Информационный критерий виброустойчивости радиоэлектронной аппаратуры

Abstract

When external interference and internal noises are available, the on-board radio electronic equipment (REE) must remain operative, processing a large amount of information during a limited period of time. A parasitic component (vibration noise) in the structure of the output signal emerging because of dynamic mechanical excitation arises a problem to ensure the REE vibration stability. The paper makes an attempt to estimate it using a non-conventional approach – from the point of view of the applied information theory through the well-known C. Shannon formula. This approach is relevant because in functioning technical systems a process of receiving and processing information occurs, which is followed by appropriate executive decision, and, therefore, when solving the engineering tasks, such universal concepts as entropy, amount of information, capacity, etc. are applicable. As a quantitative criterion for the vibration stability of the radio system, it is proposed to use the relative channel capacity, which depends on the spectral power density of the vibration noise and the bandwidth of the system. A target redistribution of the spectral power density of the vibration noise due to its transformation when passing through the system allows an increase of this parameter, i.e. gain in capacity. External vibration is treated as a limited bandwidth white noise. As an example, the case is considered when the structure of the radio channel is approximately represented as an oscillatory system with one degree of freedom. The constraint imposed on the signal-to-noise ratio is taken into account. The paper formulates conditions which, when satisfied, provide a gain in capacity, which enables to select specific parameters of the isolation system from vibration (characteristic frequency of natural oscillations and damping coefficient). Analytic expressions are obtained for the greatest amount of information perceived by active and passive type radar systems.