The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation

Effective demodulation of amplitude and phase is a requirement in wide array applications. Recent efforts have increased the performance, particular, Lyapunov demodulator allows bandwidths up to carrier frequency signal. However, being inherently restricted first-order filtering input signal, it highly sensitive components outside its passband region. This makes unsuitable for certain applications such as multifrequency atomic force microscopy (AFM). In this article, structure transformed an equivalent form generalized by exploiting internal model principle. The resulting arbitrary order easy implement, requiring only bandpass filter, single integrator, two nonlinear transformations. implemented experimentally on field-programmable gate (FPGA). Then used imaging AFM benchmarked against standard widely lock-in amplifier. amplifier achieves great noise attenuation capabilities off-mode rejection at low bandwidths, whereas shown be effective high bandwidths. We demonstrate that proposed combines best from state-of-the-art demodulators, demonstrating large rejection, excellent simultaneously.