Anastasios H. Panaretos

Learn More
An ultra-thin reconfigurable absorber concept based on metasurfaces is presented. First, an artificial magnetic conducting (AMC) metasurface absorber is examined that incorporates lumped resistors along with variable lumped capacitors, which allow its frequency response to be tuned. The parasitic effects introduced by the lumped capacitors are compensated(More)
The theoretical basis for an ultra-thin broadband absorber is established which is comprised of a mushroom-type high impedance surface (HIS) and a pixelized frequency selective surface (FSS). The latter is engineered to exhibit a prescribed series RLC circuit response and it is placed at an electrically small distance above the HIS. Through a transmission(More)
In this paper we demonstrate the feasibility of using a plasmonic core-shell particle to function as a wavelength dependent switch for integration into nanoantenna structures. First, a quasistatic analysis is performed and the necessary conditions are derived which allow the particle to operate in either a short- or an open-circuit state. These conditions(More)
The performance of a leaky-wave antenna that utilizes a sinusoidally modulated reactance surface is numerically investigated. In contrast to previously reported design methodologies, the sinusoidal reactance fluctuation is introduced in the structure by using lumped capacitors that load a frequency selective surface composed of simple uniformly distributed(More)
An ultra-thin wideband Frequency Selective Surface (FSS) type absorber consisting of a double square loop with a center patch is proposed. The admittance of the FSS is engineered so that it exhibits a capacitive response within the frequency range of interest. The latter is below the substrate's λ/4 resonance, where the substrate is characterized by(More)
The dual mode operation of a nanodipole is demonstrated using a plasmonic core-shell particle load. Specifically, the fact that the latter exhibits an equivalent Lorentz type permittivity is utilized, in order to achieve either a capacitive or an inductive impedance response. Consequently, when such a particle is inserted within the gap defined by the(More)
In this paper we theoretically investigate the feasibility of creating a dual-mode plasmonic nanorod antenna. The proposed design methodology relies on adapting to optical wavelengths the principles of operation of trapped dipole antennas, which have been widely used in the low MHz frequency range. This type of antenna typically employs parallel LC(More)
An equivalent transmission line approach is presented to quantify the wider band gap properties of non-uniform capacitively loaded mashroom-type electromagnetic bandgap (EBG) devices. The approach is based on the observation that the band gap properties of the EBG device within a parallel plate waveguide directly correspond to the attenuation factor of an(More)