Patent ID: 6107878
Filing Date: 2000-08-22
Classification: H03G,H04B

Abstract:
An apparatus for gain control comprising:linear gain control means for producing a first variable gain value in response to an overall gain value whereby:said first variable gain value is zero while the overall gain is less than a first predetermined threshold;said first variable gain value increases linearly with the overall gain while the overall gain is greater than said first predetermined threshold; andsaid first variable gain value ceases to increase once it has reached a predetermined maximum gain level;step gain control means for producing a constant gain control signal and a constant gain value in response to an overall gain value whereby:said constant gain control signal is off and said constant gain value is zero while the overall gain is less than a second predetermined threshold;said constant gain control signal is on and said constant gain value is a predetermined constant gain level while the overall gain is greater than a third predetermined threshold; andsaid constant gain control signal is subject to hysteresis between off and on and said constant gain value is subject to hysteresis between zero and said predetermined constant gain level while the overall gain is between said second predetermined threshold and said third predetermined threshold;adder means for producing a second variable gain which is the sum of:the overall gain value;the negative of said predetermined constant gain level when said constant gain control signal is on; andthe negative of said first variable gain value.