RFID Antenna

Abstract

An antenna particularly suitable for use in radio frequency identification (RFID) transponders. First and second half portions each include nominally straight conductive sections primarily defining a radiating characteristic and nominally spiral conductive sections creating a positive reactive characteristic of the antenna. The straight conductive sections have feed points for connecting the antenna into the RFID transponder, and further connect with the respective spiral conductive sections. The first and said second half portions characterize the antenna as being a dipole type, and adding an optional loop section connecting the straight conductive sections can further characterize it as being of a folded dipole type.

1 . An antenna for use in a radio frequency identification (RFID) transponder, the antenna comprising:
 a first half portion and a second half portion each including:
 a straight conductive section primarily defining a radiating characteristic of the antenna; 
 a spiral conductive section creating a positive reactive characteristic of the antenna; 
 said straight conductive section having a feed point where at the antenna can be connected into the RFID transponder; and 
 said straight conductive section effectively connecting with its respective spiral conductive section, thereby having said first half portion and said second half portion characterize the antenna as being of a dipole type. 
   
   
   
       2 . The antenna of  claim 1 , wherein said first half portion and said second half portion are mirrored opposites that lie within a plane. 
   
   
       3 . The antenna of  claim 1 , wherein said first half portion and said second half portion are formed of printed circuit board traces. 
   
   
       4 . The antenna of  claim 1 , wherein said spiral conductive sections each include two opposed spiral-shaped sub-sections. 
   
   
       5 . The antenna of  claim 1 , further comprising a loop section connecting said straight conductive sections of said first half portion and said second half portion, thereby further characterizing the antenna as being of a folded dipole type. 
   
   
       6 . The antenna of  claim 5 , wherein said first half portion and said second half portion are mirrored opposites and lie within a plane. 
   
   
       7 . The antenna of  claim 5 , wherein said first half portion and said second half portion are formed of printed circuit board traces. 
   
   
       8 . The antenna of  claim 5 , wherein said spiral conductive sections each include two opposed spiral-shaped sub-sections. 
   
   
       9 . An antenna for use in a radio frequency identification (RFID) transponder, the antenna comprising:
 first and second dipole means to radiated or receive radio frequency (RF) energy;   said first and second dipole means each including straight conductive means to primarily define a radiating characteristic of the antenna;   said first and second dipole means each further including spiral conductive means to create a positive reactive characteristic of the antenna;   said straight conductive means each effectively connecting with its respective said spiral conductive means at one end and its other end including a feed point to connect the antenna to the RFID transponder.   
   
   
       10 . The antenna of  claim 9 , wherein said first and second dipole means are mirrored opposites that lie within a plane. 
   
   
       11 . The antenna of  claim 9 , wherein said first and second dipole means are formed of printed circuit board traces. 
   
   
       12 . The antenna of  claim 9 , wherein said spiral conductive means each include two opposed spiral-shaped sub-sections. 
   
   
       13 . The antenna of  claim 9 , further comprising a loop means connecting said straight conductive means of said first dipole means and said second dipole means, thereby further characterizing the antenna as being of a folded dipole type. 
   
   
       14 . The antenna of  claim 13 , wherein said first and second dipole means are mirrored opposites that lie within a plane. 
   
   
       15 . The antenna of  claim 13 , wherein said first and second dipole means are formed of printed circuit board traces. 
   
   
       16 . The antenna of  claim 13 , wherein said spiral conductive means each include two opposed spiral-shaped sub-sections.