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.

A new kind of view for a Double oven Crystal Oscillator

Abstract: New demands for minimizing space and increasing frequency stability bring us to consider a new approach on double oven Oscillators. Main application of high performance oscillators are in "GNSS disciplined" applications. To allow the assembly on a board of 4TE width, the height of the OCXO is limited to 19 mm. A major requirement is in the micro second range at 1 day holdover. Ageing and thermally induced frequency drift are to be compensated. The frequency stability <6.10-10 in a wide temperature range -20degC to + 70degC as well as a waterproof ness to minimize the influences of humidity. The reproducibility of the frequency change must be as low as possible in the several repetitive thermal gradients to minimize the frequency hysteresis effect. The demand of synchronization networks for a daily frequency drift of <1.10-10 / day in holdover mode ask for the construction of a new mechanical-thermal structure to house the SCp3 10 MHz resonator. Various oscillator diagrams have been compared (such as Clapp and Hartley-Colpitts) by simulation. The Clapp diagram is considered as being easier for adjustment, and needing fewer components. Design and simulation of thermal structure will be described. In order to decrease the total height of the internal structure to <11 mm, the traditional internal oven is replaced by a quartz plated on one side of the specific board that represents the mass of thermal inertia. All oscillator components and crystals are heated from the other side of this board by a proportional integrated thermostat. This board becomes an "inner ovenised oscillator" and is integrated in an outer temperature stabilized structure. This structure is hermetically sealed to minimize variation induced by humidity variation that interacts as a capacity effect. This second structure is thermally controlled by another proportional integrated thermostat. Thermal and mechanical designs are described in details and main results (ageing, thermal drift, thermal hysteresis ...) as long as holdover performances are provided.

Quartz crystal oscillator

Abstract: This invention relates to an electrode arrangement for quartz oscillators. It is known that in the operation of oscillating quartz crystals, if the electrodes parallel to the quartz crystal are, at a, certain distance, certain damping effects are liable to arise as a result of the column of...

Oven for heating a crystal for a laser frequency conversion

Abstract: An oven for heating a crystal for nonlinear frequency conversion of a laser beam. A grasping device resiliently grasps together the first and second sides of the crystal while allowing for generally unrestricted thermal expansion of the crystal. A heater element and a temperature sensor are each supported by the grasping device and are each in thermal contact with the crystal. A temperature controller is connected to the heater element and the temperature sensor.

Piezo electric resonator temperature sensor

Abstract: The temperature of a quartz crystal oscillator is determined by comparison of a pair of inharmonically related overtone oxcillations of the same vibrational type, e.g. a thickness shear mode, and of the same overtone order. The use of inharmonically related signals relaxes the contraints on crystal design. The technique may be employed in a crystal controlled frequency synthesizer to provide a feedback signal for maintaining constant output frequency.

Precision Quartz Resonator Frequency Standards

Abstract: High-precision quartz crystal resonators were recently added as a part of the primary standard of frequency at the National Bureau of Standards. Their reliability over short and long periods of time resulted in establishment of a frequency and time reference system constant to 1 part in 1010 per day. Measurement equipment and methods, are described in detail. The equivalent circuit for the crystal unit is discussed and the effects of external influences such as stray capacitance, electric and magnetic fields, connecting cables, ambient temperatures, and amplitude of vibration are considered. An assessment method is discussed. This method is based on the fitting of a natural aging or drift curve for each resonator to an observed curve after sufficient performance data are obtained. The use of resonators with crystal clocks represents one of the simplest and most reliable and economical methods of establishing a precise frequency reference in terms of mean solar time and of noting deviations in the earth's rate of rotation.