Abstract:
A multimode antenna that integrates antennae of at least three modes includes antenna radiation elements of at least three modes and a common ground element. In conventional wireless communication devices, in order to achieve the multiplexing effect, a plurality of antennae is built therein, which cannot meet the requirements for both multiplexing and small size. The multimode antenna integrates antennae of a plurality of modes together and shares one ground element, which not only reduces the volume of the antenna, but also achieves a multimode antenna for a multiplex device.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention relates to a multimode antenna, and more particularly to a multimode antenna of multiplex device. 
         [0003]    2. Related Art 
         [0004]    As for wireless communication devices, an antenna is a bridge for communicating with the outside world. The design of antenna has been gradually switched from the configuration of being exposed outside into the configuration of being hidden inside. As the wireless communication device has increasingly powerful functions, from the simple function of making a call to the function of audio-visual entertainments, the design of antenna is required to have the features of high performance, low radiation, small size, and easy matching. 
         [0005]    Currently, the wireless communication device requiring an antenna includes notebook, mobile phone, mobile TV, and satellite navigation system, and so on, in which a successful antenna design is required to achieve the optimal performance. Currently, more and more integrated products have been developed, one wireless communication device may integrate the wireless communication functions, such as Third Generation (3G) mobile communication technology, Wireless Local Area Network (WLAN), and Bluetooth. Each wireless communication system requires a corresponding antenna to transceive signals, and thus, generally, a plurality of antennae may be built in one wireless communication device. 
         [0006]    The functions of wireless communication devices are getting more and more complex, and the sizes are required to get smaller and smaller, but the development of chip manufacturing process has its limitations, so under the condition that the miniaturization of silicon chip has reached the limit, the antenna mechanism is further required to become smaller, so as to be beneficial for the miniaturization of the overall configuration. 
         [0007]    Therefore, it has become an urgent problem to be solved by researches to provide a communication device having a balanced feature in both function and volume, i.e., having an antenna design of smaller volume and even having an antenna integration suitable for different applications. 
       SUMMARY OF THE INVENTION 
       [0008]    In view of the above problems, the present invention is directed to a multimode antenna, which integrates antennae of a plurality of modes together and shares one ground element, and thus not only the volume of the antenna is reduced, but the antenna may also be integrated with a current wireless communication device, thereby achieving a portable and miniaturized multimode wireless communication device. 
         [0009]    The multimode antenna according to the present invention integrates antennae of at least three modes and includes antenna radiation elements of at least three modes and a common ground element. The antenna radiation elements of at least three modes are used to transmit and receive electromagnetic signals of at least three modes. The antenna radiation elements may be, but not limited to, Wireless Local Area Network/Worldwide Interoperability for Microwave Access (WLAN/WiMax) antenna radiation element, ultra wideband (UWB) antenna radiation element, and/or wireless local area network (WLAN) antenna radiation element. The common ground element connects the antenna radiation elements of at least three modes. The common ground element is a plate-shaped ground element and conducts the current of the antenna radiation elements to the ground. The wireless communication device may be a notebook, a PDA, and definitely may be other wireless communication devices. 
         [0010]    The multimode antenna receives the signal current fed in to the multimode antenna through the signal feed-in portion and transfers the signal current to an antenna radiation element corresponding to the mode. The antenna radiation element is used to transmit and receive an electromagnetic signal corresponding to the mode. Due to the design of the multimode antenna, antennae of a plurality of mode are integrated together and share one ground element, so that not only the volume of the antenna is reduced, but the multimode antenna may also be integrated with the current wireless communication device, and thus achieving a space-saving and miniaturized multimode antenna for a multiplex device. 
         [0011]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present invention will become more fully understood from the detailed description given herein below for illustration only, which thus is not limitative of the present invention, and wherein: 
           [0013]      FIG. 1  is a schematic structural view of a first embodiment of the present invention; 
           [0014]      FIG. 2  is a schematic structural view of a second embodiment of the present invention; and 
           [0015]      FIG. 3  is a schematic structural view of a third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    The features and practice of the present invention are illustrated below in detail with reference to the accompanying drawings. 
         [0017]    The multimode antenna according to an embodiment of the present invention includes antenna radiation elements of at least three modes. The antenna radiation elements may be, but not limited to, Wireless Local Area Network/Worldwide Interoperability for Microwave Access (WLAN/WiMax) antenna radiation element, ultra wideband (UWB) antenna radiation element, and wireless local area network (WLAN) antenna radiation element. 
         [0018]    Referring to  FIG. 1 , it is a schematic structural view of a first embodiment of the present invention. A multimode antenna  100  includes a WLAN/WiMax antenna radiation element  10 , a UWB antenna radiation element  11 , a WLAN antenna radiation element  12 , and a common ground element  13 . 
         [0019]    The WLAN/WiMax antenna radiation element  10  is an inverted F-shaped antenna and includes: a radiation element  17 , a conductive pin  18 , and a signal feed-in portion  14 . The material of the WLAN/WiMax antenna radiation element  10  may be, but not limited to, copper, aluminum, and silver. 
         [0020]    The radiation element  17  is a strip-shaped radiator for transmitting and receiving electromagnetic signals with a resonance frequency f 1  (2.4 GHz-2.7 GHz). The radiation element  17  includes: a strip-shaped metal sheet  23 , a first metal sheet  24 , and a second metal sheet  25 . The side edge of the first metal sheet  24  is perpendicularly connected to one major axis side edge of the strip-shaped metal sheet  23 . The first metal sheet  24  has a geometric shape, such as square and rectangle. The side edge of the second metal sheet  25  is perpendicular to one minor axis side edge of the strip-shaped metal sheet  23 . The second metal sheet  25  has a geometric shape, such as square and rectangle. The length L 1  of the radiation element  17  is determined depending upon the wavelength λ 1  of the resonance frequency f 1  (f 1 =c/λ 1 ). The length L 1  of the radiation element  17  is approximately equal to a quarter of the wavelength λ 1  of the resonance frequency f 1 . 
         [0021]    The conductive pin  18  is located between the radiation element  17  and the common ground element  13 . One end of the conductive pin  18  is connected to a major axis side end  23   a  of the strip-shaped metal sheet  23  at the same side as the first metal sheet  24 , and the other side of the conductive pin  18  extends and is connected on the common ground element  13 . 
         [0022]    The signal feed-in portion  14  is perpendicularly connected to the other major axis side edge of the strip-shaped metal sheet  23 , for feeding in a signal current to the radiation element  17  or receiving a signal current fed out from the radiation element  17 . 
         [0023]    The WLAN antenna radiation element  12  is an inverted F-shaped antenna and includes: a radiation element  19 , a conductive pin  20 , and a signal feed-in portion  16 . The material of the WLAN antenna radiation element  12  may be, but not limited to, copper, aluminum, and silver. 
         [0024]    The radiation element  19  is a strip-shaped radiator, for transmitting and receiving an electromagnetic signal with a resonance frequency f 2  (2.4 GHz-2.5 GHz). The radiation element  19  includes: a strip-shaped metal sheet  26 , a zigzagged metal sheet  27 , and a metal sheet  28 . The zigzagged metal sheet  27  is perpendicularly connected to one major axis side edge of the strip-shaped metal sheet  26 . The side edge of the metal sheet  28  is perpendicular to the minor axis side edge of the strip-shaped metal sheet  26 . The metal sheet  28  has a geometric shape, such as square and rectangle. The length L 2  of the radiation element  19  is determined depending upon the wavelength λ 2  of the resonance frequency f 2  (f 2 =c/λ 2 ). The length L 2  of the radiation element  19  is approximately equal to a quarter of the wavelength λ 2  of the resonance frequency f 2 . 
         [0025]    The conductive pin  20  is located between the radiation element  19  and the common ground element  13 . One end of the conductive pin  20  is connected to a major axis side end  26   a  of the strip-shaped metal sheet  26  at the same side as the first metal sheet  27 , and the other end of the conductive pin  20  extends and is connected on the common ground element  13 . 
         [0026]    The signal feed-in portion  16  is perpendicularly connected to the other major axis side edge of the strip-shaped metal sheet  26 , for feeding in a signal current to the radiation element  19  or receiving a signal current fed out from the radiation element  19 . 
         [0027]    The UWB antenna radiation element  11  includes: an insulating substrate  21 , a radiation element  22 , and a signal feed-in portion  15 . The insulating substrate  21  is connected on the common ground element  13 . The radiation element  22  is connected on one side of the insulating substrate  21 , to serve as a radiator. The radiation element  22  may be, but not limited to, a metal body and a metal layer. The radiation element  22  may have a semicircular shape, a semi-oval shape, or other geometric shapes. The material of the radiation element  22  may be copper, aluminum, and silver or other conductive metals. The UWB antenna radiation element  11  is used to replace a conical antenna used in prior art, and to receive a signal current fed in from the signal feed-in portion  15  and transmit an electromagnetic signal with a resonance frequency (3 GHz-10 GHz), which may further sense an electromagnetic signal at the frequency and output the sensed signal current through the signal feed-in portion  15 . 
         [0028]    The common ground element  13  is a plate-shaped ground element and is connected to the WLAN/WiMax antenna radiation element  10 , the UWB antenna radiation element  11 , and the WLAN antenna radiation element  12  through the conductive pin  18 , the conductive pin  20 , and the insulating substrate  21  respectively. The common ground element  13  conducts the currents of the WLAN/WiMax antenna radiation element  10 , the UWB antenna radiation element  11 , and the WLAN antenna radiation element  12  to the ground. The material of the common ground element  13  is selected from a group consisting of copper, aluminum, and silver. 
         [0029]    When the antenna radiation elements of three different modes on the multimode antenna  100 , i.e., the WLAN/WiMax antenna radiation element  10 , the UWB antenna radiation element  11 , and the WLAN antenna radiation element  12 , resonantly receive electromagnetic waves corresponding to the mode thereof, the sensed signal currents may be transferred and sent out through the signal feed-in portions connected to the antenna radiation elements. Similarly, the antenna radiation elements of three different modes may also receive signal currents with the resonance frequencies corresponding to the modes thereof that are fed in from the signal feed-in portion and resonantly send out an electromagnetic wave with the resonance frequency. The multimode antenna  100  integrates antennae of three different modes by the antenna radiation elements of three different modes that share one ground element, thus achieving a function of a space-saving and miniaturized multimode wireless communication device. 
         [0030]    Referring to  FIG. 2 , it is a schematic structural view of a second embodiment of the present invention. A multimode antenna  200  includes a first WLAN antenna radiation element  50 , a UWB antenna radiation element  51 , a second WLAN antenna radiation element  52 , and a common ground element  53 . 
         [0031]    The first WLAN antenna radiation element  50  is an inverted F-shaped antenna and includes: a radiation element  57 , a conductive pin  58 , and a signal feed-in portion  54 . The material of the first WLAN antenna radiation element  50  may be, but not limited to, copper, aluminum, and silver. 
         [0032]    The radiation element  57  is a strip-shaped radiator, for resonantly transceiving an electromagnetic signal with a resonance frequency f 3  (2.4 GHz-2.5 GHz). The radiation element  57  includes: a strip-shaped metal sheet  63 , a first metal sheet  64 , and a second metal sheet  65 . The side edge of the first metal sheet  64  is perpendicularly connected to one major axis side edge of the strip-shaped metal sheet  63 . The first metal sheet  64  has a geometric shape, such as square and rectangle. The side edge of the second metal sheet  65  is perpendicular to one minor axis side edge of the strip-shaped metal sheet  63 . The second metal sheet  65  has a geometric shape, such as square and rectangle. The length L 3  of the radiation element  57  is determined depending upon the wavelength λ 3  of the resonance frequency f 3  (f 3 =c/λ 3 ). The length L 3  of the radiation element  57  is approximately equal to a quarter of the wavelength λ 3  of the resonance frequency f 3 . 
         [0033]    The conductive pin  58  is located between the radiation element  57  and the common ground element  53 . One end of the conductive pin  58  is connected to a major axis side end  63   a  of the strip-shaped metal sheet  63  at the same side as the first metal sheet  64 , and the other end of the conductive pin  58  extends and is connected on the common ground element  53 . 
         [0034]    The signal feed-in portion  54  is perpendicularly connected on the other major axis side edge of the strip-shaped metal sheet  63 , for feeding in a signal current to the radiation element  57  or receiving a signal current fed out from the radiation element  57 . 
         [0035]    The second WLAN antenna radiation element  52  is an inverted F-shaped antenna and includes: a radiation element  59 , a conductive pin  60 , and a signal feed-in portion  56 . The material of the second WLAN antenna radiation element  52  may be, but not limited to, copper, aluminum, and silver. 
         [0036]    The radiation element  59  is a strip-shaped radiator, for resonantly transceiving an electromagnetic signal with the resonance frequency f 4  (2.4 GHz-2.5 GHz). The radiation element  59  includes: a strip-shaped metal sheet  66 , a zigzagged metal sheet  67 , and a metal sheet  68 . The zigzagged metal sheet  67  is perpendicularly connected to one major axis side edge of the strip-shaped metal sheet  66 . The side edge of the metal sheet  68  is perpendicular to one minor axis side edge of the strip-shaped metal sheet  66 . The metal sheet  68  has a geometric shape, such as square and rectangle. The length L 4  of the radiation element  59  is determined depending upon the wavelength λ 4  of the resonance frequency f 4  (f 4 =c/λ 4 ). The length L 4  of the radiation element  59  is approximately equal to a quarter of the wavelength λ 4  of the resonance frequency f 4 . 
         [0037]    The conductive pin  60  is located between the radiation element  59  and the common ground element  53 . One end of the conductive pin  60  is connected to a major axis side end  66   a  of the strip-shaped metal sheet  66  at the same side as the zigzagged metal sheet  67 , and the other end of the conductive pin  60  extends and is connected on the common ground element  53 . 
         [0038]    The signal feed-in portion  56  is perpendicularly connected to the other major axis side edge of the strip-shaped metal sheet  66 , for feeding in a signal current to the radiation element  59  or receiving a signal current fed out from the radiation element  59 . 
         [0039]    The UWB antenna radiation element  51  includes: an insulating substrate  61 , a radiation element  62 , and a signal feed-in portion  55 . The insulating substrate  61  is connected on the common ground element  53 . The radiation element  62  is connected on one side of the insulating substrate  61 , to serve as a radiator. The radiation element  62  may be, but not limited to, a metal body and a metal layer. The radiation element  62  may have a semicircular shape, a semi-oval shape, or other geometric shapes. The material of the radiation element  62  may be copper, aluminum, and silver or other conductive metals. The UWB antenna radiation element  51  is used to replace the conical antenna used in prior art, and to receive a signal current fed in from the signal feed-in portion  55  and transmit an electromagnetic signal with the resonance frequency (3 GHz-10 GHz), which may further sense an electromagnetic signal at the frequency and output the sensed signal current through the signal feed-in portion  55 . 
         [0040]    The common ground element  53  is a plate-shaped ground element and it is respectively connected to the WLAN/WiMax antenna radiation element  50 , the UWB antenna radiation element  51 , and the WLAN antenna radiation element  52  through the conductive pin  58 , the conductive pin  60 , and the insulating substrate  61 . The common ground element  53  conducts the currents of the WLAN/WiMax antenna radiation element  50 , the UWB antenna radiation element  51 , and the WLAN antenna radiation element  52  to the ground. The material of the common ground element  53  is selected from a group consisting of copper, aluminum, and silver. 
         [0041]    When the first WLAN antenna radiation element  50  and the second WLAN antenna radiation element  52  on the multimode antenna  200  are antenna radiation elements of the same mode, upon resonantly receiving an electromagnetic wave with the resonance frequency (2.4 GHz-2.5 GHz) corresponding to the mode thereof, the first WLAN antenna radiation element  50  serves as a main antenna, and the second WLAN radiation element  52  serves as an auxiliary antenna, so as to improve the strength of the multimode antenna  200  in resonantly receiving and transmitting the electromagnetic signal at the resonance frequency (2.4 GHz-2.5 GHz). Therefore, the multimode antenna  200  has three-mode antenna radiation elements and is capable of resonantly transceiving electromagnetic waves with the resonance frequencies corresponding to two different modes. Once the electromagnetic wave with the resonance frequency corresponding to the mode thereof is resonantly received, the sensed signal current will be transferred and sent out through the signal feed-in portion connected to the antenna radiation element. Similarly, the antenna radiation elements of three different modes may also receive signal currents with the resonance frequencies corresponding to the modes thereof that are fed in via the signal feed-in portion and resonantly transmit electromagnetic waves with the resonance frequency. The multimode antenna  200  integrates antennae of two different modes together through the antenna radiation elements of three different modes that share one ground element, and thus achieving a function of a space-saving and miniaturized multimode wireless communication device. 
         [0042]    Referring to  FIG. 3 , it is a schematic structural view of a third embodiment of the present invention. A multimode antenna  300  includes a first WLAN antenna radiation element  80 , a second WLAN antenna radiation element  81 , a third WLAN antenna radiation element  82 , and a common ground element  83 . 
         [0043]    The first WLAN antenna radiation element  80  is an inverted F-shaped antenna and includes: a radiation element  87 , a conductive pin  88 , and a signal feed-in portion  84 . The material of the first WLAN antenna radiation element  80  may be, but not limited to, copper, aluminum, and silver. 
         [0044]    The radiation element  87  is a strip-shaped radiator, for resonantly transceiving an electromagnetic signal with the resonance frequency f 5  (2.4 GHz-2.5 GHz). The radiation element  87  includes: a strip-shaped metal sheet  93 , a first metal sheet  94 , and a second metal sheet  95 . The side edge of the first metal sheet  94  is perpendicularly connected to one major axis side edge of the strip-shaped metal sheet  93 . The first metal sheet  94  has a geometric shape, such as square and rectangle. The side edge of the second metal sheet  95  is perpendicular to one minor axis side edge of the strip-shaped metal sheet  93 . The second metal sheet  95  has a geometric shape, such as square and rectangle. The length L 5  of the radiation element  87  is determined depending upon the wavelength λ 5  of the resonance frequency f 5  (f 5 =c/λ 5 ). The length L 5  of the radiation element  87  is approximately equal to a quarter of the wavelength λ 5  of the resonance frequency f 5 . 
         [0045]    The conductive pin  88  is located between the radiation element  87  and the common ground element  83 . One end of the conductive pin  88  is connected on a major axis side end  93   a  of the strip-shaped metal sheet  93  at the same side as the first metal sheet  94 , and the other end of the conductive pin  88  extends and is connected on the common ground element  83 . 
         [0046]    The signal feed-in portion  84  is perpendicularly connected to the other major axis side edge of the strip-shaped metal sheet  93 , for feeding in a signal current to the radiation element  87  or receiving a signal current fed out from the radiation element  87 . 
         [0047]    The second WLAN antenna radiation element  81  is an inverted F-shaped antenna and includes: a radiation element  89 , a conductive pin  90 , and a signal feed-in portion  85 . The material of the second WLAN antenna radiation element  81  may be, but not limited to, copper, aluminum, and silver. 
         [0048]    The radiation element  89  is a strip-shaped radiator, for resonantly transceiving an electromagnetic signal with the resonance frequency f 6  (2.4 GHz-2.5 GHz). The radiation element  89  includes: a strip-shaped metal sheet  96 , a zigzagged metal sheet  97 , and a metal sheet  98 . The zigzagged metal sheet  97  is perpendicularly connected to one major axis side edge of the strip-shaped metal sheet  96 . One side edge of the metal sheet  98  is perpendicular to one minor axis side edge of the strip-shaped metal sheet  96 . The metal sheet  98  has a geometric shape, such as square and rectangle. The length L 6  of the radiation element  89  is determined depending upon the wavelength λ 6  of the resonance frequency f 6  (f 6 =c/λ 6 ). The length L 6  of the radiation element  89  is approximately equal to a quarter of the wavelength λ 6  of the resonance frequency f 6 . 
         [0049]    The conductive pin  90  is located between the radiation element  89  and the common ground element  83 . One end of the conductive pin  90  is connected on a major axis side end  96   a  of the strip-shaped metal sheet  96  at the same side as the zigzagged metal sheet  97 , and the other end of the conductive pin  90  extends and is connected on the common ground element  83 . 
         [0050]    The signal feed-in portion  85  is perpendicularly connected to the other major axis side edge of the strip-shaped metal sheet  96 , for feeding in a signal current to the radiation element  89  or receiving a signal current fed out from the radiation element  89 . 
         [0051]    The third WLAN antenna radiation element  82  is an inverted F-shaped antenna and includes: a radiation element  91 , a conductive pin  92 , and a signal feed-in portion  86 . The material of the third WLAN antenna radiation element  82  may be, but not limited to, copper, aluminum, and silver. 
         [0052]    The radiation element  91  is a strip-shaped radiator, for resonantly transceiving an electromagnetic signal with the resonance frequency f 7  (2.4 GHz-2.5 GHz). The radiation element  91  includes: a strip-shaped metal sheet  99 , a zigzagged metal sheet  71 , and a metal sheet  72 . The zigzagged metal sheet  71  is perpendicularly connected to one major axis side edge of the strip-shaped metal sheet  99 . The side edge of the metal sheet  72  is perpendicular to one minor axis side edge of the strip-shaped metal sheet  99 . The metal sheet  72  has a geometric shape, such as square and rectangle. The length L 7  of the radiation element  91  is determined depending upon the wavelength λ 7  the of the resonance frequency f 7  (f 7 =c/λ 7 ). The length L 7  of the radiation element  91  is approximately equal to a quarter of the wavelength λ 7  of the resonance frequency f 7 . 
         [0053]    The conductive pin  92  is located between the radiation element  91  and the common ground element  83 . One end of the conductive pin  92  is connected on a major axis side end  99   a  of the strip-shaped metal sheet  99  at the same side as the zigzagged metal sheet  71 , and the other end of the conductive pin  92  extends and is connected on the common ground element  83 . 
         [0054]    The signal feed-in portion  86  is perpendicularly connected to the other major axis side edge of the strip-shaped metal sheet  99 , for feeding in a signal current to the radiation element  91  or receiving a signal current fed out from the radiation element  91 . 
         [0055]    When the antenna radiation elements of three modes on the multimode antenna  300 , i.e., the first WLAN antenna radiation element  80 , the second WLAN antenna radiation element  81 , and the third WLAN antenna radiation element  82  are the antenna radiation elements of the same mode, upon resonantly receiving an electromagnetic wave with the resonance frequency (2.4 GHz-2.5 GHz) corresponding to the mode thereof, the multimode antenna  300  is used as a multiplex device of multiple input multiple output (MIMO). That is, without occupying additional radio frequencies, multiple paths are used to provide higher data throughput and thus increasing the coverage area and the reliability. That is, within the same time, two or more data signals may be transferred in the same radio resonance frequency (2.4 GHz-2.5 GHz). 
         [0056]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.