Reader/writer device and automatic ticket gate including the same for checking ticket

摘要

An antenna unit prevents a communication error by suppressing side lobes formed by an antenna coil segment of a reader/writer device. The antenna unit ( 200 ) is used for a reader/writer device ( 20 ) whose signal processing circuits ( 210 ) and ( 220 ) communicate with an IC card ( 10 ) via electromagnetic waves, wherein an antenna coil ( 100 ) of the IC card ( 10 ) relatively gets close to the antenna unit ( 200 ). The antenna unit ( 200 ) includes the antenna coil segment which forms a loop antenna ( 202 ) on a substrate ( 201 ) and conductor segments ( 203 ) at the periphery of the antenna coil on substantially the same plane of the antenna coil.