METHOD FOR SUPPORTING PLASTIC ROAMING OF COMBINATION-TYPED SMART CARD INSTALLED TO PORTABLE TERMINAL

摘要

PURPOSE: A method for supporting plastic roaming of a combination-typed smart card installed to a portable terminal is provided to enable other card to have the same performance even if a maker embedding an RF(Radio Frequency) antenna into the portable terminal designs/tunes the RF antenna for one specified card. CONSTITUTION: An impedance matching circuit(225) is inserted between spare terminals(C4,C8) and RF antenna start points(221a,221b) of the smart card(220), and is formed with a passive R/L/C(Resistance/impedance/Capacity) element in order to have a specified impedance value. As the impedance matching circuit is inserted, the plastic roaming is supported by providing the same RF recognition distance without regard to a sort of the mobile terminal.