Simulation of a lock-in amplifier by means of the MATHCAD symbolic software solver
Jose L. Guinon, José García-Antón, Emma María Ortega, Valentín Pérez-Herranz · Afinidad · 2003
This paper describes the simulation of a lock-in amplifier by means of the Mathcad symbolic software solver. The mathematical principles for the operation of a lock-in amplifier in the absence and in the presence of noiserespectively are explained, and the effect of the phase difference between the input signal and reference signal is also described. The same results are obtained with square or sinusoidal reference signals. Lock-in amplifiers allow measuring weak signals buried in noise, thus increasing the signal-to-noise ratio by 10 times. The animation of the lock-in amplifier can be displayed with Acrobat-Avi.