Installing in the radio equipment outside and

摘要

PPROBLEM TO BE SOLVED: To operate a reader/writer function incorporated in equipment in such a manner as to prevent the wireless communicating function of a cellphone or PHS from deteriorating in reception sensitivity. PSOLUTION: A filter constructed of a parallel circuit of a coil L and a capacitor C is connected in series with a transmitting antenna for a reader/writer so as to eliminate higher harmonics at a specific frequency affecting mobile wireless equipment. Even if the antenna of the mobile wireless equipment and the antenna of the reader/writer are mounted in close proximity to each other, the communication performance of the reader/writer is not deteriorated and the reception sensitivity of the mobile wireless equipment is prevented from deteriorating. The frequency to be attenuated is adjusted by simply changing the constants of the coil L and the capacitor C. PCOPYRIGHT: (C)2004,JPO