Patent Publication Number: US-11380977-B2

Title: Mobile device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of Taiwan Patent Application No. 109131252 filed on Sep. 11, 2020, the entirety of which is incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The disclosure generally relates to a mobile device, and more particularly, it relates to a mobile device and an antenna structure therein. 
     Description of the Related Art 
     With the advancements being made in mobile communication technology, mobile devices such as portable computers, mobile phones, multimedia players, and other hybrid functional portable electronic devices have become more common. To satisfy user demand, mobile devices can usually perform wireless communication functions. Some devices cover a large wireless communication area; these include mobile phones using 2G, 3G, and LTE (Long Term Evolution) systems and using frequency bands of 700 MHz, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, 2100 MHz, 2300 MHz, 2500 MHz, and 2700 MHz. Some devices cover a small wireless communication area; these include mobile phones using Wi-Fi and Bluetooth systems and using frequency bands of 2.4 GHz, 5.2 GHz, and 5.8 GHz. 
     Antennas are indispensable elements for wireless communication. However, antennas tend to be affected by nearby metal elements, causing interference that can impact the quality of the wireless communication. Accordingly, there is a need to propose a novel solution for solving the problems of the prior art. 
     BRIEF SUMMARY OF THE INVENTION 
     In an exemplary embodiment, the disclosure is directed to a mobile device that includes a first radiation element, a second radiation element, a third radiation element, a fourth radiation element, a fifth radiation element, and a dielectric substrate. The first radiation element is coupled to a signal source. The second radiation element is coupled to a ground voltage. The second radiation element is adjacent to the first radiation element. The third radiation element is coupled to the signal source. The first radiation element, the second radiation element, and the third radiation element substantially extend in the same direction. The fourth radiation element is coupled to the ground voltage. The fourth radiation element is disposed between the first radiation element and the second radiation element. The fifth radiation element is coupled to the ground voltage. The fifth radiation element is adjacent to the second radiation element. The first radiation element, the second radiation element, the third radiation element, the fourth radiation element, and the fifth radiation element are disposed on the dielectric substrate. An antenna structure is formed by the first radiation element, the second radiation element, the third radiation element, the fourth radiation element, the fifth radiation element, and the dielectric substrate. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a view of a mobile device according to an embodiment of the invention; 
         FIG. 2  is a diagram of return loss of an antenna structure of a mobile device according to an embodiment of the invention; 
         FIG. 3  is a diagram of radiation gain of an antenna structure of a mobile device according to an embodiment of the invention; 
         FIG. 4  is a view of a notebook computer according to an embodiment of the invention; and 
         FIG. 5  is a partial sectional view of a notebook computer according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In order to illustrate the purposes, features and advantages of the invention, the embodiments and figures of the invention are shown in detail below. 
     Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms “include” and “comprise” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . ”. The term “substantially” means the value is within an acceptable error range. One skilled in the art can solve the technical problem within a predetermined error range and achieve the proposed technical performance. Also, the term “couple” is intended to mean either an indirect or direct electrical connection. Accordingly, if one device is coupled to another device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections. 
       FIG. 1  is a view of a mobile device  100  according to an embodiment of the invention. The mobile device  100  may be a smartphone, a tablet computer, or a notebook computer. As shown in  FIG. 1 , the mobile device  100  includes a first radiation element  110 , a second radiation element  120 , a third radiation element  130 , a fourth radiation element  140 , a fifth radiation element  150 , and a dielectric substrate  170 . The first radiation element  110 , the second radiation element  120 , the third radiation element  130 , the fourth radiation element  140 , and the fifth radiation element  150  may all be made of metal materials, such as copper, silver, aluminum, iron, or an alloy thereof. It should be understood that the mobile device  100  may further include other components, such as a processor, a touch control panel, a speaker, a battery module, and a housing, although they are not displayed in  FIG. 1 . 
     A ground voltage VSS of the mobile device  100  may be provided by a ground element (not shown). For example, the aforementioned ground element may be implemented with a ground copper foil, which may be further coupled to a system ground plane (not shown) of the mobile device  100 . 
     The first radiation element  110  may substantially has an equal-width L-shape. Specifically, the first radiation element  110  has a first end  111  and a second end  112 . The first end  111  of the first radiation element  110  is coupled to a signal source  190 . The second end  112  of the first radiation element  110  is an open end. For example, the signal source  190  may be an RF (Radio Frequency) module. 
     The second radiation element  120  may substantially has a variable-width L-shape. Specifically, the second radiation element  120  has a first end  121  and a second end  122 . The first end  121  of the second radiation element  120  is coupled to the ground voltage VSS. The second end  122  of the second radiation element  120  is an open end. The second end  122  of the second radiation element  120  and the second end  112  of the first radiation element  110  may substantially extend in the same direction. In some embodiments, the second radiation element  120  includes a wide portion  124  and a narrow portion  125 . The wide portion  124  is adjacent to the first end  121  of the second radiation element  120 . The narrow portion  125  is adjacent to the second end  122  of the second radiation element  120 . It should be noted that the term “adjacent” or “close” over the disclosure means that the distance (the space) between two corresponding elements is smaller than a predetermined distance (e.g., 5 mm or shorter), or means that the two corresponding elements are touching each other directly (i.e., the aforementioned distance or space therebetween is reduced to 0). That is, the wide portion  124  of the second radiation element  120  is coupled to the ground voltage VSS. The second radiation element  120  is adjacent to the first radiation element  110 , such that a first coupling gap GC 1  is formed between the narrow portion  125  of the second radiation element  120  and the first radiation element  110 . 
     The third radiation element  130  may substantially have a straight-line shape, which may be at least partially parallel to the first radiation element  110 . Specifically, the third radiation element  130  has a first end  131  and a second end  132 . The first end  131  of the third radiation element  130  is coupled to the signal source  190 . The second end  132  of the third radiation element  130  is an open end. The second end  132  of the third radiation element  130  and the second end  112  of the first radiation element  110  may substantially extend in the same direction. 
     The fourth radiation element  140  may substantially have a rectangular shape, and it may be disposed between the first radiation element  110  and the second radiation element  120 . Specifically, the fourth radiation element  140  has a first end  141  and a second end  142 . The first end  141  of the fourth radiation element  140  is coupled to the ground voltage VSS. The second end  142  of the fourth radiation element  140  is an open end, which extends toward the narrow portion  125  of the second radiation element  120 . A second coupling gap GC 2  may be formed between the fourth radiation element  140  and the first radiation element  110 . A third coupling gap GC 3  may be formed between the fourth radiation element  140  and the narrow portion  124  of the second radiation element  120 . 
     The fifth radiation element  150  may substantially have an equal-width or variable-width L-shape. Specifically, the fifth radiation element  150  has a first end  151  and a second end  152 . The first end  151  of the fifth radiation element  150  is coupled to the ground voltage VSS. The second end  152  of the fifth radiation element  150  is an open end. The second end  152  of the fifth radiation element  150  and the second end  122  of the second radiation element  120  may substantially extend in opposite directions and away from each other. In some embodiments, the fifth radiation element  150  includes a first portion  154  and a second portion  155 . The first portion  154  is adjacent to the first end  151  of the fifth radiation element  150 . The second portion  155  is adjacent to the second end  152  of the fifth radiation element  150 . The fifth radiation element  150  is adjacent to the second radiation element  120 , such that a fourth coupling gap GC 4  may be formed between the first portion  154  of the fifth radiation element  150  and the wide portion  124  of the second radiation element  120 . 
     The dielectric substrate  170  may be an FR4 (Flame Retardant 4) substrate, a PCB (Printed Circuit Board), or an FCB (Flexible Circuit Board). The first radiation element  110 , the second radiation element  120 , the third radiation element  130 , the fourth radiation element  140 , and the fifth radiation element  150  may all be disposed on the same surface of the dielectric substrate  170 . In a preferred embodiment, a planar antenna structure  180  is formed by the first radiation element  110 , the second radiation element  120 , the third radiation element  130 , the fourth radiation element  140 , the fifth radiation element  150 , and the dielectric substrate  170 . 
       FIG. 2  is a diagram of return loss of the antenna structure  180  of the mobile device  100  according to an embodiment of the invention. The horizontal axis represents the operation frequency (MHz), and the vertical axis represents the return loss (dB). According to the measurement of  FIG. 2 , when being excited by the signal source  190 , the antenna structure  180  of the mobile device  100  can cover a first frequency band FB 1 , a second frequency band FB 2 , and a third frequency band FB 3 . The first frequency band FB 1  may be from 2400 MHz to 2500 MHz. The second frequency band FB 2  may be from 5150 MHz to 5850 MHz. The third frequency band FB 3  may be from 5925 MHz to 7125 MHz. Therefore, the antenna structure  180  of the mobile device  100  can support at least the wideband operations of conventional WLAN (Wireless Local Area Network) 2.4 GHz/5 GHz and the next-generation Wi-Fi 6e. 
     With respect to the antenna theory, the first radiation element  110  is excited to generate the second frequency band FB 2 . The second radiation element  120  is excited by the first radiation element  110  using a coupling mechanism, so as to generate the first frequency band FB 1 . The third radiation element  130  is excited to generate the third frequency band FB 3 . The fourth radiation element  140  is configured to fine-tune the impedance matching of the second frequency band FB 2  and the third frequency band FB 3 . The fifth radiation element  150  is configured to fine-tune the impedance matching of the first frequency band FB 1 . 
       FIG. 3  is a diagram of radiation gain of the antenna structure  180  of the mobile device  100  according to an embodiment of the invention. The horizontal axis represents the operation frequency (MHz), and the vertical axis represents the radiation gain (dB). According to the measurement of  FIG. 3 , the radiation gain of the antenna structure  180  of the mobile device  100  can reach at least about −6 dB or higher within the first frequency band FB 1 , the second frequency band FB 2 , and the third frequency band FB 3 . It can meet the requirements of practical application of the next-generation Wi-Fi communication system. 
     In some embodiments, the element sizes of the mobile device  100  are described as follows. The length L 1  of the first radiation element  110  may be substantially equal to 0.25 wavelength (λ/4) of the second frequency band FB 2  of the antenna structure  180  of the mobile device  100 . The length L 2  of the second radiation element  120  may be substantially equal to 0.25 wavelength (λ/4) of the first frequency band FB 1  of the antenna structure  180  of the mobile device  100 . In the second radiation element  120 , the width W 21  of the wide portion  124  may be greater than or equal to 8 mm, and the width W 22  of the narrow portion  125  may be from 2 mm to 3 mm. The length L 3  of the third radiation element  130  may be substantially equal to 0.25 wavelength (λ/4) of the third frequency band FB 3  of the antenna structure  180  of the mobile device  100 . The length L 4  of the fourth radiation element  140  may be from 4 mm to 5 mm. The width W 4  of the fourth radiation element  140  may be from 2 mm to 3 mm. The length L 5  of the fifth radiation element  150  may be longer than or equal to 10 mm. In the fifth radiation element  150 , the width W 51  of the first portion  154  may be from 2 mm to 4 mm, and the width W 52  of the second portion  155  may be from 1 mm to 3 mm. The width of the first coupling gap GC 1  may be smaller than or equal to 1 mm. The width of the second coupling gap GC 2  may be smaller than or equal to 1 mm. The width of the third coupling gap GC 3  may be smaller than or equal to 1 mm. The width of the fourth coupling gap GC 4  may be smaller than or equal to 1 mm. The above ranges of element sizes are calculated and obtained according to many experiment results, and they help to optimize the operation bandwidth and impedance matching of the antenna structure  180  of the mobile device  100 . 
       FIG. 4  is a view of a notebook computer  400  according to an embodiment of the invention. In the embodiment of  FIG. 4 , the aforementioned antenna structure  180  is applied to the notebook computer  400  which includes an upper cover housing  410 , a display frame  420 , a keyboard frame  430 , and a base housing  440 . It should be understood that the upper cover housing  410 , the display frame  420 , the keyboard frame  430 , and the base housing  440  are equivalent to the so-called “A-component”, “B-component”, “C-component”, and “D-component” in the field of notebook computers, respectively. The antenna structure  180  may be disposed at a first position  451 , a second position  452  and/or a third position  453  of the notebook computer  400 . The antenna structure  180  may be covered by the nonconductive keyboard frame  430 . The keyboard frame  430  can be considered as an antenna window of the notebook computer  400 . The electromagnetic waves of the antenna structure  180  can be transmitted through the keyboard frame  430 . 
       FIG. 5  is a partial sectional view of the notebook computer  400  according to an embodiment of the invention. In the embodiment of  FIG. 5 , the base housing  440  includes a parallel region  445  and a cutting retraction region  446 . The parallel region  445  may be substantially parallel to the keyboard frame  430 . One side of the cutting retraction region  446  may be coupled to the parallel region  445 , and the other side of the cutting retraction region  446  may be coupled to an edge of the keyboard frame  430 . Specifically, the base housing  440  has a structural bending portion  447 , which is positioned between the parallel region  445  and the cutting retraction region  446  and. Thus, the extension plane of the parallel region  445  is different from that of the cutting retraction region  446 . There is a first average distance DA 1  between the keyboard frame  430  and the parallel region  445 . There is a second average distance DA 2  between the keyboard frame  430  and the cutting retraction region  446 . The second average distance DA 2  is shorter than the first average distance DA 1 . For example, the second average distance DA 2  may be substantially a half of the first average distance DA 1 . In some embodiments, the keyboard frame  430  is positioned on a first plane E 1 , and the parallel region  445  of the base housing  440  is positioned on a second plane E 2  which is parallel to the first plane E 1 . 
     It should be noted that the antenna structure  180  is disposed between the keyboard frame  430  and the base housing  440 . The antenna structure  180  has a vertical projection T 1  on the base housing  440 , and the vertical projection T 1  is at least partially inside the cutting retraction region  446  of the base housing  440 . According to practical measurements, if the width W 21  of the wide portion  124  of the second radiation element  120  is 8 mm or longer, the radiation efficiency of the antenna structure  180  will not be affected by the close design of the cutting retraction region  446  of the base housing  440 . Therefore, the antenna structure  180  of the invention can maintain good communication quality even if the whole base housing  440  is made of a metal material. 
     The invention proposes a mobile device and a novel antenna structure therein. In comparison to the conventional design, the invention has at least the advantages of small size, wide bandwidth, and beautiful device appearance, and therefore it is suitable for application in a variety of mobile communication devices. 
     Note that the above element sizes, element shapes, and frequency ranges are not limitations of the invention. An antenna designer can fine-tune these settings or values according to different requirements. It should be understood that the mobile device and antenna structure of the invention are not limited to the configurations of  FIGS. 1-5 . The invention may merely include any one or more features of any one or more embodiments of  FIGS. 1-5 . In other words, not all of the features displayed in the figures should be implemented in the mobile device and antenna structure of the invention. 
     Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having the same name (but for use of the ordinal term) to distinguish the claim elements. 
     While the invention has been described by way of example and in terms of the preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.