5150MHz and 5850MHz. Therefore, the antenna structure of the mobile device 100 can at least support the broadband operation of WLAN (Wireless Wide Area Network) 2.4GHz/5GH.

In terms of the antenna principle, the second radiating portion 130 can be coupled and excited by the first radiating portion 120 to generate the aforementioned first frequency band FB1. In addition, the first radiation portion 120 itself can be excited to generate the aforementioned second frequency band FB2. According to the actual measurement results, the maximum current density of the first frequency band FB1 can be simultaneously distributed at the turning point 136 and the end (eg, the first end 131 and the second end 132 ) of the second radiation portion 130 . This design can make the radiation pattern of the antenna structure more uniform, and the effect will be described in detail in the embodiments of Figs. 4A and 4B.

FIG. 3 shows a radiation gain (Radiation Gain) diagram of the antenna structure of the mobile device 100 according to an embodiment of the present invention, wherein the horizontal axis represents the operating frequency (MHz), and the vertical axis represents the radiation gain (dBi). According to the measurement results in FIG. 3 , the radiation gain of the antenna structure of the mobile device 100 in the first frequency band FB1 and the second frequency band FB2 can both reach -4dBi or higher, which can meet the practical application requirements of WLAN communication.

FIG. 4A shows the radiation pattern of the conventional antenna structure. FIG. 4B shows a radiation pattern of the antenna structure of the mobile device 100 according to an embodiment of the present invention. The above radiation patterns are all measured along the XY plane in the first frequency band FB1. By comparing Figures 4A and 4B, it can be found that since the maximum current density has been properly configured, the proposed antenna structure can effectively eliminate the non-ideal zeros in the radiation pattern (as indicated by the dotted boxes 401 and 402). In other words, the antenna structure of the mobile device 100 can provide a nearly omnidirectional radiation pattern.

In some embodiments, the component dimensions of the mobile device 100 may be as follows. In the first radiation portion 120, the length L1 of the first portion 124 may be approximately equal to 0.125 times the wavelength (λ/8) of the second frequency band FB2 of the antenna structure (for example, the length L1 may be approximately between 2mm and 4mm). , and the length L2 of the second portion 125 may be approximately equal to 0.125 times the wavelength (λ/8) of the second frequency band FB2 of the antenna structure (for example, the length L2 may be approximately between 4 mm and 5 mm). That is, the total length ( L1 + L2 ) of the first radiation portion 120 may be approximately equal to 0.25 times the wavelength (λ/4) of the second frequency band FB2 of the antenna structure. In addition, the width W1 of the first portion 124 may be between 1 mm and 2 mm, and the width W2 of the second portion 125 may be between 1 mm and 2 mm. In the second radiation portion 130, the length L3 of the third portion 134 may be approximately equal to 0.5 times the wavelength (λ/2) of the first frequency band FB1 of the antenna structure, and the length L4 of the fourth portion 135 may be approximately equal to the antenna structure 0.5 times the wavelength (λ/2) of the first frequency band FB1. That is, the total length ( L3 + L4 ) of the second radiation portion 130 may be approximately equal to one wavelength (λ) of the first frequency band FB1 of the antenna structure. In addition, the width W3 of the third portion 134 may be between 1 mm and 2 mm, and the width W4 of the fourth portion 135 may be between 1 mm and 2 mm. The width of the coupling gap GC1 between the first radiation part 120 and the second radiation part 130 may be between 1 mm and 2 mm. The width WS of the dielectric substrate 170 may be between 8 mm and 10 mm. The above range of component size is obtained according to multiple experimental results, which help to optimize the operation bandwidth and impedance matching of the antenna structure of the mobile device 100 .

FIG. 5 is a schematic diagram of a mobile device 500 according to another embodiment of the present invention. Figure 5 is similar to Figure 1. In the embodiment shown in FIG. 5, the first radiation portion 520 of the mobile device 500 has a first end 521 and a second end 522, and includes a first portion 524 and a second portion 525, wherein the second The first end 131 of the radiating portion 130 and the second end 522 of the first radiating portion 520 may extend in substantially the same direction. According to the actual measurement results, even if the first radiating portion 520 is inverted as a mirror image, it will not affect the radiation performance of the antenna structure of the mobile device 500 .

FIG. 6 is a schematic diagram of a notebook computer 600 according to an embodiment of the present invention. In the embodiment of FIG. 6 , the aforementioned antenna structure can be applied to a notebook computer 600 , wherein the notebook computer 600 includes a cover casing 610 , a display frame 620 , a keyboard frame 630 , and a base casing 640 . It must be understood that the upper cover shell 610, the display frame 620, the keyboard frame 630, and the base shell 640 are respectively equivalent to the commonly known "A part", "B part", "C part", and "D part" in the field of notebook computers. item". The aforementioned antenna structure can be disposed at a first position 651 or/and a second position 652 of the notebook computer 600 , and can be covered by a non-conductive keyboard frame 630 . Alternatively, the aforementioned antenna structure can be disposed at a third position 653 or (and) a fourth position 654 of the notebook computer 600 and can be covered by the non-conductive display frame 620 . According to the actual measurement results, the notebook computer 600 using the above-mentioned design can provide an approximately omnidirectional antenna radiation pattern.

The present invention proposes a novel mobile device and antenna structure. Compared with the traditional design, the present invention has at least the advantages of approximately omnidirectionality, small size, wide frequency band, low manufacturing cost, and high communication quality, so it is very suitable for application in Among all kinds of mobile communication devices.

It is worth noting that the above-mentioned component size, component shape, and frequency range are not limitations of the present invention. Antenna designers can adjust these settings according to different needs. The mobile device and the antenna structure of the present invention are not limited to the states shown in FIGS. 1-6. The present invention may include only any one or more of the features of any one or more of the embodiments of Figures 1-6. In other words, not all the features shown in the figures need to be implemented in the mobile device and the antenna structure of the present invention at the same time.

The ordinal numbers in this specification and the scope of the patent application, such as "first", "second", "third", etc., do not have a sequential relationship with each other, and are only used to mark and distinguish two identical different elements of the name.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

100,500: Mobile Device 110: Ground Elements 120,520: First Radiant Department 121,521: The first end of the first radiating part 122,522: The second end of the first radiating part 124,524: The first part of the first radiant 125,525: The second part of the first radiant 130: Second Radiation Department 131: The first end of the second radiation part 132: The second end of the second radiation part 134: The third part of the second radiant 135: The fourth part of the second radiant 136: The turning point of the second radiant 170: Dielectric substrate 190: Signal source 401, 402: Dotted box 600: Laptop 610: Upper cover shell 620: Display border 630: Keyboard Border 640: Base shell 651: First position 652: Second position 653: Third position 654: Fourth position FB1: first frequency band FB2: Second frequency band GC1: Coupling Gap L1,L2,L3,L4: length W1,W2,W3,W4,WS: width X: X axis Y: Y axis Z: Z axis

FIG. 1 is a schematic diagram of a mobile device according to an embodiment of the present invention. FIG. 2 shows a return loss diagram of an antenna structure of a mobile device according to an embodiment of the present invention. FIG. 3 shows a radiation gain diagram of an antenna structure of a mobile device according to an embodiment of the present invention. FIG. 4A shows the radiation pattern of the conventional antenna structure. FIG. 4B shows a radiation pattern of the antenna structure of the mobile device according to an embodiment of the present invention. FIG. 5 is a schematic diagram of a mobile device according to another embodiment of the present invention. FIG. 6 is a schematic diagram of a notebook computer according to an embodiment of the present invention.

100: Mobile Devices

110: Ground Elements

120: First Radiation Department

121: The first end of the first radiation part

122: The second end of the first radiation part

124: The first part of the first radiant

125: The second part of the first radiant

130: Second Radiation Department

131: The first end of the second radiation part

132: The second end of the second radiation part

134: The third part of the second radiant

135: The fourth part of the second radiant

136: The turning point of the second radiant

170: Dielectric substrate

190: Signal source

GC1: Coupling Gap

L1,L2,L3,L4: length

W1,W2,W3,W4,WS: width

X: X axis

Y: Y axis

Z: Z axis

Claims (8)

A mobile device for eliminating zero point of radiation field, comprising: a grounding element; a first radiation part with a feeding point; a second radiation part adjacent to the first radiation part, wherein the second radiation part is a floating a connected state and presenting a long L-shape; and a dielectric substrate adjacent to the grounding element, wherein the first radiating portion and the second radiating portion are both disposed on the dielectric substrate; wherein the grounding element, the first radiating portion part, the second radiation part, and the dielectric substrate together form an antenna structure; wherein the antenna structure covers a first frequency band and a second frequency band, the first frequency band is between 2400MHz and 2500MHz, and the second frequency band The frequency band is between 5150MHz and 5850MHz; wherein the total length of the second radiation portion is approximately equal to 1 wavelength of the first frequency band. The mobile device as claimed in claim 1, wherein the first radiating portion presents a short L-shape. The mobile device of claim 1, wherein the first radiation portion comprises a first portion and a second portion coupled to each other, and the second portion is substantially perpendicular to the first portion. The mobile device of claim 1, wherein the second radiation portion comprises a third portion and a fourth portion coupled to each other, and the fourth portion is substantially perpendicular to the third portion. The mobile device of claim 1, wherein a coupling gap is formed between the second radiation portion and the first radiation portion. The mobile device as claimed in claim 1, wherein the dielectric substrate presents an L-shape of equal width. The mobile device of claim 1, wherein the total length of the first radiation portion is approximately equal to 0.25 times the wavelength of the second frequency band. The mobile device as claimed in claim 1, wherein the maximum current density of the first frequency band is distributed at the turning points and the ends of the second radiating portion.

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