Study On Storage Life Evaluation Of Microwave Amplifier

With the wide application of microwave devices in communication,telemetry,radar and other fields,especially in the field of military equipment,microwave devices are more common.Most of the military electronic equipment,in the service phase of a long time in storage or testing and other non-working state,in order to ensure the reliability of its use,storage life assessment is particularly important.In this paper,the storage life of microwave amplifier is evaluated based on a national basic evaluation technology project.There are few researches on the storage life of microwave devices at home and abroad.For this reason,the paper first completed a long time high temperature storage test for up to 6 months,and then analyzed the device parameter degradation trajectory and failure physical mechanism,and obtained the failure sensitive parameter and storage life evaluation results,which provided the test and theoretical basis for the quantitative storage life evaluation of the model microwave amplifier in China.The main contents of the paper are as follows:1.In this paper,Based on the comparative analysis of the performance,structure and key parameters of microwave amplifiers in China,the storage failure mode and physical mechanism of microwave amplifiers are studied,and the degradation trajectory of key parameters is given.2.The limit stress test scheme for the storage life evaluation of the microwave amplifier was established,and the grope test of the limit storage was completed.Through 196 hours of high temperature storage test and result analysis,the microwave amplifier’s limit storage temperature is 145℃.3.The constant stress test scheme for microwave amplifier storage life evaluation was established,and the long time high temperature storage test of about 4300 h was completed.The degradation trend of the device parameters under temperature stress is analyzed,and the sensitive parameter of microwave amplifier storage life,namely power gain,is obtained.4.Based on the failure analysis of the internal microstructure and components of the device,no traces of internal electrical damage were found,and the failure caused by electrical stress was excluded.Based on the characteristics of components and circuit topology of the device,it was obtained that the power gain degradation was caused by the reduction of the magnification times of the internal transistor.5.Through the statistical analysis and calculation of the test data,the storage life evaluation method based on lognormal distribution and log-linear fitting method were used to evaluate the life of the device.It was estimated that the average life under normal temperature was 143 years,the median life was 85 years,and the reliability of 27.5 years was 0.8671.The test results show that this type of device can basically meet the requirement that the storage life of military electronic components is higher than the baseline of 27.5 years.