Patent Grant
7315286
This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Application 2005-71312, filed Aug. 4, 2005, in the Korean Intellectual Property Office, the entire disclosure of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a portable terminal. More particularly, the present invention relates to an antenna apparatus for a portable terminal.
2. Description of the Related Art
In general, a portable terminal is an appliance for providing wireless user-to-user communication or user-to-service provider communication through one or more mobile communication base stations. A user can be provided with various content including anything from communications and short message services to mobile banking, TV broadcasting, online gaming, and video-on-demand services.
A portable terminal has an antenna apparatus for securing an acceptable good signal-receiving percentage or a good communication quality, despite the radio frequency propagation environment varying due to its surroundings. Antenna apparatuses provided in portable terminals differ in specifications, such as length, depending on the frequency bands used by the service providers that the portable terminals operate with.
Such antenna apparatuses may be classified into an internal type and an external type. An internal type antenna is provided within a housing of a portable terminal. An external type antenna protrudes outwardly from the housing. Exemplary internal type antennas include a meander line antenna, a loop antenna, an inverted L antenna, and a planar inverted F antenna (PIFA). Exemplary external type antennas include a whip antenna having an antenna element such as a helical antenna received in an antenna housing and a retractable/extendible antenna element installed on a terminal housing.
However, the construction of a conventional internal type antenna apparatus, such as a PIFA antenna, is limited in improving a specific absorption ratio induced in a human body (hereinafter, referred to as “SAR”) because the current fed through the antenna apparatuses flows in one direction. In addition, the conventional internal type antenna deteriorates communications due to the generation of noise as well as the SAR.
Accordingly, there is a need for an improved internal type antenna apparatus that improves SAR and reduces noise so as to prevent deteriorated communications.
An aspect of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of exemplary embodiments of the present invention is to provide an antenna apparatus for a portable terminal which can easily improve SAR while being housed within the terminal.
Another aspect of exemplary embodiments of the present invention is to provide an antenna apparatus for a portable terminal which can suppress the generation of noise while being housed within the terminal, thereby improving the communication quality of the terminal.
In order to achieve the above-mentioned aspect, there is provided an antenna apparatus for a portable terminal comprising a first antenna pattern, and a second antenna pattern adapted to correspond to the first antenna pattern, so that at least part of the second antenna and the first pattern are capacitively coupled, thereby configuring a divergent type antenna with the second antenna pattern.
Other objects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
The above and other objects, features, and advantages of certain embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements, features, and structures.
The matters defined in the description such as a detailed construction and elements are provided to assist in a comprehensive understanding of the embodiments of the invention and are merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
Referring to
The construction of the antenna apparatus 200 is now described in detail with reference to
The antenna apparatus 200 is a divergent type antenna in which a first antenna pattern 221 and a second antenna pattern 222 are capacitively coupled. Antenna apparatus 200 has an antenna base 201 formed of a synthetic resin so as to configure the first and second antenna patterns 221 and 222.
The antenna base 201 is installed within the top portion of the housing of the terminal 10 so as to provide means for allowing the first and second antenna patterns 221 and 222 to be installed within the housing of the terminal 10 while maintaining their shapes.
A printed circuit board 203 is mounted on the front side of the antenna base 201, on which a power feed circuit 223 for the circuit board is formed. A ground 225 is provided at one end of the printed circuit board 203. Further, one end of the first antenna pattern 221 is connected to the power feed circuit 223 of the printed circuit board 203 to receive power from the circuit. One end of the second antenna pattern 222 is provided with a ground terminal 227, which is connected with a ground and is provided on the terminal 10 at the front side of the antenna base 203.
The first and second antenna patterns 221 and 222 are configured as meander line antennas, respectively, with one end of each antenna being connected with the power feed circuit and a ground and the other end of each antenna providing a capacitive coupling. The first antenna pattern 221 is formed in a zigzag shape in the crosswise direction for interconnecting one lateral end portion and the central portion of the antenna base 201 on one side of the antenna base 201. The entire length of the first antenna pattern 221 corresponds to one half of an operational wavelength for the terminal 10.
The second antenna pattern 222, similar to the first antenna pattern 221, is also formed in a zigzag shape in the crosswise direction for interconnecting the other lateral end portion and the central portion of the antenna base 201 on the one side of the antenna base 201. The entire length of the second antenna pattern 222 corresponds to one half of the operational wavelength for the terminal 10.
The shapes of the first and second antenna patterns 221 and 222 are established such that when the current flow, in the first antenna pattern 221, is directed to the one lateral end from the central part of the antenna base 203, the current flow in the second antenna pattern 222, which is in line with the current flow in the first antenna pattern 221, is also directed toward the other lateral end from the central part of the antenna base 203.
In addition, the shapes of the first and second antenna patterns 221 and 222 are established such that when the current flow in the first antenna pattern 221 is directed toward the central part of the antenna base 203, the current flow in the second antenna pattern 222, which is in line with the current flow in first antenna pattern 221, is also directed toward the central part of the antenna base 203.
Consequently, due to the configuration of the first and second antenna patterns 221 and 222, the antenna apparatus 200 is configured as a divergent type antenna. The directions of current flowing through the first and second antenna patterns 221 and 222 are opposite to each other depending on the positions of the antenna patterns 221 and 222, so that the electromagnetic waves generated by the currents flowing through the first and second antenna patterns 221 and 222 cancel each other out, thereby improving SAR.
Meanwhile, as shown in
The characteristics of a conventional internal type antenna and the antenna apparatus 200, according to the exemplary embodiment of the present invention, will be compared below.
Table 1 below shows TIS/TRP values measured through phantom tests and SAR values measured through SAR tests for a conventional PIFA antenna and an antenna apparatus 200 according to the exemplary embodiment of the present invention.
Here, “TIS” is an abbreviation for “Total Isotropic Sensitivity,” which is the sensitivity measured around a terminal and is used to ascertain the signal-receiving performance of the terminal. “TRP” is the abbreviation for “Total Radiated Power,” which is the value of radiated power measured around a terminal and is used as a measurement for the general characteristic of the terminal.
As can be seen from the results of the experiment in Table 1, the PIFA antenna and the inventive antenna apparatus 200 exhibit similar performances in terms of TIS/TRP values measured through the phantom tests. However, in terms of SAR characteristic, when the inventive antenna apparatus is employed, the SAR characteristic is improved 25% over the conventional PIFA antenna.
As described above, the inventive antenna apparatus for a portable terminal is configured by a pair of meander antennas, which provide capacitive coupling, whereby it is easy to use the antenna apparatus within a terminal while suppressing the generation of noise. Furthermore, according to the exemplary embodiments of invention, it is easy to improve the SAR, which is an important factor for defining the performance and quality of an antenna apparatus.
While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2005-0071312 | Aug 2005 | KR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5136303 | Cho et al. | Aug 1992 | A |
| 6181282 | Gans et al. | Jan 2001 | B1 |
| 6650294 | Ying et al. | Nov 2003 | B2 |
| 6657593 | Nagumo et al. | Dec 2003 | B2 |
| 6822613 | Kubota | Nov 2004 | B2 |
| 7119743 | Iguchi et al. | Oct 2006 | B2 |
| Number | Date | Country |
|---|---|---|
| 2001-98511 | Nov 2001 | KR |
| 2002-26361 | Apr 2002 | KR |
| Number | Date | Country | |
|---|---|---|---|
| 20070030202 A1 | Feb 2007 | US |
