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. 07, 1999
Filed:
Dec. 19, 1996
Keiichi Iiyama, Hirakata, JP;
Itsuo Takamiya, Moriguchi, JP;
Masayuki Arai, Tokyo, JP;
Akihisa Yamazaki, Higashikurume, JP;
Seiki Yokozeki, Yamatokoriyama, JP;
Abstract
A data transmission and reception system according to this invention comprises a transmitter for transmitting data by modulating transmit data and a receiver for receiving and demodulating a signal from the receiver, wherein the receiver includes a parallel resonator for receiving a PSK signal; a full rectification circuit for detecting output from the parallel resonator; a low pass filter for shaping the waveform of output from the full rectification circuit; and a comparator for converting output from the low pass filter into a binary-coded signal so that demodulated signals can be obtained from the output of the comparator. Therefore, PSK signals can be demodulated without a PLL or a tank circuit, the overall system consumes a smaller amount of power and is thin and reliable, the transmitter has an amplifier that can operate efficiently, particularly with a limited power supply as in IC cards or a single power supply used for portable terminals, and the receiver is reliable even with a simple circuit using a communication method that locally suppresses the amplitude at phase change points to remove an oscillation circuit in order to reduce the size and thickness of the device.