Analysis of Signals with Parasitic Phase Modulation in Signal Genera-tors Based on DDS with Phase Distortion Autocompensation for Geoecological Monitoring Systems
Abstract
A block diagram of a signal generator based on a direct digital synthesizer with automatic phase distortion compensation for geoecological monitoring systems is considered. Analytical expressions of an arbitrary deterministic signal with single-tone phase modulation and its spectrum based on piecewise linear approximation and mathematical apparatus of Bessel functions are obtained. The amplitude spectrum of a phase-modulated periodic sequence of unipolar exponential pulses is calculated at two values of the modulation index. The results obtained describe transient processes on the output of a two-half-period rectifier in the information path of an autocompensator and can be used to analyze the effect of parasitic phase modulation (jitter) on the operating mode of the device.