Crystal oven

About: Crystal oven is a research topic. Over the lifetime, 955 publications have been published within this topic receiving 10380 citations. The topic is also known as: oven-controlled crystal oscillator & OCXO.

An Improved Overtone Crystal Oscillator with Microprocessor Temperature Compensation

Abstract: For improving the frequency-temperature characteristic of temperature compensation overtone crystal oscillator (TCOXO), a novel 120MHz TCOXO design is described in this paper. It is different from general methods, in which a compensated 40MHz 3th overtone crystal oscillator is frequency tripled. This design utilizes a 100MHz AT-cut 5th overtone crystal oscillator mixing with a 20MHz AT-cut VCXO, then the 120MHz signal is gained through the filter. In this design, AT89S52 microprocessor is chosen to control and supply the adjusted voltage which the 20MHz VCXO needs, consequently, frequency deviations of the two crystal oscillators are compensated so that the 120MHz is the stable output frequency. As the frequency deviation of the 100MHZ overtone crystal oscillator and the 20MHz VCXO is both compensated simply by the latter, which makes frequency deviations of total system even more, the piecewise linear interpolation method is used. In this work, verified experiment results of the compensation are presented. The stability of the experimental 120MHz TCOXO with microprocessor temperature compensation achieves plusmn 2 times 10-7 within the temperature range from -30 to +70degC. The adding inductance method in the common design is not contained, therefore, this novel design is helpful for improving frequency-temperature performances of TCOXO. Synchronously, frequency multiplication is substituted by mixing so that it is possible to reduce the phase noise of the high-frequency TCOXO with this method

Temperature compensated crystal oscillator and method for adjusting output frequency thereof

Abstract: A temperature compensated crystal oscillator has a crystal oscillating unit and at least one part for temperature compensation and oscillation circuits. The temperature compensated crystal oscillator has a layered structure and a planar thin film resistor. The layered structure has an upper layer on which the crystal oscillator and the part are mounted, and at least one layer on which conduction patterns are formed. The planar thin film resistor is arranged on an upper surface of a bottom layer of the layered structure so as to adjust an output frequency of the temperature compensated crystal oscillator. Therefore, an area occupied by the resistor for adjusting the output frequency can be minimized by inserting the resistor between the layers.

Self-identification of differences between aging rates of two frequencies excited in the dual-mode crystal oscillator

Abstract: In this paper we introduce an extension of the self-temperature-sensing of stress compensated (SC) quartz resonator based on simultaneous excitation of two overtones (3rd and 5th overtone) - the slow thickness-shear modes (i.e. the c modes) in dual-mode crystal oscillator (DMXO). The extension is based on implementation of a self-identification of the differences between aging rates (long-term frequency instabilities) of the two mode's frequencies simultaneously excited in the quartz resonator. Processing of two excited c mode's frequencies enables to predict their shifts due to resonator's temperature variations in a wide range, where the characteristics of the c modes are free from significant anomalies.