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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.


Papers
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01 Mar 1992
TL;DR: In this paper, the fundamentals of quartz frequency standards are reviewed, including crystal resonators and oscillators, oscillator types, and the characteristics arid limitations of temperature-compensated crystal oscillators.
Abstract: : The fundamentals of quartz frequency standards are reviewed. The subjects discussed include: crystal resonators and oscillators, oscillator types, and the characteristics arid limitations of temperature-compensated crystal oscillators (TCXO) and oven-controlled crystal oscillators (OCXO). The oscillator instabilities discussed include: aging, noise, frequency vs. temperature, warmup, acceleration effects, magnetic field effects, atmospheric pressure effects, radiation effects, and interactions among the various effects. Guidelines are provided for oscillator comparison and selection. Discussions of specifications are also included, as are references and suggestions for further reading. Oscillator, clock, frequency standard, frequency control, frequency stability, time, timing devices, quartz, quartz crystal, quartz oscillator, atomic clock, atomic frequency standard, stability, aging, noise, phase noise.

169 citations

Journal ArticleDOI
TL;DR: In this paper, a new technique is presented which makes it possible to measure the inherent short-term stability of quartz crystal resonators in a passive circuit, and it is shown that with this improved shortterm stability it should be feasible to multiply a crystal controlled source to 1 THz and obtain a linewidth of less than 1 Hz.
Abstract: A new technique is presented which makes it possible to measure the inherent short-term stability of quartz crystal resonators in a passive circuit. Comparisons with stability measurements made on crystal controlled oscillators indicate that noise in the electronics of the oscillators very seriously degrades the inherent stability of the quartz resonators for times less than 1 s. A simple model appears to describe the noise mechanism in crystal controlled oscillators and points the way to design changes which should improve their short-term stability by two orders of magnitude. Calculations are outlined which show that with this improved short-term stability it should be feasible to multiply a crystal controlled source to 1 THz and obtain a linewidth of less than 1 Hz. In many cases, this improved short-term stability should also permit a factor of 100 reduction in the length of time necessary to achieve a given level of accuracy in frequency measurements.

117 citations

Proceedings ArticleDOI
31 May 1989
TL;DR: In this article, the authors proposed a method using a harmonically related pair of c-modes of an SC-cut that is simultaneously excited in a dual-mode oscillator, and then combined to produce a thermometric frequency having a monotonic and nearly linear dependence on temperature.
Abstract: A thermometry method using resonator self-temperature-sensing is described. The method uses a harmonically related pair of c-modes of an SC-cut that is simultaneously excited in a dual-mode oscillator, and then combined to produce a thermometric frequency having a monotonic and nearly linear dependence on temperature. It avoids the activity dip problems of the b-mode and overcomes limitations of using external sensors that are subject to thermal lab and temperature gradients. This method provides a means of measuring resonator temperature with high accuracy, limited only by the stability difference between the c-mode frequencies. The concept for this dual c-mode thermometry method is presented and its implementation in a microcomputer-compensated crystal oscillator discussed. >

116 citations

Journal ArticleDOI
TL;DR: In this article, a photonic delay line is used as a frequency discriminator for measurement of the phase noise of microwave oscillators, which is suitable for a wide range of frequency without reconfiguration.
Abstract: A photonic-delay line is used as a frequency discriminator for measurement of the phase noise - hence the short-term frequency stability - of microwave oscillators. The scheme is suitable for electronic and photonic oscillators, including the optoelectronic oscillator, mode lock lasers, and other types of rf and microwave pulsed optical sources. The approach is inherently suitable for a wide range of frequency without reconfiguration, which is important for the measurement of tunable oscillators. It is also insensitive to a moderate frequency drift without the need for phase locking.

108 citations

Journal ArticleDOI
TL;DR: A 2.5-mc crystal unit was developed for use in a new, extremely stable frequency standard oscillator as mentioned in this paper, which achieved a frequency stability in the order of one part in 1010.
Abstract: A 2.5-mc crystal unit has been developed for use in a new, extremely stable frequency standard oscillator. A well-balanced design was achieved by using a 30-mm-diameter, plano-convex, polished quartz plate, coated with gold and operated on its fifth overtone. The quartz plate is mounted on its quiescent edge in an evacuated bulb, and achieves a Q of five to six million, representative of the Q of the quartz itself. The temperature coefficient, current coefficient, frequency adjustment tolerance and frequency aging of the crystal unit are all consistent with a frequency stability in the order of one part in 1010. It was necessary to develop polishing methods that would not disturb the crystal structure of the quartz plate and new methods of orienting the crystollographic axes to achieve better temperature coefficient control. New methods of mounting the quartz plate were found that avoid strain and reduce the effects of shock and vibration. The new crystal unit makes possible oscillators characterized by excellent frequency stability, small and uniform aging and straightforward design. For periods up to one month, the frequency stability of such standards compares favorably with that of atomic frequency standards.

103 citations

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20233
20228
20191
201711
201625
201524