| US 7,577,414 B2 | ||
| Methods and apparatus for automatic gain control in broadband tuners | ||
| Iuri Mehr, North Andover, Mass. (US) | ||
| Assigned to Analog Devices, Inc., Norwood, Mass. (US) | ||
| Filed on Jan. 27, 2005, as Appl. No. 11/44,710. | ||
| Prior Publication US 2006/0166633 A1, Jul. 27, 2006 | ||
| Int. Cl. H04B 1/06 (2006.01) | ||
| U.S. Cl. 455—234.1 [455/250.1] | 12 Claims |
| 1. An automatic gain control (AGC) for applying a variable gain to a broadband signal, the AGC comprising:
a variable gain amplifier adapted to receive the broadband signal as an input, the variable gain amplifier configured to apply
a variable gain to the broadband signal based on a value of a gain signal to provide an amplified broadband signal; and
a controller to provide the gain signal to the variable gain amplifier, the controller adapted to determine the value of the
gain signal based on at least one power characteristic of the amplified broadband signal,
wherein the controller includes at least one first power detector adapted to detect a first power characteristic to generate
at least one sensed value and at least one second power detector adapted to detect a second power characteristic having peak
values of the broadband signal, wherein the controller includes a default reference that is adjusted based at least on a first
number of peak values of the broadband signal exceeding a first threshold during a predetermined time interval to determine
the at least one reference value, and wherein the controller includes a comparator configured to provide an error signal indicative
of a difference between the at least one sensed value and at the least one reference value.
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