US 6,982,417 B2
Method and apparatus for detecting low-mass ions
Michel J. Adrien Baillargeon, Bartlesville, Okla. (US)
Assigned to Siemens Energy & Automation, Inc., Alpharetta, Ga. (US)
Filed on Oct. 09, 2003, as Appl. No. 10/681,947.
Prior Publication US 2005/0077466 A1, Apr. 14, 2005
Int. Cl. B01D 59/44 (2006.01)
U.S. Cl. 250—292 34 Claims
OG exemplary drawing
 
15. An apparatus for inducing ions of a predetermined mass-to-charge ratio to orbit at a resonant frequency, comprising:
a digital signal processor (DSP) configured to output a digital signal comprising a fundamental frequency;
a digital-to-analog converter (DAC) connected to the DSP for converting the digital signal to an analog excitation signal including the fundamental frequency and at least one secondary frequency greater than the fundamental frequency, the at least one secondary frequency including the resonant frequency; and
excitation plates connected to the DAC for applying the excitation signal to the ions.