Patent Application
20070085749
This application claims the benefit of Taiwan application Ser. No. 94135944, filed Oct. 14, 2005, the subject matter of which is incorporated herein by reference.
1. Field of the Invention
The invention relates in general to an electronic apparatus, and more particularly to an electronic apparatus having an antenna disposed on a surface of a housing of the apparatus.
2. Description of the Related Art
The efficiency of the conventional electronic apparatus 10 of receiving and transmitting the wireless signal depends on the antenna gain and the return loss of the antenna device 130. The antenna gain is the ratio of the wireless signal before being transmitted to the wireless signal after being received, and the return loss is the ratio of the wireless signal after return to the wireless signal before return.
However, because the antenna device 130 of the conventional electronic apparatus 10 is mounted to the circuit board 120, the antenna device 130 tends to be interfered with other electronic elements, such as capacitors or transformers, in the circuit board 120, and the antenna gain and the return loss of the antenna device 130 tend to be influenced seriously. In general, the antenna gain of the conventional electronic apparatus 10 is usually a negative value, and the specified value of the return loss is usually less than −7 dB.
In addition, if the antenna device 130 is mounted to the circuit board 120, the available layout space in the circuit board 120 is correspondingly decreased and the layout difficulty of the circuit board 120 is also increased.
It is therefore an object of the invention to provide an electronic apparatus having an antenna disposed on a surface of a housing of the apparatus. Disposing the antenna device on the surface of the electronic apparatus increases the available layout space in a circuit board and prevents the antenna device from being interfered with other devices on the circuit board.
The invention achieves the above-identified objects by providing an electronic apparatus including a housing, a circuit board, an antenna device and a feeding device. The circuit board is placed inside the housing. The antenna device disposed on a surface of the housing transmits and receives a wireless signal. The feeding device has one end electrically connected to the circuit board and the other end electrically connected to the antenna device.
Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.
For example, the housing 210 is a plastic housing whose size is 3.5 cm×2 cm×2 cm, and the circuit board 220 is a multi-layer circuit board whose size is 3.5 cm×2 cm. One layer of the circuit board 220 is, capable to be design, a ground plane whose size is 3.5 cm×2 cm. The distance form the antenna device 230 to the ground plane of the circuit board 220 substantially equals 2 cm because the antenna device 230 is disposed on the upper surface 212.
The antenna device 230 may be, for example, a linear polarized antenna or a circular polarized antenna. The antenna device 230 is made of metal and may have various patterns including the patterns of twelve constellations or animal patterns. The antenna device 230 may be plated with a metal layer, such as a gold layer or a silver layer. Alternatively, the antenna device 230 may be covered with a protection film to prevent the device from being scratched, such that the antenna device 230 may have the effects of receiving and transmitting the wireless signal as well as the draping effect.
In addition, the antenna device 230 may also be electrically connected to the feeding device 240 in various ways. For example, the antenna device 230 and the feeding device 240 may be integrally formed, the antenna device 230 may be bonded to one end of the feeding device 240, or one end of the antenna device 230 and one end of the feeding device 24O are fixed together using a screw. Thus, the electronic apparatus 20 can receive and transmit the wireless signal through the antenna device 230.
The electronic apparatus having the antenna device disposed on the surface of the housing according to the embodiment of the invention has the following advantages.
First, the available layout space in the circuit board can be enlarged. Because the antenna device is disposed on the upper surface of the housing, the available layout space in the circuit board is relatively enlarged, and the difficulty of layout on the circuit board can be reduced.
Second, the antenna gain and the return loss are increased. Because the distance from the upper surface to the lower surface is greater than λ/4, the interference of the circuit board with the antenna device is reduced, and the antenna gain and the return loss are increased.
Third, the maintenance is very convenient. Because the antenna device may be fixed to one end of the feeding device by way of bonding or screwing, the antenna device can be replaced without disassembling the housing of the electronic apparatus such that the maintenance is very convenient.
While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 94135944 | Oct 2005 | TW | national |
