About Microwave Measurement Systems, LLC

Microwave Measurement Systems is headed by Dr. Vasundara Varadan, George and Boyce Billingsley Endowed Chair and Distinguished Professor, Director of Microwave & Optics Laboratory for Imaging & Characterization University of Arkansas, Fayetteville.

Dr. Varadan, a graduate of the University of Illinois-Chicago, did a post-doctoral fellowship at Cornell and served on the faculty of the Ohio State University. She spent 22 years at the Pennsylvania State University where she was Distinguished Professor and Co-Director of the Research Center for the Engineering of Electronic & Acoustic Materials. During 2002-2004, she served as the Division Director of Electrical & Communications Systems at the National Science Foundation.

Dr. Varadan was a US Delegate in the US-China Joint Workshop on Women in Science and Technology at the United Nations Women's Conference in Beijing in 1995, and holds a number of honors in her field.

She has served as thesis advisor to 33 Ph.D. and 34 MS students and mentored 20 post-doctoral fellows who have successful careers in industry, government and academia.

Patents Held

  • Electromagnetic Shielding and Absorptive Materials, U.S. Patent No. 4,948,922 issued 1990 along with Vijay K. Varadan
  • Microwave Heating System, U.S. Patent No. 5,296,666 issued 1994 along with Vijay K. Varadan and Thomas Schaffer
  • Electromagnetic Shielding Materials, U.S. Patent : 5,366,664 issued 1994 along with Vijay K. Varadan, Neil R. Williams and Joseph W. Cresko.
  • Voltage Tunable Dielectric Ceramics, U.S. Patent : 5,557,286 issued 1996 along with Vijay K. Varadan and Fathi Selmi
  • Active Noise Control Using Piezoelectric Sensors and Actuators, U.S. Patent Application # 23687A, filed May, 1995 with Vijay K. Varadan, Xiao-Qi Bao, Kenneth B. Carney,
  • John L. Olinger and Fred S. Coffey.
  • 6525691 Miniaturized Conformal Wideband Fractal Antennas on High Dielectric Substrates and Chiral Layers, 2/11/2003 along with K.J. Vinoy, K.A. Jose and V.K. Varadan
  • 6516665 Micro-ElectroMechanical Gyroscope, 2/11/2003 along with P. Xavier, K.A. Jose and V.K. Varadan

Selected Publications

Dr. Varadan has authored 3 books and several book chapters, edited several volumes, has published over 280 journal articles and over 300 refereed conference proceedings papers. Selected papers related to microwave measurements are listed below and pdf copies are available upon request.

V. V. Varadan, and Kai Du,
"In Situ Material Characterization of Curved Samples using Analysis of Gaussian Beam Reflection from a Convex Cylindrical Shell,"
2003 IEEE AP-S International Symposium on Antennas and Propagation and USNC/CNC/URSI North American Radio Science Meeting,Columbus, Ohio, USA on June 22-27, 2003.

V. V. Varadan, and A. R. Tellakula,
"Modeling and Experimental Studies of the Complex Electromagnetic Properties of Metamaterials.",
Progress in Electromagnetics Research Symposium (PIERS 2003) Oct. 13-16, 2003 in Hawaii.

V. V. Varadan* and A. R. Tellakula,
"Experimental Studies of Negative Refractive Index in Ordered and Random Chiral Composites",
IEEE AP/URSI, June 2004.

D.K. Ghodgaonkar, V. V. Varadan & V.K. Varadan,
" A Free–Space Method for Measurement of Dielectric Constants and Loss Tangents at Microwave Frequencies",
IEEE – Trans. Instrumentation and Measurement, 37, pp. 789 – 793 (1989).

D. Ghodgaonkar, V. V. Varadan and V. K. Varadan
, " A free space method for measurement of dielectric constants and loss tangents at microwave frequencies",
IEEE Transactions on Instrumentation and Measurement, 38, 789-793 (1989).

D. Ghodgaonkar, V. V. Varadan and V. K. Varadan
, " Free Space Measurement of Complex Permittivity and Complex Permeability of Magentic Materials at Microwave frequencies",
IEEE Transactions on Instrumentation and Measurement, 39, pp. 387 – 394 (1990).

T. Guire, V.V. Varadan & V.K. Varadan
, " Effects of Chirality on Reflection of EM Waves by Planar Dielectric Slabs",
IEEE Transactions on – EMC , 32 , pp. 300–303, 1990.

M. H. Umari, D. K. Ghodgaonkar, V. V. Varadan and V. K. Varadan
, " A free space bistatic calibration technique for the measurement of parallel and perpendicular reflection coefficients of planar samples",
IEEE Transactions on Instrumentation and Measurement Techniques, 40, pp. 19 – 24, 1991.

V.V. Varadan, R. Hollinger, D. Ghodgaonkar, V.K. Varadan
, " Free Space, Broadband Measurements of High Temperature, Complex Dielectric Properties at Microwave Frequencies",
IEEE Transactions on Instrumentation and Measurement Techniques, 40, pp. 842 – 846, 1991.

V.V. Varadan, R. Ro and V.K. Varadan
, "Measurement of the Electromagnetic Properties of Chiral Composite Materials in the 8 – 40 GHz range",
Radio Science, Vol. 29, pp. 9-22, 1994.

K.A. Jose, V. V. Varadan and V. K. Varadan
, "Comparison Between Free Space And One Horn Interferometer Techniques For Radar Absorber Measurements",
Microwave Journal, September, pp. 148-154, 1998.

V.V. Varadan , K.A. Jose and V.K. Varadan
, "In Situ Microwave Characterization of Non-planar Dielectric Objects",
IEEE Transactions on Microwave Theory and Techniques, Vol. 48, pp. 388-394, 2000.

K.A. Jose, V.V. Varadan, and V.K. Varadan
, "Microwave Characterization of Dielectric Materials from 8 to 110 GHz Using a Free Space Set Up",
IEEE Microwaves and Optics Letters, Vol. 26, pp. 100-105, 2000.

K.A. Jose, V.K. Varadan, and V.V. Varadan
, "Wideband and Noncontact Charaterization of the Complex Permittivity of Liquids",
IEEE Microwaves and Optics Letters, Vol. 30, pp. 75-79, 2001.

V.V. Varadan and A, R. Tellakula
, "Measurement of the Complex Permittivity, Permeability and Refractive Index in Metamaterials Composed of Discrete Split Ring Resonators in the 8-26 GHz range",
Journal of Applied Physics, Vol. 100, 034910, 2006.

V.V. Varadan, Z. Sheng, S. Penumarthy and S. Puligalla
, "Comparison of measurement and simulation of both amplitude and phase of reflected and transmitted fields in resonant omega media",
Microwave and Optical Technology Letters, Vol. 48, No.8, pp.1549-1553, 2006.

V.V. Varadan, Swetha Puligalla and Ruyen Ro
, " S-Parameter Measurements for Oblique Angles of Incidence and Brewster Angle Studies for Metamaterial Samples",
Microwave and Optical Technology Letters, Vol. 48, pp.2619-2624, 2006.

V.V. Varadan and R. Ro
, "Unique retrieval of complex permittivity and permeability of dispersive materials from reflection and transmitted fields by enforcing causality",
IEEE Trans. MTT, Vol. 55, pp. 2224-2230, 2007.

V.V. Varadan and Liming Ji
, "Temperature Dependence of Resonances in Metamaterials",
IEEE Trans. Microwave Theory & Techniques, Vol. 58, pp. 2673-2681, 2010.