The main disadvantages of high-stability UHF generators and difficulties of using such equipment on satellites and other mobile objects are revealed. A device for converting a highly stable signal into several coherent ones is proposed. The choice of low-noise operational amplifiers (OA) as an element base for the converter is proved. Theoretical study of noise coefficients and phase noise power spectrum densities of imported and domestic low-noise operational amplifiers is done with the use of MATLAB environment. The circuit diagram of the device based on selected models of OA, which was later modified by increasing the number of output signals is designed. The necessity to revise the general structure of the circuit considering on the parasitic capacitances of the OA is declared. Its adequacy was checked with using the program package NI Multisim. The printed circuit board for direct laboratory studies of the phase noise power spectrum density of device is built. Keywords: phase noise, signal converter, UHF, hydrogen standard, low noise amplifier, current noise, voltage noise.
$^1$Peter the Great St. Petersburg Polytechnic University, Institute of Electronics and Telecommunications, Higher School of Applied Physics and Space Technologies.\
$^2$
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