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:
Feb. 17, 2009
Filed:
Jun. 04, 2004
Hiromitsu Mizukami, Suwa, JP;
Hiromitsu Mizukami, Suwa, JP;
Seiko Epson Corporation, , JP;
Abstract
When a first half of a transmission packet is sent by an FSK modulating signal, and a latter half thereof is sent by a PSK modulating signal, a received signal is converted into an intermediate frequency signal by a mixer. The converted intermediate frequency signal is switched to an FSK demodulation unit and a PSK demodulation unit by a received signal changeover switch. A frequency error detection circuit is provided in the FSK demodulation unit to detect a frequency error detection value. A demodulation circuit of a phase locked loop type of the PSK demodulation unit includes a loop filter. The frequency error detection value detected by the frequency error detection circuit is set as an initial value of this loop filter, whereby a time until lockup of a phase locked loop is reduced at the time when reception of a PSK modulating signal is started.