| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an antenna apparatus and a personal digital assistant capable of setting an optimal reactance value to each function without enlarging an antenna area in an RFID (radio frequency identification) antenna configuration including a card function and a reader/writer function. <P>SOLUTION: The antenna apparatus comprises one loop antenna 11 as an RFID antenna element, and in the middle of the loop antenna 11, a tap 12 is provided. A receiving circuit 16 of a card function and a reader/writer function and a transmission circuit 17 of the card function are connected to one terminal A of the loop antenna 11. The transmission circuit 18 of the reader/writer function is connected to the terminal B of the tap 12 in the middle of the loop antenna 11 via a switch 14 so as to be disconnected from the loop antenna 11. The loop antenna 11 is used in the card function as a whole, and a part of the loop antenna 11 to the intermediate tap 12 is used in transmission of the reader/writer function. <P>COPYRIGHT: (C)2009,JPO&INPIT |
