This technical document is a preliminary report on the study of the foliage influence on the radio wave propagation in cellular scenarios. The purpose is to evaluate the dispersion and attenuation caused by vegetations in mobile radio channels, hence we employed a channel sounder to measure received signals behind dense vegetations in the rural areas in Kanagawa, Japan. The transmitter sends a ...

Transformation optics is a recently appreciated methodology for the design of complex media that control the propagation of electromagnetic and other types of waves. The transformation optical technique involves the use of coordinate transformations applied to some region of space, providing a conceptual means to redirect the flow of waves. Successfully designed devices to date have made use of...

RF plasma sources are essential for producing semiconductor chips, but they are developed empirically, with incomplete knowledge of how they work. Inductively coupled plasmas (ICPs) employ rf fields without a dc magnetic field B0 and produce ionization well outside the skin layer. Helicon sources with a B0 can generate much higher densities but pose a number of puzzling physical questions. Of t...

The resonant-mass technique for the detection of Gravitational Waves may involve, in the near future, the cooling of very large masses (about 100 tons) from room temperature (300K) to extreme cryogenic temperatures (20mK). To cool these detectors down to cryogenic temperatures an exchange gas (helium) is used, and the heat is removed from the antenna to the cold reservoir by thermal conduction ...

This paper proposes a millimeter-wave lens antenna using 3-dimensional (3D) printing technology to reduce weight and provide stable gain performance. The consists of four-layer cylindrical gradient-index (GRIN) fed by wideband Yagi antenna. We designed fractal cell geometry achieve the desired effective permittivity for GRIN lens. Among different candidates, honeycomb structure is chosen high m...