Temperature dynamic model and temperature dynamic compensation of crystal oscillators

In thermocompensated crystal oscillators (TCXO) the compensating action is estimated as a function of environmental temperature. Experimental data show that TCXO frequency stability is essentially dependent on temperature process dynamic parameters. The origins of this phenomenon are analyzed and ways of reducing its effects are shown. A new approach is suggested, according to which the compensating action is formed as a function of two variables, i.e., the temperature and the rate of its variation. A theoretical proof of this method is given. Structural circuits of devices performing the temperature dynamic compensation are suggested. Experimental investigations of TCXO with a microprocessor-based temperature dynamic compensation system confirm the possibility of essential TCXO frequency stability improvement in nonstationary thermal conditions