Patent Grant
8982005
This application claims the priority benefit of China application serial no. 201110166829.5, filed on Jun. 21, 2011. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Field of the Invention
The invention relates to a monopole slot antenna structure, and particularly relates to a monopole slot antenna structure having a tuning slot section for conveniently adjusting suitable frequencies, and the monopole slot antenna structure being capable of operating in dual-frequency environment.
2. Description of Related Art
As Internet develops vigorously, various kinds of network platform services, such as networked communication platforms (for example, message boards, forums, community websites and so forth) or data exchange platforms (for example, web albums, official download spaces, networked space and so forth) or personal service platforms (for example, electronic mailboxes, blogs, web games and so forth), all have been involved with everyone's lives. As such, these network platform services make it convenient for people to obtain necessary data when they are at home or in working environments. In particular, prevalence of wireless communications revolves the problem in which people can only use Internet in a particular area due to length limitations of physical connections. Therefore, communication devices with wireless communication functionality such as mobile phones, personal digital assistants (PDA) or tablet computers have gradually become necessity in people's lives.
Accordingly, in current communication devices, Wi-Fi™, one of most commonly used wireless communication protocol standards, is based on IEEE 802.11 standards. Wi-Fi™ operates in 2.4 GHz frequency band (802.11 b/g/n) and 5 GHz frequency band (802.11 a/n). Since people mainly require exterior designs of communication devices to be light, slim, short and small, vendors mainly concern simplification of electronic components or shortening of built-in antenna length in design of communication devices supporting Wi-Fi™, in order to meet the aforementioned design requirements. In general, most of the vendors currently apply a monopole antenna as the built-in antenna of the communication devices since the monopole antenna has simple structure and its resonance frequency is a quarter of wavelength of the operating frequency. As such, the length of the monopole antenna is shorter. An electric current generated in a closed loop due to potential difference on the antenna makes the antenna function normally. Thus, the ground point of the electric circuit board or the body of the electronic device are usually taken as a reference ground plane of the monopole antenna. Nonetheless, any electronic components or conductors closer to the monopole antenna may influence the monopole antenna, such as forming a closed electric circuit accidentally. As such, signal quality of the electromagnetic signals received by the monopole antenna may be poor. Thus, in order to maintain good antenna functionality, the vendors seem to allocate a larger clearance area around the monopole antenna, but such allocation design will greatly increase an overall volume of the communication device.
In order to resolve the monopole antenna being too sensitive or easily influenced by surrounding objects, some vendors attempt to use a slot antenna to be the antenna of the communication device operating in dual-frequencies, since the slot antenna is not easily influenced by neighbouring electronic components or conductors. As such, it is not necessary for the vendors to allocate an additionally larger clearance area around the slot antenna. However, the resonance frequency of the slot antenna is a half of the wavelength of the operating frequency. Thus, the required antenna length is far greater than that of the monopole antenna, for example, under the same operating frequency, the length of the slot antenna is twice of that of the monopole antenna, so the overall volume of the communication device cannot be greatly reduced. Further, the slot antenna is usually a long rectangular metal frame, where there will be a long rectangular slot allocated being extended in the same direction as the long rectangular metal frame in the middle of the long rectangular metal frame. The vendors may tune a plate width between the long rectangular metal frame and the long rectangular slot, in order to adjust effects of high operating frequencies and low operating frequencies. However, in the aforementioned tuning, the location where the long rectangular metal frame corresponding to a short edge of the long rectangular slot has two tuning widths, while the location where the long rectangular metal frame corresponding to the a long edge of the long rectangular slot has fourth tuning widths. All these tuning widths will interactively influence characteristics of high operating frequencies and low operating frequencies. Therefore, the vendors require spending longer operation time for tuning the slot antenna to an expected operating frequency, which greatly lowers operation efficiency of the vendors.
Based upon the aforementioned, no matter a monopole antenna or a slot antenna, which are all limited by antenna characteristics thereof, cannot be properly designed for allocation communication devices of small volumes. Therefore, in order to revolve the aforementioned drawbacks of the conventional art, it is a major issue for related antenna design vendors to design an antenna with a shorter length and with operating frequency which can be easily tuned.
The invention is directed to a monopole slot antenna structure.
Due to the fact that antenna structures of the existing communication devices are not perfect, which may damage marketing interests of the vendors, a monopole slot antenna structure is developed by the Applicant, which is disclosed in the invention, and the monopole slot antenna structure has a tuning slot section, so as to provide the vendor with an antenna having easily-tuned operating frequency and smaller volume.
According to an embodiment of the invention, a monopole slot antenna structure is provided. Mainly, the resonance frequency of the monopole slot antenna is a quarter of a wavelength of an operating frequency of the monopole slot antenna. Further, it can easily tune suitable operating frequency of the monopole slot antenna by changing a width of the slot section thereof, in order to achieve a simple tuning operation procedure. The monopole slot antenna structure includes a dielectric substrate, the monopole slot antenna and a feed element. The monopole slot antenna is disposed on one side of the dielectric substrate and has a slot. Also, the slot includes a first slot section, a tuning slot section and a second slot section. One end of the first slot section is located at one edge of the monopole slot antenna with the other end of the first slot section being extended towards internal portions of the monopole slot antenna and being connected to the tuning slot section. One end of the second slot section is connected to the tuning slot section with the other end of the second slot section being extended away from the first slot section. A length of the first slot section is less than or equal to a length of the second slot section. Moreover, the feed element is disposed correspondingly to the second slot section, and is configured for exciting the monopole slot antenna to generate a first operating frequency band and a second operating frequency band. Under the circumstance of increasing the width of the slot section, i.e. in a direction corresponding to an extending direction of the first slot section or the second slot section, the frequency corresponding to the second operating frequency is accordingly lowered. As such, the vendors can adjust the frequency of the second operating frequency band by changing the width of the slot, thereby enabling a communication device in which the monopole slot antenna structure of the invention is disposed therein to operate in an expected dual-frequency environment.
In order to make the aforementioned and other features and advantages of the invention comprehensible, several exemplary embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Since a monopole slot antenna has a resonance frequency of a quarter of a wavelength of its operating frequency, antenna length of the monopole slot antenna can be greatly reduced in comparison with a slot antenna. However, sensitivity of the monopole slot antenna is lower than that of the monopole antenna. It is disclosed that Applicant of the invention therefore designs a novel antenna structure whose operating frequency can be easily tuned by using the aforementioned characteristics of the monopole slot antenna.
The invention provides a monopole slot antenna structure, which is applicable to a wireless communication device with dual-frequency operating functionality. Referring to
Following the aforementioned descriptions, referring back to
In order to clearly illustrate characteristics of the monopole slot antenna 1 of the invention, and describe how the variations of the widths W1 and W2 of the tuning slot section 134 can actually influence corresponding operating frequency bands, the following embodiments are described with adjustments of the width W1 of the tuning slot section 134. Referring back to both
Referring back to
It is herein noted that, though the aforementioned embodiments are described with an example of the slot being in the L shape, in other embodiments of the invention, the vendors can make variations of the slot shape according to actual electric circuit requirements or frequency requirements. For example, referring to
It is noted that though the embodiments shown in
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
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