Programa del congreso

Serrated reflector systems are widely used in com-pact range antenna measurement (CATR) setups. Besides max-imizing the size of the reflector, serrations are essential forimproving the size and quality of quiet zones. Multiple serrationgeometries are available in the literature but, for the most part,there seems to be no evident relationship between the char-acteristic parameters of these geometries and their implicationin quiet zones’ size and quality. Optimization algorithms andcomparison metrics are needed in order to reach an optimumedge serrations geometry. This work presents a method tooptimize an offset reflector system that can be generalized toany CATR reflector setup.

In this paper we present a broadband circularly polarized low profile metasurface (MTS) antenna. A metasurface of 3x4 rectangular cells is first analyzed using characteristic mode analysis (CMA). As a result, two modes with orthogonal current distribution and almost 90º phase difference are selected to contribute to the circular polarization radiation.

Finally, an appropriate rotated coplanar waveguide (CPW) feeding line is chosen to excite the two modes. The simulation results show 3-dB axial ratio band of 13.8% (5.6-6.43GHz), an impedance bandwidth of 24.1%, and a peak gain of 8dBi. The dimensions of the proposed design are 1.0λ0×1.0λ0×0.059λ0.

RF energy harvesting through the use of rectennas, an element with which DC power is obtained from electromagnetic waves found in free space, is currently gaining momentum as new designs are being proposed. The state of the art of harvesting is mostly focused on the design of single-band rectennas. However in this paper, a multi-tone system has been designed where several frequency bands will be collected. The design of the proposed rectenna is based on both short-circuited patch antenna and Crofton-Walton rectifier. The simulation results are shown, obtaining really good efficiency and reflection coefficient values. The main conclusion reached in this work is that a multi-tone system is more challenging than a single-frequency system with advantages such as higher DC output voltage, efficiency and diversity.

Este artículo propone una antena de cuatro puertos con respaldo de cavidad de banda ancha para aplicaciones de estaciones base interiores. La antena está compuesta por una cavidad abierta de forma cuadrada con un bloque aislante en forma de X situado en el centro y 4 monopolos dispuestos de forma simétrica en la apertura de la cavidad. Para su diseño se ha utilizado una metodología basada en el análisis de modos característicos (CMA) para identificar los modos que contribuyen al acoplamiento y justificar el uso del bloque en forma de X para incrementar el aislamiento entre puertos. La antena dispone de cuatro diagramas de radiación unidireccionales y un ancho de banda (S₁₁<-10 dB) que opera desde 1.55 GHz hasta 6 GHz (118%), cubriendo la mayoría de las bandas 5G sub-6 GHz. El aislamiento entre puertos es de mínimo 16 dB y la eficiencia superior al 84%. La antena es de fácil fabricación y presenta un tamaño compacto de 129.5 x 129.5 x 28.2 mm³ (0.68λ x 0.68λ x 0.15λ, a la frecuencia mínima f=f_min=1.55 GHz).

A circularly polarized implantable antenna (CPIA)

working at industrial, scientific, and medical (ISM) band (915)

MHz is presented in this communication. The proposed CPIA

consists of a meandered line surrounded by a U-structure

to guarantee circular polarization. With this combination, we

achieve a wideband axial ratio (AR) of 27 % from 770 to

1010 MHz, and a wideband reflection coefficient of 20 % from

809.4 to 989.8 MHz. Moreover, 12 m distance communication

is guaranteed for a link margin of about 30 dB. The antenna

has a compact size of 0.01 × 0.01 λ<sup>2, which makes it a good

candidate for implantable devices.