Scientists / Open questions

George V. Eleftheriades

Metamaterials; electromagnetics; antennas

12 questions

Truncation error bounds, lossy and nonreciprocal extension, conditioning, and systematic numerical validation of the generalized scattering matrix identities for mode-matched waveguide junctions
Rigorous local-to-global theory for reflectionless wide-angle refracting metasurfaces designed by local impedance matching (generalized S-parameters)
Beam-Squint Limits and Fully-Printed Realization of Passive NRI-TL Leaky-Wave Antennas
Systematic delineation of the field transformations realizable by passive lossless metasurfaces using auxiliary evanescent fields
Nonreciprocal unit-cell prescriptions and general matched termination of finite 2-D negative-refractive-index transmission-line lattices beyond the electrically short-cell limit
Convergent computation, stability, optical-frequency realization, and performance limits of space-time-periodic diffraction gratings
True real-time active interior electromagnetic cloaking: broadband and pulsed operation, three-dimensional dielectric objects, and unknown incident fields
Autonomous Huygens surfaces: discontinuous-field wavefront manipulation without a priori knowledge of the incident field, in three dimensions and for arbitrary objects
Scaling Non-Foster NGD-Based Squint-Free Series-Fed Antenna Arrays: Large-Array Gain, Noise, and Stability Accumulation, Mutual-Coupling-Accurate Beam Pointing, and Continuous Beam Steering
Open problems in wide-angle impedance matching (WAIM) metasurfaces for dipole phased arrays: homogenized-model validity, extreme-scan-angle impedance extraction, and wideband multilayer realization
Platform integration, pattern symmetry, and fabrication robustness of the broadband dual-mode NRI-TL metamaterial-loaded monopole antenna
Nonideal analysis, physical implementation, and systematic synthesis of the generalized negative-refractive-index transmission-line (NRI-TL) unit cell for dual-band and quad-band microwave components

Back to open problems

Truncation error bounds, lossy and nonreciprocal extension, conditioning, and systematic numerical validation of the generalized scattering matrix identities for mode-matched waveguide junctions

Rigorous local-to-global theory for reflectionless wide-angle refracting metasurfaces designed by local impedance matching (generalized S-parameters)

Beam-Squint Limits and Fully-Printed Realization of Passive NRI-TL Leaky-Wave Antennas

Systematic delineation of the field transformations realizable by passive lossless metasurfaces using auxiliary evanescent fields

Nonreciprocal unit-cell prescriptions and general matched termination of finite 2-D negative-refractive-index transmission-line lattices beyond the electrically short-cell limit

Convergent computation, stability, optical-frequency realization, and performance limits of space-time-periodic diffraction gratings

True real-time active interior electromagnetic cloaking: broadband and pulsed operation, three-dimensional dielectric objects, and unknown incident fields

Autonomous Huygens surfaces: discontinuous-field wavefront manipulation without a priori knowledge of the incident field, in three dimensions and for arbitrary objects

Scaling Non-Foster NGD-Based Squint-Free Series-Fed Antenna Arrays: Large-Array Gain, Noise, and Stability Accumulation, Mutual-Coupling-Accurate Beam Pointing, and Continuous Beam Steering

Open problems in wide-angle impedance matching (WAIM) metasurfaces for dipole phased arrays: homogenized-model validity, extreme-scan-angle impedance extraction, and wideband multilayer realization

Platform integration, pattern symmetry, and fabrication robustness of the broadband dual-mode NRI-TL metamaterial-loaded monopole antenna

Nonideal analysis, physical implementation, and systematic synthesis of the generalized negative-refractive-index transmission-line (NRI-TL) unit cell for dual-band and quad-band microwave components