Модель оценки долговечности СВЧ-транзисторов большой мощности
A study evaluating the durability of the model of microwave power transistors
The article analyzes the methods of evaluation of calibration intervals of measuring instruments in the design. Describes recommended methods based on the use of indicators of reliability, in the examples it is shown that for electronic measuring instruments, their use may lead to inadequate results. Alternatively, a method based on the use of durability indicators, and examples confirming the possibility of its application in project evaluation of the primary calibration intervals.
The article examines the creation of program to assess the performance durability of radio-signals processing devices. This type devices are widely used in various communication systems and performance durability of these devices have a significant impact on performance durability communication systems. In the currently accepted methods of assessment of the durability indicators of device can be performing calculations in two stages (approximate and refined calculation). This is when a large number of elements significantly increases the complexity associated, primarily, with the search data on the durability characteristics. Therefore, given in the methods the model used for the conversion of durability indicators of the maximum allowed modes and conditions of the use of elements (approximate calculation) to operating modes (refined calculation), is quite simple. However, the use of such models although not strongly influences the complexity of the calculations, but may lead to less accurate estimates of durability indicators. This error will be greater than the maximum allowed modes and the conditions of application of elements differ from operating modes. However, modification of models aimed at improving the accuracy of the calculations that will lead not only to increased complexity of the calculations, but also requirements for the qualification of specialists and, consequently, to the need to create appropriate software and databases. In addition, the need to create such software due to the lack of commercial software tools for the calculation of reliability of domestic and foreign manufacturers of modules of calculation of durability. When creating the calculation program of durability indicators of the radio-signals processing devices were the main requirements, the scheme of information exchange with CAD-systems and specialized CAE-systems, to determine the composition of software modules and the functioning algorithm of the program and designed the model database according to the durability characteristics of elements. This research carried out in 2015 was supported by "The National Research University "Higher School of Economics" Academic Fund Program" grant (No. 15-05-0029).
The report considers the issues of forecasting the reliability parameters of modern on-board equipment of spacecrafts. The expediency of using the results of tests of equipment and it’s components for resistance to the effects of ionizing radiation to predict the reliability parameters. Substantiated the possibility of alpha-time distribution for the MTBF prediction of reliability and durability of the CMOS integrated circuit. Shown the calculated ratios for estimating the probability of failure-free operation, the mean time between failure and minimum service life. Given possible ways of increasing the life of modern on-board equipment of spacecrafts by using specialized methods of protection against ionizing radiation of space. This study (research grant No 14-05-0038) was supported by The National Research University - Higher School of Economics’ Academic Fund Program in 2014.
The computational model of the temperature sensors integrated on the IC chip with power transistors is developed. The 2D/3D problem of sensor placement is mathematically described by the classic heat transfer equation coupled with the equation for current density distribution. It is shown that parasitic effects of sensor current displacement and thermo-emf generation resulting from a temperature gradients (Seebeck effect) must be taken into account. For this purpose the special differential equation is introduced. The examples of point- and strip-like temperature sensors modeling for power BJTs and ICs are demonstrated.
Assessment of the durability of microwave transistors