Reliable and integrated technique for determining resonant frequency in radio frequency resonators. Application to a high-precision resonant cavity-based displacement sensor

Rigoberto Jauregui; Estibaliz Asua; Joaquin Portilla; Victor Etxebarria

doi:10.1063/1.4915317

Reliable and integrated technique for determining resonant frequency in radio frequency resonators. Application to a high-precision resonant cavity-based displacement sensor

Rev Sci Instrum. 2015 Mar;86(3):034709. doi: 10.1063/1.4915317.

Authors

Rigoberto Jauregui¹, Estibaliz Asua¹, Joaquin Portilla¹, Victor Etxebarria¹

Affiliation

¹ Department of Electricity and Electronics, University of the Basque Country (UPV/EHU), Leioa 48940, Spain.

PMID: 25832260
DOI: 10.1063/1.4915317

Abstract

This paper presents a reliable and integrated technique for determining the resonant frequency of radio frequency resonators, which can be of interest for different purposes. The approach uses a heterodyne scheme as phase detector coupled to a voltage-controlled oscillator. The system seeks the oscillator frequency that produces a phase null in the resonator, which corresponds to the resonant frequency. A complete explanation of the technique to determine the resonant frequency is presented and experimentally tested. The method has been applied to a high-precision displacement sensor based on resonant cavity, obtaining a theoretical nanometric precision.