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:
May. 21, 2002
Filed:
Apr. 15, 1999
Nokia Mobile Phones Limited, Espoo, FI;
Abstract
The invention relates to a method and radio receiver for attenuating spurious signals when receiving ( to ) radio signals, when radio signals are mixed ( ) to a second frequency, which may be the baseband frequency, for example. Spurious signals are caused by balance errors in the mixer ( ) which result from component value fluctuations within tolerance limits. According to the invention, mixing is balanced by setting ( ) variable-level bias voltages and/or currents to transistors in the mixer circuit ( ). An advantage of the invention is that even-order spurious signals caused by balance errors in the mixing of a signal to a second frequency are considerably attenuated. The invention finds particular utility in a mobile communications device, for example.