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. 07, 1999
Filed:
Oct. 07, 1997
Juha Rapeli, Oulu, FI;
Nokia Mobile Phones Limited, Espoo, FI;
Abstract
The invention relates to a circuit arrangement for generating two signals having a phase difference of approximately 90 degrees. The invention is preferably applied in the demodulator of a radio receiver. In order to shift the phase of a signal one idea of the invention is to use a distributed resistance/capacitance circuit or a distributed RC circuit (Z.sub.10, Z.sub.20) in connection with a signal amplifying means (A.sub.1, A.sub.2). The operation of the circuit is not frequency dependent and a circuit adjustment is not necessarily required in order to calibrate the phase difference, because the distributed RC circuit can provide an substantially constant phase shift of .+-.45 degrees over a wide frequency range. The whole circuit can be integrated into one component, because a distributed RC circuit is easily made on the same integrated circuit substrate as the amplifying means, and thus the circuits can be made into a small size and at low manufacturing costs.