Patent Application
20100060525
1. Field of the Invention
The present invention relates to an antenna, and particularly to a multi-band antenna operating at various wireless communication bands.
2. The Related Art
A conventional multi-band antenna is shown in
However, because the first radiating portion 20 and the second radiating portion 30 of the antenna body 100 are disposed in a common plane, the occupancy space of the antenna body 100 is relative large. If the occupancy space is reduced, the characteristic and the function of transmitting and receiving electromagnetic signals of the multi-band antenna would drop.
Accordingly, an object of the present invention is to provide a multi-band antenna with improved structure to reduce the occupancy space without weakening the characteristic of transmitting and receiving electromagnetic signals. The multi-band antenna includes a feed-in element having a feed-in point thereon. A first connecting portion extends from one side of the feed-in element. A ground element connected to one side of the first connecting portion has a ground point thereon. The ground element is parallel to the feed-in element. A holding portion substantially perpendicularly extends from a side of the ground element opposite the first connecting portion. A second connecting portion substantially perpendicularly bends and extends from a side of the feed-in element opposite the first connecting portion. A first radiating portion extends from one side of the second connecting portion. A second radiating portion extends from the other side of the second connecting portion opposite the first radiating portion. The first radiating portion and part of the second radiating portion are disposed at one side of the holding portion. The rest part of the second radiating portion is disposed at the other side of the holding portion.
When the multi-band antenna is configured to a printed circuit board, the first radiating portion and part of the second radiating portion are disposed at one side of the printed circuit board and the rest part of the second radiating portion is disposed at the other side of the printed circuit board, and therefore, the occupancy space of the multi-band antenna is reduced without the characteristic and the function of transmitting and receiving electromagnetic signals of the multi-band antenna being weakened.
The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which:
Referring to
A middle portion of the side of the feed-in element 1 opposite the first connecting portion 2 perpendicularly bends and extends in a direction away from the holding portion 4 downwardly to form a second connecting portion 5. A right side of the second connecting portion 5 extends rightward to form a first radiating portion 6. The first radiating portion 6 is a high-frequency radiating portion and disposed at one side of the holding portion 4. The first radiating portion 6 includes a first section 61 extending from the right side of the second connecting portion 5 and a second section 62 perpendicularly bending and extending inwardly from a bottom side of the first section 61. The first section 61 is perpendicular to the feed-in element 1 and the second section 62 is parallel to the feed-in element 1.
A left side of the second connecting portion 5 extends leftward to form a second radiating portion 7. The second radiating portion 7 is a lower-frequency radiating portion and includes a first section 71, a second section 72, a third section 73, a fourth section 74 and a fifth section 75, all of which are connected with each other in sequence. The first section 71 extends from the left side of the second connecting portion 5 and is perpendicular to the feed-in element 1. The second section 72 perpendicularly bends and extends inwardly from a bottom side of the first section 71. The second section 72 is parallel to the feed-in element 1 and disposed such that a gap is defined between the two. The third section 73 perpendicularly extends from an end of an inner side of the second section 72 opposite the first section 71. The fourth section 74 perpendicularly extends rightward from an end of an inner side of the third section 73 opposite the second section 72 and is parallel to the feed-in element 1. The fifth section 75 perpendicularly extends from an end of an inner side of the fourth section 74 opposite the third section 73 and is parallel to the third section 73. The first section 71, the second section 72, parts of the third section 73 and the fifth section 75 are disposed at the same side of the holding portion 4 as the first radiating portion 6. The rest parts of the third section 73 and the fifth section 75, the fourth section 74 are disposed at the other side of the holding portion 4 opposite the first radiating portion 6.
As the total electrical length from the feed-in point 11 of the feed-in element 1 to the end of the first radiating portion 6 via the second connecting portion 5 is substantially equal to a quarter of the wavelength corresponding to a frequency 1850 MHz, the first radiating portion 6 resonates at frequency bands DCS1800 and PCS1900.
As the total electrical length from the feed-in point 11 of the feed-in element 1 to the end of the fifth section 75 of the second radiating portion 7 via the second connecting portion 5 is substantially equal to a quarter of the wavelength corresponding to a frequency 920 MHz, the second radiating portion 7 resonates at a frequency band GSM900.
When the multi-band antenna is configured to a printed circuit board 100, the printed circuit board 100 is fixed between the first holding portion 41, the second holding portion 42 and the third holding portion 43. Screws (not shown) engage with the mounting holes 441 of the holding plate 44 to fix the multi-band antenna onto the printed circuit board 100. The first radiating portion 6, the first section 71 and the second section 72 of the second radiating portion 7, parts of the third section 73 and the fifth section 75 of the second radiating portion 7 are disposed at one side of printed circuit board 100. The rest parts of the third section 73 and the fifth section 75, the fourth section 74 of the second radiating portion 7 are disposed at the other side of the printed circuit board 100.
As described above, when the multi-band antenna is configured to the printed circuit board 100, the first radiating portion 6, the first section 71 and the second section 72 of the second radiating portion 7 and parts of the third section 73 and the fifth section 75 of the second radiating portion 7 are disposed at one side of printed circuit board 100. The rest parts of the third section 73 and the fifth section 75, the fourth section 74 of the second radiating portion 7 are disposed at the other side of the printed circuit board 100. With this construction, the occupancy space of the multi-band antenna is reduced without the characteristic and the function of transmitting and receiving electromagnetic signals of the multi-band antenna being weakened. Furthermore, the multi-band antenna can reduce the influence between the first radiating portion 6 disposed at one side of the printed circuit board 100 and the second radiating portion 7 disposed at the other side of the printed circuit board 100, and therefore, the characteristic and the function of transmitting and receiving electromagnetic signals are enhanced.
The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to those skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.
