This application claims priority of Chinese Application No. 201010282201.7, filed on Sep. 14, 2010.
1. Field of the Invention
The present invention relates to an antenna system and an electronic apparatus having the same, more particularly to an antenna system with multiple planar dipole antennas and an electronic apparatus having the same.
2. Description of the Related Art
Most modern wireless network products, such as wireless access points, are compact and lightweight. Therefore, how to reduce space occupied by antennas in the wireless network products without significant adverse impact to antenna performance is always among the subjects of endeavor in the antenna industry.
Conventional monopole antennas, such as one disclosed in Taiwanese patent No. M377714, are bulky and require electrical connection to additional grounding planes. On the other hand, fabrication of antennas with three-dimensional metal structures generally involves multiple bending processes, which can be time-consuming and costly. In addition, planar inverted-F antennas generally have a relatively poor range of gain values (typically about 3 dBi at 2.4 GHz and 4 dBi at 5 GHz), and are characterized by non-broadside radiation (i.e., poor radiation directivity).
Therefore, an object of the present invention is to provide a multi-band antenna system with high directionality and high gain.
Another object of the present invention is to provide an antenna system that is small and low cost, that has a low profile, and that is suitable for application to small wireless network products.
Accordingly, an antenna system of the present invention includes an antenna module and a system module.
The antenna module includes a substrate including opposite first and second surfaces, and a plurality of planar dipole antennas disposed on the first surface of the substrate. Each of the planar dipole antennas includes a short-circuit section that has a grounding segment and two sides, a pair of first radiator sections that are operable in a first frequency band and that are connected electrically and respectively to the two sides of the short-circuit section, and a pair of second radiator sections that are operable in a second frequency band. Each of the second radiator sections has a feed-in portion and an extending portion, the feed-in portion being connected electrically to the short-circuit section and having a distal end distal from the short-circuit section, the extending portion extending from the distal end of the feed-in portion of the respective one of the second radiator sections. One of the second radiator sections of each of the planar dipole antennas has a feed-in segment. The planar dipole antennas are arranged such that geometric centers of the planar dipole antennas are respectively spaced apart from a center point bounded by the planar dipole antennas by a predetermined distance, such that each of the planar dipole antennas is spaced apart from an adjacent one of the planar dipole antennas by a predetermined minimum distance, and such that, for each of the planar dipole antennas, the feed-in segment, the grounding segment, and the center point are disposed on a same line.
The system module has a grounding plane that faces toward and that is spaced apart from and parallel to the second surface of the substrate.
A further object of the present invention is to provide an electronic apparatus including an antenna module and a system module.
Accordingly, an electronic apparatus of the present invention includes a housing, and an antenna module and a system module disposed in the housing.
The antenna module includes a substrate including opposite first and second surfaces, and a plurality of planar dipole antennas disposed on the first surface of the substrate. Each of the planar dipole antennas includes a short-circuit section that has a grounding segment and two sides, a pair of first radiator sections that are operable in a first frequency band and that are connected electrically and respectively to the two sides of the short-circuit section, and a pair of second radiator sections that are operable in a second frequency band. Each of the second radiator sections has a feed-in portion and an extending portion, the feed-in portion being connected electrically to the short-circuit section and having a distal end distal from the short-circuit section, the extending portion extending from the distal end of the feed-in portion of the respective one of the second radiator sections. One of the second radiator sections of each of the planar dipole antennas has a feed-in segment. The planar dipole antennas are arranged such that geometric centers of the planar dipole antennas are respectively spaced apart from a center point bounded by the planar dipole antennas by a predetermined distance, such that each of the planar dipole antennas is spaced apart from an adjacent one of the planar dipole antennas by a predetermined minimum distance, and such that, for each of the planar dipole antennas, the feed-in segment, the grounding segment, and the center point are disposed on a same line.
The system module has a grounding plane that faces toward and that is spaced apart from and parallel to the second surface of the substrate.
The Patent Application file contains at least one Drawing executed in color. Copies of this Patent or Patent Application Publication with the color drawings will be provided by the Office upon request and payment of the necessary fee.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
Referring to
The antenna module 10 includes a substrate 1 and a plurality of planar dipole antennas 2. In this embodiment, the substrate 1 includes opposite first and second surfaces 11, 12, is formed with a through hole 13 for extension of signal-feed cables 6 therethrough, and is preferably made of dielectric materials, such as glass fiber (FR4). In addition, the antenna module 10 includes three planar dipole antennas 2 each being a half-wavelength dipole antenna. However, configuration of the planar dipole antennas 2 may be otherwise in other embodiments. Although the substrate 1 of this embodiment is a circular substrate, configuration of the substrate 1 is not limited to such.
Referring to
For each of the planar dipole antennas 2: the first radiator sections 4 extend in an extending direction and are connected electrically and respectively to two sides of the short-circuit section 3; the short-circuit section 3 extends substantially parallel to the extending direction, has a grounding segment 31, and is disposed on a first side of the first radiator sections 4; and the second radiator section 5 have extending portions 52 that extend substantially parallel to the extending direction and that are disposed on a second side of the first radiator sections 4 opposite to the first side.
For each of the planar dipole antennas 2, each of the second radiator sections 5 further has a feed-in portion 51 that is connected electrically to the short-circuit section 3 and that has a distal end distal from the short-circuit section 3. The extending portion 52 of each second radiator section 5 extends from the distal end of the respective feed-in portion 51. The feed-in portion 51 of one of the second radiator sections 5 of each of the planar dipole antennas 2 has a feed-in segment 53 disposed thereon. It is to be noted that, for each of the planar dipole antennas 2, the extending portions 52 of second radiator sections 5 and the first radiator sections 4 are connected electrically to the feed-in portion 51.
For each of the planar dipole antennas 2, the feed-in portions 51 are spaced apart from each other by a first gap 32, the feed-in segment 53 and the grounding segment 31 are spaced apart from each other by a second gap 33, and the first and second gaps 32, 33 are in spatial communication with each other.
Through disposing the planar dipole antennas 2 on the first surface 11 of the substrate 1 using PCB techniques, fabrication costs can be lower. Moreover, through adjusting the second gap 33 and the short-circuit section 3 of each of the planar dipole antennas 2, the antenna module 10 maybe configured to exhibit a balanced relationship between capacitive reactance and inductive reactance, thereby achieving an ideal impedance bandwidth in each of the first and second frequency bands.
In this embodiment, for each of the second radiator sections 5 of each of the planar dipole antennas 2, the extending portion 52 has a first end connected electrically to the distal end of the feed-in portion 51, a second end distal from the distal end of the feed-in portion 51, and a width that increases gradually from the first end to the second end. Such a configuration ensures that the second radiator sections 5 have a relatively wide operating bandwidth. However, configuration of the planar dipole antennas 2 is not limited to such. Specifically, referring to
It is to be noted that, in contrast to the planar dipole antenna 2 of the preferred embodiment shown in
Referring to
By virtue of the symmetrical structure of the antenna module 10, mutual coupling among the planar dipole antennas 2 may be reduced, and the same extent of isolation may be ensured for the planar dipole antennas 2. Furthermore, the multi-antenna system 100 is thus able to achieve a symmetrical radiation/communication coverage space.
The system module 20 is a system circuit board having a grounding plane 201 (e.g., a metal plane) that faces toward and that is spaced apart from and parallel to the second surface 12 of the substrate 1 such that the grounding plane 201 is able to reflect radiation from the antenna module 10. Radiation patterns of the multi-antenna system 100 thus exhibit high directivity and gain. Moreover, the system module 20 preferably has a multi-layer structure, of which the top layer is a thin metal layer serving as the grounding plane 201, and each of remaining layers is independently one of a dielectric layer and a circuit layer. It is to be noted that, in other embodiments, the antenna module 10 and the system module 20 may be spaced apart from each other so as to enable disposing of various electronic components therebetween. Furthermore, the substrate 1 occupies an area not larger than that occupied by the system module 20 such that the system module 20 is able to substantially reflect signals radiated by the planar dipole antennas 2.
Referring to
Referring again to
In summary, the multi-antenna system 100 is operable in the 2.4/5 GHz wireless local area network frequency bands, radiates signals with high directivity and high gain, and is characterized by relatively high isolation. Impedance matching of the multi-antenna system 100 may be adjusted through adjusting the second gap 33 and the short-circuit section 3. In addition, the planar dipole antennas 2 are arranged such that the signal-feed cables 6 may be kept from overlapping with the planar dipole antennas 2, thereby reducing interference therebetween. Moreover, the system module 20 is able to improve directivity of signals radiated by the antenna module 10.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Number | Date | Country | Kind |
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2010 1 0282201 | Sep 2010 | CN | national |
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Number | Date | Country | |
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20120062437 A1 | Mar 2012 | US |