This paper investigates practical implementation aspects of a novel hybrid chamber concept that has been recently introduced for over-the-air testing wireless devices.The allows to synthesize spectrum plane waves (PWs) incident on device under test from wide range anglesof-arrival (AoAs) through exploiting multiple field scattering inside the overmoded waveguide chamber.An optimal design approach wave generator (PWSG) array is presented considering: (i) antenna impedance matching desired...

In this paper, different methods for practical numerical radio frequency exposure compliance assessments of base station products were investigated. Both multi‐band antennas and designed multiple input output (MIMO) transmission schemes considered. For the case, various standardized assessment evaluated in terms resulting distance with respect to reference levels basic restrictions International Commission on Non‐Ionizing Radiation Protection. single (cumulative) distances determined using...

Optimization of the current distribution is used to analyze how small antennas are affected by amplitude constraints on near field and lossy background media. The optimal antenna that minimizes stored energy, for a prescribed radiated in given direction, with limited set control points, formulated as convex optimization problem. analysis also extended media using frequency-derivative approximation energy. results suggest many fundamental problems involving near-field can be analyzed optimization.

We extend the autocorrelation-based approaches currently used in standards to full correlation-matrix-based order identify correlation between both spatially adjacent and non-adjacent samples reverberation-chamber measurements. employ a scalar metric that allows users number of effectively uncorrelated new types stirring sequences. To make these practical enhance their accuracy, we implement thresholding technique retains related important aspects chamber configuration such as loading...

5th-generation mobile network systems operating in millimeter-wave bands will employ base stations with integrated active antenna systems. Such are capable of beam-tracking using narrow beams obtained from arrays. Regulatory limits for unwanted radio frequency and Over-The-Air methods TRP emissions needed. The method investigated here uses power density measurements on a spherical surface an anechoic chamber. Two major challenges such are: need large number angular points search worst case...

Transient electromagnetic wave propagation in a stratified, anisotropic, dispersive medium is considered. Specifically, the direct scattering problem addressed. The dispersive, anisotropic modeled by constitutive relations (a 3 × matrix-valued susceptibility operator) containing time convolution integrals. In general case, nine different kernels characterize medium. An incident plane impinges obliquely upon finite slab consisting of stratified scattered fields are obtained as convolutions...

Multiple-input-multiple-output (MIMO) is a technique to achieve high data rates in mobile communication networks. Simulations are performed at both the antenna level and Long-Term Evolution (LTE) system assess performance of realistic handheld devices with dual antennas 750 MHz. It shown that MIMO works very well gives substantial gain user quarter-wavelength separation.

An algorithm to compute the radiation center of an antenna, using Spherical wave expansion (SWE) far field or directly, is introduced. The method based on angular momentum that uniquely defined for any antenna pattern. as phase reference point where minimized and corresponds minimizing variations in In addition, this approach also allows determination current distribution axis.

ABSTRACT This paper discusses the restrictions that dissipation forces on material parameters and responses of bi-anisotropic media. The treatment is a general time domain analysis where six-vector formalism applied. Energy conditions set limitations optical response dyadics dyadic susceptibility kernels have to be satisfied regardless dependence fields. will treat in detail resulting for Examples are given some special cases. Also uniqueness equivalence aspects constitutive relations discussed.

5G base stations are gradually evolving into Active Antenna Systems, improving the link budget with beam-steering capabilities. As such antenna arrays typically eight wavelength large or more, question of reducing footprint far-field testing facilities has experienced a growing interest. Recent research results have established that it is possible to conduct accurate Over- The-Air measurements around peak radiation, at an effective distance which can be as low 20% Fraunhofer distance,...

An inverse medium scattering problem for a homogeneous slab of anisotropic dispersive is presented. The to recover the dyadic susceptibility kernel from reflection kernels obliquely incident transient electromagnetic plane waves. A time domain technique, based on wave splitting and invariant imbedding, used. Mirror images enter into formalism in natural way are therefore discussed. This leads simplified class mirror image symmetric media. solved numerically stability algorithm tested using...

A robust phase-retrieval method with stable convergence and back-propagation properties for quick experimental whole body specific absorption rate (SAR) assessments is presented. combination of a fast coarse more accurate gradient-based used to optimise the overall performance. To prevent solution being trapped in local minimum, several initial phase distributions are used. An measurement procedure has been developed which reduces time by roughly factor 2.5–4 at common mobile communication...

Current standardized procedures for measurements of the Specific absorption rate (SAR) mobile phones and radio base station antennas include a volumetric scan electric field strength induced in head or body phantom. Assessment multi-band whole-body SAR requires repeated scanning over large part phantom is time-consuming. In order to reduce total evaluation time, different methods have been proposed estimate from measurement data based on sparse surface scanning. These rely fitting with...

Reverberation chambers are widely recognized as a time-efficient testing facility for various applications. The spatial uniformity based on the power transfer function is critical characteristic of chamber that affects measurement uncertainty. To gain more insights into behavior we introduce complementary metric: K-gamma factor. This metric, inspired by well-established K-factor, quantifies unstirred contributions each antenna individually and highly sensitive to configuration placement....

In cellular radio network simulations the modeling of terminal antennas is often extremely simplified. this paper results from a study on impact using realistic in LTE system are presented. Results downlink measured radiation patterns number typical multi-antenna terminals have been compared with an ideal antenna model. The showed that was weak scenario high intercell interference while substantial performance degradation could be observed low interference. Cell-edge throughput found to most...

A hybrid, reconfigurable anechoic-reverberation antenna measurement chamber was recently introduced with the vision to enable fast characterization of active radiated power and directive characteristics in a single environment. The initial studies included its design analysis plane wave spectrum generator scenario. In present work, we investigate reconfiguration capabilities for performing total (TRP) measurements. We show how different types interchangeable hybrid modules allow realizing...

This paper investigates the characterization and calibration procedure of hybrid over-the-air (OTA) measurement chamber. We present a prototype chamber analyze its capabilities to generate plane wave spectrum in practice. A planar field scanner is used acquire embedded element fields array for test zone (TZ) synthesis post-processing. The repeatability acquisition evaluated. It shown that synthesized TZ meets 3GPP specifications variations generators (PWG) presence imperfections.

A measurement-based method for RF exposure compliance boundary assessment base station antennas is presented. full-sphere near-field measurement used as input data, thereby avoiding spatial truncation. Combined use of spherical and cylindrical modes allows evaluation close to the antenna. The error compliant with current standards.