Patent Application
20120105297
This Application claims priority of Taiwan Patent Application No. 099137594, filed on Nov. 2, 2010, the entirety of which is incorporated by reference herein.
1. Field of the Invention
The present invention relates to an antenna, and in particular relates to a reverse helical beam antenna.
2. Description of the Related Art
An E-book is popularly utilized as a medium for electronic document reading. Nowadays, E-books have output interfaces such as a screen and an amplifier, and is gradually utilized for watching digital television programs.
Contractible digital television antennas and externally connected digital television antennas are utilized in conventional E-books. The contractible digital television antenna is made up of expensive metal materials, and costs thereof have increased. The externally connected digital television antennas have improved transmission; however, externally connecting wire of the externally connected digital television antenna may cause some inconvenience.
An antenna for transmitting a wireless signal is provided. The antenna includes a radiator and a ground structure. The ground structure surrounds the radiator. The ground structure includes a low-band spiral portion, a band separation portion and a high-band spiral portion. The low-band spiral portion and the high-band spiral portion are respectively connected to two ends of the band separation portion.
The antenna of the embodiment of the invention satisfies digital television signal transmission requirements with decreased dimensions. The antenna of the embodiment can be utilized in an electronic device and provides improved transmission. The electronic device can be an E-book, notebook or other electronic devices.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
The ground structure 120 surrounds the radiator 110, but is separated from the radiator 110. The ground structure 120 comprises a low-band spiral portion 121(A), a band separation portion 122(B) and a high-band spiral portion 123(C). The low-band spiral portion 121(A) and the high-band spiral portion 123(C) are respectively connected to two ends of the band separation portion 122(B). The low-band spiral portion 121(A) is electrically connected to the ground conductor 131.
The band separation portion 122(B) separates the low-band spiral portion 121(A) from the high-band spiral portion 123(C). In this embodiment, the band separation portion 122(B) is spiral, and an extending length (distance between the low-band spiral portion and the high-band spiral portion) of the band separation portion 122(B) is longer than 20 mm to reduce interference between the low-band spiral portion 121(A) and the high-band spiral portion 123(C). In this embodiment, the pitch of the band separation portion 122(B) is 4.5 mm˜6.5 mm, and the number of coils thereof is 3˜4.
With reference to
In this embodiment, the free end 112 of the radiator 110 is located on a border between the band separation portion 122(B) and the high-band spiral portion 123(C). The length of the radiator 110 is one-eighth of a wavelength of a central frequency of the wireless signal. The central frequency is 620˜650 MHz, and the length of the radiator 110 is 57˜60 mm. The radiator 110 is electrically connected to the feed conductor (positive electricity), and the ground structure 120 is electrically connected to the ground conductor (negative electricity), and the negative pole (ground structure) therefore surrounds the positive pole (radiator). The bandwidth of the antenna of the embodiment of the invention can be increased by modifying the low-band spiral portion 121(A) and the high-band spiral portion 123(C).
The antenna of the embodiment of the invention can be disposed on the body or inside of the body of the electronic device, and provides improved transmission.
Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| TW099137594 | Nov 2010 | TW | national |
