Showing papers on "Crystal oven published in 1992"
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
Patent•
07 Feb 1992
TL;DR: In this article, a device for determining the concentration of a substance in a solution by making use of a quartz oscillator is described, where at least one of a plurality of electrodes for applying an electrical voltage to a crystal wafer is separated from the crystal wafers, and the space between the separated electrode and the crystal Wafer is filled with a conductive substance.
Abstract: Herein disclosed is a device for determining the concentration of a substance in a solution by making use of a quartz oscillator In the device, at least one of a plurality of electrodes for applying an electrical voltage to a crystal wafer is separated from the crystal wafer, and the space between the separated electrode and the crystal wafer is filled with a conductive substance The electrode-separated piezoelectric crystal oscillator thus obtained can be made more highly accurate, smaller-sized and more inexpensive
87 citations
Patent•
30 Mar 1992
TL;DR: A wide frequency deviation voltage controlled crystal oscillator includes a multiple section bandpass filter consisting of a plurality of crystal or ceramic elements as discussed by the authors, which can be adjusted to a wider range of frequencies than prior art oscillators.
Abstract: A wide frequency deviation voltage controlled crystal oscillator includes a multiple section bandpass filter containing a plurality of crystal or ceramic elements. One embodiment includes a plurality of crystals which are connected into parallel conduction paths. The crystals have resonant frequencies which are separated by small, selected intervals so that the oscillator may be adjusted to a wider range of frequencies than prior art oscillators. Alternatively, the same result may be achieved by using crystals with the same resonant frequency and connecting each crystal to a capacitor having a selected value. In another embodiment a multiple section crystal or ceramic bandpass filter is substituted for the parallel conduction paths. The principles of the invention are applicable to a number of different devices, including the ringing circuits used in color televisions to perpetuate the color bursts which appear in the blanking intervals of the incoming TV signals.
46 citations
Patent•
10 Mar 1992TL;DR: In this article, a high-frequency apparatus using a quartz crystal resonator including a voltage controlled oscillator, a temperature compensated quartz crystal oscillator and the like is described, in which the resonator itself is bonded with coupling of silicon, oxygen, hydrogen, hydroxyl group, and other groups directly to a semiconductor substrate having an active element.
Abstract: Disclosed is a high-frequency apparatus using a quartz crystal resonator including a voltage controlled oscillator, a temperature compensated quartz crystal oscillator and the like, in which a quartz crystal resonator itself is bonded with coupling of silicon, oxygen, hydrogen, hydroxyl group and the like directly to a semiconductor substrate having an active element, thus being integrated in a unitary body
17 citations
Patent•
15 Jan 1992
TL;DR: In this paper, a differential mixer oscillator employing two transistors in a differential pair as the sustaining amplifier for a quartz crystal resonator at some first high frequency is described, and the bias current of the differential pair is modulated at a second high frequency derived from some second frequency generating source, typically a second quartz crystal resonance.
Abstract: A differential mixer oscillator employing two transistors in a differential pair as the sustaining amplifier for a quartz crystal resonator at some first high frequency. The bias current of the differential pair is modulated at a second high frequency derived from some second frequency generating source, typically a second quartz crystal resonator, and the product terms are available at the collectors of the two transistors for selective filtering. The differential mixer oscillator may be employed in multiples, and with a variety of current sources, such as a Colpitts oscillator circuit.
14 citations
27 May 1992
TL;DR: The Navy Navigation Satellite System (NNSS) uses precision quartz crystal oscillators to provide time and frequency in the orbiting spacecraft, and frequency changes for multiple oscillators, which were observed for 28 years of operational service in the orbital environment, are discussed.
Abstract: The Navy Navigation Satellite System (NNSS) uses precision quartz-crystal oscillators to provide time and frequency in the orbiting spacecraft. The frequency changes for multiple oscillators during many years of operational service in the orbital environment are discussed. The primary frequency changes are believed to be caused by mass transfer to and from the resonator, stress relief in the resonator mounting structure and electrodes, and ionizing radiation of the quartz resonator. >
10 citations
09 Nov 1992
TL;DR: In this paper, a sensor based on the crystal oscillator has been used to reduce the uncertainty gap in compensation and a specific integrated circuit has been designed to produce thermal data from a dual mode oscillator and correct the output frequency.
Abstract: Digital compensation in temperature techniques for crystal oscillators is presented. Error due to temperature and compensation data resolution is evaluated. Different thermal coefficients between sensor and crystal are studied through experiments on dynamic and static sweeps in temperature. A sensor based on the crystal oscillator has been used to reduce the uncertainty gap in compensation. A specific integrated circuit has been designed to produce thermal data from a dual mode oscillator and correct the output frequency. The calibration function has been programmed in a HCMOS microcontroller, where the thermal transient is evaluated to optimize power consumption. >
5 citations
27 May 1992
TL;DR: In this paper, a self-temperature compensated crystal oscillator (S-TCXO) with cut quartz crystal resonators was successfully obtained with frequency deviation of +30/-150 ppb over a wide temperature range of -30 to +85 degrees C, without any external temperature compensation.
Abstract: Frequency temperature behavior and hysteresis of self-temperature compensated crystal oscillators (S-TCXOs) using cut quartz crystal resonators are described. A S-TCXO is successfully obtained with frequency deviation of +30/-150 ppb over a wide temperature range of -30 to +85 degrees C, without any external temperature compensation. The thermal hysteresis of S-TCXOs is extremely small for the excursion of fall-temperature to rise-temperature, but occurs somewhat for the excursion of rise-temperature to fall-temperature. The variation quantity for each S-TCXO is less than 0.38 ppm in frequency deviation for the temperature excursion of -45 to +90 and -45 degrees C. Aging quantity after pre-aging for about two weeks is found to be 0.3 ppm at a mean value of eight samples for one year and two months. >
2 citations
Patent•
18 Dec 1992
TL;DR: In this article, a measuring head measures displacement by variation in frequency of an oscillator due to movement of a core in a coil, and the signal from the oscillator is used to gate a high frequency crystal clock into a counter.
Abstract: A measuring head (1) measures displacement by variation in frequency of an oscillator due to movement of a core in a coil. The signal from the oscillator is used to gate a high frequency crystal clock (10) into a counter (12). The count is representative of the change in frequency of the oscillator and thus the displacement to be measured. The count is compared by a microprocessor (14) with a look-up table (16) stored in the memory during initial calibration. The operating and processing electronics connected to the sensor head (1) are mounted in a connector which can be directly coupled to connectors of other sensors to form a bus connecting multiple sensors to a host.
2 citations
Patent•
10 Mar 1992
TL;DR: Jitter attenuators with a phase detector (104) to control a crystal oscillator to remove jitter where the phase detector includes both a sequential phase/frequency detector (200) of low transistor count and an arrangement of two sequential phase and frequency detectors (198 and 200) to increase gain this article.
Abstract: Jitter attenuators (100) with a phase detector (104) to control a crystal oscillator to remove jitter wherein the phase detector includes both a sequential phase/frequency detector (200) of low transistor count and an arrangement of two sequential phase/frequency detectors (198 and 200) to increase gain and two drivers for the crystal oscillator.
1 citations
TL;DR: In this article, a new controller type specially designed to avoid many of the long and short-term stability problems that standard proportional controllers induce in the oscillator circuit is presented, which can improve the warm-up performance when required.