The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 2013
Filed:
Feb. 27, 2008
Kenji Waku, Kanagawa, JP;
Tadashi Koyama, Kanagawa, JP;
Masayuki Saito, Kanagawa, JP;
Yasuhiro Katayama, Kanagawa, JP;
Katsuji Morishita, Kanagawa, JP;
Shinobu Kato, Kanagawa, JP;
Kenji Waku, Kanagawa, JP;
Tadashi Koyama, Kanagawa, JP;
Masayuki Saito, Kanagawa, JP;
Yasuhiro Katayama, Kanagawa, JP;
Katsuji Morishita, Kanagawa, JP;
Shinobu Kato, Kanagawa, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
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.