Directional Antenna and Smart Antenna System Using the Same
The present invention discloses a directional antenna for a portable device. The directional antenna includes at least one antenna, disposed on a side of a display of the portable device, for utilizing a metal part of the display as a reflector to generate a directional radiation pattern.
This application claims the benefits of U.S. Provisional Application No. 61/382,922, filed on Sep. 15, 2010 and entitled “SMART ANTENNA AND SYSTEM USING THE SAME”, U.S. Provisional Application No. 61/422,660, filed on Dec. 14, 2010 and entitled “SMART ANTENNA SYSTEM”, and U.S. Provisional Application No. 61/425,252, filed on Dec. 21, 2010 and entitled “PORTABLE DEVICE WITH SMART ANTENNA” the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a directional antenna and smart antenna system using the same, and more particularly, to a directional antenna and smart antenna system using the same capable of utilizing a metal part of a display of a portable device as a reflector to generate a directional radiation pattern.
2. Description of the Prior Art
Antenna design is crucial to a portable device with wireless communication function, such as wireless local area network (WLAN) or other mobile communication systems. In a conventional wireless communication device, one or a plurality of omni directional antennas are used to receive radio signals from all directions. Antenna diversity technique is also used to determine which one or more omni-directional antennas should be used to receive or transmit signals. However, the efficiency and gain of omni directional antennas are not good enough. Hence, there's a need for an antenna design that provides smarter and better receiving quality.
SUMMARY OF THE INVENTIONIt is therefore an object of the present invention to provide a directional antenna and smart antenna system using the same capable of utilizing a metal part of a display of a portable device as a reflector to generate a directional radiation pattern.
The present invention discloses a directional antenna for a portable device. The directional antenna includes at least one antenna, disposed on a side of a display of the portable device, for utilizing a metal part of the display as a reflector to generate a directional radiation pattern.
The present invention further discloses a smart antenna system for a portable device. The smart antenna system includes a plurality of directional antennas. Each directional antenna includes at least one antenna, disposed on a side of a display of the portable device, for utilizing a metal part of the display as a reflector to generate a directional radiation pattern. All of directional radiation patterns generated by the plurality of directional antennas substantially form an omni directional radiation pattern.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
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Noticeably, compared with an omni directional antenna, an ordinary directional antenna has many advantages in a corresponding directional radiation pattern, such as high gain for desired signal, long transmission distance, better received signal strength indication (RSSI), low side lobe for interference, low noise floor, and low power consumption under the same Equivalent isotropically radiated power (EIRP) requirement, etc. Therefore, in such a configuration, the omni directional radiation pattern substantially formed by the directional radiation patterns DRP1-DRP4 has better efficiency than an omni directional radiation pattern formed by one or a plurality of omni directional antennas. As a result, the smart antenna system 10 can have better gain and efficiency.
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Noticeably, the spirit of the present invention is to utilize a metal part of a display of a portable device as a reflector to generate a directional radiation pattern, such that all directional radiation patterns generated can substantially form an omni directional patter and thus have better gain and efficiency. Those skilled in the art shout make modifications or alterations accordingly. For example, the portable device 12 is preferably a laptop, but can be a tablet computer, a mobile phone, etc.
Besides, the at least one antenna of the directional antenna 30 is not limited to any feeding type, antenna type or number, as long as the at least one antenna can be disposed on one of the left side, the right side, the bottom side and the top side of the display 14, where the space is very narrow, to utilize a metal part of a display as a reflector to generate a directional radiation pattern. For example, the at least one antenna of the directional antenna 30 is not limited to be series-fed, and can be parallel-fed as well; the at least one antenna of the directional antenna 30 is not limited to be dipole antenna, and can be folded dipole antenna or other antenna types.
On the other hand, the at least one antenna of the directional antenna 50 is also not limited to any feeding type, antenna type or number, as long as the at least one antenna can be disposed on the back side of the display 14, where the space is very thin but broad, to utilize a metal part of a display as a reflector to generate a directional radiation pattern. For example, the at least one antenna of the directional antenna 50 is not limited to be parallel-fed, and can be series-fed as well, as long as two of the at least one antenna of the directional antenna 50 have a specific phase difference, such that the two of the at least one antenna of the directional antenna 50 have constructive interference in a far field.
In the prior art, efficiency and gain of omni directional antennas are not good enough. In comparison, the present invention utilize the metal part of the display as a reflector to generate directional radiation patterns, so as to substantially form an omni directional patter with better gain and efficiency. Moreover, the present invention provides a series feed dipole array antenna design for the left side, the right side, the bottom side and the top side of the display, and a parallel feed patch array antenna for a back side of the display, so as to generate directional radiation with higher gain and efficiency.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Claims
1. A directional antenna for a portable device, comprising:
- at least one antenna, disposed on a side of a display of the portable device, for utilizing a metal part of the display as a reflector to generate a directional radiation pattern.
2. The directional antenna of claim 1, wherein two of the at least one antenna has constructive interference in a far field.
3. The directional antenna of claim 1, wherein the at least one antenna is disposed on one of a right side, a left side, a top side and a bottom side of the display of the portable device.
4. The directional antenna of claim 3, wherein the at least one antenna is series-fed.
5. The directional antenna of claim 4, wherein two of the at least one antenna have a specific phase difference, such that the two of the at least one antenna have constructive interference in a far field.
6. The directional antenna of claim 3, wherein the at least one antenna is parallel-fed.
7. The directional antenna of claim 3 further comprising a pad, located at a feeding point of the at least one antenna, for impedance matching.
8. The directional antenna of claim 3, wherein the at least one antenna is at least one dipole antenna.
9. The directional antenna of claim 3, wherein the at least one antenna is at least one folded dipole antenna.
10. The directional antenna of claim 1, wherein the at least one antenna is disposed on a back side of the display of the portable device.
11. The directional antenna of claim 10, wherein the at least one antenna is parallel-fed.
12. The directional antenna of claim 10, wherein the at least one antenna is series-fed.
13. The directional antenna of claim 12, wherein two of the at least one antenna have a specific phase difference, such that the two of the at least one antenna have constructive interference in a far field.
14. The directional antenna of claim 10, wherein the at least one antenna is at least one patch antenna.
15. A smart antenna system for a portable device, comprising:
- a plurality of directional antennas, each directional antenna comprising: at least one antenna, disposed on a side of a display of the portable device, for utilizing a metal part of the display as a reflector to generate a directional radiation pattern;
- wherein all of directional radiation patterns generated by the plurality of directional antennas substantially form an omni directional radiation pattern.
16. The smart antenna system of claim 15, wherein two of the at least one antenna has constructive interference in a far field.
17. The smart antenna system of claim 15, wherein the at least one antenna is disposed on one of a right side, a left side, a top side and a bottom side of the display of the portable device.
18. The smart antenna system of claim 17, wherein the at least one antenna is series-fed.
19. The smart antenna system of claim 18, wherein two of the at least one antenna have a specific phase difference, such that the two of the at least one antenna have constructive interference in a far field.
20. The smart antenna system of claim 17, wherein the at least one antenna is parallel-fed.
21. The smart antenna system of claim 17, wherein the each directional antenna further comprises a pad, located at a feeding point of the at least one antenna, for impedance matching.
22. The smart antenna system of claim 17, wherein the at least one antenna is at least one dipole antenna.
23. The smart antenna system of claim 17, wherein the at least one antenna is at least one folded dipole antenna.
24. The smart antenna system of claim 15, wherein the at least one antenna is disposed on a back side of the display of the portable device.
25. The smart antenna system of claim 24, wherein the at least one antenna is parallel-fed.
26. The smart antenna system of claim 24, wherein the at least one antenna is series-fed.
27. The smart antenna system of claim 26, wherein two of the at least one antenna have a specific phase difference, such that the two of the at least one antenna have constructive interference in a far field.
28. The smart antenna system of claim 24, wherein the at least one antenna is at least one patch antenna.
Type: Application
Filed: Feb 14, 2011
Publication Date: Mar 15, 2012
Inventor: Min-Chung Wu (Hsinchu County)
Application Number: 13/026,299
International Classification: H01Q 1/44 (20060101);