16 research outputs found
Least Upper Bounds of the Powers Extracted and Scattered by Bi-anisotropic Particles
The least upper bounds of the powers extracted and scattered by
bi-anisotropic particles are investigated analytically. A rigorous derivation
for particles having invertible polarizability tensors is presented, and the
particles with singular polarizability tensors that have been reported in the
literature are treated explicitly. The analysis concludes that previous upper
bounds presented for isotropic particles can be extrapolated to bi-anisotropic
particles. In particular, it is shown that neither nonreciprocal nor
magnetoelectric coupling phenomena can further increase those upper bounds on
the extracted and scattered powers. The outcomes are illustrated further with
approximate circuit model examples of two dipole antennas connected via a
generic lossless network.Comment: 9 pages, 1 figure
Resonant meta-surface superstrate for single and multifrequency dipole antenna arrays
The design of a multifrequency dipole antenna array
based on a resonant meta-surface superstrate is proposed. The behavior
of a single element that is closely placed to a meta-surface is
experimentally investigated. The proposed meta-surface is based
on resonating unit cells formed by capacitively loaded strips and
split ring resonators. By tuning a dipole antenna to the pass band
of the meta-surface, the physical area is effectively illuminated enhancing
the radiation performance. The gain, radiation efficiency
and effective area values of the whole configuration are compared
to the ones obtained with a single dipole without superstrate. Radiation
efficiency values for the proposed configuration of more
than 80% and gain values of more than 4.5 1 dB are obtained.
Based on this configuration, simulated results of a multifrequency
antenna array are presented. Distinctive features of this configuration
are high isolation between elements (20 dB for a distance of lambda0/4), and low back radiation
All-dielectric woodpile horn antennas
This paper is devoted to EBG horn antennas. This novel type of all-dielectric horn antennas is based on complex hollow defects in woodpile structures and can be used for creating compact arrays and provide a promising solution for millimeter and terahertz devices. A novel concept of feeding EBG horn antennas via evanescent fields existing in periodic structures is presented. The principle of creating all-dielectric pyramidal horn antennas based on woodpile structure with hollow defects is proposed. Different horn antennas based on woodpile structures and characterized by large operating bandwidths and high levels of directivity and efficiency were designed, fabricated and measured.3 page(s
Hyperbolic Lens Antenna in Groove Gap Waveguide Technology at Submillimeter waves
International audienceIn this paper, a flat hyperbolic lens antenna using Groove Gap Waveguide (GGW) technology is designed at 300 GHz. A GGW horn antenna is used to feed the metamaterial lens placed in a parallel plate waveguide (PPW), in order to increase the directivity in the direction of propagation. The combination of both devices, the metalens and the GGW antenna, achieves excellent radiation performance
Flat Hyperbolic Lens antenna in Gap Waveguide at 300 GHz
International audienc
Electromagnetic Band Gap Waveguide for the Millimetre Range
International audienc