Centre National De La Recherche Scientifique

Senseor

Ecole Nationale Superieure De Mecanique Et Des Microtechniques (ensmm)

Gilles Martin

Sylvain Ballandras

Jean-Michel Friedt

Christophe Droit

Thomas Baron

Yannick Gruson

Valérie Soumann

A temperature-controlled RF resonator. The resonator includes an insulating thermal enclosure within which are implemented: at least one resonant element configured to deliver an RF output signal when supplied with an RF input signal; at least one heating element configured to supply thermal energy within the thermal enclosure when the at least one heating element is powered by an LF electric power signal; and at least one temperature sensor configured to deliver an LF electric measurement signal as a function of the temperature inside the thermal enclosure. Such an RF resonator has at least one input/output port crossing the insulating thermal enclosure and propagating at least: one signal from among the RF signals; and another signal from among the LF electric signals.

Temperature-controlled radio-frequency resonator and corresponding radio-frequency oscillator

A method of interrogating a surface acoustic wave differential sensor formed by two resonators is provided, wherein the method allows the measurement of a physical parameter by determination of the difference between the natural resonant frequencies of the two resonators, which difference is determined on the basis of the analysis of a signal representative of the level of a signal received as echo of an interrogation signal, for a plurality of values of a frequency of the interrogation signal in a domain of predetermined values; the analysis can be based on the cross-correlation of the said signal representative of the level according to a splitting into two distinct frequency sub-bands. An advantage is that it may be implemented in a radio-modem.

Method of interrogation of a differential sensor of acoustic type having two resonances and device implementing the method of interrogation

A method of remotely interrogating a passive sensor, comprising at least one resonator, so as to determine the resonant frequency of said resonator, having a resonant frequency response defined by the design of said resonator, includes: a preliminary frequency-scan step for interrogating said resonator over a frequency range allowing for the rapid determination of a first resonant frequency (fr) of said resonator by detecting the amplitude of the response signal of said resonator; a first step of a first couple of interrogations of said resonator at a first frequency (f) and a second frequency (f) such that: f=fr&#x2212;f/2 and f=fr+f/2, fbeing smaller than the width at half-maximum of the resonant frequency response defined by the design, allowing a first couple of amplitudes (Pf, Pf) of first and second reception signals to be defined; a second step of determining the amplitude difference (&#x394;(Pf&#x2212;Pf)), said difference being signed; a third step allowing a first resonant frequency (fr), controlled by said signed amplitude difference, to be defined and having the formula fr=fr+K*[&#x394;(Pf&#x2212;Pf)&#x2212;Ca], where Ca is a control set-point and K is a constant; and the reiteration of the first, second and third steps comprising the definition of an (i+1)th resonant frequency (fr) from an ith resonant frequency (fr) having the formula: fr=fr+K*[&#x394;(Pf&#x2212;Pf)&#x2212;Ca], so as to obtain a determined resonant frequency (fr) such that the signed amplitude difference (&#x394;(Pf&#x2212;Pf)) is equal to the control set-point (Ca).

Method of rapidly interrogating elastic wave sensors

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Chatillon le Duc, France

Gilles Martin