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:
Jan. 07, 1992
Filed:
Nov. 15, 1990
Hiroshi Noguchi, Tokyo, JP;
Nobuo Tsukamoto, Tachikawa, JP;
Arata Nakagoshi, Kokubunji, JP;
Atushi Hoshi, Tokyo, JP;
Masato Horaguchi, Sendai, JP;
Hitachi, Ltd., Chiyoda, JP;
Kokusai Electric Co., Ltd., Tokyo, JP;
Abstract
The invention relates to a demodulator and to a radio receiver having such a demodulator and, more particularly, to a demodulator for demodulating signals which were digitized by a direct detecting method in which a circuit scale is small and an electric power consumption is small. Particularly, it is a characteristic that a limiter in the demodulator comprises: a circuit for obtaining absolute values of the digital signals (I signal, Q signal) which are produced from an angle modulated wave and whose phases are mutually orthogonal; a circuit for outputting the sum (.vertline.I.vertline.+.vertline.Q.vertline.) of the absolute values or the larger one M(.vertline.I.vertline., .vertline.Q.vertline.) of the absolute values; a controller for producing a control signal according to an output of the above circuit; and scalers which change the amplitudes of the first and second digital signals in accordance with the control signal and which are constructed by a plurality of shift registers and adders.