The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation
Effective demodulation of amplitude and phase is a requirement in a wide array of applications. Recent efforts have increased the demodulation performance, in particular, the Lyapunov demodulator allows bandwidths up to the carrier frequency of the signal. However, being inherently restricted to fir...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IEEE
2022-01-01
|
| Series: | IEEE Open Journal of Control Systems |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/9790310/ |
| _version_ | 1827918839240720384 |
|---|---|
| author | Michael R. P. Ragazzon Saverio Messineo Jan Tommy Gravdahl David M. Harcombe Michael G. Ruppert |
| author_facet | Michael R. P. Ragazzon Saverio Messineo Jan Tommy Gravdahl David M. Harcombe Michael G. Ruppert |
| author_sort | Michael R. P. Ragazzon |
| collection | DOAJ |
| description | Effective demodulation of amplitude and phase is a requirement in a wide array of applications. Recent efforts have increased the demodulation performance, in particular, the Lyapunov demodulator allows bandwidths up to the carrier frequency of the signal. However, being inherently restricted to first-order filtering of the input signal, it is highly sensitive to frequency components outside its passband region. This makes it unsuitable for certain applications such as multifrequency atomic force microscopy (AFM). In this article, the structure of the Lyapunov demodulator is transformed to an equivalent form and generalized by exploiting the internal model principle. The resulting generalized Lyapunov demodulator structure allows for arbitrary filtering order and is easy to implement, requiring only a bandpass filter, a single integrator, and two nonlinear transformations. The generalized Lyapunov demodulator is implemented experimentally on a field-programmable gate array (FPGA). Then it is used for imaging in an AFM and benchmarked against the standard Lyapunov demodulator and the widely used lock-in amplifier. The lock-in amplifier achieves great noise attenuation capabilities and off-mode rejection at low bandwidths, whereas the standard Lyapunov demodulator is shown to be effective at high bandwidths. We demonstrate that the proposed demodulator combines the best from the two state-of-the-art demodulators, demonstrating high bandwidths, large off-mode rejection, and excellent noise attenuation simultaneously. |
| first_indexed | 2024-03-13T03:49:34Z |
| format | Article |
| id | doaj.art-27bb4f0fa9844bf4927376673ec4a6ef |
| institution | Directory Open Access Journal |
| issn | 2694-085X |
| language | English |
| last_indexed | 2024-03-13T03:49:34Z |
| publishDate | 2022-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Open Journal of Control Systems |
| spelling | doaj.art-27bb4f0fa9844bf4927376673ec4a6ef2023-06-22T16:06:41ZengIEEEIEEE Open Journal of Control Systems2694-085X2022-01-011698410.1109/OJCSYS.2022.31811119790310The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase EstimationMichael R. P. Ragazzon0https://orcid.org/0000-0003-3770-5154Saverio Messineo1https://orcid.org/0000-0003-1592-4428Jan Tommy Gravdahl2https://orcid.org/0000-0002-5663-0795David M. Harcombe3https://orcid.org/0000-0002-9866-5806Michael G. Ruppert4https://orcid.org/0000-0003-2286-4929Department of Engineering Cybernetics, Norwegian University of Science and Technology, Trondheim, NorwayEmbedded AI, Silicon Austria Labs, Linz, AustriaDepartment of Engineering Cybernetics, Norwegian University of Science and Technology, Trondheim, NorwaySchool of Engineering, University of Newcastle, Callaghan, NSW, AustraliaSchool of Engineering, University of Newcastle, Callaghan, NSW, AustraliaEffective demodulation of amplitude and phase is a requirement in a wide array of applications. Recent efforts have increased the demodulation performance, in particular, the Lyapunov demodulator allows bandwidths up to the carrier frequency of the signal. However, being inherently restricted to first-order filtering of the input signal, it is highly sensitive to frequency components outside its passband region. This makes it unsuitable for certain applications such as multifrequency atomic force microscopy (AFM). In this article, the structure of the Lyapunov demodulator is transformed to an equivalent form and generalized by exploiting the internal model principle. The resulting generalized Lyapunov demodulator structure allows for arbitrary filtering order and is easy to implement, requiring only a bandpass filter, a single integrator, and two nonlinear transformations. The generalized Lyapunov demodulator is implemented experimentally on a field-programmable gate array (FPGA). Then it is used for imaging in an AFM and benchmarked against the standard Lyapunov demodulator and the widely used lock-in amplifier. The lock-in amplifier achieves great noise attenuation capabilities and off-mode rejection at low bandwidths, whereas the standard Lyapunov demodulator is shown to be effective at high bandwidths. We demonstrate that the proposed demodulator combines the best from the two state-of-the-art demodulators, demonstrating high bandwidths, large off-mode rejection, and excellent noise attenuation simultaneously.https://ieeexplore.ieee.org/document/9790310/Amplitude estimationatomic force microscopydemodulatorsfeedbackfield programmable gate arraysfilters |
| spellingShingle | Michael R. P. Ragazzon Saverio Messineo Jan Tommy Gravdahl David M. Harcombe Michael G. Ruppert The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation IEEE Open Journal of Control Systems Amplitude estimation atomic force microscopy demodulators feedback field programmable gate arrays filters |
| title | The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation |
| title_full | The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation |
| title_fullStr | The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation |
| title_full_unstemmed | The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation |
| title_short | The Generalized Lyapunov Demodulator: High-Bandwidth, Low-Noise Amplitude and Phase Estimation |
| title_sort | generalized lyapunov demodulator high bandwidth low noise amplitude and phase estimation |
| topic | Amplitude estimation atomic force microscopy demodulators feedback field programmable gate arrays filters |
| url | https://ieeexplore.ieee.org/document/9790310/ |
| work_keys_str_mv | AT michaelrpragazzon thegeneralizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT saveriomessineo thegeneralizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT jantommygravdahl thegeneralizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT davidmharcombe thegeneralizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT michaelgruppert thegeneralizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT michaelrpragazzon generalizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT saveriomessineo generalizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT jantommygravdahl generalizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT davidmharcombe generalizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation AT michaelgruppert generalizedlyapunovdemodulatorhighbandwidthlownoiseamplitudeandphaseestimation |