Abstract:
The invention relates to an ultra wideband antenna with band-notched characteristics, particularly to an ultra wideband antenna capable of suppressing transmission and reception in a particular frequency range. The ultra wideband antenna includes: a substrate; a grounding unit, installed on the substrate and scooped with a first slot and a first strip hole; a signal feeding unit, installed on the substrate and including a horizontal portion and a vertical portion, in which the horizontal portion is located in the first slot and the vertical portion is located in the first strip hole; a first complementary, separate, circular resonator; and a second complementary, separate, circular resonator, wherein the first complementary, separate, circular resonator and the second complementary, separate, circular resonator are installed in the horizontal portion of the signal feeding unit and are connected with each other.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to an ultra wideband antenna with band-notched characteristics, particularly to an ultra wideband antenna capable of suppressing transmission and reception in a particular frequency range through providing two complementary, separate, circular resonators, connected with each other, in a signal feeding unit. 
         [0003]    2. Description of Related Art 
         [0004]    Accompanied by rapid growth of demand of radio transmission over a short distance, wireless communication of local area networks and variety of personal mobile communication products, the quantity and speed of transmission of radio communication data are increasing. In view of that, in February, 2002, the Federal Communications Commission approved that ultra wideband technology may be used in a general commercial communication system, and regulates that ultra wideband communication is a high transmission, low power and short distance communication system. However, the frequency range of the ultra wideband (from 3.1 GHz to 10.6 GHz) includes the frequency band, such as 5.150 GHz to 5.875 GHz, used in a wireless local area network (WLAN). Thus, interference of the communication signals between the ultra wideband communication and the WLAM system will be incurred. 
         [0005]    Therefore, in order to allow the ultra wideband communication to become more practicable, those engaged in the industry submit many solutions to suppress signals transmitted or received in the operation frequency band of the WLAN for the ultra wideband communication, so as to reduce the afore-mentioned signal interference. As described below, there are three conventional ultra wideband antennas with band-notched characteristics that are able not to transmit or receive a high frequency signal in the operation frequency band (5 GHz to 6 GHz) of the WLAN. 
         [0006]    As shown in  FIG. 1A , the first conventional ultra wideband antenna with band-notched characteristics includes a substrate  11 , a grounding unit  12 , a signal feeding unit  13 , and a rectangular strip slot  14 . The substrate  11  is preferably a microwave substrate with FR-4 material. The grounding unit  12  is installed on the substrate  11  and scooped with a first slot  121  and a first strip hole  122 , in which the first strip hole  122  is communicated with the first slot  121  and extended to a side  111  of the substrate  11 . In addition, the signal feeding unit  13  is installed on the substrate  11  and includes a horizontal portion  131  and a vertical portion  132 , in which the horizontal portion  131  is in the first slot  121  and the vertical portion  132  is in the first strip hole  122 . 
         [0007]    As shown in  FIGS. 1A and 1B , the first slot  121  of the grounding unit  12  is a rectangular strip slot and the shape of the horizontal portion  131  of the signal feeding unit  13  is rectangular. Further, the material of the grounding unit  12  and the signal feeding unit  13  is metal. Furthermore, the rectangular strip slot  14  is installed on the horizontal portion  131  of the signal feeding unit  13  and has an opening  141 , in which the direction of the opening of the rectangular strip slot  14  is parallel to the extension direction of the vertical portion  132  of the signal feeding unit  13  and the length of the rectangular strip slot  14  is 21.4 mm. 
         [0008]    Besides, the sizes of various labels for the first conventional ultra wideband antenna with band-notched characteristics as shown in  FIGS. 1A and 1B  are listed in the following Table 1: 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 label 
                 size (mm) 
                 label 
                 size (mm) 
                 label 
                 size (mm) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 L 
                 35 
                 W 
                 33 
                 Ls 
                 23 
               
               
                 Ws 
                 13 
                 t 
                 2 
                 Sf 
                 0.4 
               
               
                 Wf 
                 3.6 
                 AB 
                 10.8 
                 AE 
                 4 
               
               
                   
               
             
          
         
       
     
         [0009]    Therefore, in the first conventional ultra wideband antenna with band-notched characteristics, the “band-notched unit” is constituted by the rectangular strip slot  14  such that the first conventional ultra wideband antenna with band-notched characteristics is able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. The detailed characteristic curves, such as return loss and gain, will be shown together with those of the present invention in the following. 
         [0010]    As shown in  FIG. 2A , the second conventional ultra wideband antenna with band-notched characteristics includes a substrate  21 , a grounding unit  22 , a signal feeding unit  23 , and a complementary, separate, circular resonator  24 . The substrate  21  is preferably a microwave substrate with FR-4 material. The grounding unit  22  is installed on the substrate  21  and scooped with a first slot  221  and a first strip hole  222 , in which the first strip hole  222  is communicated with the first slot  221  and extended to a side  211  of the substrate  21 . In addition, the signal feeding unit  23  is installed on the substrate  21  and includes a horizontal portion  231  and a vertical portion  232 , in which the horizontal portion  231  is in the first slot  221  and the vertical portion  232  is in the first strip hole  222 . 
         [0011]    As shown in  FIGS. 2A and 2B , the first slot  221  of the grounding unit  22  is a rectangular slot and the shape of the horizontal portion  231  of the signal feeding unit  23  is rectangular. Further, the material of the grounding unit  22  and the signal feeding unit  23  is metal. Furthermore, the complementary, separate, circular resonator  24  is installed on the horizontal portion  231  of the signal feeding unit  23  and includes a first rectangular strip slot  241  and a second rectangular strip slot  242 , in which the first rectangular strip slot  241  surrounds the second rectangular strip slot  242 . The first rectangular strip slot  241  and the second rectangular strip slot  242  respectively have an opening  243  and an opening  244  and the direction of the opening of the first rectangular strip slot  241  is opposite to the direction of the opening of the second rectangular strip slot  242 . Furthermore, the direction of the opening of the first rectangular strip slot  241  is parallel to the extension direction of the vertical portion  232  of the signal feeding unit  23 . 
         [0012]    Besides, the sizes of various labels for the second conventional ultra wideband antenna with band-notched characteristics as shown in  FIGS. 2A  and  2 B are listed in the following Table 2: 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 label 
                 Size (mm) 
                 label 
                 size (mm) 
                 label 
                 size (mm) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 L 
                 35 
                 W 
                 33 
                 Ls 
                 23 
               
               
                 Ws 
                 13 
                 t 
                 2 
                 Sf 
                 0.4 
               
               
                 Wf 
                 3.6 
                 AB 
                 10.8 
                 AE 
                 4 
               
               
                 g 
                 0.1 
                 c 
                 0.2 
                 d 
                 0.4 
               
               
                 r 
                 0.9 
               
               
                   
               
             
          
         
       
     
         [0013]    Therefore, in the second conventional ultra wideband antenna with band-notched characteristics, the “band-notched unit” is constituted by the complementary, separate, circular resonator  24  such that the second conventional ultra wideband antenna with band-notched characteristics is able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. The detailed characteristic curves, such as return loss and gain, will be shown together with those of the present invention in the following. 
         [0014]    As shown in  FIG. 3A , the third conventional ultra wideband antenna with band-notched characteristics includes a substrate  31 , a grounding unit  32 , a signal feeding unit  33 , a first complementary, separate, circular resonator  34  and a second complementary, separate, circular resonator  35 . The substrate  31  is preferably a microwave substrate with FR-4 material. The grounding unit  32  is installed on the substrate  31  and scooped with a first slot  321  and a first strip hole  322 , in which the first strip hole  322  is communicated with the first slot  321  and extended to a side  311  of the substrate  31 . In addition, the signal feeding unit  33  is also installed on the substrate  31  and includes a horizontal portion  331  and a vertical portion  332 , in which the horizontal portion  331  is in the first slot  321  and the vertical portion  332  is in the first strip hole  322 . 
         [0015]    As shown in  FIGS. 3A and 3B , the first slot  321  of the grounding unit  32  is a rectangular slot and the shape of the horizontal portion  331  of the signal feeding unit  33  is rectangular. Further, the material of the grounding unit  32  and the signal feeding unit  33  is metal. Furthermore, the first complementary, separate, circular resonator  34  and the second complementary, separate, circular resonator  35  are installed on the horizontal portion  331  of the signal feeding unit  33 , and the first complementary, separate, circular resonator  34  and the second complementary, separate, circular resonator  35  are spaced apart from a distance S in installation. 
         [0016]    As shown in  FIG. 3B , the first complementary, separate, circular resonator  34  includes a first rectangular strip slot  341  and a second rectangular strip slot  342 , in which the first rectangular strip slot  341  surrounds the second rectangular strip slot  342 . The first rectangular strip slot  341  and the second rectangular strip slot  342  respectively have an opening  343  and an opening  344  and the direction of the opening of the first rectangular strip slot  341  is opposite to the direction of the opening of the second rectangular strip slot  342 . Furthermore, the direction of the opening of the first rectangular strip slot  341  is parallel to the extension direction of the vertical portion  332  of the signal feeding unit  33 . In addition, the second complementary, separate, circular resonator  35  includes a third rectangular strip slot  351  and a fourth rectangular strip slot  352 , in which the third rectangular strip slot  351  surrounds the fourth rectangular strip slot  352 . The third rectangular strip slot  351  and the fourth rectangular strip slot  352  respectively have an opening  353  and an opening  354  and the direction of the opening of the third rectangular strip slot  351  is opposite to the direction of the opening of the fourth rectangular strip slot  352 . Furthermore, the direction of the opening of the first rectangular strip slot  341  is parallel to the direction of the opening of the third rectangular strip slot  351 . 
         [0017]    Besides, the sizes of various labels for the third conventional ultra wideband antenna with band-notched characteristics as shown in  FIGS. 3A and 3B  are listed in the following Table 3: 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 label 
                 Size (mm) 
                 label 
                 size (mm) 
                 label 
                 size (mm) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 L 
                 35 
                 W 
                 33 
                 Ls 
                 23 
               
               
                 Ws 
                 13 
                 t 
                 2 
                 Sf 
                 0.4 
               
               
                 Wf 
                 3.6 
                 AB 
                 10.8 
                 AE 
                 4 
               
               
                 g 
                 0.1 
                 c 
                 0.2 
                 d 
                 0.4 
               
               
                 r 
                 0.9 
                 S 
                 0.2 
               
               
                   
               
             
          
         
       
     
         [0018]    Therefore, in the third conventional ultra wideband antenna with band-notched characteristics, the “band-notched unit” is constituted by that the first complementary, separate, circular resonator  34  and the second complementary, separate, circular resonator  35  are spaced apart from a distance S in installation, such that the third conventional ultra wideband antenna with band-notched characteristics is able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. The detailed characteristic curves, such as return loss and gain, will be shown together with those of the present invention in the following. 
         [0019]    As described above, in the three conventional ultra wideband antennas with band-notched characteristics, either the suppression ability of the “band-notched unit” is insufficient, or the “band-notched unit” occupies a big area of the substrate. Therefore, it is necessary in the industry to have an ultra wideband antenna with band-notched characteristics, having better suppression ability and occupying a smaller substrate area. 
       SUMMARY OF THE INVENTION 
       [0020]    It is an objective of the invention to provide an ultra wideband antenna with band-notched characteristics, capable of suppressing transmission and reception of a high frequency signal in a particular frequency range, such as a frequency band in a WLAN. 
         [0021]    It is further an objective of the invention to provide an ultra wideband antenna with band-notched characteristics, in which the “band-notched unit” occupies a small substrate area. 
         [0022]    In order to accomplish the above objectives, the invention provides an ultra wideband antenna with band-notched characteristics, comprising: a substrate; a grounding unit, installed on the substrate and scooped with a first slot and a first strip hole, the first strip hole being communicated with the first slot and extended to a side of the substrate; a signal feeding unit, installed on the substrate and including a horizontal portion and a vertical portion, in which the horizontal portion is located in the first slot and the vertical portion is located in the first strip hole; a first complementary, separate, circular resonator; and a second complementary, separate, circular resonator, in which the first complementary, separate, circular resonator and the second complementary, separate, circular resonator are installed in the horizontal portion of the signal feeding unit, and are connected with each other. 
         [0023]    In the ultra wideband antenna with band-notched characteristics of the invention, due to that the first complementary, separate, circular resonator and the second complementary, separate, circular resonator are installed in the horizontal portion of the signal feeding unit and are connected with each other to form a “band-notched unit”, the invention will be able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. Thus, in operation, the ultra wideband antenna with band-notched characteristics of the invention will not interfere with the WLAN system. Further, in the ultra wideband antenna with band-notched characteristics of the invention, since the first complementary, separate, circular resonator and the second complementary, separate, circular resonator are connected with each other, the substrate area occupied by the “band-notched unit” of the invention is smaller that that of the conventional ultra wideband antennas with band-notched characteristics. 
         [0024]    Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1A  is a schematic diagram showing a first conventional ultra wideband antenna with band-notched characteristics. 
           [0026]      FIG. 1B  is a schematic diagram showing a “band-notched unit” of the first conventional ultra wideband antenna with band-notched characteristics. 
           [0027]      FIG. 2A  is a schematic diagram showing a second conventional ultra wideband antenna with band-notched characteristics. 
           [0028]      FIG. 2B  is a schematic diagram showing a “band-notched unit” of the second conventional ultra wideband antenna with band-notched characteristics. 
           [0029]      FIG. 3A  is a schematic diagram showing a third conventional ultra wideband antenna with band-notched characteristics. 
           [0030]      FIG. 3B  is a schematic diagram showing a “band-notched unit” of the third conventional ultra wideband antenna with band-notched characteristics. 
           [0031]      FIG. 4A  is a schematic diagram showing an ultra wideband antenna with band-notched characteristics of the invention. 
           [0032]      FIG. 4B  is a schematic diagram showing a “band-notched unit” of the ultra wideband antenna with band-notched characteristics of the invention. 
           [0033]      FIG. 5  is a schematic diagram showing variation of return loss in dependence of change of frequency in a frequency range from 2 GHz to 12 GHz for the three conventional ultra wideband antennas with band-notched characteristics and the ultra wideband antenna with band-notched characteristics of the invention. 
           [0034]      FIG. 6  is a schematic diagram showing variation of gain in dependence of change of frequency in a frequency range from 2 GHz to 12 GHz for the three conventional ultra wideband antennas with band-notched characteristics and the ultra wideband antenna with band-notched characteristics of the invention. 
           [0035]      FIG. 7  is a schematic diagram showing variation of return loss in dependence of change of frequency for the ultra wideband antenna with band-notched characteristics of the invention through physical measurement and CST software simulation. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0036]    As shown in  FIG. 4A , the ultra wideband antenna with band-notched characteristics of the invention comprises: a substrate  41 , a grounding unit  42 , a signal feeding unit  43 , a first complementary, separate, circular resonator  44  and a second complementary, separate, circular resonator  45 . The substrate  41  is preferably a microwave substrate with FR-4 material. The grounding unit  42  is installed on the substrate  41  and scooped with a first slot  421  and a first strip hole  422 , in which the first strip hole  422  is communicated with the first slot  421  and extended to a side  411  of the substrate  41 . In addition, the signal feeding unit  43  is also installed on the substrate  41  and includes a horizontal portion  431  and a vertical portion  432 , in which the horizontal portion  431  is in the first slot  421  and the vertical portion  432  is in the first strip hole  422 . 
         [0037]    As shown in  FIG. 4A , the first slot  421  of the grounding unit  42  is a rectangular slot and the shape of the horizontal portion  431  of the signal feeding unit  43  is rectangular. Further, the material of the grounding unit  42  and the signal feeding unit  43  is metal. Furthermore, the first complementary, separate, circular resonator  44  and the second complementary, separate, circular resonator  45  are installed on the horizontal portion  431  of the signal feeding unit  43 , and the first complementary, separate, circular resonator  44  and the second complementary, separate, circular resonator  45  are connected with each other. 
         [0038]    As shown in  FIG. 4B , the first complementary, separate, circular resonator  44  includes a first rectangular strip slot  441  and a second rectangular strip slot  442 , in which the first rectangular strip slot  441  surrounds the second rectangular strip slot  442 . The first rectangular strip slot  441  and the second rectangular strip slot  442  respectively have an opening  443  and an opening  444  and the direction of the opening of the first rectangular strip slot  441  is opposite to the direction of the opening of the second rectangular strip slot  442 . Furthermore, the direction of the opening of the first rectangular strip slot  441  is parallel to the extension direction of the vertical portion  432  of the signal feeding unit  43 . In addition, the second complementary, separate, circular resonator  45  includes a third rectangular strip slot  451  and a fourth rectangular strip slot  452 , in which the third rectangular strip slot  451  surrounds the fourth rectangular strip slot  452 . The third rectangular strip slot  451  and the fourth rectangular strip slot  452  respectively have an opening  453  and an opening  454  and the direction of the opening of the third rectangular strip slot  451  is opposite to the direction of the opening of the fourth rectangular strip slot  452 . Furthermore, the direction of the opening of the first rectangular strip slot  441  is parallel to the direction of the opening of the third rectangular strip slot  451 . 
         [0039]    Besides, the sizes of various labels for the ultra wideband antenna with band-notched characteristics of the invention as shown in  FIGS. 4A and 4B  are listed in the following Table 4: 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 label 
                 Size (mm) 
                 label 
                 size (mm) 
                 label 
                 size (mm) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 L 
                 35 
                 W 
                 33 
                 Ls 
                 23 
               
               
                 Ws 
                 13 
                 t 
                 2 
                 Sf 
                 0.4 
               
               
                 Wf 
                 3.6 
                 AB 
                 10.8 
                 AE 
                 4 
               
               
                 g 
                 0.1 
                 c 
                 0.2 
                 d 
                 0.4 
               
               
                 r 
                 1.03 
               
               
                   
               
             
          
         
       
     
         [0040]    Further, as shown in  FIG. 4B , the first rectangular strip slot  441  of the first complementary, separate, circular resonator  44  is communicated with the third rectangular strip slot  451  of the second complementary, separate, circular resonator  45 . Thus, in the ultra wideband antenna with band-notched characteristics of the invention, the “band-notched unit” is constituted by integrating the first complementary, separate, circular resonator  44  with the second complementary, separate, circular resonator  45  into one body. 
         [0041]    As described below, accompanied by illustration of  FIGS. 5 ,  6  and  7 , it is proved that the ultra wideband antenna with band-notched characteristics of the invention indeed is able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. 
         [0042]      FIG. 5  is a schematic diagram showing variation of return loss in dependence of change of frequency in a frequency range from 2 GHz to 12 GHz for the three conventional ultra wideband antennas with band-notched characteristics and the ultra wideband antenna with band-notched characteristics of the invention, which is obtained by simulation through CST software. 
         [0043]    As shown in  FIG. 5 , Curve A shows the variation of return loss in dependence of change of frequency for the first conventional ultra wideband antenna with band-notched characteristics as shown in  FIG. 1 . Curve B shows the variation of return loss in dependence of change of frequency for the second conventional ultra wideband antenna with band-notched characteristics as shown in  FIG. 2 . Curve C shows the variation of return loss in dependence of change of frequency for the third conventional ultra wideband antenna with band-notched characteristics as shown in  FIG. 3 . Curve D shows the variation of return loss in dependence of change of frequency for the ultra wideband antenna of the invention as shown in  FIG. 4 . 
         [0044]    It may be seen from  FIG. 5  that Curve D provides the lowest resonant frequency (about 5.5 GHz) and Curve C provides the second lowest resonant frequency (about 6.5 GHz). Therefore, in the ultra wideband antenna with band-notched characteristics of the invention, the return loss in the frequency range from 5 GHz to 6 GHz is evidently higher than that in the remaining frequency range. In addition, the return loss in the frequency range from 5 GHz to 6 GHz of the ultra wideband antenna with band-notched characteristics of the invention is the highest, as compared with that respectively of the three conventional ultra wideband antennas with band-notched characteristics, while the mismatch loss of the invention is about 4.3 dB. Such a fact reveals that in the ultra wideband antenna with band-notched characteristics of the invention, the suppression effect of the “band-notched unit” formed by connecting the first complementary, separate, circular resonator with the second complementary, separate, circular resonator is extremely good, such that the ultra wideband antenna with band-notched characteristics of the invention is able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. 
         [0045]      FIG. 6  is a schematic diagram showing variation of gain in dependence of change of frequency in a frequency range from 2 GHz to 12 GHz for the three conventional ultra wideband antennas with band-notched characteristics and the ultra wideband antenna with band-notched characteristics of the invention, which is obtained by simulation through CST software. 
         [0046]    As shown in  FIG. 6 , Curve E shows the variation of gain in dependence of change of frequency for the first conventional ultra wideband antenna with band-notched characteristics as shown in  FIG. 1 . Curve F shows the variation of gain in dependence of change of frequency for the second conventional ultra wideband antenna with band-notched characteristics as shown in  FIG. 2 . Curve G shows the variation of gain in dependence of change of frequency for the third conventional ultra wideband antenna with band-notched characteristics as shown in  FIG. 3 . Curve H shows the variation of gain in dependence of change of frequency for the ultra wideband antenna of the invention as shown in  FIG. 4 . 
         [0047]    It may be seen from  FIG. 6  that Curve H provides the lowest gain value (about 5.5 GHz) and Curve G provides the second lowest gain value (about 6.5 GHz). Therefore, in the ultra wideband antenna with band-notched characteristics of the invention, the gain in the frequency range from 5 GHz to 6 GHz is evidently lower than that in the remaining frequency range. In addition, the gain in the frequency range from 5 GHz to 6 GHz of the ultra wideband antenna with band-notched characteristics of the invention is the lowest, as compared with that respectively of the three conventional ultra wideband antennas with band-notched characteristics. Such a fact reveals that in the ultra wideband antenna with band-notched characteristics of the invention, the suppression effect of the “band-notched unit” formed by connecting the first complementary, separate, circular resonator with the second complementary, separate, circular resonator is extremely good, such that the ultra wideband antenna with band-notched characteristics of the invention is able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. 
         [0048]      FIG. 7  is a schematic diagram showing variation of return loss in dependence of change of frequency for the ultra wideband antenna with band-notched characteristics of the invention through physical measurement and CST software simulation. As shown in  FIG. 7 , Curve I shows variation of the return loss in dependence of change of the frequency through physically measuring the ultra wideband antenna with band-notched characteristics of the invention. Curve J shows variation of the return loss in dependence of change of the frequency through the CST software simulation. 
         [0049]    It may be seen from  FIG. 7  that in the ultra wideband antenna with band-notched characteristics of the invention, the return loss in the frequency range from 5 GHz to 6 GHz is the highest, and such a fact is verified by that the result obtained by the CST software simulation coincides with the result obtained by the physical measurement. 
         [0050]    In view of the above, in the ultra wideband antenna with band-notched characteristics of the invention, due to that the first complementary, separate, circular resonator and the second complementary, separate, circular resonator are installed in the horizontal portion of the signal feeding unit and are connected with each other to form a “band-notched unit”, the invention will be able not to transmit or receive a high frequency signal in the frequency range from 5 GHz to 6 GHz. Thus, in operation, the ultra wideband antenna with band-notched characteristics of the invention will not interfere with the WLAN system. Further, in the ultra wideband antenna with band-notched characteristics of the invention, since the first complementary, separate, circular resonator and the second complementary, separate, circular resonator are connected with each other, the substrate area occupied by the “band-notched unit” of the invention is smaller that that of the conventional ultra wideband antennas with band-notched characteristics. 
         [0051]    The above embodiments are merely exampled to interpret the invention for the sake of convenience. What is claimed by the invention should be based on what is described in the claims of the application, while not limited to the above embodiments.