Abstract:
The present disclosure pertains to a transponder device ( 10 ) having an antenna arrangement and a chip ( 13 ) disposed on an antenna substrate ( 11 ), wherein the antenna arrangement comprises at least a first antenna unit formed as a loop antenna ( 16 ) that is connected electrically conductively to contact surfaces ( 14, 15 ) of the chip via conductor ends of an antenna conductor ( 17 ) that is used for the formation of the loop antenna, and wherein the antenna arrangement besides the first antenna unit comprises at least one further antenna unit formed as a dipole antenna ( 19 ).

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains to a transponder device having an antenna arrangement and a chip disposed on an antenna substrate, wherein the antenna arrangement includes at least a first antenna unit formed as loop antenna that is connected electrically conductively to contact surfaces of the chip via conductor ends of an antenna conductor that is used for the formation of the loop antenna. 
       BACKGROUND 
       [0002]    Transponder devices of the aforecited type are known in various embodiments. For instance, transponder devices of this type are designed as a tag to be connected to objects to be marked, or are also employed in card format, for instance embodied as a “chip card”, to be used in authentication systems, particularly in connection with access or use authorizations. 
         [0003]    The known transponder devices of the aforecited type are in each embodiment configured to the respectively used frequency range of the data transmission between the chip of the transponder device and a reading device. Thereby, in practice, basically the high frequency range with a standardization of the transmission frequency at 13.56 MHz and the ultra-high frequency range have become widely used. The corresponding transponder devices are hence equipped with a loop antenna or a dipole antenna depending on the frequency range used. 
       SUMMARY 
       [0004]    Embodiments of the present invention include a transponder device that can be employed both in the high frequency range and in the ultra-high frequency range. 
         [0005]    An embodiment of the present invention includes a transponder device having an antenna arrangement and a chip disposed on an antenna substrate, wherein the antenna arrangement comprises at least a first antenna unit formed as loop antenna that is connected electrically conductively to contact surfaces of the chip via conductor ends of an antenna conductor that is used for the formation of the loop antenna. 
         [0006]    In the transponder device according to an embodiment of the invention, the antenna arrangement disposed on the antenna substrate, besides the first antenna unit formed as loop antenna, has at least one further antenna unit formed as dipole antenna. 
         [0007]    The transponder device according to an embodiment of the invention can hence be employed both in the high frequency range and in the ultra-high frequency range, without the need to provide for a plurality of transponder devices that are each assigned to the various frequency ranges. 
         [0008]    If, according to a preferred embodiment, the dipole antenna has two conducting branches that are each formed of an antenna conductor, wherein the ends thereof are connected electrically conductively to contact surfaces of the chip, thus the loop antenna and the dipole antenna as well are connected electrically conductively to contact surfaces of the chip, providing for a data transmission in the ultra-high frequency range between a reading device and the chip, which can be performed directly via the dipole antenna operating in the ultra-high frequency range, without requiring the loop antenna to be used as a signal transmission element. Thus, it is for instance also possible to use the loop antenna in parallel and simultaneously respectively with the dipole antenna for data transmission, such that a transmission of various data in the various frequency ranges can be performed simultaneously. 
         [0009]    If the dipole antenna has two conducting branches that are each formed of an antenna conductor, wherein the ends thereof are connected electrically conductively to one another via a connection part, data transmission between the reading device and the chip can be performed via the dipole antenna, whereby an inductive coupling is used between the dipole antenna and the loop antenna. 
         [0010]    In an embodiment, the antenna conductor of the first antenna unit and the antenna conductors of the second antenna unit can be connected electrically conductively to one another, such that the dipole antenna is used as a receiving and transmitting antenna and that the loop antenna essentially serves as an electrical conductor for connection to the dipole antenna in a data transmission in the ultra-high frequency range. 
         [0011]    An electrically conductive connection of this type between the antenna conductor of the loop antenna and the antenna conductors of the dipole antenna can be realized in an especially advantageous manner via a connection part formed as a joint conductor section of the antenna conductor of the loop antenna and at least one of the antenna conductors of the dipole antenna. Thus, a coherent continuously formed antenna unit can firstly be used as a high frequency antenna and secondly also as an ultra-high frequency antenna, whereby a section of the antenna arrangement serves both for realizing the loop antenna and also for realizing the dipole antenna. 
         [0012]    If the dipole antenna with its conducting branches defines an antenna field and the loop antenna is arranged inside of the antenna field, it is possible to use the edges of the antenna substrate over their entire length for forming the conducting branches. 
         [0013]    If, according to an embodiment, the dipole antenna with its conducting branches defines an antenna field and the loop antenna is arranged outside of the antenna field, it is possible to use the edges of the antenna substrate over their entire length for forming the loop antenna, such that the circumferential periphery of the surface of the antenna substrate can be advantageously used for providing both a large winding length and a large number of windings respectively. 
         [0014]    An embodiment can provide an improvement if the antenna conductor of the loop antenna is arranged on the antenna substrate in such a manner that it defines the circumference of the antenna field and that the dipole antenna is arranged inside of the antenna field. 
         [0015]    It can be advantageous in an embodiment, especially for frequency tuning of the dipole antenna, if the antenna conductors of the dipole antenna have varying structural characteristics. 
         [0016]    Although the structural characteristics of the dipole antenna and the loop antenna can be identical, in an especially preferred embodiment of the invention, the antenna conductors of the dipole antenna and the antenna conductor of the loop antenna are formed by varying structural characteristics, such that the formation of the respective conductors can be specifically adapted to the space conditions prevailing on the substrate surface of the antenna substrate, or also, to superimpose upon the original antenna functions of the dipole antenna and the loop antenna respectively further functions, for instance mechanical functions. Thus it can be favorable to have the dipole antenna formed by wire being embedded into the surface of the substrate. 
         [0017]    For instance it can be advantageous if the loop antenna has a wire conductor mounted onto the surface of the substrate as an antenna conductor—particularly by embedding the wire into the surface of the substrate—and if the dipole antenna has a conductor pattern formed by a metallization of the surface of the substrate as an antenna conductor. 
         [0018]    Regardless of the fact that the loop antenna designed as a wire conductor antenna exhibits a particularly high efficiency, the wire conductor besides its antenna function can also fulfil a support function providing mechanical support for the antenna substrate. In addition, a loop antenna formed as a wire conductor also proves to be highly resistant to dynamic alternating stresses that can occur during use of a chip card. Hence, a wire conductor antenna formed for instance circumferentially within the outer periphery can provide stabilizing protection for a dipole antenna formed in the interior of the wire conductor antenna by means of a metallization pattern on the substrate surface. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0019]    In the following, embodiments of the transponder device will be described in more detail on the basis of the drawings, whereby 
           [0020]      FIG. 1  illustrates a transponder device in a first embodiment; 
           [0021]      FIG. 2  illustrates a transponder device in a second embodiment; 
           [0022]      FIG. 3  illustrates a transponder device in a third embodiment: 
           [0023]      FIG. 4  illustrates a transponder device in a fourth embodiment; 
           [0024]      FIG. 5  illustrates a transponder unit in a fifth embodiment; 
           [0025]      FIG. 6  illustrates a transponder unit in a sixth embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]      FIG. 1  illustrates a transponder device  10  having a chip module  12  that is arranged on an antenna substrate  11  and that in the present situation comprises a chip  13  that is connected electrically conductively to a loop antenna  16  via chip connection surfaces  14 ,  15 . In case of the exemplary embodiment illustrated in  FIG. 1 , the loop antenna  16  is formed by an antenna conductor  17  connecting the chip connector areas  14  and  15  of the chip module with one another using the single-winding number. 
         [0027]    Apart from the loop antenna  16  there is disposed on a substrate surface  18  of the antenna substrate  11  a dipole antenna  19  having two conducting branches  21  and  22  merging into one another in a connection part  20 . The conducting branches  21  and  22  are each formed in a meander-like fashion and extend, inclusive of the connection part  20 , along a longitudinal edge  23  and a transversal edge  24  respectively of the antenna substrate  11 . 
         [0028]    In case of the exemplary embodiment of the transponder device  10  illustrated in  FIG. 1 , the antenna conductor  17  of the loop antenna  16  and an antenna conductor  25  forming the dipole antenna  19  on the substrate surface  18  are formed identically. Both, the antenna conductor  17  and the antenna conductor  25  are formed by a metallization pattern formed by deposition onto the substrate surface  18 . However, it would likewise also be possible to form both the antenna conductor  17  as well as the antenna conductor  25  as a wire conductor which is mounted onto the substrate surface  18  by means of laying. 
         [0029]    In the transponder device  10  illustrated in  FIG. 1 , a coupling section  26  of the loop antenna  16  is arranged essentially in parallel to the connection part  20  of the dipole antenna  19 . Thereby, the overlap length L formed between the coupling section  26  and the connection part  20  as well as a coupling distance A formed between the coupling section  26  and the connection part  20  are selected such that a desired inductive coupling between the dipole antenna  19  and the loop antenna  16  is enabled. 
         [0030]    As is also apparent from  FIG. 1 , the dipole antenna  19 , with its conducting parts  21 ,  22  that extend in the illustrated exemplary embodiment along the longitudinal edge  23  and the transversal edge  24  respectively, mounts an antenna field having the loop antenna  16  disposed therein. 
         [0031]      FIG. 2  illustrates a transponder device  27  corresponding to the transponder device  10  illustrated in  FIG. 1  and having a chip module  12  that is contacted with a loop antenna  46  via chip connection surfaces  14 ,  15 . 
         [0032]    Different from the transponder device  10 , the transponder device  27  has a dipole antenna  28 , wherein the conducting branches  29 ,  30  thereof are each formed of an antenna conductor  31  that corresponds to an antenna conductor  47  of the loop antenna  46  contacted electrically conductively with the chip connection surfaces  14 ,  15  of the chip module  12 . 
         [0033]    In the exemplary embodiment of the transponder device  27  illustrated in  FIG. 2 , the conducting branches  29 ,  30  of the dipole antenna  28  are connected to one another via a connection part  32 , at the same time connecting electrically conductively the chip connection surfaces  14 ,  15  to one another. In addition, in the transponder device  27  both the antenna conductor  31  of the dipole antenna  28  and the antenna conductor  47  of the loop antenna  46  are correspondingly formed as wire conductors. Differing therefrom, the antenna conductors can also be formed by a conductor pattern created by metallization of the substrate surface. 
         [0034]    In the exemplary embodiment illustrated in  FIG. 2 , the loop antenna  46  is arranged outside of an antenna field  58  defined by the conducting leads  29 ,  30  of the dipole antenna  28 . 
         [0035]      FIG. 3  illustrates a transponder device  33  having a chip module  12  arranged on the substrate surface  18  of the antenna substrate  11 , wherein the chip connection surfaces  14 ,  15  thereof are connected to an antenna conductor  17  forming a loop antenna  34 . The loop antenna  34  has a connection part  48  at the same time forming the electrically conductive connection between conducting leads  35 ,  36  of a dipole antenna  37 . In the exemplary embodiment illustrated in  FIG. 3 , the conducting branches  35 ,  36  are formed of an antenna conductor  38  formed as a wire conductor on the substrate surface  18  in a meander-like fashion. Diverging from the illustrated embodiment of the transponder device  33 , it is also possible to form the antenna conductor  38  forming the conducting branches  35 ,  36 , differing from the antenna conductor  17  formed as a wire conductor of the loop antenna  16 , by a conductor pattern formed by metallization of the substrate surface  18 . 
         [0036]      FIG. 4  illustrates a transponder device  39  formed essentially identically to the transponder device  27  illustrated in  FIG. 2 , differing in that in place of the dipole antenna  28  there is disposed a dipole antenna  40  having conducting branches  41 ,  42 , formed of varying antenna conductors  43 ,  44 . In the situation at hand, the antenna conductor  43  is formed of a wire conductor mounted onto the substrate surface  18  of the antenna substrate  11 , and wherein the antenna conductor  44  forming the conducting lead  42  is formed by a conductor pattern formed by deposition of a metallization onto the substrate surface  18 . Corresponding to the dipole antenna  28  of the transponder device  27  ( FIG. 2 ), the conducting branches  41 ,  42  of the dipole antenna  40  are connected to one another via a connection part  32  formed by a wire conductor, as it is the case with the antenna conductor  43 . 
         [0037]      FIG. 5  illustrates a transponder device  45  having a loop antenna  51  that extends along a peripheral edge  50  of the substrate  11  and that has a plurality of antenna windings that in the present situation are formed of an antenna conductor  52  formed as a wire conductor. In an antenna field  53  defined by the loop antenna  51 , there is disposed a dipole antenna  54 , wherein the conducting branches  55 ,  56  thereof just like the conductor ends of the antenna conductor  52  of the loop antenna  51  are connected electrically conductively to the chip connection areas  14 ,  15  of the chip module  12 . 
         [0038]      FIG. 6  illustrates a transponder device  57  having a dipole antenna  58  and a loop antenna  59  each being connected electrically conductively to the chip connection areas  14 ,  15  of the chip module  12 . Differing from the transponder device  27  shown in  FIG. 2  the dipole antenna  58  exhibits two branches  60 ,  61  not extending in a serpentine shape but being stretched out straight. The dipole antenna  58  may be formed by embedded wire or by a metallization pattern.