IEEE AP-MTT Seminar - Monday, October 28, 2013

Posted: 

"Electromagnetic Analysis of Radiometer Calibration Targets"

Presented by Dr. Srikumar Sandeep

ETS - Lindgren

Date: 1:00 - 2:00 PM   Monday, October 28, 2013

Place: MRC Conference Room, ElectroScience Laboratory, 1330 Kinnear Rd, Columbus, OH

Abstract: Accurate electromagnetic  analysis is essential for designing wideband radiometer calibration targets as well as for understanding the electromagnetic wave interaction with these highly absorbing structures. To serve this purpose a three dimensional, parallelized, dispersive finite difference time domain (FDTD) engine had been developed. I present the various aspects associated with this FDTD formulation. Time domain modeling of the dispersive radar absorbent material is performed by fitting the measured complex permittivity and permeability data to a series of Debye like terms using genetic algorithm (GA) optimization. The reflectivity spectra of calibration targets of various geometries in the frequency range [6, 200] GHz is obtained and compared to the geometrical optics limit and a finite element solution.

The developed code is applicable only for the case of normal plane wave incidence. To circumvent this limitation, a novel numerical method was developed for the time domain analysis of periodic, dispersive structures in the case of obliquely incident plane wave. This method uses the Laguerre Marching-On-In-Degree (MoD), where the time dependence of  field variables and constitutive parameters are expressed as an expansion of Laguerre basis functions. I will also allude to the open problem of estimating near field thermal emission from thermally inhomogeneous bodies of arbitrary geometry.  This has applications in radiometry as well as nanoscale radiative heat transfer.

 

Bio:  Dr. Srikumar Sandeep (Kumar) received M.S. and PhD in electrical engineering from University of Colorado, Boulder in 2011 and 2012 respectively. He worked as a research associate in University of Colorado, Boulder for one year after obtaining the PhD. His technical interests include applied electromagnetics, computational electromagnetics and remote sensing. He has 2 years industrial experience in software development and embedded systems.