Patent Grant
9142876
This application claims the priority benefit of Taiwan application serial no. 99109633, filed on Mar. 30, 2010. 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 subject application generally relates to a planar antenna, and more particularly, to a planar antenna of a handheld device.
2. Description of Related Art
Multi-input multi-output (MIMO) is a term used for describing the transmission of radio signals between multiple antennas. In short, MIMO refers to the use of multiple antennas respectively at a transmitter and a receiver, wherein signals are transmitted and received by the antennas at the transmitter and the receiver so that the service quality provided to each user is improved. Compared to a conventional signal-antenna system, the MIMO technology offers an increased frequency available ratio such that the system can transmit data more efficiently with limited wireless bandwidth.
Generally speaking, a planar antenna requires a clearance area. If two planar antennas are respectively disposed at two different sides of a handheld device, a greater total clearance area is required by the two planar antennas and which is disadvantageous to the circuit layout of the handheld device. Besides, there may not be enough space for respectively disposing two planar antennas at two different sides of a handheld device. The closer the two planar antennas are, the more serious the problem of signal interference is. Moreover, the problem of signal interference is aggravated if three or more antennas are disposed in a handheld device.
Accordingly, the subject application is directed to a planar antenna with improved performance in radio signal transceiving.
The subject application is also directed to a handheld device, wherein two antennas are integrated into one antenna so that noise interference to the antenna is reduced.
The subject application provides a planar antenna including a connecting portion, a first antenna portion, and a second antenna portion. The first antenna portion comprises a first feed point and a first ground point. A first end of the first antenna portion is connected to a first end of the connecting portion. The first feed point is located between the first end and a second end of the first antenna portion. The first ground point is located between the first feed point and the first end of the first antenna portion. The second antenna portion comprises a second feed point and a second ground point. A first end of the second antenna portion is connected to a second end of the connecting portion. The second feed point is located between the first end and a second end of the second antenna portion. The second ground point is located between the second feed point and the first end of the first antenna portion.
According to an embodiment of the subject application, the connecting portion sets with a width, and the impedance of the connecting portion is in a positive correlation to the width thereof. According to another embodiment, the connecting portion sets with a length, and the impedance of the connecting portion is in a negative correlation to the length thereof.
According to an embodiment of the subject application, the first antenna portion includes a radiating portion and an extending portion, wherein the extending portion is extended outwards from the radiating portion, the first feed point and the first ground point are disposed at the extending portion, and a center frequency of the first antenna portion is determined according to the distance between the first feed point and the first ground point.
According to an embodiment of the subject application, the second antenna portion includes a radiating portion, a first extending portion, and a second extending portion, wherein the first extending portion and the second extending portion are respectively extended outwards from the radiating portion, the second feed point and the second ground point are respectively disposed at the first extending portion and the second extending portion, and a center frequency of the second antenna portion is determined according to a signal path length between the second feed point and the second ground point.
According to an embodiment of the subject application, the first antenna portion includes a first radiating portion, and the second antenna portion includes a second radiating portion. The frequency of the first antenna portion is determined according to the length of the first radiating portion, and the frequency of the second antenna portion is determined according to the length of the second radiating portion, wherein the frequency of the first antenna portion and the frequency of the second antenna portion are substantially with fundamental-harmonic relationships.
According to an embodiment of the subject application, the connecting portion, the first antenna portion, and the second antenna portion are made of a flexible conductive material, and the planar antenna is flexibly disposed at a fixing device to present a three-dimensional (3D) structure.
The subject application also provides a handheld device including a planar antenna and a system ground plane. The planar antenna comprises a first feed point, a first ground point, a second feed point, and a second ground point. The first ground point and the second ground point are located between the first feed point and the second feed point. The system ground plane is electrically connected to the first feed point, the first ground point, the second feed point, and the second ground point.
As described above, in the subject application, two antennas are integrated into one planar antenna, and the planar antenna comprises two feed points and two ground points, wherein the ground points are located between the feed points. Thereby, interference between antennas is eliminated and the space disposition of the antenna is improved.
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.
In a conventional multi-input multi-output (MIMO) handheld device, signal interference between planar antennas is serious and the planar antennas are difficult to be disposed.
In an embodiment of the subject application, two planar antennas are integrated into one planar antenna so that the total clearance area of the planar antenna is reduced and interference between two planar antennas is avoided. Reference will now be made in detail to exemplary embodiments of the subject application, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
In
The planar antenna 11 is integrated with a MIMO function, and which comprises two feed points and two ground points. The feed point F1 and the ground point G1 are considered as the signal input/output terminals of the antenna portion 20, and the feed point F2 and the ground point G2 are considered as the signal input/output terminals of the antenna portion 30. In other words, the handheld device can carry out wireless communication through the antenna portion 20 and/or the antenna portion 30.
It should be noted that the connecting portion 40 is a conductive body connected between the antenna portions 20 and 30, and which changes the impedance between the antenna portions 20 and 30. In other words, those skilled in the art can adopt a connecting portion 40 of different impedance according to their actual requirement so that an impedance matching effect can be achieved. As a result, signal interference between antennas is reduced. Besides, by integrating the antenna portions 20 and 30, the total clearance area required by the antenna portions 20 and 30 is also reduced compared to that required by respectively disposed antennas.
Even though a possible pattern of the handheld device and the planar antenna thereof has been described in foregoing embodiment, it should be understood by those having ordinary knowledge in the art that different manufacturers have different designs of the handheld device and the planar antenna thereof. Thus, the application of the subject application is not limited to aforementioned possible pattern. In other words, it is within the scope and sprit of the subject application as long as the planar antenna comprises at least two feed points and at least two ground points and the ground points are located between the feed points. A few more embodiments of the subject application will be further described below so that those having ordinary knowledge in the art can further understand the spirit of the subject application and implement the subject application.
It should be understood by those skilled in the art that the pattern of the planar antenna and the dispositions of the feed points and the ground points illustrated in
For example, the operating frequency of the antenna portion 20 may be changed by changing the length of the radiating portion 201. Similarly, the operating frequency of the antenna portion 30 may be changed by changing the length of the radiating portion 301.
Additionally, the center frequency of the antenna portion 20 may be changed by changing the distance between the feed point F1 and the ground point G1. Similarly, the center frequency of the antenna portion 30 may be changed by changing the distance between the feed point F2 and the ground point G2.
The pattern of the connecting portion 40 illustrated in
Even though the feed point F2 and the ground point G2 are disposed at the same extending portion 302 in
The length of the radiating portion may also be changed according to the actual requirement by those skilled in the art.
The pattern of the radiating portion may also be changed according to the actual requirement by those skilled in the art so as to improve the radiation pattern and the transceiving quality of the antenna or reduce signal interference of the antenna.
Because the planar antenna 17 is made of a flexible conductive material, it is flexible. The planar antenna 17 is flexibly disposed at a fixing device (for example, an antenna carrier, the casing of the handheld device, or any component or module in the handheld device) to form a three-dimensional (3D) structure.
The planar antenna described in the present disclosure can be applied by those skilled in the art to wireless communication systems adopting MIMO techniques, such as WIMAX, GPS, and 3G, etc. In addition, the frequency of each antenna portion in the planar antenna can be fine tuned by those skilled in the art by using a matching circuit.
As described above, in the subject application, two antennas are integrated into one planar antenna comprising at least two feed points and at least two ground points, wherein the ground points are located between the feed points. Thereby, the layout of the planar antenna is made more flexible, and signal interference to the planar antenna is reduced. In addition, an embodiment of the subject application may further have following advantages:
1. The impedance of the connecting portion can be changed by changing the shape of the connecting portion, so that an impedance matching effect is achieved.
2. The center frequency of the antenna can be changed by changing the signal transmission path between the ground points and the feed points.
3. The operating frequency of the antenna can be changed by changing the length of the radiating portion of the antenna.
4. The two antennas in a planar antenna have radiating portions of different lengths. The two antennas operate at different harmonic frequencies but operating at the same bandwidth. Accordingly, signal interference is reduced.
5. The planar antenna is flexibly disposed at a fixing device to form a 3D structure.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the subject application without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the subject application cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 99109633 A | Mar 2010 | TW | national |
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| Number | Date | Country | |
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| 20110241962 A1 | Oct 2011 | US |
