There are many inventions described and illustrated herein. In one aspect, the present inventions relate to oscillator systems which employ a plurality of microelectromechanical resonating structures, and methods to control and/or operate same. The oscillator systems are configured to provide and/or generate one or more output signals having a predetermined frequency over temperature, for example, (1) an output signal having a substantially stable frequency over a given/predetermined range of operating temperatures, (2) an output signal having a frequency that is dependent on the operating temperature from which the operating temperature may be determined (for example, an estimated operating temperature based on a empirical data and/or a mathematical relationship), and/or (3) an output signal that is relatively stable over a range of temperatures (for example, a predetermined operating temperature range) and is “shaped” to have a desired turn-over frequency.

Oscillator system having a plurality of microelectromechanical resonators and method of designing, controlling or operating same

Potentialities are investigated for using acousto-optic cells based on a TeO 2 crystal to stabilize a microwave signal generated by an optoelectronic oscillator. Bulk acoustic waves at two radio frequencies (RF) near 60 MHz are launched in the two identical cells providing a required locking on of a microwave signal. Differences between RF signals are up to 400 kHz to follow quality factor of the optic resonator typically in the range of 5×10 8 . Critical alignment of the two cells is performed thanks to an extraordinary polarized laser beam launched at a very low Bragg angle of light incidence. Moreover, the system is operating for any resonator to be inserted into the optoelectronic oscillator with a Q factor in the range of 2×10 7 −10 11 .

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Investigation in acousto-optic laser stabilization for crystal resonator-based optoelectronic oscillators

There are many inventions described and illustrated herein. In one aspect, the present inventions relate to a temperature measurement system comprising (1) a first microelectromechanical resonator to generate a first output signal having a frequency that varies with operating temperature, wherein the first microelectromechanical resonator includes a frequency function of temperature; (2) a second microelectromechanical resonator to generate a second output signal having a frequency that varies with operating temperature, wherein the second microelectromechanical resonator includes a frequency function of temperature; and (3) frequency division circuitry, coupled to the first and second microelectromechanical resonators, to determine data which is representative of the operating temperature of the first and/or second microelectromechanical resonator using (i) data which is representative of the frequency of the first output signal and (ii) data which is representative of the frequency of the second output signal. The frequency division circuitry may include circuitry to divide the frequency of the first output signal by the frequency of the second output signal (whether in digital or analog domain).

Microelectromechanical oscillator having temperature measurement system, and method of operating same

Temperature measurement system having a plurality of microelectromechanical resonators and method of operating same

There is disclosed a whispering gallery oscillator for producing a low noise microwave output signal. The whispering gallery oscillator comprises a dielectric resonator 1 comprising paramagnetic ions 34 . A pump signal 5 is coupled by a coupler 7 to the paramagnetic ions to excite 19 the paramagnetic ions 34 . The paramagnetic ions 34 decay 17 and thus excite a whispering gallery mode 15 of the dielectric resonator 1 . The whispering gallery mode 15 is coupled by a coupler 10 to give an output signal 9 . The whispering gallery mode 15 has a high Q (Q≈10 7 ) resonance. The high Q resonance results in a low-noise output signal 9 . The paramagnetic ions 34 act as a MASER that is distributed about the dielectric resonator 1 . In some embodiments, the whispering gallery oscillator may be locked to a frequency standard.

Whispering gallery oscillator

LPMO has undertaken the building of a cryogenic sapphire oscillator with the support of the french space and metrology agencies (CNES and BNM). The aim of this project is to provide a reference oscillator presenting short frequency stability better than 5.10/sup -14/ in order to fulfill reference tests requirements for spatial and metrological applications. The cryogenic oscillator can operate on different frequencies ranging from 8 to 13 GHz 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/sup -4/) affecting the resonator frequencies theoretical determination. Then a special synthesis chain has to be designed in order to transform 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 100 MHz signal from an X-band reference. The performances of the two realized prototypes will enable to transform better than 5.10/sup -14/ short term frequency stability.

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

This paper presents the design, realisation and measurement of a X band oscillator at 9.2 GHz in the frame of the PHARAO project (The In-Orbit Cold Atom Atomic Clock Project) lead by the CNES. It has been designed following innovative method which has led to a ultra low phase noise of ?80 dBc/Hz@100 Hz from carrier with a ?30 dB/decade slope.

M. Chaubet

Papers

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

A GaInP/GaAs HBT-Based Low Phase Noise Oscillator in X Band for Metrology Application