Abstract: A digital synthesizer includes a digital radio frequency memory (DRFM) for storing phase values and corresponding digital signals. The digital synthesizer includes a digital processing circuit receiving input from the DRFM, the circuit including tapped delay lines and a summer summing the output of the tapped delay lines. The digital synthesizer includes a signal modulator independently synthesizing within each tapped delay line a frequency modulated and gain scaled signal, wherein input to the tapped delay lines are phase values from the DRFM.

Abstract: A method and system for signal processing, especially useful as a signal repeater, i.e. for simulating the characteristic echo signature of a preselected target. The system has a digital radio frequency memory (DRFM) and associated circuitry, including digital tapped delay lines, and a modulator in each delay line to impose both amplitude and frequency modulation in each line.

Abstract: A method and system for signal processing, especially useful as a signal repeater, i.e. for simulating the characteristic echo signature of a preselected target. The system has a digital radio frequency memory (DRFM) and associated circuitry, including digital tapped delay lines, and a modulator in each delay line to impose both amplitude and frequency modulation in each line. Use of digital semiconductor technology increases the bandwidth and sensitivity of such a repeater over prior analog based systems, reduces the noise of the repeated signal, reduces size and cost of such a system, and permits real time alteration of operating parameters, permitting rapid and adaptive shifting among different kinds of targets to be simulated. Preferably the associated circuitry is unitary with, and part of, the DRFM.