Abstract: The high frequency oscillator includes a piezo-electric crystal (1) which is connected to at least two exciter electrodes (3, 4) and means which make it possible to apply on the one hand to the electrodes (3, 4) electric excitation power for the crystal according to a useful vibratory mode which is selected to determine a frequency reference, and on the other hand additional electric power for exciting the crystal according to an overtone vibratory mode which is distinct from the useful vibrational mode. Means (46, 47) are also provided to regulate the electric excitation power of the crystal according to the useful vibratory mode in a predetermined and constant proportion in relation to the additional electric power. The invention makes it possible to compensate, using the isochronism deficiency stemming from the additional vibration on the useful mode, the indirect amplitude-frequency effect stemming from the additional vibration, and vice versa.

Abstract: A resonator with an integrated infrared thermostat, having a sealed casing enclosing reflectors including concave spherical domes covered with an interior coating of reflecting metal, placed on either side of a piezoelectric crystal, an infrared heating means device positioned on either side of the crystal in front of the spherical domes, and a temperature sensor including a thermocouple of two thin metal layers superimposed seriatim on one side of the active part of the crystal and constituting additionally and simultaneously one of the excitation electrodes for the crystal.

Abstract: A temperature-compensated quartz oscillator having a first plate of quartz that carries a first electrode which displays a sensitivity to temperature that exceeds that of the piezoelectric quartz wafer which comprises a first resonator which vibrates at a reference frequency f.sub.M. The first plate cooperates with the first electrode and a third electrode to form a second quartz resonator. Means for applying to the first and third electrodes an excitation electric power to drive the active portion of the first plate according to a mode which is sensitive to temperture, at a frequency f.sub.T close to, but slightly different from, the reference frequency f.sub.M. Means for comparing, which enable comparison of signals at the terminals of the second and third electrodes, and control means for the regulating means for applying an excitation electric power from the active portion of the piezoelectric wafer.

Abstract: An autothermostatic high frequency oscillator comprising a piezoelectric resonator of the type having electrodes which are not adhered to the crystal. The contact between the part of the crystal 1 serving to support the vibrating part of the crystal and the dielectric plates 2,3 supporting the excited electrodes is limited to a discontinuous surface of reduced scope constituted by a finite number of elements of contact surface. At least an infra-red reflector screen (200) located at the very interior of the water tight cavity (400) surrounding the resonator is situated immediately adjacent said resonator and the electric power applied to the excited electrodes is at least in the range of about 50 microwatts. The invention permits one to achieve oscillators with small consumption of energy and high stability.