Patent Application
20050253761
The present invention relates to an antenna assembly, more particularly to a built-in antenna assembly for a wireless telecommunication apparatus, such as a cellular-phone handset.
Due to rapid innovation in the electronic communication technology, dual-band or triple-band mobile cellular phones are available in the market, lately. For a businessman who travels a lot, a mobile phone with dual-band capability is preferred since the mobile phone can switch frequencies once required. In other words, it can operate in dual bands (such as 800-MHz and 1900-MHz). Most users prefer a compact mobile phone to a bulky-size one since the former has high reliability in the signal transmitting and receiving ability. 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. It is therefore the prime object of the manufacture to improve the functionality of the quality of the antenna assembly in the cellular-phone handset.
The aforesaid conventional antenna assembly is generally fabricated in the mobile phone such that the latter possesses a fashion design as far as the external appearance is concerned when compared to those mobile phones having externally-mounted antenna assemblies. The built-in antenna assembly requires lesser assembling steps, thereby shortening the production time of the mobile phone. However, the built-in antenna assembly is said to suffer from insufficient of communication band and impedance matching phenomenon, which, in turn, results in difficulties during the designing process of the built-in antenna assembly.
The object of the present invention is to provide a built-in antenna assembly for use in a mobile phone, the antenna assembly has a unique structure to provide dual-band capability and a compact size.
Another object of the present invention is to provide a built-in antenna assembly which has impedance matching ability to enhance the freedom of matching impedance of the mobile phone.
In one aspect of the present invention, a built-in antenna assembly is provided for use in a mobile phone. The antenna assembly accordingly includes: a base board defining a grounding domain and a dielectric domain; a ground metal layer fabricated on the grounding domain in the base board; a dielectric medium, being a perspective structure, mounted on the dielectric domain in the base board and having an upper surface and at least one lateral surface; a first metal strip including a wave-like strip section mounted on the upper surface of the dielectric medium and having a feed-in end, and a lateral strip section mounted on the lateral surface of the dielectric medium and having a first open end; and a second metal strip fabricated on the lateral surface of the dielectric medium and having a coupling end coupled electrically to the ground metal layer and a second open end. After assembly, the first and second metal strips and the ground metal layer cooperatively form an oscillator by virtue of electromagnetic induction to posses a specific frequency range, thereby permitting transmitting and receiving data signals under multi frequencies within the specific frequency range. The second metal strip is adapted to adjust impedance matching of the antenna assembly.
In another aspect of the present invention, a mobile phone is provided to include: a base board defining a grounding domain and a dielectric domain; a signal processing circuit fabricated on the base board for processing wireless signals; and an antenna assembly. The antenna assembly includes: a dielectric medium, being a perspective structure, mounted on the dielectric domain in the base board and having an upper surface and at least one lateral surface, a first metal strip including a wave-like strip section mounted on the upper surface of the dielectric medium and having a feed-in end coupled electrically to the signal processing circuit for transmitting and receiving the wireless signals, and a second metal strip fabricated on the lateral surface of the dielectric medium, and having a coupling end coupled electrically to the ground metal layer. After assembly, the first and second metal strips and the ground metal layer cooperatively form an oscillator by virtue of electromagnetic induction to have a specific frequency range, thereby permitting transmitting and receiving wireless signals under multi frequencies within the specific frequency range.
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
As illustrated, the base board 22, preferably a printed circuit board, is disposed stationarily and securely within the outer casing (not shown), and has an upper surface defining a dielectric domain 26 and a lower surface opposite to the upper surface and defining a grounding domain 24. The signal processing circuit 25 is fabricated on the upper surface of the base board 22 for processing outgoing and incoming wireless signals, which are received or transmitted through the antenna assembly 23. The antenna assembly 23 has a feeding end 321 coupled electrically to the signal processing circuit 25 so as to permit transmitting and receiving of the processed signals. A detailed structure of the antenna assembly 23 is described in the following paragraph.
Referring to FIGS. 2 to 3B, the antenna assembly 23 includes a ground metal layer 28, a dielectric medium 30, a first metal strip 32, and a second metal strip 34. The ground metal layer 28 is disposed on the grounding domain 24 in the base board 22 for grounding purposes. The dielectric medium 30 is a perspective structure, is mounted on the dielectric domain 26 in the base board 22, and has an upper surface 301 and four lateral surfaces 302, 303, 304, 305 extending downwardly from the upper surface 301. In this embodiment, the dielectric medium 30 is the atmosphere or any substance having a dielectric constant similar to the atmosphere. Alternatively, the dielectric medium 30 can be chosen from a group consisting of ceramic materials, FR-4 and FR-5 standard laminates, and PTFE (polytetrafluoroethylene), since all these substances have the dielectric constant similar to the atmosphere. The first metal strip 32 includes a wave-like strip section 322 that is mounted on the upper surface 301 of the dielectric medium 30 and that has the feed-in end 321 coupled electrically to a matching circuit (not shown) in the base board 22 for transmitting and receiving the wireless signals. The first metal strip 32 further includes a lateral strip section 323 that is mounted on the lateral surfaces 302, 303 of the dielectric medium 30 and that a first open end 324. The wave-like strip section 322 of the first metal strip 32 has a saw configuration when viewed from a lateral side thereof (see
The aforesaid antenna assembly 23 is generally used in the mobile phone of GSM (Global system for Mobile communication) and DCS (Digital Communication System) standards such that the handset can be operated within the ranges 880-960 MHz and 1710-1880 MHz. In this embodiment, the first and second metal strips 32, 34 has a dimension of 20×10×8 mm2, the ground metal layer 28 has a dimension of 40×80 mm2, while the dielectric medium 30 has a thickness of 8 mm. The feed-in end 321 may have a length of 2 mm.
In summary, the antenna assembly employed in the mobile phone of the present invention provides the following advantages over the conventional techniques:
(1) The antenna assembly 23 is fabricated on the main board of the wireless telecommunication apparatus. It is a built-in type and therefore eliminates the assembly steps;
(2) The antenna assembly 23 is formed by bending the tiny metal strip into different configuration, thereby minimizing the size of the antenna assembly, which, in return, provides a larger space for mounting of the other components on the base board to increase the functionality of the handset equipped with the antenna assembly.
(3) By making a proper adjustment between the tiny metal strip and the ground metal layer, the impedance matching ability of the antenna assembly is enhanced, thereby lowering the difficulties encountered in the impedance matching operation.
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 |
|---|---|---|---|
| 93113601 | May 2004 | TW | national |
