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. 03, 1996
Filed:
Sep. 17, 1992
Toshihiro Hara, Tokyo, JP;
NEC Corporation, , JP;
Abstract
In a radio telephone apparatus of the TDMA/TDD system, signal transmission and reception are conducted by use of carriers having an identical frequency. This leads to a problem that the transmission intermediate frequency carrier and the transmission RF carrier enter the receiver section in an identical housing, thereby causing a cochanncl interference. To overcome this difficulty, there is disposed a frequency division modulator including a frequency divider for dividing by four a local signal having a frequency which is four times that of the intermediate frequency to obtain a carrier having a frequency shifted from that of the local signal by 90.degree.. Signal to be modulated is subjected to an orthogonal modulation according to the carrier wave to produce an intermediate frequency carrier. The operation of the modulator is stopped in a signal reception state to prevent the intermediate frequency carrier undergone the orthogonal modulation from being produced.