National Biomedical Electron Paramagnetic Resonance Center

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Jason W. Sidabras

Microwave Engineer

Department of Biophysics
Medical College of Wisconsin
8701 Watertown Plank Road
Milwaukee, WI 53226-0509
Phone: 414-955-7355
Fax: 414-955-6512


Research Interests

Mr. Sidabras graduated from the Milwaukee School of Engineering in 2003 with a BS in Electrical Engineering Technology and from Marquette University in 2010 with an MS in Electrical Engineering. Throughout the MSOE curriculum, he took independent study courses in electromagnetics and wireless design. Mr. Sidabras was hired as an intern at the National Biomedical EPR Center in June 2003 and quickly became immersed in the resonator design team, which consists of Drs. Hyde and Mett.

At Marquette University, Mr. Sidabras studied under the direction of Dr. James E. Richie, who specializes in analytical electromagnetics and numerical techniques. Mr. Sidabras' master's thesis included discourse on both numerical and analytical optimization on 100 kHz field modulation slots for use in EPR. A formal Green’s function approach was taken to understand the physics of a modulation slot and to use directly to optimize the slot geometry for production of a uniform 100 kHz field modulation profile over the sample region.

Mr. Sidabras is integral to the development of resonator dynamics where computer simulations probe the relationships between sample properties and electromagnetics using boundary-value numerical methods such as finite-element modeling mixed with analytical models. This field of study represents an interface between electromagnetic theory and laboratory experiments.

He also maintains, a user-driven Web site devoted to the EPR community and used to strengthen information and maintain a knowledge-base on niche subjects.

Recent activities include:

  • Uniform 100 kHz field modulation for cylindrical TE011 cavities
  • Dual loop-gap resonator for pulse experiments at 94 GHz
  • Optimized PTFE extrusions, taking advantage of the properties of having the sample placed in a perpendicular orientation to the electric field, resulting in EPR signal improvements
  • EPR and MRI resonance development (250 MHz–260 GHz) 

Mr. Sidabras' work has resulted in one U.S. patent and several publications.  Publications on PubMed


Hyde JS, Bennett B, Walter ED, Millhauser GL, Sidabras JW, Antholine WE. EPR of Cu2+ prion protein constructs at 2 GHz using the g(perpendicular) region to characterize nitrogen ligation. Biophys. J. 96:3354-3362 (2009).

Mett RR, Sidabras JW, Hyde JS. Coupling of waveguide and resonator by inductive and capacitive irises for EPR spectroscopy. Appl. Magn. Reson. 35:285-318 (2009).

Mett RR, Sidabras JW, Golovina IS, Hyde JS. Dielectric microwave resonators in TE(011) cavities for electron paramagnetic resonance spectroscopy. Rev. Sci. Instrum. 79:094702 (2008).

Froncisz W, Camenisch TG, Ratke JJ, Anderson JR, Subczynski WK, Strangeway RA, Sidabras JW, Hyde JS. Saturation recovery EPR and ELDOR at W-band for spin labels. J. Magn. Reson. 193:297-304 (2008).

Sidabras JW, Mett RR, Froncisz W, Camenisch TG, Anderson JR, Hyde JS. Multipurpose EPR loop-gap resonator and cylindrical TE011 cavity for aqueous samples at 94 GHz. Rev. Sci. Instrum. 78:034701 (2007).

Hyde JS, Froncisz W, Sidabras JW, Camenisch TG, Anderson JR, Strangeway RA. Microwave frequency modulation in CW EPR at W-band using a loop-gap resonator. J. Magn. Reson. 185:259-263 (2007).

Sidabras JW, Mett RR, Hyde JS. Aqueous flat-cells perpendicular to the electric field for use in electron paramagnetic resonance spectroscopy, II: Design. J. Magn. Reson. 172:333-341 (2005).
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Page Updated 08/03/2012