Patent Description:
With the advancements being made in mobile communication technology, mobile devices have become more common.

<CIT> describes an antenna apparatus with a dielectric substrate, a feed point, a first radiation conductor, a second radiation conductor, and a through-hole conductor.

<CIT> describes a dual-band inverted-F antenna with shorted parasitic elements.

<CIT> describes wireless communication systems based on multi-frequency antennas each operating at different frequency bands for wireless communications, including multi-frequency antennas based on metamaterial structures.

<CIT> describes an antenna structure placed next to a pivot structure of the mobile device and a parasitic element placed next to a high-frequency radiation element extending from a feeding element, so as to resonate with the high-frequency radiation element to generate a resonant mode for compensating the lack of a high-frequency bandwidth.

<CIT> relates to a mobile device. The mobile device includes a body, an antenna structure, and a floating radiation element.

Antennas are indispensable elements of mobile devices that support wireless communication. However, antennas tend to be affected by nearby metal elements. Thus, antenna elements may experience interference, and overall communication quality may suffer as a result. Alternatively, the SAR (Specific Absorption Rate) may be too high to meet legal requirements. Accordingly, there is a need to propose a novel solution for solving the problems of the prior art.

In an exemplary embodiment, the disclosure is directed to a mobile device that includes a main radiation element, a parasitic radiation element, and an additional radiation element. The main radiation element has a first notch. The main radiation element includes a feeding region coupled to a signal source, and a grounding region coupled to a ground voltage. The parasitic radiation element is coupled to the ground voltage. The parasitic radiation element is adjacent to the feeding region. The additional radiation element is coupled to the main radiation element. The additional radiation element and the parasitic radiation element substantially extend in the same direction. An antenna structure is formed by the main radiation element, the parasitic radiation element, and the additional radiation element.

The main radiation element substantially has a rectangular shape with a first corner, a second corner, a third corner and a fourth corner. The feeding region is positioned at the first corner. The additional radiation element is coupled to the second corner.

In some embodiments, the parasitic radiation element substantially has an L-shape.

In some embodiments, the additional radiation element substantially has a straight-line shape.

In some embodiments, the first notch of the main radiation element is positioned between the second corner and the third corner. The main radiation element further has a second notch which is adjacent to the fourth corner.

In some embodiments, a coupling gap is formed between the parasitic radiation element and the main radiation element. The width of the coupling gap is shorter than or equal to <NUM>.

In some embodiments, the distance between the additional radiation element and the parasitic radiation element is longer than or equal to <NUM>.

The antenna structure covers a first frequency band from <NUM> to <NUM>, a second frequency band from <NUM> to <NUM>, and a third frequency band from <NUM> to <NUM>.

In some embodiments, the length of the parasitic radiation element is substantially equal to <NUM> wavelength of the third frequency band.

In some embodiments, the mobile device includes a metal back cover and a keyboard frame. The metal back cover includes a cutting retraction region. The antenna structure is disposed between the keyboard frame and the metal back cover. The antenna structure has a vertical projection on the metal back cover, and the whole vertical projection is inside the cutting retraction region.

The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:.

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 openended 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> is a top view of a mobile device <NUM>. The mobile device of <FIG> lacks the second notch of the independent claim. Nevertheless, the mobile device of <FIG> is useful for the understanding of the invention.

For example, the mobile device <NUM> may be a smartphone, a tablet computer, or a notebook computer. As shown in <FIG>, the mobile device <NUM> at least includes a main radiation element <NUM>, a parasitic radiation element <NUM>, and an additional radiation element <NUM>. The main radiation element <NUM>, the parasitic radiation element <NUM>, and the additional radiation element <NUM> may all be made of metal materials, such as copper, silver, aluminum, iron, or their alloys. It should be understood that the mobile device <NUM> may further include other components, such as a display device, a speaker, a touch control module, a power supply module, and/or a housing, although they are not displayed in <FIG>.

The main radiation element <NUM> may substantially have a rectangular shape with a first corner <NUM>, a second corner <NUM>, a third corner <NUM>, and a fourth corner <NUM>. The main radiation element <NUM> includes a feeding region <NUM> coupled to a signal source <NUM>, and a grounding region <NUM> coupled to a ground voltage VSS. The signal source <NUM> may be an RF (Radio Frequency) module. The ground voltage VSS may be provided by a system ground plane (not shown). The feeding region <NUM> may be positioned at the first corner <NUM> of the main radiation element <NUM>. In addition, the main radiation element <NUM> has a first notch <NUM>, which may substantially have a square shape or a small rectangular shape. In some embodiments, the first notch <NUM> of the main radiation element <NUM> is positioned between the second corner <NUM> and the third corner <NUM> (e.g., it is substantially positioned at the central point between the second corner <NUM> and the third corner <NUM>).

The parasitic radiation element <NUM> may substantially have an L-shape. In some embodiments, the parasitic radiation element <NUM> is independent of the main radiation element <NUM>. The parasitic radiation element <NUM> is adjacent to the feeding region <NUM> of the main radiation element <NUM>. A coupling gap GC1 may be formed between the parasitic radiation element <NUM> and the feeding region <NUM> of the main radiation element <NUM>. It should be noted that the term "adjacent" or "close" over the disclosure means that the distance (spacing) between two corresponding elements is smaller than a predetermined distance (e.g., <NUM> or shorter), or means that the two corresponding elements directly touch each other (i.e., the aforementioned distance/spacing therebetween is reduced to <NUM>). Specifically, the parasitic radiation element <NUM> has a first end <NUM> and a second end <NUM>. The first end <NUM> of the parasitic radiation element <NUM> is coupled to the ground voltage VSS. The second end <NUM> of the parasitic radiation element <NUM> is an open end, which extends away from the main radiation element <NUM>. The parasitic radiation element <NUM> is at least partially parallel to the additional radiation element <NUM>.

The additional radiation element <NUM> may substantially have a straight-line shape. Specifically, the additional radiation element <NUM> has a first end <NUM> and a second end <NUM>. The first end <NUM> of the additional radiation element <NUM> is coupled to the second corner <NUM> of the main radiation element <NUM>. The second end <NUM> of the additional radiation element <NUM> is an open end. In some embodiments, the second end <NUM> of the additional radiation element <NUM> and the second end <NUM> of the parasitic radiation element <NUM> substantially extend in the same direction (e.g., both of them may be far away from the main radiation element <NUM>).

In a preferred embodiment, an antenna structure <NUM> is formed by the main radiation element <NUM>, the parasitic radiation element <NUM>, and the additional radiation element <NUM>. The antenna structure <NUM> may be a planar and disposed on the same surface of a dielectric substrate, such as an FR4 (Flame Retardant <NUM>) substrate, a PCB (Printed Circuit Board), or an FCB (Flexible Circuit Board), but it is not limited thereto.

<FIG> is a diagram of return loss of the antenna structure <NUM> of the mobile device <NUM> according to an embodiment of the invention. The horizontal axis represents operation frequency (MHz), and the vertical axis represents the return loss (dB). According to the measurement of <FIG>, the antenna structure <NUM> can cover a first frequency band FB1, a second frequency band FB2, and a third frequency band FB3. For example, the first frequency band FB1 may be from <NUM> to <NUM>, the second frequency band FB2 may be from <NUM> to <NUM>, and the third frequency band FB3 may be from <NUM> to <NUM>. Thus, the antenna structure <NUM> of the mobile device <NUM> can support at least the wideband operations of WLAN (Wireless Local Area Networks) <NUM>/<NUM>.

<FIG> is a top view of a mobile device <NUM> according to another embodiment of the invention. <FIG> is similar to <FIG>. In the embodiment of <FIG>, a main radiation element <NUM> of the mobile device <NUM> has a first notch <NUM> and a second notch <NUM>, and includes a feeding region <NUM> coupled to the signal source <NUM> and a grounding region <NUM> coupled to the ground voltage VSS. The main radiation element <NUM> may substantially have a rectangular shape with a first corner <NUM>, a second corner <NUM>, a third corner <NUM>, and a fourth corner <NUM>. Specifically, the second notch <NUM> of the main radiation element <NUM> may substantially have a thin and long rectangular shape, which is adjacent to the fourth corner <NUM>. The structural features of the parasitic radiation element <NUM> and the additional radiation element <NUM> have been described in the embodiment of <FIG>, and they will not be illustrated again herein. An antenna structure <NUM> is formed by the main radiation element <NUM>, the parasitic radiation element <NUM>, and the additional radiation element <NUM>.

<FIG> is a diagram of return loss of the antenna structure <NUM> of the mobile device <NUM> according to another embodiment of the invention. The horizontal axis represents operation frequency (MHz), and the vertical axis represents the return loss (dB). According to the measurement of <FIG>, the antenna structure <NUM> can also cover the first frequency band FB1, the second frequency band FB2, and the third frequency band FB3 as mentioned above. Thus, the antenna structure <NUM> can also support the wideband operations of WLAN <NUM>/<NUM>. It should be noted that after the second notch <NUM> is added to the main radiation element <NUM>, the impedance matching of the antenna structure <NUM> is significantly improved within the first frequency band FB1.

In some embodiments, the operation principles of the antenna structure <NUM> of the mobile device <NUM> are as follows. A first current path PA1 is formed from the feeding region <NUM> through the second corner <NUM> and the first notch <NUM> to the third corner <NUM>, and it can be excited to generate the first frequency band FB1. A second current path PA2 is formed from the second end <NUM> of the additional radiation element <NUM> through the second corner <NUM> and the first notch <NUM> to the third corner <NUM>, and it can be excited to generate the second frequency band FB2. According to practical measurements, the incorporation of the first notch <NUM> can decrease the central frequency of the second frequency band FB2 (e.g., decreased by about <NUM>), and also increase the design independency between the first frequency band FB1 and the second frequency band FB2. Furthermore, the parasitic radiation element <NUM> can be excited by the main radiation element <NUM> using a coupling mechanism, so as to generate the third frequency band FB3 and increase the operation bandwidth of WLAN <NUM>.

In some embodiments, the element sizes of the antenna structure <NUM> of the mobile device <NUM> are as follows. The length of the first current path PA1 is substantially equal to <NUM> wavelength (λ/<NUM>) of the first frequency band FB1 of the antenna structure <NUM>. The length of the second current path PA2 is substantially equal to <NUM> wavelength (λ/<NUM>) of the second frequency band FB2 of the antenna structure <NUM>. The length L1 of the parasitic radiation element <NUM> may be substantially equal to <NUM> wavelength (λ/<NUM>) of the third frequency band FB3 of the antenna structure <NUM>. The length L2 of the first notch <NUM> of the main radiation element <NUM> is from <NUM> to <NUM>. The width W2 of the first notch <NUM> of the main radiation element <NUM> is from <NUM> to <NUM>. The length L3 of the second notch <NUM> of the main radiation element <NUM> is shorter than or equal to <NUM>. The width W3 of the second notch <NUM> of the main radiation element <NUM> is shorter than or equal to <NUM>. The length L4 of the additional radiation element <NUM> may be shorter than or equal to <NUM> (e.g., from <NUM> to <NUM>). The width W4 of the additional radiation element <NUM> may be greater than the width W1 of the parasitic radiation element <NUM>. For example, the width W4 of the additional radiation element <NUM> may be from <NUM> to <NUM> times the width W1 of the parasitic radiation element <NUM>. The length L5 of the grounding region <NUM> of the main radiation element <NUM> may be from <NUM> to <NUM>. The width of a coupling gap GC2 between the parasitic radiation element <NUM> and the feeding region <NUM> of the main radiation element <NUM> may be shorter than or equal to <NUM>. The distance D1 between the additional radiation element <NUM> and the parasitic radiation element <NUM> may be longer than or equal to <NUM>. The distance D2 between the feeding region <NUM> and the grounding region <NUM> of the main radiation element <NUM> may be from <NUM> to <NUM>. The total length of the antenna structure <NUM> may be about <NUM>. The total width of the antenna structure <NUM> may be about <NUM>. The above ranges of element sizes are calculated and obtained according to many experiment results, and they help to optimize the bandwidth and impedance matching of the antenna structure <NUM>.

For example, the proposed antenna structure <NUM> (or <NUM>) may be applied to a convertible mobile device <NUM>, which includes an upper cover housing <NUM>, a display device <NUM>, a keyboard frame <NUM>, a metal back cover <NUM>, and a hinge element <NUM>. By using the hinge element <NUM>, the convertible mobile device <NUM> can operate in a notebook mode or a tablet mode. It should be understood that the upper cover housing <NUM>, the display device <NUM>, the keyboard frame <NUM>, and the metal back cover <NUM> are equivalent to the so-called "A-component", "B-component", "C-component", and "D-component" in the field of notebook computers. The proposed antenna structure <NUM> (or <NUM>) may be disposed in the space between the keyboard frame <NUM> and the metal back cover <NUM>. It should be noted that the metal back cover <NUM> includes a cutting retraction region <NUM>, so as to make the whole device thin and light. The antenna structure <NUM> (or <NUM>) has a vertical projection on the metal back cover <NUM>, and the whole vertical projection is inside the cutting retraction region <NUM> of the metal back cover <NUM>.

<FIG> is a diagram of the convertible mobile device <NUM> operating in the notebook mode according to an embodiment of the invention. <FIG> is a diagram of the convertible mobile device <NUM> operating in the tablet mode according to an embodiment of the invention. The arrows in <FIG> and <FIG> represent the probing directions of SAR (Specific Absorption Rate) test. According to practical measurements, the antenna structure <NUM> (or <NUM>) of the invention can effectively overcome the negative influence caused by its too short distance to the metal back cover <NUM>, regardless of the mobile device <NUM> operating in the tablet mode or notebook mode. Therefore, the convertible mobile device <NUM> including the antenna structure <NUM> (or <NUM>) can easily pass the SAR test prescribed by laws.

The invention proposes a novel mobile device and a novel antenna structure for covering WLAN frequency bands. Even if the proposed antenna structure is applied to a cutting retraction region of a metal back cover, it can still reduce the original SAR by <NUM>% or more. In comparison to the convention design, the invention has at least the advantages of small size, low SAR, wide bandwidth, and low manufacturing cost, 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 <FIG>. The invention may merely include any one or more features of any one or more embodiments of <FIG>. 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.

Claim 1:
A mobile device (<NUM>), comprising:
a main radiation element (<NUM>), having a first notch (<NUM>) and a second notch (<NUM>), wherein the main radiation element (<NUM>) comprises a feeding region (<NUM>) configured to be coupled to a signal source (<NUM>) and a grounding region (<NUM>) configured to be coupled to a ground voltage (VSS);
a parasitic radiation element (<NUM>), configured to be coupled to the ground voltage (VSS),
wherein the parasitic radiation element (<NUM>) is adjacent to the feeding region (<NUM>); and
an additional radiation element (<NUM>), coupled to the main radiation element (<NUM>), wherein the additional radiation element (<NUM>) and the parasitic radiation element (<NUM>) substantially extend in a same direction; wherein
an antenna structure (<NUM>) is formed by the main radiation element (<NUM>), the parasitic radiation element (<NUM>) and the additional radiation element (<NUM>);
the main radiation element (<NUM>) has a substantially rectangular shape with a first corner (<NUM>), a second corner (<NUM>), a third corner (<NUM>), and a fourth corner (<NUM>);
a first current path (PA1) is formed from the feeding region (<NUM>) through the second corner (<NUM>) and the first notch (<NUM>) to the third corner (<NUM>);
a second current path (PA2) is formed from a second end (<NUM>) of the additional radiation element (<NUM>) through the second corner (<NUM>) and the first notch (<NUM>) to the third corner (<NUM>);
the antenna structure (<NUM>) covers a first frequency band (FB1) from <NUM> to <NUM>, a second frequency band (FB2) from <NUM> to <NUM>, and a third frequency band (FB3) from <NUM> to <NUM>;
a length of the first current path (PA1) is substantially equal to <NUM> wavelength of the first frequency band (FB1);
a length of the second current path (PA2) is substantially equal to <NUM> wavelength of the second frequency band (FB2); and
both the first current path (PA1) and the second current path (PA2) extend around the first notch (<NUM>);
the second notch (<NUM>) is arranged adjacent to the fourth corner (<NUM>);
a length of the first notch (<NUM>) is from <NUM> to <NUM>, and a width of the first notch (<NUM>) is from <NUM> to <NUM>; and
a length of the second notch (<NUM>) is shorter than or equal to <NUM>, and a width of the second notch (<NUM>) is shorter than or equal to <NUM>.