Quasi-optimization approach for millimeter wave imaging of multilayered dielectric media

ABSTRACT

In this paper, a quasi-optimization approach involving a two-step method for the millimeter wave imaging of the stratified media is proposed. The proposed method makes use of reflection data of the test media in the mm-wave band of 26-40 GHz, whose equivalent time domain data are also available using the standard IFFT routines. In the first step, a simple analytical method is applied to extract the real permittivity and the physical thickness of each layer from time domain reflection data. In the second step, an efficient optimization method is proposed to extract material parameters of each layer more accurately from the spectral domain reflection coefficients. The extracted real permittivity and thickness of each layer from the first step provide a quite good estimated value for the next optimization process and thus overall computation time is considerably reduced. The proposed method is experimentally tested for a number of multilayered media comprising various materials.

KEYWORDS:

• Complex permittivity
• multilayered media
• optimization
• reflection coefficients
• time domain reflect method

ORCID

Surya Prakash Singh http://orcid.org/0000-0002-8216-0643

Additional information

Notes on contributors

Surya Prakash Singh

Surya Prakash Singh is currently pursuing a Ph.D. degree in electrical engineering with the Indian Institute of Technology, Kanpur, India. He is also with the Department of electronic and communication IIIT Bhubaneswar, Odisha, India. His current research interests include the development of imaging and characterization techniques in the THz and millimeter wave.

Nilesh Kumar Tiwari

Nilesh Kumar Tiwari is currently pursuing a Ph.D. degree in electrical engineering with the Indian Institute of Technology, Kanpur, India. His current research interests include the design of microwave planar sensors for the electromagnetic characterization of materials.

M. Jaleel Akhtar

M. Jaleel Akhtar is currently working as an Associate Professor in the Department of Electrical Engineering, IIT Kanpur, Kanpur, India. He has authored two books, two book chapters, and has authored or co-authored over 200 papers in various peer-reviewed international journals and conference proceedings. His current research interests include RF, microwave and THz imaging, microwave nondestructive testing, metamaterial-inspired RF sensors, SIW-based RF devices and sensors, RF energy harvesting, plasmonic devices, functional materials, wideband electromagnetic absorbers. Dr. Akhtar is a fellow of the Institution of Electronics and Telecommunication Engineers, New Delhi, India, and a Life Member of the Indian Physics Association and the Indo-French Technical Association. He served as a Chair of the IEEE Microwave Theory and Techniques Society, Uttar Pradesh Chapter, from 2013 to 2015, and the Vice-Chair of the IEEE, Uttar Pradesh Section, in 2015.