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:
Aug. 12, 1997
Filed:
Jul. 31, 1995
Bo-Gyu Na, Kyungki-do, KR;
SamSung Electronics Co., Ltd., Suwo, KR;
Abstract
A transmitting/receiving signal processing circuit incorporates a frequency discrimination demodulator and a frequency synthesis local oscillator having a heterodyne phase locked loop for high speed switching. The transmitting/receiving signal processing circuit is used in a digital cordless communication device and has a transmitter for converting a signal input through a speaker and transmitting the converted signal as a radio wave via an antenna. A receiver converts a signal received by the antenna and then transmits the converted signal to a user in a time division communication system using a single frequency channel for transmission and reception according to constant time periods. A frequency synthesizer is also provided and includes a first phase lock loop for synthesizing a reference frequency for channel conversion; a switching stage providing a local oscillation signal from the receiver as a heterodyning source in a receiving mode, and providing a signal multiplied by the reference frequency as the heterodyning source in a transmission mode; and a second phase locked loop connected between the first phase locked loop and the receiver, for receiving the heterodyning source and generating transmitting/receiving frequencies in the transmission/receiving modes, respectively.