1. Field of the Invention
The present invention relates to antenna technology and, more particularly, to an antenna assembly that can switch between an omnidirectional antenna mode and directional antenna mode, and an antenna assembly that can switch between a vertically polarized antenna mode and horizontally polarized antenna mode.
2. Description of the Related Art
In a wireless communication system, such as a wireless local area network (WLAN), a communication link is established between a network device and a terminal device for information transfer. Here, the network device should be able to move randomly depending on actual application scenarios and different environments or should be installed on a fixed structure, such as a wall.
In certain cases, it is desirable for the same network device to support multiple installation modes. For example, in an office, it is desirable to install the access point device located in the wireless local area network on a wall or to place the access point device on a desk.
When a network device can be moved, an omnidirectional antenna is often needed for receiving and sending data. When a network device with an omnidirectional antenna is installed on a wall, a large portion of the signals may be absorbed and reflected by the wall. As a result, the emitted signals are weakened or the signal component reflected by the wall counteracts the signal component in the desired direction. At the time of signal reception, the absorption and reflection of the signals by the wall, and the noises and interferences reflected by the wall will all affect the signal receiving performance of the network device.
The present patent application utilizes the exemplary WLAN for the following description but the technical solution provided by the present application is also applicable to other wireless communication systems. WLAN can provide wireless network access and high-speed internet access at home, in the office and other places without a network connection cable. For example, in an office, it is very convenient for users to keep their notebook PCs connected to the network in different rooms, without having to repeatedly connect the network cable.
Today, most WLAN network devices use an omnidirectional antenna by default. For certain WLAN network devices, it is acceptable to replace the original antenna with a different antenna. For such network devices, an antenna interface that is compatible with the device may be installed on the WLAN network device, for example, a directional antenna interface and omnidirectional antenna interface. If directional antenna is needed, a directional antenna can be installed on the device. Likewise, if an omnidirectional antenna is needed, the original directional antenna can be replaced with an omnidirectional antenna.
Even so, most conventional antennas for network devices still cannot adapt well to different application scenarios and installation locations. Moreover, in different network device applications, a considerable load of extra antenna debugging work is needed, such as frequent changes of the antenna, making it very inconvenient to use the network device.
It is therefore an object of the present invention to provide an antenna assembly which can switch between an omnidirectional antenna mode and directional antenna mode.
It is a further object of the present invention to also provide an antenna assembly which can switch between a vertically polarized antenna mode and a horizontally polarized antenna mode.
These and other objects and advantages are achieved in accordance with the invention by providing an antenna assembly which comprises a first directional antenna, a second directional antenna, and a switcher for switching the antenna assembly between an omnidirectional antenna mode and a directional antenna mode, where the first directional antenna and the second directional antenna are arranged in a back-to-back configuration. Here, the switcher comprises a device connection terminal, and a first and a second antenna connection terminal, where the device connection terminal is used to connect to a wireless device, and the first and second antenna connection terminals connect to the first directional antenna and the second directional antenna, respectively. Moreover, when both antenna connection terminals of the switcher are selected, the antenna assembly operates in the omnidirectional antenna mode. When one of the first and second antenna connection terminals of the switcher is selected, the antenna assembly operates in the directional antenna mode.
In an alternative embodiment, the switcher comprises a divider/combiner and an on-off radiofrequency (RF) switch, where the divider/combiner comprises one input terminal and two output terminals. Here, the input terminal connects to the device connection terminal, one of the two output terminals connects to the first antenna connection terminal, and the other one of the two output terminals connects to the second antenna connection terminal through the RF switch. When the RF switch connects the output terminal to the second antenna connection terminal, the antenna assembly operates in the omnidirectional antenna mode. On the other hand, when the RF switch disconnects the output terminal from the second antenna connection terminal, the antenna assembly operates in the directional antenna mode.
Preferably, the switcher comprises a divider/combiner, and a first, a second and a third single-pole-double-throw (SPDT) RF switch, where the divider/combiner comprises one input terminal and two output terminals. Here, the input terminal connects to the device connection terminal through the first SPDT RF switch, one of the two output terminals connects to the first antenna connection terminal through the second SPDT RF switch, and the other one of the two output terminals connects to the second antenna connection terminal through the third SPDT RF switch. Moreover, a gating terminal of the first SPDT RF switch connects to a gating terminal of the third SPDT RF switch, and the first SPDT RF switch and the third SPDT RF switch perform synchronized switching. When the first SPDT RF switch connects the device connection terminal to the input terminal while the third SPDT RF switch connects the output terminal to the second antenna connection terminal, the antenna assembly operates in the omnidirectional antenna mode. Moreover, after the first SPDT RF switch and the third SPDT RF switch perform synchronized switching, and when the device connection terminal is connected to the second antenna connection terminal, the antenna assembly operates in the directional antenna mode.
Preferably, the switching of the antenna mode is controlled by a software program.
In preferred embodiments, the antenna assembly further comprises a proximity sensor and a control unit, where the proximity sensor is used to detect the installation position of said wireless device, and transmits the detected installation position information to the control unit, the control unit is used to-control status switching of each of the RF switches in accordance with the detected installation position information.
In another embodiment, the antenna assembly comprises a horizontally polarized antenna, a vertically polarized antenna, and a switcher for switching said antenna assembly between the horizontally polarized antenna mode and the vertically polarized antenna mode, where the switcher comprises a device connection terminal, and a first and a second antenna connection terminal. Here, the device connection terminal is used to connect to a wireless device, and the first and second antenna connection terminals connect to the horizontally polarized antenna and the vertically polarized antenna, respectively. When only the first antenna connection terminal is selected, the antenna assembly operates in the horizontally polarized antenna mode. On the other hand, when, only the second antenna connection terminal is selected, the antenna assembly operates in the vertically polarized antenna mode.
Optionally, the horizontally polarized antenna and the vertically polarized antenna are arranged in one plane.
Optionally, the horizontally polarized antenna and the vertically polarized antenna are arranged in different planes.
In preferred embodiments, the switcher comprises an SPDT RF switch, where the input terminal of the SPDT RF switch connects to the device connection terminal, and the two gating terminals of the SPDT RF switch connect to the first and the second antenna connection terminals, respectively. When the SPDT RF switch connects the device connection terminal to the first antenna connection terminal, the antenna assembly operates in the horizontally polarized antenna mode. On the other hand, when the SPDT RF switch connects the device connection terminal to the second antenna connection terminal, the antenna assembly operates in the vertically polarized antenna mode.
Preferably, the switching of the antenna mode is controlled by a software program.
In preferred embodiments, antenna assembly also comprises an inclination sensor and a control unit. Here, the inclination sensor is used to detect the angle of inclination of the wireless device, and transmits the detected angle of inclination information to the control unit, Here, the control unit is used to control the switching of the antenna modes according to the detected angle of inclination information.
With the antenna assembly provided by the disclosed embodiments of the present invention, directionalities of the antenna directional pattern or antenna polarization modes of the antenna assembly can be flexibly switched, which enables a wireless device to be well-adapted to the demands of different application scenarios and installation positions for data receiving and sending, and simplifies the use and operation of the wireless device. In addition, the disclosed embodiments of the present invention provide a further proximity sensor and inclination sensor in the two kinds of antenna assemblies, and enables the antenna assembly switching under control of a separate control unit according to detection information from the proximity sensor. As a result, the directionality of the antenna directional profile or antenna polarization modes of the antenna assembly can be self-adaptively adjusted, and the use and operation of the wireless device become much easier.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
The following content will describe the illustrative embodiments of the present invention in detail with reference to the attached figures, so that persons of ordinary skill in the art can clearly understand the above and other features as well as the advantages of the present invention, wherein in the figures:
a is a graphical plot illustrating a radiation power curve in an omindirectional antenna mode when configuring the antenna assembly of
b is a graphical plot illustrating a radiation power curve in directional antenna mode when configuring the antenna assembly of
In order to further clarify the purposes, technical solution and advantages of the present invention, more details are given below in conjunction with drawings and embodiments. It shall be understood that the particular embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention.
In a wireless communication system, in order to reduce the extra work in adapting the network devices in actual applications and to simplify the use and operation of network devices, the present invention provides an antenna assembly comprising multiple antennas, where the antenna assembly can flexibly switch between different operational modes so that the network device can adapt optimally to the transceiving needs of different application scenarios and installation positions.
The present invention provides an antenna assembly that can switch between an omnidirectional antenna mode and a directional antenna mode. The antenna assembly comprises a first directional antenna, a second directional antenna, and a switcher for switching the antenna assembly between the omnidirectional antenna mode and the directional antenna mode, where the first directional antenna and the second directional antenna are arranged in a back-to-back manner. The switcher comprises a device connection terminal, and a first and a second antenna connection terminal, where the device connection terminal is used to connect to a wireless device, such as a WLAN network device, and the first and second antenna connection terminals connect to the first directional antenna and the second directional antenna, respectively. When both antenna connection terminals of the switcher are selected, the antenna assembly operates in the omnidirectional antenna mode. When one of the two antenna connection terminals of the switcher is selected, the antenna assembly operates in the directional antenna mode.
In a first embodiment, the antenna assembly can switch between the directional antenna mode and omnidirectional antenna mode through the switcher shown in
In the embodiment depicted in
a is a graphical plot illustrating a radiation power curve in the omnidirectional antenna mode when configuring the antenna assembly of
b is a graphical plot illustrating a radiation power curve in the directional antenna mode when configuring the antenna assembly of the first embodiment to receive and send signals. As shown in
According to the antenna radiation power curve profile shown in
In the antenna assembly in accordance with an alternative embodiment of the invention, the first directional antenna and the second directional antenna have the same structure as that shown in
When the SPDT RF 1 connects the device connection terminal to the input terminal, while SPDT RF 3 connects the output terminal to the second antenna connection terminal, both the directional antenna 1 and directional antenna 2 can obtain the feed source, and the antenna assembly works in the omnidirectional antenna mode. After the SPDT RF switch 1 and SPDT RF switch 3 complete the synchronized switch, and when the device connection terminal and the second antenna connection terminal are selected, only the directional antenna 2 can obtain the feed source, and the antenna assembly operates in the directional antenna mode.
In the antenna assembly in accordance with the alternative embodiment of the invention, the purpose of setting SPDT RE 2 in the switcher is to ensure that the resistances of the two antenna connection terminals of the switcher match each other. When the divider/combiner by design alone can solve the problem of different insertion losses at its two output terminals, and ensure that the resistances of the two antenna connection terminals match each other, the switcher in the contemplated embodiment can be simply the one used in the previously described embodiment.
In the contemplated embodiments of the antenna assembly of the present invention, the switching of the antenna assembly operational mode, or the status switching of each of the RF switches, can be controlled by the software program. According to different application scenarios and different installation positions of the network device, the operational mode of the antenna assembly can be configured through the software program. The configuration instructions sent from the software program can be further converted into controlling voltages by a logical circuit, and the status switching of the RF switches can be controlled through different controlling voltages.
In addition, the antenna assembly in accordance with the contemplated embodiments of the present invention may also comprise a proximity sensor and a control unit. Here, the proximity sensor is used to detect the installation positions, for example, installed on a wall or a desk, of the wireless device that incorporates the antenna assembly, and transmit the detected installation position information to the control unit. The control unit controls the status switching of each of the RF switches according to the different installation positions, thus switching the operational mode of the antenna assembly. For example, when the proximity sensor detects that the antenna device is installed near a wall, the control unit can control the antenna assembly so that it operates in the directional antenna mode according to such installation position detection information. When the proximity sensor detects that the wireless device is installed in a location at which no obstacle is located close by, the control unit can accordingly control the antenna assembly to operate in the omnidirectional antenna mode. In this way, the antenna assembly can self-adaptively adjust its H-plane antenna directional pattern according to different application scenarios and installation positions of the wireless device, so that different usage demands can be satisfied more flexibly and conveniently.
In a different wireless communication system, electromagnetic wave signals can be transmitted in a different polarized mode, such as the commonly-used horizontally polarized mode or vertically polarized mode. Accordingly, a horizontally polarized antenna or vertically polarized antenna is required to send and receive such electromagnetic wave signals. Furthermore, depending on the installation positions of the wireless device, for example, whether the wireless device is vertically or horizontally installed, it may also be necessary to adjust the antenna polarization mode of the wireless device.
The contemplated embodiments of the present invention also provide an antenna assembly that can switch between horizontal polarized antenna mode and vertically polarized antenna mode. Here, the antenna assembly comprises a horizontally polarized antenna, a vertically polarized antenna, and a switcher for switching the antenna assembly between the horizontally polarized antenna mode and the vertically polarized antenna mode. In this case, the switcher comprises a device connection terminal, a first antenna connection terminal and a second antenna connection terminal, the device connection terminal is used to connect to a wireless device, and the first and second antenna connection terminals connect to the horizontally polarized antenna and vertically polarized antenna, respectively. When only the first antenna connection terminal is selected, the antenna assembly operates in the horizontally polarized antenna mode. When only the second antenna connection terminal is selected, the antenna assembly operates in the vertically polarized antenna mode.
In the embodiment depicted in
When the SPDT RF switch connects the device connection terminal to the first antenna connection terminal, only antenna 1 can obtain the feed source, and the antenna assembly operates in the horizontally polarized antenna mode. When the SPDT RF switch connects the device connection terminal to the second antenna connection terminal, only antenna 2 can obtain the feed source, and the antenna assembly operates in the vertically polarized antenna mode.
In the currently contemplated embodiment, optionally, the horizontally polarized antenna and the vertically polarized antenna can also be arranged in different planes, for example, the two antenna planes are perpendicular to each other to adapt to different installation modes and application needs of the wireless device.
In the antenna assembly in accordance with the embodiment shown in
According to different application scenarios and installation positions of the network device, the polarization mode of the antenna assembly can be configured through the software program. The configuration instructions sent from the software program can be further converted to controlling voltages by a logical circuit, and the status switching of the RF switch can be controlled through different controlling voltages, so as to control the polarization mode switching of the antenna assembly.
In addition, the antenna assembly of
Thus, while there are shown, described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the illustrated apparatus, and in its operation, may be made by those skilled in the art without departing from the spirit of the invention. Moreover, it should be recognized that structures shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice.
This is a U.S. national stage of International Application No. PCT/CN2008/000738, filed on 10 Apr. 2008. The entire content of the application is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CN2008/000738 | 4/10/2008 | WO | 00 | 12/30/2010 |