Abstract: The apparatus for and method of generating a coherent signal whose amplit, frequency and phase can be accurately controlled. A first and second signal are synthesized digitally in response to separate frequency and phase input data. The second synthesized signal is heterodyned with a coherent oscillator signal. This heterodyned signal, in turn, is heterodyned with the first synthesized signal to produce a coherent signal generator output. The amplitude of the generator output signal may be varied in accordance with attenuation input data. A phase modulator provides phase shift key modulation of the output signal in accordance with a phase control signal. In addition, a switch gates the output of the final mixer under control of a switch control circuit which determines the pulse width and timing of the signal generator output.

Abstract: A method of processing an electronic signal so as to facilitate the reduction of spurious signals, which includes mixing the electronic signal with a first synthesized signal of varying frequency to form a combined signal, passing the combined signal through at least one electronic component to produce an exiting signal, and mixing the exiting signal with a second synthesized signal of varying frequency which is correlated to the first synthesized signal, to form an output signal having spurious signals which are spread.