The noise characteristics of multichannel systems of forming signals based on hybrid frequency synthesizers with automatic\ncompensation of phase distortions of direct digital synthesizers, which are used in the composition of georadars with synthesized\naperture, are investigated. It is established that the phase noise of the output signals of the formers at the 1 kHz detuning from the\ncarrier oscillation at the output frequencies of the devices in the range from500 to 3500MHz is characterized by a level ofminus 100\n- minus 130 dB. In this case, the circuit of the signal former based on a hybrid frequency synthesizer with direct digital synthesizer\nas a reference oscillator of a phase locked loop is characterized by the worst noise characteristics but with the highest degree of\nautocompensation (about 13 dB). Conversely, the circuit of the signal former based on a hybrid frequency synthesizer with direct\ndigital synthesizer as a support generator of the phase-locked loop has the best phase noises level from the considered variants of\ndevices and least degree of autocompensation (about 6 dB).
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