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:
Apr. 22, 2008
Filed:
Apr. 06, 2005
Taiwa Okanobu, Tokyo, JP;
Taiwa Okanobu, Tokyo, JP;
Sony Corporation, , JP;
Abstract
In order to improve various characteristics of a receiving circuit for digital radio services, circuits are provided for forming two local oscillation signals, whose frequencies are both the center frequency between a first ensemble and a second ensemble, and whose phases differ by 90° from each other. Furthermore, there are provided mixer circuits for frequency-converting the received signal into intermediate frequency signals in accordance with the local oscillation signals, phase-shift circuits to which the intermediate frequency signals are supplied, and an addition/subtraction circuit for performing one of addition and subtraction of the outputs of the phase-shift circuits. In addition, there are provided intermediate frequency filters to which the output signal of the addition/subtraction circuit is supplied and demodulation circuits to which the output signals of the intermediate frequency filters are supplied. By switching the process in the addition/subtraction circuit to addition or subtraction, the signals of the first ensemble and the second ensemble are selectively extracted from the demodulation circuits.