Square-Signal-Based Algorithm for Analog Lock-In Amplifiers

摘要: Dual-phase lock-in amplifiers (LIAs) are designed to extract information (amplitude and phase) from signals buried in high noise levels. In spite of their popularity, use has been traditionally limited input sinusoidal waves with symmetric power supplies. This paper presents an algorithm that enables single-supply analog LIAs properly process square waves. Formed by linear equations, its computational implementation is much simpler than the traditional algorithm. Moreover, applied battery-operated microcontrolled systems where can be generated embedded microcontroller, it intrinsic advantages such as simplicity, versatility, reduction size. Experimental results validate proposed algorithm, confirming enormous possibilities sensing applications.