Patent Application
20120026044
This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 99214403 filed in Taiwan, R.O.C. on 2010 Jul. 28, the entire contents of which are hereby incorporated by reference.
1. Technical Field
The present invention relates to an antenna, and more particularly to a monopole antenna.
2. Related Art
An antenna is a necessary element in a wireless communication device, and in despite of continuous development of communication technologies, the antenna is still indispensable. With the fast development of wireless communication from a low frequency to a high frequency, an application scope thereof is developed from national defense communication and military application to communication networks and consumer electronic products, and a matching antenna is also developed from an exposed antenna to a light, thin, short, and small hidden antenna. It may be known that the wireless communication is inseparable from lives. When the communication device adopts a hidden antenna, a volume of the product is reduced, and the user cannot perceive an antenna structure from the appearance, so as to eliminate fears of the user for electromagnetic waves.
For a single feed and printed micro-strip antenna, a required antenna length is wavelength of an operating frequency. For a frequency band of 2.4 GHz commonly used in a wireless network, the required antenna length is approximately 30 mm. The current consumer electronic product is required to be light, thin, short, and small, which are keys that limit the volume of the electronic product, so it is still an urgent subject for modification on how to reduce a space occupied by the antenna.
Accordingly, the present invention is mainly directed to a monopole antenna, so as to alleviate disadvantages of a conventional antenna, thereby reducing a space occupied by the antenna.
The present invention provides a monopole antenna disposed on a substrate with a first surface and a second surface. The monopole antenna includes: a feeding point, disposed on the first surface of the substrate, for inputting and outputting electrical signals corresponding to the electromagnetic-wave signals; a radiation unit, disposed on the first surface of the substrate; and a reflecting element, disposed on the second surface of the substrate, and corresponding to a position of the second radiation section. The radiation unit includes: a feeding section, having one end electrically connected to the feeding point; a first radiation section, having one end electrically connected to the other end of the feeding section; a second radiation section, having one end electrically connected to the other end of the first radiation section, in which the second radiation section and the feeding section are respectively placed at two sides of a longitudinal axis of the first radiation section; and a third radiation section, having one end electrically connected to the first radiation section, in which the third radiation section and the feeding section are respectively placed at the two sides of the longitudinal axis of the first radiation section.
Preferred embodiments and efficacies of the present invention are described below with reference to the accompanying drawings.
The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein:
a is a schematic view of a first surface according to an embodiment of the present invention;
b is a schematic view of a second surface according to the embodiment of the present invention;
The present invention is described in detail with reference to the specific embodiments, and the accompanying drawings are used for auxiliary description. Numerals mentioned in the description are referred to the reference numerals.
a and 1b are schematic views according to an embodiment of the present invention. In the embodiment, the present invention provides a monopole antenna applicable to a wireless network, and more particularly to a wireless network card. Here, the frequency of the electromagnetic-wave signals is preferably 2.4 GHz, but the present invention is not limited hereto.
The monopole antenna is disposed on the substrate 1 with a first surface 11 and a second surface 12.
Referring to
The second radiation section 33 and the feeding section 31 are respectively placed at two sides of a longitudinal axis of the first radiation section 32. One end of the third radiation section 34 is electrically connected to the first radiation section 32. The third radiation section 34 and the feeding section 31 are respectively placed at the two sides of the longitudinal axis of the first radiation section 32.
Here, the first radiation section 32 and the feeding section 31 form a first included angle 51, and the first radiation section 32 and the second radiation section 33 form a second included angle 52, in which both the first included angle 51 and the second included angle 52 are acute angles. The second radiation section 33 and the third radiation section 34 of the monopole antenna are substantially respectively a part of two concentric circles, that is, the second radiation section 33 and the third radiation section 34 are bent towards the same direction, and are in parallel with each other. Particularly, a circle center of the concentric circles is located near the third radiation section 34. A length ratio of the third radiation section 34 to the second radiation section 33 is between 50% and 80%, and preferably ⅔. Through the design, a space occupied by the radiation unit 3 is effectively reduced.
A total length of the feeding section 31, the first radiation section 32, and the second radiation section 33 according to the embodiment of the present invention is 10 mm. That is to say, as compared with the prior art, the length is approximately reduced by ⅔. However, as the length is reduced, inductive composition of the antenna is reduced. In the present invention, a current flow is changed by the second included angle 52, and then an inductance value is increased by the third radiation section 34 extended from the second radiation section 33. Next, a notch 35 is disposed at a connection position between the first radiation section 32 and the third radiation section 34, thereby adjusting a capacitance value. Here, the notch 35 may be located at an opposite side of the second radiation section 33.
Referring to
the frequency according to the embodiment of the present invention when the reflecting element 4 corresponds to the position of the third radiation section 34. When the reflecting element 4 corresponds to the position of the third radiation section 34, as an operating frequency band of the monopole antenna according to the embodiment of the present invention is determined by the second radiation section 33 and the reflecting element 4, effects of the embodiment of the present invention cannot be achieved.
To sum up, through the present invention, the monopole antenna having the smaller length is surely provided, thereby facilitating to add more elements with other functions in the consumer electronic product or reduce the volume of the consumer electronic product under the limited volume situation.
While the present invention has been described by the way of example and in terms of the preferred embodiments, it is to be understood that the invention need not to be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 99214403 | Jul 2010 | TW | national |
