Microwave Superconductivity

1
Microwave Superconductivity
Stephen K. Remillard Physics remillard_at_hope.edu 61
6-395-7507
Education and experiences Ph.D. The College of
William and Mary (1993) B.S., Calvin College
(1988) Grand Valley State University, Visiting
Asst. Prof (2005-7) Calvin College, Visiting
Assistant Professor (2004-5) ISCO International,
Director of Engineering (1994-2003)
Areas of expertise Solid State Physics,
Microwave Techniques in Measurement,
Superconductivity
Our work with high temperature superconductors
can only be carried out at very low, or
cryogenic, temperatures. So the platform for the
experiment begins with a cryogenic refrigerator
which cools the superconductors to about 50
degrees above absolute zero. We use a sapphire
resonator, pictured above, to immerse the
superconductors in a microwave field which offers
us the rare opportunity to observe electrical
resistance in the superconducting material.
Using a mix of cryogenic and microwave
techniques, we are studying the nature of this
resistance. Of particular interest is the
nonlinear surface resistance. Just as the
ballast in a fluorescent light offers a
resistance that changes with the current flowing
through it, the superconductors surface
resistance changes with current. This
nonlinearity gives rise to distortion in
signals passing through superconducting
electronic devices. Our research seeks to
understand the sources of this nonlinearity, and
will hopefully have a direct impact on the future
of cryogenic electronics.
Grants and awards Microwave Materials Designs,
Ltd. Pty., Corporate sponsorship, Microwave
Device Science and Technology (2007-2008)
Key publications S.K. Remillard et al., A Review
of HTS Thick Film Microwave Filter Technology, J.
of Supercond., 19, no. 7-8, pp. 523-530
(2006). S. K. Remillard, et al. Three-Tone
Intermodulation Distortion Generated by
Superconducting Bandpass Filters, IEEE Trans.
Appl. Superconductivity, 13, 3797 (2003). S.K.
Remillard et al., Field Deployable Microwave
Filters Made from YBa2Cu3O7-d Thick Films, J. of
Supercond., no. 14, p. 47 (2001).
Acknowledgements MMD, Ltd. Pty. of Australia