Patent Application
20120242546
This Application claims priority of Taiwan Patent Application No. 100110322, filed on Mar. 25, 2011, the entirety of which is incorporated by reference herein.
1. Field of the Invention
The present invention relates to an antenna module, and in particular relates to an antenna module with increased impedance bandwidth.
2. Description of the Related Art
Conventional planar inverted F antennas include a feed conductor, a radiator, a ground element and a short element. The radiator is connected to the feed conductor. The short element connects to the radiator and the ground element. Conventionally, the short element grounds an end of the radiator to improve impedance matching. However, conventional design has poor impedance matching effect, and cannot satisfy increasing requirement of bandwidths.
An antenna module is provided, includes a radiator, a feed conductor, a ground element, a ground conductor and a short conductor. The feed conductor is connected to the radiator. The ground conductor connects the radiator and the ground element. The short conductor connects the feed conductor and the ground conductor.
In the embodiments of the invention, a short path is built by the short conductor which is separated from the radiator. A capacitance effect is formed between the short conductor and the radiator (equivalent capacitance in series with the radiator), and an inductance effect is formed between the short conductor and the ground element (equivalent inductance in parallel connected with the ground element) to reduce imaginary parts of impedance and to increase impedance bandwidth. The transmission bands of the antenna modules of the embodiments of the invention conform to the GSM850/900/DCS/PCS, UMTS BAND 1/BAND 2/BAND 5/BAND 8,802.11 a/b/g standards.
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.
In this embodiment, the ground conductor 140 is parallel to the feed conductor 120. The radiator 110 is parallel to the ground element 130. The short conductor 150 is respectively perpendicular to the ground conductor 140 and the feed conductor 120.
The radiator 110 includes a first section 111, a second section 112 and a third section 113. The second section 112 is connected to the first section 111. The third section 113 is connected to the first section 111. The ground conductor 140 and the feed conductor 120 are respectively connected to the first section 111. The second section 112 is U shaped. The third section 113 is longitudinal. The second section 112 surrounds the third section 113. The second section 112 transmits a low band signal (824 MHz˜960 MHz), and the third section 113 transmits a high band signal (1710 MHz˜2170 MHz).
A gap is formed between the short conductor 150 and the first section 111. The short conductor 150, the feed conductor 120, the ground conductor 140 and the first section 111 form a first opening 161. The short conductor 150, the feed conductor 120, the ground conductor 140 and the ground element 130 form a second opening 162. The first opening 161 is quadrilateral, for example, a rectangular.
In the embodiment, the inductance effect generated by the short conductor 150 can be modified by changing the width of the short conductor 150. The capacitance effect generated by the short conductor 150 can be modified by changing an included angle between the short conductor 150 and the feed conductor 120 or an included angle between the short conductor 150 and the ground conductor 140 (in this embodiment a distance between the short conductor 150 and the radiator 110 is about 2˜3 mm).
In one embodiment, the length of the short conductor can be quarter of wavelength of a low band signal, and the impedance bandwidth for low frequency bands can therefore be further increased. The short conductor can be taken as an impedance matching circuit, which provides impedance matching via capacitance and inductance effects generated thereby to improve impedance matching effect and impedance bandwidth of the antenna module.
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 |
|---|---|---|---|
| TW100110322 | Mar 2011 | TW | national |
