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:
Dec. 21, 2010
Filed:
Mar. 20, 2007
Yukinori Akamine, Kokubunji, JP;
Satoshi Tanaka, Kokubunji, JP;
Akio Yamamoto, Hiratsuka, JP;
Kazuaki Hori, Yokohama, JP;
Yukinori Akamine, Kokubunji, JP;
Satoshi Tanaka, Kokubunji, JP;
Akio Yamamoto, Hiratsuka, JP;
Kazuaki Hori, Yokohama, JP;
Renesas Electronics Corporation, Kanagawa, JP;
Abstract
In a direct conversion receiver, to cancel a DC offset generated in the baseband processing block, negative feedback arrangements comprising a gain control amplifier and a low-pass filter are respectively attached to the I and Q signal branches of the baseband block following mixer outputs. The gain control amplifier in each negative feedback circuit is gain adjusted so that the product G·B of the gain G of a primary gain control amplifier and its own gain B will be constant and thereby the DC offset is cancelled. This DC offset cancellation can be applied in a continuous receiving system with no intermittent time during a receiving operation. Capacitance elements located off-chip can be reduced to those to be used only in the low-pass filters in the negative feedback circuits, whereas many off-chip capacitance elements have been required to be inserted between each stage of gain control amplifiers in conventional baseband chains.