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:
Apr. 03, 2001
Filed:
Oct. 18, 1999
Jeng-Rern Yang, Tao Yuan, TW;
Tsung-Han Yang, Hsinchu, TW;
Abstract
This invention relates to a battery-free circuit device for RF identifying tag. It is advantageous that the electric potential across the antenna coil induced by the change of the alternating magnetic field of the radio wave signals is independent of the modulational switching of the RF identifying tag during the positive half cycles when the antenna is receiving the radio wave signals from the card reader, and that the efficiency of the voltage-charging rectifier circuit remains constant when the data are delivered into the card reader. Furthermore, in this invention, the modulational amplitude of the signals is larger than that in the prior art, thus the propagating distance is longer and it shows better accuracy and reliability in data reading.