DMS SV Automatic Phase Offset Calibration
AssigneeDH Technologies Development Pte. Ltd.
InventorAndrei TUDOR
Life of this patent
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Abstract
In one aspect, a circuit for generating an asymmetric waveform for application to electrodes of a differential mobility mass (DMS) spectrometer is disclosed, which includes two digital waveform synthesizers for generating digital waveforms, which are converted to analog waveforms for application to electrodes of the DMS spectrometer. Analog feedback signals associated with the applied waveforms are digitized and a digital passband filter is employed to filter the digital feedback signals, which are then employed to determine a phase correction signal for application to at least one of the digital waveform synthesizers for maintaining a substantially constant phase difference between the waveforms generated by the digital waveform synthesizers.
Claims19
A phase compensation circuit for adjusting a phase difference between first and second analog waveforms applied to two electrodes of a differential mobility mass spectrometer, wherein said analog waveforms are generated based on first and second digital waveforms respectively produced by first and second digital waveform synthesizers, comprising:
- a feedback circuit for generating first and second analog feedback signals each associated with one of said first and second analog waveforms,
- at least one analog-to-digital converter configured to receive first and second analog feedback signals and convert said first and second analog feedback signals into respective first and second digital feedback signals,
- at least one digital passband filter configured to receive said first and second digital feedback signals and generate first and second filtered digital feedback signals by substantially filtering out from each of the digital feedback signals associated with each waveform a contribution associated with the other waveform due to cross-talk between said analog waveforms applied to the electrodes,
- a phase comparator for determining a phase difference between said first and second filtered digital feedback signals, and
- a controller for applying a correction signal determined based on said phase difference to at least one of said first and second digital waveform synthesizers.
A differential mobility mass (DMS) spectrometer, comprising:
- a first and a second electrode,
- a first digital waveform synthesizer for generating a first digital waveform,
- a first digital-to-analog converter for receiving said first digital waveform and generating a first analog waveform,
- a second digital waveform synthesizer for generating a second digital waveform,
- a second digital-to-analog converter for receiving said second digital waveform and generating a second analog waveform,
- a feedback circuitry configured to generate first and second analog feedback signals associated with said first and second analog waveforms, respectively, and converting said analog feedback signals to respective first and second digital feedback signals,
- a first and a second digital passband filter for receiving said first and said second digital feedback signals and generating a first and a second filtered digital feedback signal, respectively,
- a phase comparator for receiving said first and second filtered digital feedback signals and generating first and second frequency spectra associated with said first and second digital feedback signals, respectively, said phase comparator further configured to employ said first and second frequency spectra to determine a phase difference between the first and second filtered digital feedback signals, and
- a controller configured to receive said phase difference and to generate a phase error signal for application to at least one of said first and second digital waveform synthesizers for maintaining a desired phase difference between the waveforms generated by said first and second waveform synthesizers.
Dependencies are inferred from the claim text.