Programa del congreso

In this work we present the experimental characterization of a terahertz (THz) superoscilatory lens implemented on an ultra-thin metasurface (thickness <0.04λ0). This metalens improves the transmission efficiency and the focal properties of other super-oscillatory lenses found in the literature based on different design modalities (such as lenses based on opaque and transparent areas). At the frequency fexp = 295 GHz, the manufactured metalens improves by 25% the classical resolution limit imposed by the diffraction of electromagnetic waves, showing at the same time a gain of 18.2 dB and a very low side lobe level (13 dB). In addition, the metalens achieves a resolution better than the diffraction limit in a fractional bandwidth greater than 18% and high levels of transmission and focusing efficiency. The novel design procedure on which the proposed device is based opens new doors for obtaining devices with potential applications in THz imaging techniques, microscopy and communications, among others

In this communication, the reconfigurability mechanisms for beam steering at a fixed frequency in a leaky-wave antenna based on Huygens metasurfaces are reviewed. A preliminary design for a forward-to-backward scanning antenna at 24 GHz is proposed based on the use of a commercial liquid crystal (er ranging from 2.46 to 3.54). The simulation results show that the beam steers when the permittivity of the liquid crystal (partially filling the waveguide, with a 560 um high layer) is reconfigured. It is shown that the antenna can meet the challenges of this technology (a very thin layer of liquid crystal and a not very wide range of permittivity) while obtaining scanning from -15 to 15º maintaining the directivity around 17 dBi, including broadside.

In this communication, the behavior of a chiral metasurface that takes advantage of oblique incidence to transform the polarization state of the incident wave is analyzed. In contrast with other publications, the novelty of this work lies on the distribution of the chiral particles. The proposed metasurface has been characterized using the finite difference time domain engine of the full wave 3D EM simulator, Keysight EMPro. With the aid of this numerical tool, different configurations have been studied: sawtooth profile and zigzag profile structures, with different mutual twist angle and angle of incidence. The combination of intrinsic and extrinsic chirality shows a great influence on the circular dichroism.

Abstract- In this paper, we have designed a Substrate Integrated Waveguide Slotted Antenna (SIW-SA) covered by a metasurface. Thanks to this planar technology, we reduce the manufacturing complexity and its volume. The design process of a SIW and an 8 slot antenna following a Chebyshev distribution to control the SLL is presented. We will compare the performance of this antenna with a conventional one and demonstrate the improvement in the radiation aperture. This comparison shows that gain enhancement is achieved when the metasurface is used, thanks to the increase of effective area. Besides, the bandwidth of this new configuration is not affected, being similar in both cases.

This work contains the numerical study of a highly efficient and ultrathin bi-layer PB HWP metasurface consisting of H-shaped, elements with a transmission efficiency of 90.15% and a thickness < λ/13. A numerical analysis along with the measurements confirmed the device’s ability to convert a CP wave’s handedness at 87 GHz. Furthermore, a metalens composed by identical H-shaped bi-layered PB HWP meta-atoms is numerically demonstrated showing an excellent behavior at 87 GHz.