1. Technical Field
The disclosure generally relates to antenna assemblies and particularly to an antenna assembly having a wider bandwidth and a reduced size.
2. Description of Related Art
To communicate in multi-band communication systems, a bandwidth of an antenna of a wireless communication device such as a mobile phone should be wide enough to cover frequency bands of the multi-band communication systems. In addition, because of the miniaturization of the wireless communication device, space occupied by the antenna is compressed and limited. Therefore, it is necessary to design the antenna take up a smaller space.
Therefore, there is room for improvement within the art.
Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the disclosure.
The carrier 10 may be a printed circuit board (PCB). The carrier 10 includes a first surface 11 and an opposite second surface 12. The first surface 11 includes an antenna mounting area 112. The antenna mounting area 112 is defined as an area where no conductive elements such as batteries, speakers, charge coupled devices (CCDs) are positioned to prevent interference from the conductive members to the antenna assembly 100.
The first antenna 40 includes a connecting arm 41, a first radiating arm 42, and a pair of combining portions 43 interconnecting the connecting arm 41 and the first radiating arm 42. The first radiating arm 42 and the connecting arm 41 are substantially strip-shaped and parallel to each other. A length of the connecting arm 41 is shorter than a length of the first radiating arm 42. Each combining portion 43 is substantially U-shaped and includes a first combining section 431, a second combining section 432, and a third combining section 433. The first combining section 431 is parallel to and spaced from the third combining section 433. The second combining section 432 is perpendicularly connected between the first combining section 431 and the third combining section 433. A length of the first combining section 431 is slightly shorter than a length of the third combining section 433. A distal end of the first combining section 431 opposite to the second combining section 432 is perpendicularly connected to one end of the connecting arm 41. A distal end of the third combining section 433 opposite to the second combining section 432 is perpendicularly connected to the first radiating arm 42. Thus, the connecting arm 41, the pair of combining portions 43, and a portion of the radiating arm 42 form a closed substantially U-shaped structure.
The feed end 20 is a substantially rectangular sheet perpendicularly connected to a middle portion of the connecting arm 41. The feed end 20 is positioned on a plane perpendicular to the first antenna 40.
The second antenna 50 includes a second radiating arm 51 and a pair of radiating units 52 and forms a hollow 3D open space. The first antenna 40 is positioned inside the 3D space of the second antenna 50. The second radiating arm 51 is substantially strip-shaped having a length slightly longer than that of the first radiating arm 42. Two ends of the second radiating arm 51 are respectively connected to one of the radiating units 52.
Each radiating units 52 includes a first radiating portion 521, a second radiating portion 522 connected to the first radiating portion 521, and a connecting portion 523 connected between the first radiating portion 521 and the second radiating arm 51.
The first radiating portion 521 is a substantially rectangular frame having an opening. The first radiating portion 521 includes two opposite first band sections 5211, a second band section 5212, and a third band section 5213 opposite to the second band section 5212. The second band section 5212 is perpendicularly connected between the first band sections 5211. A length of the third band section 5213 is slightly shorter than that of the second band section 5212. The third band section 5213 is perpendicularly connected to one of the first band sections 5211 and forms the opening with the other of the first band sections 5211.
The second radiating portion 522 is substantially L-shaped. The second radiating portion 522 includes a first radiating section 5221 and a second radiating section 5222 perpendicularly connected to the first radiating section 5221. An end of the first radiating section 5221 opposite to the second radiating section 5222 is perpendicularly connected to an end of the third band section 5213. An end of the second radiating section 5221 perpendicularly extends a distance along a direction opposite to the first radiating section 5221 to form one of the ground ends 30.
The connecting portion 523 is also substantially L-shaped. The connecting portion 523 includes a first connecting section 5231 and a second connecting section 5232 perpendicularly connected to the first connecting section 5231. The first connecting section 5231 perpendicularly extends from an end of one of the first band sections 5211 and is collinear with the third band section 5213. The second connecting section 5232 is perpendicularly connected to an end of the second radiating arm 51.
The metal member 60 is positioned on the second surface 12. In this embodiment, the metal member 60 is a housing of a universal serial bus (USB) connector.
The metal member 60 is configured to electronically connect to the ground ends 30 by a microstrip line, or a coaxial cable, etc. and provide a ground path for the antenna assembly 100 so that the antenna assembly 100 can obtain a better impedance matching.
In addition, each ground end 30 forms a first gap 21 with the feed end 202, and the first radiating arm 42 forms a second gap 23 with the second radiating arm 51. In use, because of the first gaps 21 and the second gap 23, the first antenna 40 is coupled with the second antenna 50. The first antenna 40 and the second antenna 50 cooperatively activate a low frequency band resonance mode so that the antenna assembly 100 can work at a first frequency band such as GSM frequency band. Meanwhile, the first antenna 40 independently activates a high frequency band resonance mode so that the antenna assembly 100 can works a second frequency band such as WCDMA frequency band.
Therefore, the antenna assembly 100 has a widen bandwidth by the coplanar-waveguide feed structure of the feed end 20 and the ground ends 30 and the resonance between the first antenna 40 and the second antenna 50. Moreover, the first antenna 40 is positioned between the two radiating units 52 of the second antenna 50 so that the antenna assembly 100 has a compressed and reduced volume.
It is believed that the exemplary embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.
Number | Date | Country | Kind |
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10211525 | Apr 2013 | TW | national |