US 4,234,804 A · Signal correction for electrical gain control systems

Abstract

The present invention relates to an electrical gain control system which provides a first signal logarithmically related to an input signal, sums a gain control signal with the first signal; and then provides an output signal which is an antilogarithmic function of the sum of the gain control signal and first signal. In accordance with the present invention in order to at least partially compensate for errors in the output signal arising from inherent characteristics of the components of the system, the system is improved by comparing the input signal and the output signal; generating an error correction signal in response to the comparison as a function of the errors in the output signal; and summing the error correction signal with the first signal and the gain control signal so as to reduce the error in the output signal.

Claims16

Dependent claims

In an electrical gain control system including first signal converting means for providing at its output a first output signal logarithmically related to an input signal;

means coupled with respect to the output of said first signal converting means for summing a gain control signal with said first output signal;
and second signal converting means for providing at its output a second output signal which is an anti-logarithmic function of the sum of said first output signal and said gain control signal, the improvement comprising:
signal generating means for comparing said input signal and said second output signal and for generating, in response to said comparison, an error correction signal as a function of the distortion in said second output signal;
and
means coupled with respect to the output of said first signal converting means for summing said error correction signal with said first output signal and said gain control signal so as to reduce said distortion in said second output signal.

2 more elements

In an electrical gain control system including two signal paths for respectively transmitting the positive and negative polarity portions of an input electrical signal, each of said paths including (1) corresponding first signal converting means for providing at its output a first output signal logarithmically related to the corresponding portion of said input signal;

(2) means coupled with respect to the output of said first signal converting means for summing a gain control signal with said first output signal;
and (3) second signal converting means for providing at its output a second output signal which is an antilogarithmic function of the sum of said first output signal and said gain control signal, the improvement comprising:
signal generating means for comparing said input signal and each said second output signal and for generating, in response to said comparison, an error correction signal as a function of the distortion in said each second output signal;
and
summing means coupled with respect to the output of each of the first signal converting means for summing said error correction signal of each signal path with the corresponding first output signal and gain control signal in each of the respective signal paths so as to reduce said distortion in said second output signal.

2 more elements

Dependencies are inferred from the claim text.

Signal correction for electrical gain control systems

Life of this patent

Signal correction for electrical gain control systems

Life of this patent

Abstract

Claims16