Antenna device and communication device using antenna device

摘要

An antenna apparatus ( 60 ) is provided which is used in a recorder and/or player to write and read data to and from a contactless IC card ( 1 ). The antenna apparatus ( 60 ) includes a loop coil ( 61 ) to radiate an electromagnetic field for magnetic coupling with a loop coil ( 4 ) at the IC card ( 1 ) to send and receive data to and from the IC card ( 1 ), and a magnetic sheet ( 62 ) disposed to face the main side of the loop coil ( 61 ), opposite to the main side facing the IC card ( 1 ). The magnetic sheet ( 62 ) has the specific permeability mu' and product Ms.t of saturation magnetization Ms and thickness t thereof set in accordance with a necessary range of communications with the contactless IC card ( 1 ).