Department of Electrical Engineering and Materials Research Institute

1. An Overview of the Penn State Computational Electromagnetics and Antennas Research Lab (CEARL) Douglas H. Werner, Director Department of Electrical Engineering and Materials Research Institute Pennsylvania State University University Park, PA 16802 http://labs.ee.psu.edu/labs/dwernergroup/ dhw@psu.edu

2. Computational Electromagnetics and Antennas Research Lab http://labs.ee.psu.edu/labs/dwernergroup/ • Prof. Douglas H. Werner, Director • Prof. Pingjuan L. Werner, Associate Director • Dr. Matthew G. Bray, Post doc • Dr. Do-Hoon Kwon, Post doc • Dr. Xiande Wong, Post doc • Prof. Alkim Akyurtlu, Affiliate • Dr. Rene J. Allard, Affiliate • Dr. Bruce R. Long, Affiliate • Dr. Ling Li, Affiliate • Jeremy A. Bossard, Ph.D. Student • Douglas J. Kern, Ph.D. Student • Joshua S. Petko, Ph.D. Student • Thomas G. Spence, Ph.D. Student • Zikri Bayraktar, M.S. Student • Xiaotao Liang, M.S. Student • Michael Pellen, M.S. Student • Krishna Prakash, M.S. Student • Robert Shaw, M.S. Student • Brian Rybicki, M.S. Student • Paul Cristman, Undergraduate Honors Student

3. Computational Electromagnetics and Antennas Research Lab-- Notable Contributions -- • EM/Antenna Optimization Techniques • Among the early contributors to applications of Genetic Algorithms • First to combine Iterated Function Systems with GAs (IFS-GA) • Developed efficient GA schemes using Neural Networks (NN-GA) • Pioneered in the recent development of Adaptive Genetic Algorithms • Developed/applied new Particle Swarm Optimization (PSO) techniques • Numerical EM Modeling Techniques • Solved long-standing EM problem which led to the development of first efficient thick-wire MoM code • First group to successfully develop dispersive FDTD formulation for general bi-anisotropic media (BIA-FDTD) • Developed FDTD code combined with SPICE for the efficient analysis of periodic structures with passive and/or active loads • Developing efficient hybrid techniques for modeling conformal antennas mounted on electrically large platforms (including optimization) • Developed Periodic Finite-Element Boundary-Integral (FE-BI) Code for efficient analysis and design of metallodielectric and all-dielectric FSS • Developed a suite of computational modeling codes for the analysis and design (including optimization) of metamaterials for RF to visible wavelength applications

4. Computational Electromagnetics and Antennas Research Lab-- Notable Contributions (Continued) -- • Antenna Technology • Pioneered in the development of fractal antenna/array designs • First to apply Genetic Algorithms to the design of fractal antennas/arrays • First to develop antenna array synthesis techniques that optimize radiation pattern and driving point impedances simultaneously • First to apply Particle Swarm Optimization (PSO) techniques to antenna array synthesis problems • Developed Model-Based Parameter Estimation Schemes (MBPE) for antenna applications • Introduced concept of stochastic antennas • Developed new concepts for reconfigurable, ultra-wideband, and miniature low-profile antennas • Recently introduced a new class of modular broadband antenna arrays based on applications of tiling theory • Developing a variety of novel meta-materials for advanced antenna applications (including concepts for multi-band, ultra-wideband and tunable electromagnetic bandgap surfaces, negative and zero index media, bi-anisotropic media and meta-ferrites) • Investigating Terahertz designs/applications of FSS and antennas

5. What are metamaterials? • Metamaterials are engineered composites that exhibit superior properties not observed in the constituent materials or nature. (DARPA Defense Sciences Office) • We are interested in the design of electromagnetic metamaterials for RF, IR and visible wavelength applications.

6. Metamaterials • Chiral Materials • Artificial Magnetic Conductors (AMCs) • Band-Gap Structures (EBGs and PBGs) • Negative Index Materials (NIMs) • Chiral Negative Index Materials (CNIMs) • Zero Index Materials (ZIMs) • Chiral Zero Index Materials (CZIMs)

7. Electromagnetic Analysis and Optimization of Metamaterials Periodic FEBI Method (inhomogeneous all-dielectric structures) Periodic MoM (metallo-dielectric FSS structures) Periodic FDTD Method (including anisotropic, chiral, and bi-anisotropic materials) Genetic Algorithms Particle Swarm Optimization

8. Genetically-Optimized Dual Band EBG Phase (degrees) GA Optimized Dual-Band High Impedance FSS Design FSS Cell Geometry Tx = Ty = 2.96 cm εr = 13h = 0.293 cm D. J. Kern, D. H. Werner, A. Monorchio, L. Lanuzza, and M. J. Wilhelm, “The Design Synthesis of Multi-band Artificial Magnetic Conductors Using High Impedance Frequency Selective Surfaces,” Special Issue on Artificial Magnetic Conductors, Soft/Hard Surfaces, and other Complex Surfaces, IEEE Transactions on Antennas and Propagation, Vol. 53, No. 1, pp. 8-17, Jan. 2005.

9. EXAMPLES OF HIGH-IMPEDANCE AMC SURFACES

10. Transmission (dB) expt theory Wavelength (µm) 30 μm Genetic algorithm FSS multiband filter User-defined design criteria: stopband wavelength and attenuation Excellent (>10 dB attenuation) multiband filter performance superior to state-of-the-art conventional designs in the IR

11. GA-Synthesized FSS with Fabrication Constraints • GA Design Parameters: • 0.5 µm polyimide substrate • Stopbands at 3 THz and 7 THz • Passbands from 1 THz to 10 THz 38.3 µm Cell Size Inverse geometry gives passbands at resonance.

12. 20µm 100nm Au Nanowire Antennas Au-nanowire template-based synthesis Au-nanowire antenna modeling Nanoantenna arrays and being investigate for self-assembled multi-spectral IR detector arrays

13. FDTD Simulations of Gold Nanowire Antennas Total Field Distribution at 800 nm for L=265 nm, w=55 nm, g=15 nm The maximum field intensity in the dipole gap vs wavelength

14. Plane wave pulse scattering off of an Au NanoDipole (Ex field )

15. Tunable NIM-ZIM-PIM Nematic Liquid Crystal Matrix Dispersed with Dielectric (non-magnetic) Core-Shell Spheres I. C. Khoo, D. H. Werner, and A. Diaz, “Nano-Dispersed Liquid Crystal with Tunable Negative-Zero-Positive Refractive Indices,” Optics and Photonics News, Vol. 17, No. 12, p. 33, Dec. 2006.