Patent ID: 6934522
Filing Date: 2005-08-23
Classification: H03G,H04B

Abstract:
1. An automatic gain control apparatus, comprising: an RF automatic gain controller operable to control a gain of a radio frequency signal; a frequency converter operable to frequency convert the radio frequency signal into an intermediate frequency signal; an IF automatic gain controller operable to control a gain of the intermediate frequency signal; a level detector operable to detect a signal level of the intermediate frequency signal with the gain controlled, and operable to generate a level signal; and an automatic gain control signal generator operable to generate, based on the level signal, an RF automatic gain control signal for controlling said RF automatic gain controller and an IF automatic gain control signal for controlling said IF automatic gain controller, so as to separately control said RF automatic gain controller and said IF automatic gain controller, wherein said automatic gain control signal generator either fixes the gain of said IF automatic gain controller if a level, indicated by the level signal, is higher than one of a plurality of predetermined levels and lower than or equal to another one of the plurality of predetermined levels, or else changes the gain of said IF automatic gain controller.