Mobile device

A mobile device includes a first nonconductive support member, a second nonconductive support member adjacent to, and lower than, the first nonconductive supporting member, and an antenna structure that includes a first radiating portion disposed on the first nonconductive support member, a second radiating portion disposed on the first nonconductive support member and extending in a direction opposite to the first radiating portion, a feeding element, and a connecting portion disposed on the first nonconductive support member and the second nonconductive support member that couples the first radiating portion and the second radiating portion to each other and to the feeding element, wherein the first nonconductive support member is part of a visible outside edge portion of the mobile device.

This application claims the benefit of Taiwan Application Serial No. 107110286, filed Mar. 26, 2018, the subject matter of which is incorporated herein by reference.

TECHNICAL FIELD

Embodiments of the present invention are directed to an antenna for a mobile device.

BACKGROUND

As mobile communication technology has continued to develop, mobile devices have become increasingly popular. Such devices include, for example, portable computers, mobile phones, multimedia players, and other hybrid portable electronic devices. In order to meet popular demand, mobile devices are configured for wireless communication. Some wireless communication configurations provide long-range coverage, while other wireless communication configurations provide short-range coverage. Example long-range communication coverage configurations include mobile phones that use 2G, 3G, and Long Term Evolution (LTE) systems in the 700 MHz, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, 2100 MHz, 2300 MHz, and 2500 MHz bands. Example short-range communication coverage configurations include Wi-Fi and Bluetooth systems that use the 2.4 GHz, 5.2 GHz, and 5.8 GHz frequency bands.

To achieve aesthetically pleasing mobile devices, designers often incorporate metal components including, e.g., metal case components. However, such metal components can detrimentally impact an antenna supporting wireless communication in the aforesaid bands, thereby reducing the overall communication performance of the mobile device. It is therefore desirable to provide a mobile device and associated antenna structure that addresses problems related to metal components incorporated in mobile device designs.

SUMMARY

In one embodiment there is provided a mobile device including a first nonconductive support member, a second nonconductive support member adjacent to, and lower than, the first nonconductive supporting member, and an antenna structure that includes a first radiating portion disposed on the first nonconductive support member, a second radiating portion disposed on the first nonconductive support member and extending in a direction opposite to the first radiating portion, a feeding element, and a connecting portion disposed on the first nonconductive support member and the second nonconductive support member that couples the first radiating portion and the second radiating portion to each other and to the feeding element, wherein the first nonconductive support member is part of a visible outside edge portion of the mobile device.

In an embodiment, the connecting portion comprises a first connecting portion and a second connecting portion, the second connecting portion coupling the first radiating portion and the second radiating portion to each other, and the first connecting portion coupling the feeding element to the second connecting portion. The first connecting portion may be disposed on the first nonconductive support member and the second nonconductive support member, and the second connecting portion is disposed on the first nonconductive support member

The feeding element may be disposed on the second nonconductive support member.

The mobile device may further include a display having a display frame surrounding the display, wherein the display frame is disposed in a notch created by a difference in height between the first nonconductive support member and the second nonconductive support member.

The antenna structure may be configured to resonate at a low frequency band, a first high frequency band and a second high frequency band. The low frequency band may be between 2400 MHz and 2500 MHz, the first high frequency band may be between 5000 MHz and 5300 MHZ, and the second high frequency band may be between 5300 MHz and 5700 MHz.

In an embodiment, the mobile device is a laptop computer.

A stripe-like gap may be created between the first radiating portion and at least a portion of the feeding element.

The mobile device may further include a coaxial cable having an inner conductor and an outer conductor, the inner conductor couple to a feed point of the feeding element, and the outer conductor couple to a ground plane of the mobile device.

DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1Ais a plan view of a portion of a mobile device according to an embodiment of the present invention andFIG. 1Bis a side view of a portion of the mobile device according to an embodiment of the present invention, and reference is made to both of these figures in the following description.

As noted, a mobile device100may be, e.g., a smart phone, a notebook computer, or a notebook computer. As shown inFIGS. 1A and 1B, the mobile device100at least includes: a first nonconductive support member110, a second nonconductive support member120, and an antenna structure130. Those skilled in the art will appreciate that, although not shown inFIGS. 1A and 1B, the mobile device100may further include other components such as a display device, a speaker, a touch control module, a power supply module and a housing.

The first nonconductive support member110and the second nonconductive support member120may be made of, e.g., a plastic material. In one embodiment, the first nonconductive support member110may form part of an “appearance edge portion” of the mobile device100, i.e., a visible outside edge portion of the mobile device100that a user can directly observe with his/her eye. The second nonconductive support member120may be an antenna placement platform or a display placement platform, on which an antenna structure or a display can be disposed.

The first nonconductive support member110and the second nonconductive support member120are adjacent to each other and have different heights in the Z-axis. For example, the height H1of the first nonconductive support member110may be greater than the height H2of the second nonconductive support member120. In one possible embodiment, height H1may be more than twice the height H2. In the instant description, the word “adjacent” may mean that the distance between two corresponding elements is less than a predetermined distance (for example, 1 mm or less), and may also mean that the two corresponding elements are in direct contact with each other.

In addition, the first nonconductive support member110and the second nonconductive support member120may have different widths on the Y-axis. For example, the width W1of the first nonconductive support member110may be smaller than the width W2of the second nonconductive support member120.

Those skilled in the art will appreciate that the shapes of the first nonconductive support member110and the second nonconductive support member120are not limited to the shapes depicted in the figures, but can be modified according to different needs.

The antenna structure130may be made of a metal material, and may be configured as follows. The antenna structure130includes a feeding element140, a first connecting portion150, a second connecting portion160, a first radiating portion170, and a second radiating portion180. The antenna structure130has a three-dimensional structure and is formed on the first nonconductive support member110and the second nonconductive support member120having the aforementioned height difference. For example, the second connecting portion160, the first radiating portion170, and the second radiating portion180may be distributed only on the first nonconductive support member110, the feeding element140may be only distributed on the second nonconductive support member120, and the first connecting portion150may be distributed on the first nonconductive support element110and the second nonconductive support element120at the same time.

In some embodiments, a metal-free region190is formed between one edge111of the first nonconductive support member110and one of the second connecting element160, the first radiating portion170, and the second radiating portion180. The metal-free region190may be formed as an elongated rectangle having an equal width W3.

The feeding element140may substantially assume an L-shape. The feeding element140has a first end141and a second end142. The first end141of the feeding element140is coupled to a feeding point FP. A signal source (not shown) may be coupled to the feeding point FP. The first connecting portion150may substantially assume a rectangular shape, and the second connecting portion160may also substantially assume another rectangular shape. The width W4of the first connecting portion150may be greater than the width W5of the second connecting portion160. The first connecting portion150is coupled to the second end142of the feeding element140. The second connecting portion160is coupled to the first connecting portion150. Both the first connecting portion150and the second connecting portion160are substantially between the first radiating portion170and the second radiating portion180.

The first radiating portion170may substantially have a straight stripe or bar shape. The first radiating portion170has a first end171and a second end172. The first end171of the first radiating portion170is coupled to the feeding element140via the second connecting portion160and the first connecting portion150. The second end172of the first radiating portion170is an open end. A gap G1may be formed between the first radiating portion170and the feeding element140, which may substantially assume an elongated straight stripe, or rectangular, shape. The second radiating portion180may substantially assume another straight stripe shape. The second radiating portion180has a first end181and a second end182. The first end181of the second radiating portion180is coupled to the feeding element140through the second connecting portion160and the first connecting portion150. The second end182of the second radiating portion180is an open end. The length L2of the second radiating portion180is shorter than the length L1of the first radiating portion170. The width of each of the first radiating portion170and the second radiating portion180may be the same as the width W5of the second connecting portion160. The second end172of the first radiating portion170and the second end182of the second radiating portion180may extend in different or opposite directions. For example, the second end172of the first radiating portion170may extend in the +X axis direction, and the second end182of the second radiating portion180may extend in the −X axis direction.

In some embodiments, the mobile device100is a convertible mobile device and is operable in either a notebook mode or a tablet mode. While operating in either the notebook mode or the tablet mode, the antenna structure130of the mobile device100can have similar operating performance as described below.

FIG. 2is a graph showing return loss of the antenna structure depicted inFIGS. 1A and 1Bwhen the mobile device operates in the notebook mode according to an embodiment of the present invention, andFIG. 3is a graph showing return loss of the antenna structure depicted inFIGS. 1A and 1Bwhen the mobile device operates in the tablet mode according to an embodiment of the present invention.

Referring toFIGS. 2 and 3, the horizontal axis represents operating frequency (MHz) and the vertical axis represents return loss (dB). According to measurement results shown inFIGS. 2 and 3, the antenna structure130can cover a low frequency band FBL, a first high frequency band FBH1, and a second high frequency band FBH2. The low frequency band FBL is between 2400 MHz and 2500 MHz, the first high frequency band FBH1is between 5000 MHz and 5300 MHz, and the second high frequency band FBH2is between 5300 MHz and 5750 MHz. Therefore, the antenna structure130can support at least wireless local area network (WLAN) 2.4 GHz/5 GHz dual band operation.

FIG. 4is a graph of antenna efficiency of the antenna structure depicted inFIGS. 1A and 1Baccording to the present invention. In the figure, the horizontal axis represents operating frequency (MHz) and the vertical axis represents antenna efficiency (dB). In addition, a first curve CC1represents the characteristics of the antenna structure130when the mobile device100operates in the notebook mode, and a second curve CC2represents the characteristics of the antenna structure130when the mobile device100operates in the tablet mode. As shown inFIG. 4, the antenna efficiency of the antenna structure130in the low-frequency band FBL may be about −4.5 dB, and the antenna efficiency in the first high-frequency band FBH1and the second high-frequency band FBH2may be about −5 dB. Such performance meets the practical application requirements of general mobile communication devices in the several bands discussed herein.

The principle of antenna operation of the mobile device100may be described as follows. The feeding element140, the first connecting portion150, the second connecting portion160, and the first radiating portion170can jointly excite a fundamental resonant mode to form the aforementioned low frequency band FBL. The feeding element140, the first connecting portion150, the second connecting portion160, and the first radiating portion170can further jointly generate a higher-order resonant mode to form the aforementioned first high-frequency band FBH1(two times the low frequency). The feeding element140and the first connecting portion150may jointly excite and generate a resonant mode to form the aforementioned second high frequency band FBH2. A combination of the first connecting portion150and the second connecting portion160can be used to fine tune the low frequency band FBL, the first high frequency band FBH1, and impedance matching for the second high frequency band FBH2to simultaneously increase the antenna structure130's high and low frequency bandwidth. Further, the combination of one of the second connecting portion160and the second radiating portion180can be used to fine tune the impedance matching for the first high frequency band FBH1and the second high frequency band FBH2to increase the high frequency bandwidth of the antenna structure130.

In one implementation, the size of the components of the mobile device100are as follows. A total radiation length may be defined as including the feeding element140, the first connecting portion150, the second connecting portion160, and the first radiating portion170(i.e., from the first end141, past the second end142, the first connecting portion150, and the second connecting portion160). The total length of the connecting portion160, the first end171, and the second end172may be substantially equal to 0.5 wavelength (λ/2) of the low-frequency band FBL. The total length of the feeding element140and the first connecting portion150(i.e., the total length from the first end141, the second end142, and the junction of the first connecting portion150and the second connecting portion160) may be approximately equal to 0.5 wavelength (λ/2) of the second high-frequency band FBH2.

The height H1of the first nonconductive support member110may be about 3 mm. The height H2of the second nonconductive support member120may be between 1.2 mm and 1.4 mm, inclusive. The width W1of the first nonconductive support member110may be about 2 mm. The width W2of the second nonconductive support member120may be about 4.5 mm. The width W3of the metal-free region190may be between 1 mm and 1.2 mm, inclusive. The length L1of the first radiating portion170may be approximately four times the length L2of the second radiating portion180. The length L3of each of the first connecting portion150and the second connecting portion160may be between 3 mm and 5 mm, inclusive. The total width (W4+W5) of the first connecting portion150and the second connection portion160may be between 3 mm and 4 mm, inclusive. The width of the gap G1may be between 1 mm and 2 mm, inclusive.

In the mobile device100of the present invention, the antenna structure130can serve as a hidden antenna. That is, the antenna structure130can be integrated with the appearance edge portion of the mobile device100(e.g., the first nonconductive support member110may correspond to the “thickness” side of the mobile device100). As will be seen with reference toFIG. 5A, the height difference between the first nonconductive support member110and the second nonconductive support member120achieves the purpose of hidden design. In addition, the edge portion of the mobile device100and the antenna structure130may further be treated with a spray and coat process to reduce the visual difference between the non-metal and metal portions to mask any difference in appearance.

It is noted that the metal-free region190on the first nonconductive support member110may be reserved for use in adhering (or gluing) an appearance mechanism element of the mobile device100. In such a design, the total width of the antenna structure130on the Y axis and the total height on the Z axis can be effectively reduced, so that desired miniaturization of the mobile device100can be achieved. The disclosed antenna structure130has good impedance matching and no additional antenna placement platform is needed. As such, the present invention can reduce manufacturing costs in connection with radio frequency (RF) and electromagnetic compatibility (EMC) solutions. At the same time, the overall weight of the mobile device100may be reduced.

FIG. 5Ais a side view of another configuration of the mobile device according to an embodiment of the present invention.FIG. 5Ais similar toFIG. 1B. In the embodiment shown inFIG. 5A, a mobile device500further includes a display device510, a display frame520, a coaxial cable540, and a metal back cover550, and metal foil560.

FIG. 5Bis a plan view of a portion of the mobile device according to another embodiment of the present invention. To avoid visual masking, only the first nonconductive support member110, the second nonconductive support member120, the antenna structure130, and the coaxial cable540are shown.

In the embodiments ofFIGS. 5A and 5B, the mobile device500is a notebook computer, and the metal back cover550and the display frame520respectively refer to a “piece A” and a “piece B” of the notebook computer. The display frame520may be made of a non-conductive material, such as a plastic. Display frame520is adjacent display510and may surround each of four edges of the display510. More specifically, the display frame520extends into a height-difference notch530defined by the first nonconductive support member110and the second nonconductive support member120. Since the display frame520is non-conducting, it can be directly attached to the first nonconductive support member110and the antenna structure130to improve overall structural stability, and does not adversely affect the radiation pattern of the antenna structure130. The display510, itself, may not be suitable for direct contact with the antenna structure130as it typically includes metal components.

A source (not shown) may be coupled to the feed point FP via coaxial cable540to excite antenna structure130. Coaxial cable540includes a center conductor541and a conductive sheath542. The center conductor541of the coaxial cable540is coupled to the feed point FP. Conductive sheath542of coaxial cable540is coupled to metal back cover550via metal foil560. It is noted that the coaxial cable540is disposed between the display510and the second non-conducting support member120and is adjacent the metal back cover550. Such a design can hide the coaxial cable540in the internal space of the mobile device500, so as to avoid interference of the coaxial cable540with the antenna structure130and other elements of the mobile device500. The metal foil560can be a grounded copper foil, which can be attached to the conductor housing542of the coaxial cable540and extend to the metal back cover550. The metal back cover550is adjacent the first nonconductive support member110, the second nonconductive support member120, the antenna structure130, and the display510, so that the metal back cover550can be considered as a ground plane of the antenna structure130. In this design, the metal back cover550does not interfere with the radiation pattern of the antenna structure130, but can further enhance the radiation efficiency of the antenna structure130.

Thus, the present invention proposes a novel mobile device that includes a hidden antenna structure. Such an antenna structure can be integrated with the metal back cover (piece A) or the display frame (piece B), and can effectively utilize the space of the appearance edge portion of the mobile device and its adjacent portion. In general, the present invention has at least a small size, a wide frequency band, a reduced manufacturing cost, reduced overall weight, and an aesthetically pleasing appearance for a mobile device, and is therefore very suitable for use in a variety of narrow-frame (thin) mobile communication devices.

The above description is intended by way of example only.