Kyocera Corporation

Shinobu Kato

Masayuki Saito

Tadashi Koyama

Kenji Waku

Yasuhiro Katayama

Katsuji Morishita

A portable electronic device and a magnetic field antenna circuit are provided for making it possible to keep an antenna resonance frequency in a fixed range even if temperature changes. A mobile telephone device () is provided with a second communication unit driven by a chargeable battery () to execute a predetermined function and an RFID unit () accompanied with magnetic communication. The RFID unit () includes a magnetic antenna unit (), which can transmit or receive a wireless signal by a magnetic field, and a capacitor (), one terminal of which is connected with the magnetic antenna unit () to generate a predetermined resonance frequency. The capacitor () is characterized in having a temperature-reactance characteristic reverse to an amount of an inductance value that fluctuates as the magnetic antenna unit () changes in accordance with temperatures.

Growing community of inventors

Kanagawa, Japan

Shinobu Kato