Patent Grant
7292194
1. Field of the Invention
The present invention relates generally to an antenna, and more particularly to an inverted-F antenna used in a portable electronic device.
2. Description of the Prior Art
With the development of wireless communication, more and more portable electronic devices, for example notebook, install an antenna system for working in a Wireless Local-area Network (WLAN). Transmitting and receiving signals plays an important role in wireless communication process. In recent years, a majority of WLAN base on Bluetooth technical standard or 802.11 technical standard. Antenna according to Bluetooth technical standard is based on 2.4 GHz frequency band, and according to 802.11 technical standard is based on 2.4 GHz and 5 GHz. So, antennas in notebook mostly work in the above frequency bands at the present time.
However, an antenna used in a notebook or other portable electronic devices is very prone to be affected by environment. Same antenna used in different notebooks or other portable electric devices may have different performance function and effect because of the different environments. So, an antenna may work well in one notebook but cannot work well in another notebook unless necessary modulations are made to the antenna.
Usually, manufacture can alter length and breadth of radiating portion of an antenna made from a metal patch or make little change in impedance matching portion to suit different portable electric devices. However, such settlement means increases complex degree of making an antenna and goes against industrialization manufacture.
Hence, in this art, an inverted-F antenna to overcome the above-mentioned disadvantages of the prior art will be described in detail in the following embodiment.
A primary object, therefore, of the present invention is to provide an antenna assembly which is capable of modulating impedance.
A second object, therefore, of the present invention is to provide a method of modulating impedance of above antenna.
In order to implement the above object and overcomes the above-identified deficiencies in the prior art, an inverted-F antenna in accordance with the present invention forming in a metal patch, comprises a radiating element, a grounding element, and a impedance matching element with a impedance matching space. The impedance matching element connects the radiating element and the grounding element. A metal foil locates in the impedance matching space and connects to the impedance matching element.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings.
Reference will now be made in detail to a preferred embodiment of the present invention.
Referring to
Referring to
The radiating element 2 comprises a first radiating section 20 extending in a longitudinal direction, a second radiating section 21 extending in a direction opposite to that of the first radiating section 20, and a third radiating section 22 arranged below the first, second radiating section 20, 21 with parallel relationship to the first and second radiating sections 20, 21. The first radiating section 20 and the second radiating section 21 are connected at a first site (no labeled). The third radiating section 22 connects to the impedance matching element 3 at a second site 9. An upright bar 23 extending from the first site to the second site 9 connects the first, second, and third radiating sections 20, 21, and 22. The impedance matching element 3 comprises a first connecting section 30, a third connecting section 32 parallel to the first connecting section 30, and a vertical second connecting section 31 connecting the first connecting section 30 and the third connecting section 32. The first connecting section 30, the second connecting section 31, and the third connecting section 32 together formed an impedance matching space 8. The impedance matching element 3 shows a lying U shape. The third radiating section 22 extends away from the left end of the first connecting section 30.
The grounding element 5 extends from the third connecting section 32 and locates in a plane perpendicular to the plane in which the impedance matching element 3 and the radiating element 2 locate. The grounding element 5 has a pair of installing sections 51 each comprising a hole and respectively extending perpendicularly from an edge of the grounding element 5 into the plane of the impedance matching element 3 and the radiating element 2.
Referring to
The feeding line 4 comprises an inner conductor 40 electrically connecting to the radiating element 2 and a metal braiding layer 41 electrically connecting to the grounding element 5. The inner conductor 40 is soldered at the second site 9 which is served as the feeding point. The metal shell 6 is of L-shape comprising a vertical section attached to the radiating element 2 and matching element 3 and a horizontal section attached to the grounding element 5.
The first radiating section 20, the third radiating section 22, the impedance matching element 3, the grounding element 5, and the feeding line 4 together form a first inverted-F antenna 11 receiving and transmitting high frequency signals (4.9-5.35 GHz, 5.47-5.87 GHz). The second radiating section 21, the impedance matching element 3, the grounding element 5, and the feeding line 4 together form a second inverted-F antenna 11 receiving and transmitting lower frequency signals (2.4 GHz-2.5 GHz).
The metal foil 7 is attached to the vertical section of the metal shell 6 of the antenna assembly 1 and is located adjacent to the middle post 52, such arrangement of the metal foil 7 aids to be corresponding to the impedance matching space 8 of the antenna 11. The impedance matching element 3 contacts with the metal foil 7 when install the antenna 11 on the metal shell 6. According to different environments of different notebooks, user just needs to choose a suitable metal foil 7 matching the input impedance of the antenna 11. In the preferred embodiment of the present invention, the metal foil 7 is an aluminum foil, but in alternative embodiments, the metal foil 7 is also made from other materials, such as copper foil. In addition, the metal shell 6 maybe a part of a notebook, or a separate member attached with the metal foil 7 to be settled in the notebook.
The method of modulating the impedance of the antenna 11 of the present invention comprises following steps. The first step is to choose a rectangle metal piece. The second step is to calculate qualified lengths of the first radiating section 20, the second radiating section 21, and the third radiating section 22. The third step is to calculate and confirm a length and shape of the impedance matching element 3. The fourth step is to achieve the radiating element 2, the impedance matching element 3 having impedance matching space 8, and the grounding element 5 by digging slots in the rectangle metal piece according to said calculations. The fifth step is to decide the location of the feeding point 9 and provide the feeding line 4 connecting to the second site 9. The sixth step is to choose a metal shell 6 and a metal foil 7 attached to the location of the metal shell 6 corresponding to the impedance matching space 8. The seventh step is to install the antenna 11 on the shell 6 and make the impedance matching element 3 contacting with the metal foil 7.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 94124101 A | Jul 2005 | TW | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6861986 | Fang et al. | Mar 2005 | B2 |
| 7034754 | Hung et al. | Apr 2006 | B2 |
| 20050073462 | Lin et al. | Apr 2005 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20070075902 A1 | Apr 2007 | US |
