DTXCO thermal converter realized by means of a metal film temperature sensor deposited on the crystal plate

Temperature compensated crystal oscillator parameters are dependent to great extent on the accuracy of crystal temperature measurements. The most prominent results were attained for DTCXO with resonator-temperature sensitive element configuration based on dual-mode excitation principle. In this case parameter high stability is attained and the temperature lag between temperature sensor and a measurement object is practically avoided. The investigation of an alternative crystal temperature measurement procedure shows that high DTCXO performances can be attained without dual-mode excitation. A thin metal film deposited along the crystal plate contour is used as a primary thermosensor. To increase the stability and the accuracy of temperature measurement a thermal converter had been developed using the principle of digital-analog system of automatic frequency control. Using by way of example a simple DTCXO with AT-cut crystal and piece-wise compensation function theoretic and experimental investigation were carried out