Long-term stability (aging) of evacuated hybrid OCXO

The work is devoted to research in frequency stability of miniature integrated OCXO packaged in TO-8 vacuum holder. Since a number of electronic components and materials are involved in the unit design such investigations are of primary interest. The paper describes results of a long-term stability (aging) test of the OCXO during the period of about 2 years. Besides aging, various experiments including retrace and frequency hysteresis measurements are described. Experiments proved that the hybrid technology is suitable for fabrication of high stability miniature OCXO.