Accession Number : ADD006515
Title : Twobit A/D Conversion Apparatus without a Signal Derived Automatic Gain Control.
Descriptive Note : Patent,
Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC
Personal Author(s) : Covitt,Arthur L
Report Date : 18 Sep 1979
Pagination or Media Count : 5
Abstract : The present invention utilizes a receiver demodulator to provide an accurate analog to digital conversion of a phase modulated carrier without a signal derived automatic gain control (AGC). The two-bit A/D conversion apparatus utilizes a pair of rectifier units to resolve the carrier baseband residue into a pair of quadrature channel voltages. The quadrature channel voltages are continuously applied as control signals to the A/D converters to select the instantaneously appropriate binary output signal from each channel. For any signal-to-noise ratio input exceeding an acceptable minimum, the output is independent of input signal amplitude and therefore the A/D converter performs a function equivalent to an ideal instantaneous automatic gain control (IAGC). The digitized outputs are sequentially sampled in a decommuator unit and applied respectively to a pair of digital matched filters for digital signal processing appropriate to the particular type of phase modulation used in the present embodiment.
Descriptors : *Patents, *Analog to digital converters, Orthogonality, Carrier frequencies
Subject Categories : Computer Hardware
Distribution Statement : APPROVED FOR PUBLIC RELEASE