No abstract

Held modeling of noise properties of the three schemes of hybrid frequency synthesizers on the basis of PLL and direct digital synthesizer with automatic compensation of phase noise. Interference suppression of hybrid synthesizers performed by isolating the law of parasitic phase deviation of the output signal of the digital synthesizer and changing the modulating voltage of controlled oscillator of the PLL in accordance with the law of selected phase deviation. The graphs power spectral density of phase noise of individual blocks of hybrid synthesizers are drawn and estimated degree of suppression of phase noise in the output signal of the analyzed devices. Keywords-direct digital synthesizer, hybrid frequency synthesizer, PLL, interference compensation, phase noise spectral densityI.

For the safe operation of Unmanned Aerial Vehicles (UAVs), an effective Automatic Control System (ACS) is necessary, which for successful operation requires high accuracy of the initial information about the UAV’s position in space. Based on the analysis of the shortcomings of the known orientation systems, a phase-metric method of goniometric (angular) control based on accelerometric and gyroscopic transducers for positioning the UAV is proposed, which has a higher accuracy and a wider range of measurement angles. The conducted study showed that in a wide range of rotation angles from 10 to 90 degrees, the root mean square error (RMS) of the results of calculating the rotation angle using the phase-metric method is 8,78 times less than the RMS of the results of calculating the rotation angle using the arctangent function. Reducing the error determines the effectiveness of the proposed method in UAV control systems.

The generalized expressions of steady coefficients of regulation of the linear converter are obtained. Research of parametrical stability of the scheme with two types of filters of operating paths is performed. Index Terms -amplitude-phase converter, stability, continuous piecewise-linear functions.