Patent Application
20060187128
The present invention relates to an antenna assembly, more particularly to a built-in antenna assembly for use in a foldable mobile phone (generally known as flip cell phone).
Due to rapid innovation in the electronic communication technology, a mobile phone becomes an inevitable instrument in our daily life. Without it, he or she feels loss in touch with his friends and relatives. In order to achieve high reliability in the transmitting and receiving signals, the quality and functionality of the antenna assembly play a major role in the mobile phone. There are generally two types of antenna assembly used in the mobile phone, i.e. built-in antenna assembly (which is generally contained within the casing of the mobile phone) or an exposed type (i.e. the antenna assembly projects outwardly from the casing of the mobile phone). A mobile phone with a built-in antenna assembly is preferred to when compared to ones having an exposed antenna assembly, since the latter may accidentally collides with an object, thereby rendering the ruin of the mobile phone. In addition, the built-in antenna assembly provides more attractive appearance. For aesthetic and portability reasons, the mobile phone is generally constructed in compact size. It is therefore the prime object of the manufacture to improve the functionality of the quality of the antenna assembly in the mobile phone.
When a monopole antenna is used as the built-in antenna assembly in the foldable mobile phone, the antenna assembly provides fine transmitting ability. However, a clear area of the mobile phone may affect the transmitting ability by of the antenna assembly (i.e. The clear area is located under the antenna assembly of the mobile phone without any metal material). When the mobile is in the folded position, the clear area changes, thereby deviating the resonance frequency and causing degradation of the signal transmission bandwidth. Under this condition, the vertical direction of the transmission characteristic of the antenna assembly gets worse.
Referring to
The object of the present invention is to provide a built-in antenna assembly for use in a foldable mobile phone, the antenna assembly has a unique structure to provide the similar characteristic when the mobile phone is the first and second operating modes, i.e. whether the mobile phone is in an unfolded or folded position.
Another object of the present invention is to provide a foldable mobile phone having an antenna assembly which provides the similar characteristic regardless of its positions, i.e. whether the mobile phone is in an unfolded or folded position.
In one aspect of the present invention, an antenna assembly is provided for use in a foldable mobile phone. The mobile phone includes at least one first base board and a switching unit for determining whether the mobile phone is in a first operating mode or a second operating mode. The antenna assembly accordingly includes: a radiating metal strip fabricated on the first base board and having a feeding leg and a short-circuit leg; and a matching circuit fabricated on the first base board and coupled electrically to the short-circuit leg in order to provide impedance matching for the antenna assembly. When the mobile phone is disposed in the first operating mode, the switching unit causes disengagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly to a monopole type antenna, and when the mobile phone is disposed in the second operating mode, the switching unit causes engagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly to an inverted F-type antenna such that either in the first operating mode or the second operating mode, the antenna assembly has similar characteristic by virtue of the impedance matching provided by the matching circuit.
In another aspect of the present invention, a mobile phone is provided to include: a lower member having a first base board; an upper member disposed above the lower member, and having a second base board; a switching unit for determining whether the mobile phone is in a first operating mode or a second operating mode; and an antenna assembly fabricated on the first base board for transmitting and receiving wireless signals. The antenna assembly includes: a radiating metal strip fabricated on the first base board, and having a feeding leg and a short-circuit leg; a matching circuit fabricated on the first base board and coupled electrically to the short-circuit leg in order to provide impedance matching for the antenna assembly, and a signal-processing module for processing outgoing and incoming wireless signals. When the mobile phone is disposed in the first operating mode, the switching unit causes disengagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly to a monopole type antenna. When the mobile phone is disposed in the second operating mode, the switching unit causes engagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly to an inverted F-type antenna such that either in the first operating mode or the second operating mode, the antenna assembly has similar characteristic by virtue of the impedance matching provided by the matching circuit.
In still another object of the present invention, an antenna assembly is provided for use in a mobile phone in order to transmit and receive wireless signals. The mobile phone includes a lower member, an upper member coupled pivotally to the lower member, and a switching unit for determining whether the mobile phone is in a first operating mode or a second operating mode. The antenna assembly includes: a radiating metal strip fabricated on the first base board, and having a feeding leg and a short-circuit leg; and a matching circuit fabricated on the first base board and coupled electrically to the short-circuit leg in order to provide impedance matching for the antenna assembly. When the mobile phone is disposed in the first operating mode, the upper member is spaced apart from the lower member such that the switching unit causes disengagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly to a monopole type antenna. When the mobile phone is disposed in the second operating mode, the upper member abuts against the lower member such that the switching unit causes engagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly to an inverted F-type antenna such that either in the first operating mode or the second operating mode, the antenna assembly has similar characteristic by virtue of the impedance matching provided by the matching circuit.
Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiments of this invention, with reference to the accompanying drawings, in which:
Referring to
In this embodiment, the first base board 220 has a dimension of 40×80 mm2 while the second base board 240 has a dimension slightly smaller than the first base board 220. The switching unit 26 includes a projection 260 projecting outwardly from the cover member 24 and a retention recess 262 formed in the main body 22 such that extension and not extension of the projection 260 with respect to the retention recess 262 can determine the modes (i.e. folded or unfolded position) of the mobile phone of the present invention.
The antenna assembly 30 is fabricated on the first base board 220 for transmitting and receiving wireless signals. The antenna assembly 30 includes a radiating metal strip 32, a matching circuit 34, and a signal-processing module 36. The radiating metal strip 32 is fabricated on an insulated plate 31 by screen-printing technology. The insulated plate 31 has a dimension of 9×13×30 mm3, and is mounted on the first base board 220. Tiny brass strip can serve as the radiating metal strip 32. The radiating metal strip 32 has a feeding leg 320 and a short-circuit leg 322. The feeding leg 320 is used for coupling electrically the signal-processing module 36 in such a manner that the signal-processing module 36 can process the outgoing and incoming radio signals by utilizing the embedded electrical circuits (such as wave-filtering circuit, amplifier circuit). The short-circuit leg 322 has one end coupled to the radiating metal strip 32 and the other end coupled to the matching circuit 34 so that the latter provides an impedance matching for the antenna assembly 30.
The antenna assembly 30 is preferably allotted to a predetermined transmission frequency. The radiating metal strip 32 is constructed in such a manner to have a length equivalent to a quarter of the predetermined transmission frequency. In one embodiment of the present invention, the matching circuit 34 has a π-shaped configuration or T-shaped configuration. As illustrated in
When the mobile phone 20 of the present invention is disposed in the first operating mode (i.e. unfolded position), the switching unit 26 causes disengagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly 30 to a monopole type antenna, and when the mobile phone is disposed in the second operating mode (i.e. folded position), the switching unit 26 causes engagement of the short-circuit leg with respect to the ground, thereby turning the antenna assembly 30 to an inverted F-type antenna. Under this condition, whether the mobile phone 20 of the present invention is in the first operating mode or the second operating mode, the antenna assembly has similar characteristic (such as resonance frequency, bandwidth, the impedance matching of 50 ohms) by virtue of the impedance matching provided by the matching circuit 34.
An important aspect to note is that though the foldable mobile phone is illustrated in the present invention, but the antenna assembly 30 can be employed to several other types of mobile phones. It is therefore hope that scope and spirit of the present invention should encompass other modifications as well.
In summary, by virtue of presence of the antenna assembly 30 in the mobile phone 20 of the present invention, the latter possesses the similar characteristic in the folded and unfolded positions, thereby eliminating the occurrence of accidental collision of the exposed antenna assembly with an object as encountered during use of the conventional mobile phone.
While the invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 94104781 | Feb 2005 | TW | national |
