An update on the TMXO

Improvements made to enhance the performance and to improve the manufacturability of the tactical miniature crystal oscillator (TMXO) are presented. The results of these efforts are described in detail. The TMXO was radiation-hardened to tactical levels. Phase noise was reduced to -125 dBc/Hz at 10 Hz offset, with a floor of -160 dBx/Hz. The lowest structural resonance was increased to 1800 Hz. Numerous manufacturability improvements are described. In addition to a large number of process changes, the package has been improved, the number of thick-film screenings has been reduced from 13 to 2, and the circuit itself as well as circuit components have been changed extensively, both to enhance performance and to simplify assembly and alignment. Principal specifications of the improved TMXO are given