Kenneth J Weber

US Patent:

7031395, Apr 18, 2006

Filed:

Mar 29, 2002

Appl. No.:

10/109834

Inventors:

Jeffrey M. Hinrichs - San Diego CA, US
Brian J. Rosenkoetter - Herndon VA, US
Robert R. Harnden - Redondo Beach CA, US
Kenneth B. Weber - Redondo Beach CA, US
Mark Kintis - Manhattan Beach CA, US
Donald R. Martin - Redondo Beach CA, US
William M. Skones - Manhattan Beach CA, US
Kai E. Johnson - Redondo Beach CA, US

Assignee:

Northrop Grumman Corporation - Los Angeles CA

International Classification:

H03M 3/00
H04B 14/06

US Classification:

375245, 341134

Abstract:

An apparatus for converting a digital input signal to an analog signal for transmission. The input signal can include more than one carrier signal. A plurality of delta-sigma modulation loop circuits are connected in an increasing order of operating frequency so as to reduce a word length of the input signal. A tuning circuit adjusts the signal frequency to a transmitting frequency for conversion to analog by a digital-to-analog converter. A first loop circuit is implemented using CMOS gates, and a second loop circuit and the tuning circuit are implemented using indium phosphide gates. The apparatus allows a high-resolution, wide-band RF multiple-carrier signal to be re-quantized to a lower-resolution signal while an acceptable signal-to-noise ratio is maintained.