Antenna of portable electronic devices

An antenna used in portable electronic devices includes a first antenna unit shaped as a planar inverted-F antenna (PIFA) and a second antenna unit shaped as a loop antenna and connected to the first antenna unit. The first antenna unit receives/sends wireless signals at relatively higher frequencies, the second antenna unit receives/sends wireless signals at relatively lower frequencies, and the first antenna unit is coupled with the second antenna unit to regulate the working frequency band of the antenna.

BACKGROUND

1. Technical Field

The present disclosure relates to antennas, and particularly to an antenna used in portable electronic devices.

2. Description of Related Art

Generally, antennas used in the portable electronic devices are very small due to the small size of the portable electronic devices. When working conditions of the portable electronic devices (e.g., ambient temperatures, humidity, and taken/placed manners) changes, working characteristics of these antennas are easily influenced because of their sizes. Thus, frequency offset of the antennas may occur, i.e., the frequencies of wireless signals that can be transferred by the antennas may change. As a result, communication quality of the portable electronic devices may be adversely affected.

Therefore, there is room for improvement within the art.

DETAILED DESCRIPTION

FIG. 1andFIG. 2schematically show an antenna100according to an exemplary embodiment, for use in portable electronic devices. The antenna100can be installed in a portable electronic device and connected to a conventional circuit board200of the portable electronic device to receive/send wireless signals when the portable electronic device is used in wireless communications.

The circuit board200includes a flat main surface220and a flat side surface230perpendicularly connected to the main surface220. One end of the side surface230includes a recess, which forms a receiving portion240. The receiving portion240includes a flat assembly surface250parallel to the side surface240. A grounding connector252and a feed connector254are mounted on the assembly surface250and electrically connected to the circuit board200.

The antenna100is made of conductive materials and includes a first antenna unit10and a second antenna unit30.

The first antenna unit10is a planar inverted-F antenna (PIFA), which includes a first radio member12, a first grounding member14, and a first feed member16. The first radio member12, the first grounding member14, and the first feed member16are all flat sheets and are positioned to be coplanar with each other. The first radio member12includes a first radio portion122, a second radio portion124, and a third radio portion126, which are all longitudinal flat sheets. An end of the second radio portion124is perpendicularly connected to an end of the first radio portion122. The third radio portion126is perpendicularly connected to another end of the second radio portion124and is parallel to the first radio portion122.

The first grounding member14is a longitudinal flat sheet. The first feed member16is a rectangular flat sheet. The second radio portion124, the third radio portion126, the first grounding member14, and the first feed member16are all positioned at a same side of the first radio portion122. The first feed member16is perpendicularly connected to another end of the first radio portion122and is parallel to the second radio portion124. The first grounding member14is perpendicularly connected to the first radio portion122, positioned between the second radio portion124and the first feed member16and adjacent to the first feed member16, and is parallel to the second radio portion124and the first feed member16.

The second antenna unit30is a loop antenna, which includes a second radio member32, a second grounding member34, and a second feed member36. The second radio member32is a flat sheet positioned parallel to the plane in which the first antenna unit10is positioned. The second radio member32includes a fourth radio portion322, a fifth radio portion324, and a sixth radio portion326.

The fourth radio portion322is an L-shaped flat sheet including a first section322aand a second section322b. The first section322aand the second section322bare both longitudinal flat sheets. A projection332pof the first section322a, which is formed on a plane P in which the first antenna unit10is positioned, is positioned between the first radio portion122and the third radio portion126, and is parallel to the first radio portion122and the third radio portion126, as shown inFIG. 2. An end of the second section322bis perpendicularly connected to an end of the first section322a. Another end of the first section322ais aligned with an end of the first feed member16.

The fifth radio portion324is a longitudinal flat sheet. An end of the fifth radio portion324is perpendicularly connected to another end of the second section322b, and the fifth radio portion324and the first section322aare respectively positioned at two sides of the second section322b. The first section322aand the fifth radio portion324are positioned parallel to each other and extend away from the second section322balong two opposite directions, correspondingly.

The sixth radio portion326is an L-shaped flat sheet positioned coplanar with the fourth radio portion322and includes a third section326aand a fourth section326b. The third section326aand the fourth section326bare both longitudinal flat sheets. An end of the third section326ais perpendicularly connected to another end of the fifth radio portion324, and the third section326ais parallel to the second section322b. An end of the fourth section326bis perpendicularly connected to another end of the third section326a. The fourth section326b, the fifth radio portion324, and the fourth radio portion322are positioned at a same side of the third section326a. The fourth section326bis parallel to the fifth radio portion324and the first section322a.

The second grounding member34is a rectangular flat sheet coplanar with the second radio member32. The second grounding member34is perpendicularly connected to another end of the fourth section326b, and the third section326aand the second grounding member34are respectively positioned at two sides of the fourth section326b. An end of the second grounding member34is aligned with an end of the first grounding member14. The second feed member36is a connecting section. Two ends of the second feed member36are respectively perpendicularly connected to the end of the first section322aand the end of the first feed member16that are aligned with each other, such that the first antenna unit10and the second antenna unit30are connected together.

In assembly, conventional electronic components (not shown) of the portable electronic device can be mounted on the main surface220. The antenna100is received in the receiving portion240. The grounding connector252is connected to the first grounding member34, and is further connected to the second grounding member36via the first grounding member34. The feed connector254is connected to both the end of the first grounding member14and the end of the second grounding member34that are aligned with each other. Thus, the antenna100is mounted on a side edge of the circuit board200and does not occupy much space.

In use, the circuit board200provides feed signals to the first feed member16via the feed connector254, and the feed signals are transmitted to the second feed member36via the first feed member16. Both the first antenna unit10and the second antenna unit30can be grounded by the grounding connector252. Thus, the first antenna unit10and the second antenna unit30operate as antennas. Particularly, the first antenna unit10can receive/send wireless signals at relatively higher frequencies (e.g., about 2.6 GHz), and the second antenna unit30can receive/send wireless signals at relatively lower frequencies (e.g., about 2.38 GHz). Furthermore, the first antenna unit10and the second antenna unit30can be coupled with each other. The coupling between the first antenna unit10and the second antenna unit30can change the impedance of the antenna100, and further regulate the working frequency band of the antenna100, such that the multiband antenna100can be used to receive/send wireless signals across a wide frequency band.

Referring toFIG. 3, as known in experiments, in a frequency band of about 2.40 GHz-2.485 GHz, the return loss (RL) of the antenna100is acceptable. Therefore, the multiband antenna100can be used in WLAN communication systems (Wireless Local Area Network, using wireless signals at working frequency of about 2400 MHz). When the working conditions of the portable electronic device (e.g., ambient temperatures, humidity, and taken/placed manners) change, the coupling between the first antenna unit10and the second antenna unit30can be used to regulate the working frequency band of the antenna100and compensate the changes of the working frequency caused by the changed working conditions (i.e., compensate the influence of the frequency offset). According to experiments, when the portable electronic device with the antenna100installed therein is manually held, the frequency offset of the antenna100is not evident, and the antenna100can also normally receive/send wireless signals used in WLAN communication systems. The distance between the first radio member12and the second radio member32can be regulated to obtain a desirable coupling effect.

In the present disclosure, the outer dimension of the exemplary multiband antenna100is about 26.8 mm×4.0 mm×0.8 mm. The distance between the two planes in which the first radio member12and the second radio member32are respectively positioned is about 0.4 mm. Apparently, the antenna100is very small in size, and can be easily mounted on the side edge of the circuit board and received in the housing of the portable electronic device.

The present antenna100is small in size and has good communication quality in at a plurality of frequency bands used in wireless communication, which can allow further size reductions of portable electronic devices employing the antenna100. Note that the dimensions set forth herein are exemplary of the working frequencies also mentioned herein. Accordingly, the dimensions of the antenna100are not limited to the dimensions set forth in this specification.