The World Radiocommunication Conference 2015 (WRC-15) identified a number of frequency bands between 24 and 86 GHz as candidate frequencies for future cellular networks. In this article, an extensive review propagation characteristics challenges related to the use millimeter wave (mm-wave) in wireless systems is presented. Reference existing path-loss models including atmospheric material attenuation recommendations International Telecommunication Union (ITU) Geneva, Switzerland, given, need...

Recent advances in the photonics and optics industries have produced great demand for ever more sophisticated optical devices, such as photonic crystals. However, crystals are notoriously difficult to manufacture. Increasingly, therefore, researchers turned towards naturally occurring structures inspiration a wide variety of elaborate techniques been attempted copy harness biological processes manufacture artificial structures. Here, we describe simple, direct process producing an device by...

An original all-dielectric design that performs cloaking at 0.58 THz is demonstrated. The cloak consists of radially positioned micrometer-sized ferroelectric cylinders which exhibit under Mie theory a strong magnetic resonance. Full-wave simulations coupled with field-summation retrieval technique were employed to adjust the rods plasma frequency; hence, radial distribution in permeability cloak. behavior complete micro-structured device was simulated and results unambiguously show good...

We report on the tunability, by a magnetic field, of negative permeability metamaterial consisting stacked arrays broadside-coupled split ring resonators infiltrated with liquid crystals (LCs). The resonant frequency shift was numerically assessed rigorous anisotropic analysis reorientation LC molecules. Experiments were carried out prototype designed and fabricated for X-band operation nematic compound optical birefringence Δn=0.18. Scattering parameters vectorial shows good agreement...

This work presents an analysis of dense multipath components (DMC) in industrial workshop. Radio channel sounding was performed with a vector network analyzer and virtual antenna arrays. The specular were estimated the RiMAX algorithm. DMC covariance structure data model validated. Two parameters studied: distribution radio power between multipath, reverberation time. accounted for 23% to 70% total power. A significant difference powers line-of-sight nonline-of-sight observed, which can be...

This letter presents an extensive multidimensional analysis of line-of-sight (LOS) experimental data and simulations at 60 GHz over a 9-GHz bandwidth. Numerical versions the measured multiple-input-multiple-output (MIMO) channel transfer functions were obtained with ray-tracing engine that includes single-order diffuse scattering. The received power, RMS delay spread (DS), maximum excess (MED) computed from both simulated indicate scattering improves ray-tracing-based modeling. Moreover,...

A novel localization framework is presented based on ultra-wideband (UWB) channel sounding, employing a triangulation method using the geometrical properties of propagation paths, such as time delay arrival, angle departure, and their estimated variances. In order to extract these parameters from UWB sounding data, an extension high-resolution RiMAX algorithm was developed, facilitating analysis frequency-dependent multipath parameters. This then tested by performing indoor measurements with...

Abstract A method is presented for predicting and precisely controlling the structure of photonic crystals fabricated using sacrificial‐layer atomic layer deposition. This technique provides a reliable fabrication high‐quality non‐close‐packed inverse shell opals with large static tunability precise structural control. By sacrificial during opal infiltration, inverse‐opal pore size can be increased sub‐nanometer resolution without distorting lattice to allow high degree dielectric...

In this paper, a novel pilot-aided iterative algorithm is developed for MIMO-OFDM systems operating in fast time-varying environment. An L-path channel model with known path delays considered to jointly estimate the multi-path Rayleigh complex gains and Carrier Frequency Offset (CFO). Each gain time-variation within one OFDM symbol approximated by Basis Expansion Model (BEM) representation. auto-regressive (AR) built parameters be estimated. The performs recursive estimation using Extended...

For the first time, response of personal exposimeters (PEMs) is studied under diffuse field exposure in indoor environments. To this aim, both numerical simulations, using finite-difference time-domain method, and calibration measurements were performed range 880-5875 MHz covering 10 frequency bands Belgium. Two PEMs mounted on body a human male subject calibrated on-body an anechoic chamber (non-diffuse) reverberation (RC) (diffuse fields). This was motivated by fact that electromagnetic...

Topological tuning of photonic crystals significantly changes their photonic-band properties. Significant modification inverse opal topology by heat treatment and a two-step atomic layer deposition infiltration process is demonstrated, facilitating precise control The figure shows topologies at different degrees backfilling.

The photonic bands of two-dimensional (2D) triangular lattice crystal Si slab waveguides were statically tuned using low temperature atomic layer deposition (ALD) TiO2. Angular dependent reflectance measurements bare and coated devices well fitted by three-dimensional finite-difference time-domain calculations. technique not only allows the physics band effects in 2D crystals to be systematically studied but also demonstrates large static tuning precise fine-scale control over frequency...

The condition of both relative permittivity and permeability equal to $\ensuremath{-}1$ in negative index photonic crystals was addressed by the retrieval so-called Bloch impedance. dispersion characteristics a crystal made an array air holes InGaAsP semiconductor layer were first compared (i) solving eigenvalue problem plane wave expansion (ii) calculating complex transmission reflection coefficients for finite slab. From latter, effective refractive impedance are deduced using transfer...

This paper presents a comprehensive analysis of the polarization characteristics specular and dense multipath components (SMC DMC) in large industrial hall based on frequency-domain channel sounding experiments at 1.3 GHz with 22-MHz bandwidth. Twenty-nine positions were measured under line-of-sight (LOS) obstructed LOS (OLOS) scenarios. The RiMAX maximum-likelihood estimator is used to extract full-polarimetric SMC DMC from measurement data by taking into account polarimetric radiating...

Electromagnetic field exposure (EMF) has grown to be a critical concern as consequence of the ongoing installation fifth-generation cellular networks (5G). The lack measurements makes it difficult accurately assess EMF in specific urban area, Spectrum cartography (SC) relies on set recorded by spatially distributed sensors for generation maps. However, when spatial sampling rate is limited, significant estimation errors. To overcome this issue, map addressed missing data imputation task.We...

Full dielectric electromagnetic cloaks are studied in this paper for considering the possibility of achieving effective permeability gradients by taking advantage a magnetic Mie resonance high-κ ceramics. Extreme performance sensitivity to dispersion complex parameters, which could be problematic practical realization, is pointed out. In second stage, we apply transformation optics magnification and high-resolution focusing highly anisotropic metal–dielectric flat lenses.

This work presents a novel localization scheme based on Ultra-Wideband (UWB) channel sounding, employing triangulation method that makes use of the geometrical properties propagation paths, such as time arrival (ToA), angle departure (AoD) and (AoA). An extension to high-resolution RiMAX algorithm was developed, facilitating analysis UWB frequency-dependent parameters, allowing for target node in Line-of-Sight (LoS), Obstructed-LoS (OLoS), Non-LoS (NLoS) scenarios.

The objective of this paper is to study the wideband characteristics radio channel in a tunnel environment, not only delay spread, but also angle departure/arrival rays, their relative weights and delays, which are important values for Multiple-Input Multiple-Output applications. In order achieve goal, measurement campaign has been carried out straight arched over frequency band extending from 2.8 5.0GHz distance varying 50m up 500m. First, variations impulse response spread versus between...

An original experimental protocol is developed to assess the whole-body absorption cross section of objects with arbitrary shapes and materials in diffuse fields at any operating frequency. This approach important for dosimetry specifically realistic environments wherein can be prominent. For this application, knowledge specific rate critical determined from human wholebody section. The obtained measurements performed a stirred-mode reverberating chamber processed high-resolution parameter...

Abstract Experimentally assessing the whole‐body specific absorption rate (SAR wb ) in a complex indoor environment is very challenging. An experimental method based on room electromagnetics theory (accounting only line‐of‐sight as specular path) validated using numerical simulations with finite‐difference time‐domain method. Furthermore, accounts for diffuse multipath components (DMC) total by considering reverberation time of investigated room, which describes all losses environment. The...

This paper describes the architecture of a fully parallel multiple-input multiple-output (MIMO) channel sounder. It has been designed to give in real-time full polarimetric matrix which is then exploited display, for example, bi-directional characteristics as angle arrival (AoA) and departure (AoD) multipath components. 16×16 sounder, working at center frequency 1.35 GHz, uses an OFDM transmission scheme with 80 MHz bandwidth. Applications this sounder are illustrated by studying outdoor...

Due to rapid changes in the environment, vehicular communication channels no longer satisfy assumption of wide-sense stationary uncorrelated scattering. The non-stationary fading process can be characterized by assuming local stationarity regions with finite extent time and frequency. scattering function (LSF) channel correlation (CCF) provide a framework characterize mean power scatterers, respectively. In this paper, we estimate LSF CCF from measurements collected vehicle-to-infrastructure...

In this letter, a polarization diversity technique applied to massive multiple-input-multiple-output (MIMO) in an industrial environment is proposed. The main idea use dual-polarized elements at the fixed array and adequately choose their for each communication channel between given user. For same number of antenna ports, such configuration allows decreasing, by factor 2, geometrical size and, thus, minimizing spatial nonstationarity over array. Performance approach evaluated terms sum-rate...

Large three-dimensional photonic band gap (PBG) structures offer revolutionary advances in controlling light emission and propagation. However, current techniques are not yet adequate to fabricate large area with optimum properties. Inverse shell opals a ``bottom-up'' approach fabrication but limited by the small full PBG lack of appropriate materials for operation visible where most impact is expected. From electric-field power profile investigations inverse opals, we describe effect...