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This paper presents a circularly-polarized dual-band antenna for Ka-band satellite communications which operates simultaneously in both civil and military downlink (17.7–21.2 GHz) and uplink (27.5–31 GHz) bands. The antenna is composed of a metallic ridged cavity that is perforated with a crossed-slot. This cavity is excited in sequential rotation through four feeding coaxial cables, thus producing...
A simple low-cost mobile ground terminal antenna for Ka-band satellite communications is presented. The antenna is composed of a shaped dielectric lens which tilts and rotates in front of a feed to direct the beam. The wideband feed system is composed of a quad-ridged horn with a slant aperture and a coaxial-to-quad-ridged circular waveguide transition. The lens allows simple mechanical...
Broadcast television is one of the most important telecommunications systems in Brazil. Such relevance in the socio-cultural context requires a continuous pursuit of technical excellence in order to offer an increasingly attractive product to the viewer. Therefore, it is mandatory to care about the coverage and quality of the TV signal, especially when it comes to Digital TV. In this scenario, it...
In this work, we study the dielectric properties and structure of the BiYWO6 dielectric resonator (DR) obtained by microwave assisted fast solid state synthesis. The crystal structure of BiREWO6 (RE=rare earth) can be associated to the Bi2WO6 perovskite structure. It was observed that the crystalline structure was attributed to a monoclinic phase with space group A12/m1. The agreement between experimental...
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