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
      Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE