title: Dual-Phase Lock-In Amplifier Based on FPGA for Low-Frequencies Experiments.
abstract: Photothermal techniques allow the detection of characteristics of material without invading it. Researchers have developed hardware for some specific Phase and Amplitude detection (Lock-In Function) applications, eliminating space and unnecessary electronic functions, among others. This work shows the development of a Digital Lock-In Amplifier based on a Field Programmable Gate Array (FPGA) for low-frequency applications. This system allows selecting and generating the appropriated frequency depending on the kind of experiment or material studied. The results show good frequency stability in the order of 1.0 × 10(-9) Hz, which is considered good linearity and repeatability response for the most common Laboratory Amplitude and Phase Shift detection devices, with a low error and standard deviation.
authors.affiliation: Laboratorio de Mecatrónica, Universidad Autónoma de Querétaro, Cerro de las Campanas, Col. Las Campanas, S/N, Querétaro 76010, Mexico. gonzalo.macias@uaq.mx.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Macias-Bobadilla
authors.affiliation: Laboratorio de Mecatrónica, Universidad Autónoma de Querétaro, Cerro de las Campanas, Col. Las Campanas, S/N, Querétaro 76010, Mexico. juvenal@ieee.org.
authors.forename: Juvenal
authors.initials: J
authors.lastname: Rodríguez-Reséndiz
authors.affiliation: Laboratorio de Mecatrónica, Universidad Autónoma de Querétaro, Cerro de las Campanas, Col. Las Campanas, S/N, Querétaro 76010, Mexico. georgina.mota@uaq.mx.
authors.forename: Georgina
authors.initials: G
authors.lastname: Mota-Valtierra
authors.affiliation: Laboratorio de Mecatrónica, Universidad Autónoma de Querétaro, Cerro de las Campanas, Col. Las Campanas, S/N, Querétaro 76010, Mexico. genaro.soto@uaq.mx.
authors.forename: Genaro
authors.initials: G
authors.lastname: Soto-Zarazúa
authors.affiliation: Laboratorio de Mecatrónica, Universidad Autónoma de Querétaro, Cerro de las Campanas, Col. Las Campanas, S/N, Querétaro 76010, Mexico. carmaury@hotmail.com.
authors.forename: Maurino
authors.initials: M
authors.lastname: Méndez-Loyola
authors.affiliation: Laboratorio de Mecatrónica, Universidad Autónoma de Querétaro, Cerro de las Campanas, Col. Las Campanas, S/N, Querétaro 76010, Mexico. dr.mariano.g@ieee.org.
authors.forename: Mariano
authors.initials: M
authors.lastname: Garduño-Aparicio
keywords: Field-Programmable-Gate-Array; Lock-In-Amplifier; Phase-Shift-Detection; frequency-stability