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:
Mar. 01, 2011
Filed:
Dec. 04, 2009
Naohiro Matsui, Kanagawa, JP;
Naohiro Matsui, Kanagawa, JP;
Renesas Electronics Corporation, Kawasaki-shi, Kanagawa, JP;
Abstract
In a wireless communications system, it is important to realize a limiter operation by which a differential amplifier for amplifying a local signal may stably supply an output signal having a constant amplitude. However, when a signal handled by the system has a high frequency, a gain of the differential amplifier is reduced and the limiter operation may not be performed appropriately. The differential amplifier is configured employing a double cascode connection to enhance an output impedance, an upper transistor of the double cascode connection realizes enhancement in gain and frequency characteristics based on a positive feedback signal, and a lower transistor of the double cascode connection controls an operating point and suppresses an allowable output voltage range by operating in a linear region and based on a negative feedback signal to facilitate the limiter operation.