Directive optical leaky wave antennas (OLWAs) with tunable radiation pattern are promising integrated optical modulation and scanning devices. OLWAs fabricated using CMOS-compatible semiconductor planar waveguide technology have the potential of providing high directivity with electrical tunability for modulation and switching capabilities. We experimentally demonstrate directive radiation from...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Zhou Du Name of the doctoral dissertation Development of Characterization Methods for Antennas and Quasi-Optics Publisher School of Electrical Engineering Unit Department of Radio Science and Engineering Series Aalto University publication series DOCTORAL DISSERTATIONS 8/2015 Field of research Radio Engineering Manuscript subm...

language and emotion are two related systems in use, in that one system (emotions) impacts the performance of the other (language). both of them share their functionality in communication. since the nature of foreign language classrooms is ideally interactional, emotional intelligence (ei) gains importance. the aim of this study was to find out whether one's total emotional quotient and its com...

fresnel zone plate antenna (fzpa) was considered as a recieving antenna. an expression of electric field on axis of antenna produced by an incidente plane wave was found . the expression was used for calculation of gain, efficiency and optimum phase correcting function. several fzpa are fabricated and tested. experimental and theoretical results were compared and it was shown that there was a g...

Usually acoustic beamformer or directive microphones are used in order to focus on known potential locations emitting sounds so as to identify and extract their major noise components. However performances of these techniques depend on the number of microphones and the a priori knowledge of the source locations. Based on the measurement of phase delays between sensors and short-time Fourier tra...

One of the long-standing problems in antenna engineering is the realization of highly directive beams using low-profile devices. In this paper, we provide a solution to this problem by means of Huygens' metasurfaces (HMSs), based on the equivalence principle. This principle states that a given excitation can be transformed to a desirable aperture field by inducing suitable electric and (equival...

This work presents directional radio channel measurements in the W-band using a commercial versatile channel sounder based on a vector network analyzer (VNA), capable of measuring scattering parameters from 75 to 500 GHz with frequency converters. The commercial setup has been modified by increasing the distance for one of the converters using precision coaxial cables and avoiding the use of am...

This letter presents a 4 × single-layer dual-band array antenna operating in the K- and Ka-band using gap waveguide (GW) technology. Radiating elements consist of I-shaped slots located on top plate backed by novel coaxial cavity with dual-frequency operation. The two ports, one for each band, radiates directive far field pattern linear polarization. A wideband corporate-feed network is used to...