| 摘要 |
PROBLEM TO BE SOLVED: To increase the transmission/reception sensitivity of the loop antenna of a noncontact memory card. SOLUTION: On a film sheet 11 on the top surface of the noncontact memory card 1, an IC chip 25 and a chip capacitor 26 which store and process information are mounted. Further, loop antennas are arranged at four places (antennas 21 to 24). Specific phase feeding is performed for the antennas 21 to 24 and currents flaw as shown by arrows respectively. Coils forming the loop antennas 21 to 24 are made to resonate through the capacitor 26 to obtain different resonance frequencies. |
