Patent ID: 6859504

Claim:
An automatic gain control comprising: (a) a plurality of automatic gain control elements, each said automatic gain control element producing an output in response to an input and a bias, an input being substantially the same for each of said plurality automatic gain control elements; (b) a discriminator to select an output of an automatic gain control element having a relatively greater signal to noise ratio as an output for said automatic gain control; and (c) at least one of the following: (i) wherein a value of said bias applied to one of said automatic gain control elements does not equal a value of said bias applied to another of said automatic gain control elements; (iii) wherein said discriminator comprises a filter having a frequency response substantially matching a frequency spectrum of a reference signal and arranged to filter the plurality of outputs of said automatic gain control elements, and a selector to select an output of said filter having a relatively greater signal to noise ratio: (iv) wherein an automatic gain control element includes a mode switch connecting said automatic gain control element to operate in one of a closed loop operating mode and an open loop operating mode, and a mode control responsive to the output of said automatic gain control element to cause said mode switch to select one of said closed loop and said open loop operating modes; (v) wherein an automatic gain control element includes a mode switch connecting said automatic gain control element to operate in an open loop mode with an unique initial gain voltage, and a mode control responsive to the output of said automatic gain control element to cause said mode switch to select a closed loop operating mode; (vi) wherein an automatic gain control element comprises a memory to store an integration value used in processing a signal.