Northrop Grumman Systems Corporation

Robert R Harnden

Mark Kintis

Donald R Martin

Kenneth Weber

Jeffrey Mark Hinrichs

William Marvin Skones

Donald L Lochhead

Mark V Keller

Kai E Johnson

Brian J Rosenkoetter

A multi-carrier receiver system and method for receiving a transmission frequency multi-carrier signal include a feedforward cancellation loop. A frequency conversion circuit generates an intermediate frequency (IF) multi-carrier signal based on the transmission frequency multi-carrier signal. The feedforward cancellation loop generates an amplitude corrected multi-carrier signal based on the IF multi-carrier signal such that the amplitude corrected multi-carrier signal has a reduced dynamic range with respect to the IF multi-carrier signal. A primary A/D converter having a significantly lower dynamic range requirements can therefore generate a digital multi-carrier signal based on the amplitude corrected multi-carrier signal. The feedforward cancellation loop therefore enables the primary A/D converter to process multi-carrier signals without the need for large dynamic range requirements.

Feedforward amplitude cancellation topology for multi-carrier applications

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.

Apparatus and methods for digital-to-analog conversion

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Redondo Beach, CA, United States of America

Robert R Harnden