Abstract: A filter or multicoupler has at least one resonator which can be electronically tuned by a tuning device, has at least one tuning element such as a tuning capacitor, a switching element for selectively connecting the tuning element electronically to the resonator, and a control device for the switching element. The resonator is a coaxial quarter-wave resonator with a central component having free surface perpendicular to the central axis for mounting of tuning devices.

Abstract: A method of controlling the amplitude of the microwave signal applied to an atomic clock comprising an atomic resonator and a device for interlocking an ultra-stable oscillator in follow-up relationship with the atomic resonance, adapted to produce the signal from which the microwave signal is derived, the method consisting in transforming the amplitude of the microwave signal before its application to the atomic jet resonator according to a law such that the shape of the curve of atomic response versus the amplitude of the microwave signal be symmetrical over a wide extent about the vertical line passing through the maximum of the response.