Realization of a 5 and 10 MHz High Performance Isolation Distribution Amplifier for short term frequency stability measurements of frequency sources

International audienceOur Laboratoire National d'Essai (LNE) associate laboratory is accredited to deliver calibration certificates in the short term domain. For spectral density of phase noise and short term frequency stability measurements, it is necessary to have the best reference source signals. However, the noise of the distribution amplifier has to be the weakest possible in order to keep the lowest noise floor. In order to deliver references signals, we achieve a high performances distribution amplifier. In terms of Allan variance, performance of the realized four channels distribution amplifier is respectively better than sigmay(to=1s) = 1,4.10-14 and 7,3.10-15 at 5 and 10 MHz. The intrinsic spectral density of phase noise is then better than Sphi(1Hz) = –141,4 dB.rad²/Hz at 5 MHz and –141 dB.rad²/Hz at 10 MHz with a 1/f slope

Development of a 5 MHz frequency difference pre-multiplier for a short term frequency stability bench of the oscillators

This paper reports the realization of a 5 MHz frequency difference x10 pre-multiplier, developed in the laboratory to replace an obsolete one. The principle we chose is to synthesize a 45 MHz and a 50 MHz from a reference signal and from the signal to be measured, and to subtract one to the other to generate a 5 MHz, whose precision on the measurement is increased by a factor 10. Obtained Allan variance y() at 1 s is 5.10-14 and output spectral density of phase noise floor is about -160 dBc/Hz at 5 MHz

Design and realisation of a 100MHz synthesis chain from an X-band reference signal

LPMO has undertaken the building of a cryogenic sapphire oscillator with the support of th french Space and Metrolgy agencies (CNES and BNM). The aim of this project is to provide a reference oscillator presenting short frequency stability better than 5.10-14 in order to fulfill reference tests requirements for spacial and metrological applications. The cryogenic oscillator can operate on different frequencies ranging from 8 to 13GHz depending on the sapphire resonator mode chosen as reference. The exact output signal frequency is not ‘a priori' known with a great accuracy due to the large relative uncertainties (of the order of 10-4) affecting the resonator frequencies theoritical determination. Then a special synthesis chain has to be designed in order to transfert the cryogenic oscillator performances to a reference signal whose frequency is fully compatible with most of Time and Frequency instrumentation. In this paper, we present the design, realization and preliminary tests of a synthesis chain generating a 100MHz signal from an X-band reference. The performances of the two realyzed prototypes will enable to transfert better than 5.10-14 short term frequency stability

Short Surface Elastic Pulse Generation

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Detecting response of square and circular Si/AlN/Al membranes transducers by Laser Vibrometry Doppler and Impedancemeter

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Modeling and detecting response of micromachining square and circular membranes transducers based on AlN thin film piezoelectric layer

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Mechanical behavior of T-shaped A1N membrane based on thin film elongation acoustic resonator

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Development of a 5 MHz frequency difference pre- multiplier for a short term frequency stability bench of the oscillators

Abstract-This paper reports the realization of a 5 MHz frequency difference x10 pre-multiplier, developed in the laboratory to replace an obsolete one. The principle we chose is to synthesize a 45 MHz and a 50 MHz from a reference signal and from the signal to be measured, and to subtract one to the other to generate a 5 MHz, whose precision on the measurement is increased by a factor 10. Obtained Allan variance σy(τ) at 1 s is 5.10 -14 and output spectral density of phase noise floor is about -160 dBc/Hz at 5 MHz

Screening of spherical moulds manufactured isotropically in plasma etching conditions

International audience<font face="arial, helvetica"&gt<span style="font-size: 13px;"&gtMicro-moulding is a critical rapid prototypingprocess chain used for a wide range of applications. This studydemonstrates that it is possible to manufacture mould at lowexcitation frequency plasma (380 kHz), on a silicon substrate usingfluorinated chemistry. According to the mask aperture designed andprocess time, the cavities profile characteristics, depending onthe plasma chemistry, were analysed to predict the degree ofanisotropy and the curvature. We show the possibility of creatingcurvature shapes with a desirable conic constant k of 1.25. Inparticular, we highlighted the smallest aperture sizes are moreattractive for replicating optical micro-lens arrays using siliconmoulds. Otherwise, the largest aperture sizes gain more attentionfor optoelectronics, microsystems, and microfluidicsapplications.</span&gt</font&g