US 5,422,643 A · High dynamic range digitizer

Abstract

A digitizer suitable for digitizing input signals having a high dynamic range. The digitizer is microprocessor controlled and comprises an input stage, a multi-channel attenuator or amplifier bank, a multiplexer and a analog-to-digital (A/D) converter. The function of the multi-channel bank is to move the input signal within the range of the A/D converter. The input signal to be digitized is fed through the input stage to each of the channels in the attenuator bank. The signal is scaled by each respective channel in the attenuator bank. The multiplexer is used to switch the scaled signal which is within the range of the A/D converter for digitizing. The digitized sample is then corrected according to the attenuation or gain factor of the scaled channel. The digitizer includes a comparator bank which is used to determine the channel with the widest signal range within the range of the A/D converter. The digitizer also includes a channel calibrator for calibrating the actual gain or attenuation of each channel. In another aspect, the digitizer can be implemented using an optical front-end comprising an optical beam splitter, optical attenuators and amplifier banks. The optical front-end provides improved noise immunity and faster speed of operation.

Claims13

Dependent claims

A digitizer capable of digitizing an input signal with a large dynamic range, said digitizer comprising:

(a) an input port for receiving the input signal;
(b) a scaling bank for scaling the input signal, said scaling bank being coupled to the input port, and having a plurality of channels and each channel including an output and scaling means for producing at said output a scaled signal corresponding to the input signal;
(c) a switch coupled to the outputs of said scaling bank and having a switch output and switching means for producing at the switch output one of said scaled signals;
(d) an analog-to-digital converter having an analog input coupled to said switch output for receiving said scaled signal, and including a data output port and digitizing means for converting said scaled signal into a digital signal for output at said data output port;
and
(e) means for selecting one of said scaled signals having an input port coupled to the outputs of said channels in said scaling bank and an output port;
(f) controller means coupled to said switch and to the output port of said means for selecting for controlling said switching means to select one of said scaled signals and said digitizing means for converting said scaled signal.

4 more elements

Dependencies are inferred from the claim text.

High dynamic range digitizer

Life of this patent

High dynamic range digitizer

Life of this patent

Abstract

Claims13