DEVELOPMENT AND RESEARCH OF UNIVERSAL RELIABILITY MODELS OF AN ACTIVE PHASED ANTENNA ARRAY OF A MULTIFUNCTIONAL RADAR STATION

Abstract

The paper provides a brief analysis of the AFAR reliability models proposed by scientists and engineers over the past 20 years. The reliability model of the receiving AFAR is considered according to the criterion of permissible increase in the minimum level of the side lobes of the radiation pattern of the amplitude-phase distribution of the antenna array. The reliability model of the transmitting AFAR is analyzed according to the criterion of the permissible decrease in the maximum radar range. It is shown that the considered reliability models are approximate (they use the exponential distribution law of AFAR failures) and therefore can only be used to approximate the mean time between failure of the antenna array. To determine the probabilistic indicators of AFAR reliability: the probability of failure-free operation, the failure rate, the distribution density of failures, the gamma-percent resource, etc. more universal reliability models are needed that take into account the structure and complexity of constructing an antenna array as a system consisting of a huge number of primary and backup receivers transmitting channels and modules. In the work, universal reliability models of the AFAR reliability of a multifunctional radar with a two-level structural reliability scheme (two-level AFAR) were developed and investigated. Universal reliability models take into account two basic physical criteria of AFAR failure: an acceptable decrease in the maximum level of radar range and an acceptable increase in the minimum level of side lobes of the antenna array radiation pattern. As the laws of distribution of failures of the emitting (transmitting) and receiving channels and modules of the antenna array, an exponential distribution (characterizes sudden failures), a nonmonotonic diffusion distribution (characterizes gradual failures), and a composition of the exponential and diffusive nonmonotonic distribution law (characterizes the joint manifestation of sudden and gradual failures). The article presents equations and formulas for determining the reliability indicators of a transmitting, receiving and receiving-transmitting AFAR: the average operating time to failure, the probability of failure-free operation, etc. Three illustrative examples of calculating the reliability indicators of a transmitting, receiving, and transmitting AFAR with an exponential distribution are considered channel failures and antenna array modules. The analysis of the effect of the failure rates of the emitting channels and the modules of the secondary power sources on the mean time between failures of the AFAR is performed.

The universal AFAR reliability models presented in the article are recommended to be used when developing new multifunctional radars with AFAR, and can also be useful to students and graduate students of universities and universities in the educational process.