Patent Application
20150061954
The subject matter herein generally relates to an antenna assembly.
Antennas are usually assembled in a wireless communication device to send and/or receive signals.
Antennas are usually assembled in a wireless communication device to send and/or receive signals. Commonly, frequencies of the antennas are broadened by adding an additional antenna based on a main antenna.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure.
Several definitions that apply throughout this disclosure will now be presented.
The term “substantially” is defined to be essentially conforming to the particular dimension, shape or other word that substantially modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like.
The base board 11 is a substantially flat board and can be made of a dielectric material, such as an epoxy resin glass fiber. The base board 11 includes a first surface 111 and a second surface 112 parallel with, and opposite to, the first surface 111. The first surface 111 can be a top surface of the base board 11. The second surface 112 can be a bottom surface of the base board 11.
The ground plane 13 can be formed by a conductive foil, such as copper foil, and can be plated on the first surface 111. That is, the first surface 111 is covered with the ground plane 13. In the embodiment, there is no conductive foil plated on a portion of the first surface 111 (for example, a corner of the first surface 111) to expose a portion of the first surface 111.
The antenna 15 is defined by removing a portion of the conductive foil to expose the dielectric material of the base board 10.
The matching unit 17 further includes a switch module 172, a first inductor L1, a second inductor L2, and an adjustable capacitor C. The switch module 172 includes a first switch S1 and a second switch S2. The first switch S1 and the second switch S2 can be mechanical switches, electronic switches or chips. An end of the first switch S1 is electronically connected to the RF output terminal 171. Another end of the first switch S1 is electronically connected to an end of the first inductor L1. An end of the second switch S2 is electronically connected to the RF output terminal 171. Another end of the second switch S2 is electronically connected to an end of the second inductor L2. Another end of the first inductor L1 and another end of the second inductor L2 are electronically connected together and are both electronically connected to the antenna 15 and an end of the adjustable capacitor C. Another end of the adjustable capacitor C is grounded.
In the embodiment, an inductance of the first inductor L1 is about 1.8 nH, an inductance of the second inductor L2 is about 8 nH, a capacitance of the adjustable capacitor C is about 2 pF to 4.5 pF.
When the first switch S1 is turned on and the second switch S2 is turned off, the first inductor L1 and the adjustable capacitor C are selected to be electronically connected to the RF output terminal 171 by the turned-on first switch S1. Signal output by the RF output terminal 171 is transmitted to the antenna 15 by the first inductor L1 and the adjustable capacitor C. When the first switch S1 is turned off and the second switch S2 is turned on, the second inductor L2 and the adjustable capacitor C are selected to be electronically connected to the RF output terminal 171 by the turned-on second switch S2. Signal output by the RF output terminal 171 is transmitted to the antenna 15 by the second inductor L2 and the adjustable capacitor C.
When the first inductor L1 or the second inductor L2 is selected, the adjustable capacitor C can be adjusted to match with the first inductor L1 or the second inductor L2 for matching an impedance of the antenna 15 to broaden a bandwidth of the antenna 15 in a high-frequency band. When the first switch S1 is turned on and the second switch S2 is turned off to select the first inductor L1 and the adjustable capacitor C, a capacitance of the adjustable capacitor C can be adjusted to a first value (for example, 3.5 Pf), and the antenna 15 can be adjusted to a dual-frequency mode from a single-frequency mode to obtain a first bandwidth. When the first switch S1 is turned off and the second switch S2 is turned on to select the second inductor L2 and the adjustable capacitor C, a capacitance of the adjustable capacitor C can be gradually increased from a second value, and a central frequency of the antenna 15 can be moved to a low-frequency range to obtain a second bandwidth. In this embodiment, the capacitance of the adjustable capacitor C is gradually increased from 3.3 Pf to 3.7 Pf and 4.5 Pf.
When the first switch S1 is turned off and the second switch S2 is turned on to select the second inductor L2 and the adjustable capacitor C, a capacitance of the adjustable capacitor C can be gradually decreased from the second value, and the central frequency of the antenna 15 can be moved to a high-frequency range to obtain a third bandwidth. In this embodiment, the capacitance of the adjustable capacitor C is gradually decreased from 3.3 Pf to 2.9 Pf, 2.6 Pf, 2.35 Pf, and 2 Pf.
As shown in
In other embodiments, the first inductor L1 can be replaced by a plurality of inductors that the sum of the inductances of the plurality of inductors is equal to the inductance of the first inductor L1. The second inductor L2 can be replaced by a plurality of inductors that the sum of the inductances of the plurality of inductors is equal to the inductance of the second inductor L2.
The embodiments shown and described above are only examples. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013205292191 | Aug 2013 | CN | national |
