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.

Temperature and trim effect compensation of a VCXO using a multidimensional segmented polynomial array

Abstract: Voltage Controlled Crystal Oscillators (VCXOs) are widely used and well known frequency control products. VCXOs are typically characterized by having wide frequency pulling ranges (greater than ±50ppm). These oscillators are also uncompensated for temperature performance. This means temperature performance of ±20ppm or more is typical over the industrial range of −40 to 85 °C. Trim effect is a skewing of the frequency versus temperature performance of a crystal oscillator as the frequency is pulled (trimmed) away from the oscillator's nominal frequency. Even though unwanted, the degradation of performance from trim effect is something generally accepted as a characteristic of VCXOs. This paper focuses on a method of compensating crystal oscillator temperature and trim effect using a multi-dimensional segmented polynomial array. The inherent trim effect has been reduced from approximately ±11ppm down to ±0.5ppm. This is a 22-fold improvement over the inherent performance. The theory of this compensation method will be discussed, and data showing the results of temperature and trim effect compensation on actual oscillators will be presented.

Development of high-stability miniaturized oven controlled crystal oscillator

Abstract: This paper reports on the development of a high-stability miniaturized Oven Controlled Crystal Oscillator (OCXO) in the size of 9.7 mm × 7.5 mm based on the analog oscillation circuit combined with the conventional temperature sensing circuit using a thermistor and related discrete electrical components. The finite element method (FEM) is implemented to optimize the oven stability of the oven structure. As a result, a highly stable oven performance less than ±1°C variation within the ambient temperature ranging from −40 to 85°C is both numerically analyzed and experimentally demonstrated. Consequently, this result implies that the frequency stability of the miniaturized OCXO can achieve less than ±20 ppb using an AT-cut crystal.

Crystal resonators as frequency substandards

Abstract: Methods for the measurement of the resonant frequency of a piezo-electric quartz vibrator are considered, and advantages are shown to be gained by using the phase/frequency response rather than the amplitude/frequency response to determine the resonance point. Equipment is described which can determine the resonant frequency of 100-kc/s quartz vibrators to ± 1 part in 108, provided that the damping of the vibrator is sufficiently low (Q-factor greater than 100 000), The equipment operates only over a narrow frequency range 100 kc/s ± 10 c/s, and has been useful for crystal resonator development studies. It is concluded, also, that quartz resonators may usefully supplement the oscillator units of a large frequency-standard installation.