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The authors present the design of a tunable 433 MHz antenna that is tailored for wearable wireless sensor applications. This study first presents a detailed analysis of the measured impedance characteristics of a chosen antenna under test (AUT) in varying proximity to a human test subject. Instead of limiting the analysis to the head and hand only, this analysis measures the AUT impedance at varying distances from 11 different body positions. A novel antenna equivalent circuit model is then developed that enables both the free-space and total on-body AUT impedance variation to be rapidly computed using a circuit simulator instead of the requirement for computationally intensive finite-element methods for example. The design and characterisation of a tunable matching network that enables AUT impedance matching for 11 different positions on the human body is then outlined. Finally, a fully-autonomous 433 MHz tunable antenna is demonstrated. The antenna occupies a small printed circuit board area of 51 × 28 mm and is printed on standard FR-4 material with the tuner completely integrated into the antenna itself. Prototype measurements show an improvement of 3.9 dB in power delivery to the antenna for a load voltage standing wave ratio of 17:1, with a maximum matching loss of 0.84 dB and S 11 (−10 dB) ≥ 18 MHz for all load conditions.

International audience; In this paper, a 5G MIMO mobile phone prototype including four antennas working in the 10-13.2 GHz band is designed. The objective of the study is to evaluate the negative impact due to the user's hand in frequencies higher than 10 GHz. A 3D spherical near-field scanner with fixed Antenna Under Test (AUT) is leveraged in order to measure a 3D radiation pattern with a real human hand impact. S-parameters, radiation pattern and efficiency are presented. First results show that radiation pattern and efficiency are strongly impacted by the hand. This effect has to be carefully considered for millimeter Wave handheld terminal design.

International audience; A designed microstrip grid array antenna at 94 GHz in a low-temperature co-fired ceramic (LTCC) technology was fabricated and measured. The designed and measured results are in good agreement. They show a 10-dB impedance bandwidth of 5.12 GHz from 90 GHz to 95.12 GHz (or 5.45% at 94 GHz), a maximal peak realized of 17.1 dBi with a 3-dB gain bandwidth of 5.5 GHz from 92.0 GHz to 97.5 GHz (or 5.85% at 94 GHz). These good performances make the microstrip grid array antenna a suitable candidate for 94-GHz applications.

TOPICA (Torino Polytechnic Ion Cyclotron Antenna) code is an innovative tool for the 3D/1D simulation of Ion Cyclotron Radio Frequency (ICRF) antennas, i.e. accounting for realistic 3D antenna geometries and for accurate 1D plasma models. The tool calculates the antenna input parameters at the feeding ports given the exact port excitation. Moreover, it calculates the current distribution and electric field maps wherever specified. The recent upgraded parallelized version of TOPICA permits the analysis of large and complex antenna structures in a reasonable simulation time (less than one day). A detailed analysis of the performances of two ITER ICRF antenna geometries has been carried out, underlining the strong dependence and the asymmetries of the antenna input parameters due to plasma conditions. An optimization of the antenna dimensions has also been accomplished. Electric current distribution on conductors in the vacuum region and electric field distribution in the vacuum region and at the interface with plasma edge have been calculated as well. The analysis shows the strong capabilities of the parallelized TOPICA code as a predictive tool and its usefulness to ICRF antennas final design.

The paper reports on ongoing benchmark numerical simulations of antenna input impedance parameters in the ion cyclotron range of frequencies with different coupling codes: CST Microwave Studio, TOPICA and ANTITER 2. In particular we study the validity of the approximation of a magnetized plasma slab by a dielectric medium of suitably chosen permittivity. Different antenna models are considered: a single‐strap antenna, a 4‐strap antenna and the 24‐strap ITER antenna array. Whilst the diagonal impedances are mostly in good agreement, some differences between the mutual terms predicted by Microwave Studio and TOPICA have yet to be resolved.

A simple and effective method to avoid the truncation error in antenna near-field measurements is presented. The method can be applied to planar or cylindrical near-field setups, whenever it is possible to vary the distance between the antenna under test and the probe during the scanning procedure.

Great social concern has risen about the potential health hazard of living near a cellular telephony base-station antenna, and certain technical questions have been posed on the appropriate way to measure exposure in its vicinity. In this paper, standard spherical near–near field transformation is proposed to obtain the electromagnetic field close to the antenna in free space conditions. The field obtained in this way allows to define an exclusion zone from the exposure compliance point of view, but also makes possible to bound the error committed by standard field measurement procedures. Furthermore, the visualization of the electromagnetic field in the proximity of the antenna in free space conditions, allows to define clearance templates that have to be met in the siting of the antenna in complex environments in order not to obstruct its main beam.

A number of interferometric methods applied to array diagnosis are investigated. Numerical and experimental results show that interferometric algorithms which are not affected by spectrum overlapping problems allow a more accurate evaluation of the excitation coefficients.