Abstract: A low phase noise frequency synthesizer includes arranged in series, a first mixer receiving a reference signal at a reference frequency Fr, a loop filter and a voltage-controlled oscillator delivering a microwave signal at a second frequency FO slaved to a multiple of reference frequency Fr, the frequency synthesizer further includes: means of multiplication of the frequency FO of the microwave signal by a factor N strictly greater than 1, means of correction of the frequency N·FO of the output signal of the multiplication means to restore frequency N·FO to an interval [FOmin, FOmax] where output frequency FO would vary if multiplication factor N=1, means of division of the frequency Fj of the output signal of the correction means by a factor equal to the expected ratio between frequency Fj and reference frequency Fr, the frequency division means connected at output to the second input of the first mixer.

Abstract: The present disclosure relates to a method for repairing a portion of an acoustic panel for a nacelle of an aircraft turbojet engine. The panel includes an acoustic skin in which a plurality of acoustic holes are drilled, a solid skin, and a cellular acoustic structure. The cellular acoustic structure, being arranged between the acoustic skin and the solid skin, has a plurality of cells, each of which has one or more drainage openings arranged in one or more of the walls forming each cell. The method includes a step of: defining a part of the acoustic panel to be cut; forming a cutting area closed by the acoustic skin; injecting a resin through the acoustic holes; positioning a replacement cellular acoustic structure in the cutting area and on the acoustic skin; forming a solid replacement skin on the replacement cellular acoustic structure.

Abstract: A low phase noise frequency synthesizer, comprising, arranged in series, a first mixer receiving a reference signal at a reference frequency Fr, a loop filter and a voltage-controlled oscillator delivering a microwave signal at a second frequency FO slaved to a multiple of reference frequency Fr, further comprises: means of multiplication of the frequency FO of said microwave signal by a factor N strictly greater than 1, means of correction of the frequency N.FO of the output signal of the multiplication means configured to restore frequency N.FO to an interval [FOmin, FOmax] where output frequency FO would vary if multiplication factor N=1, means of division of the frequency Fj of the output signal of the correction means by a factor equal to the expected ratio between frequency Fj and reference frequency Fr, the frequency division means being connected at output to the second input of the first mixer.

Abstract: The present disclosure relates to a method for repairing a portion of an acoustic panel for a nacelle of an aircraft turbojet engine. The panel includes an acoustic skin in which a plurality of acoustic holes are drilled, a solid skin, and a cellular acoustic structure. The cellular acoustic structure, being arranged between the acoustic skin and the solid skin, has a plurality of cells, each of which has one or more drainage openings arranged in one or more of the walls forming each cell. The method includes a step of: defining a part of the acoustic panel to be cut; forming a cutting area closed by the acoustic skin; injecting a resin through the acoustic holes; positioning a replacement cellular acoustic structure in the cutting area and on the acoustic skin; forming a solid replacement skin on the replacement cellular acoustic structure.