The fifth generation (5G) has developed a lot of interest, and there have been many reported initiatives in both industry and academics. Multiple-input-multiple-output (MIMO) is the most promising wireless access technique for next-generation networks in terms of spectral and energy efficiency (MIMO). In 4G systems, 2-Element MIMO antennas are already used, while 5G mobile terminals for smartphone hand-held devices are projected to use a bigger number of elements. The placement of many antennas in the restricted space of a smartphone PCB is one of the most critical challenges. As a result, for sub-6 GHz 5G applications, a new design technique based on dual-polarised antenna resonators for 6-Element, 8-Element MIMO configuration is proposed. The proposed MIMO design could improve the smartphone antenna system's chan-nel capacity, diversity function, and multiplexing gain, making it appropriate for 5G applica-tions. For distinct prospective bands of the sub-6 GHz spectrum, such as 2.6, 3.6, and 5.8 GHz, different types of novel and compact diversity MIMO antennas using Patch, Slot, and Planar inverted F antenna (PIFA) resonators are examined. Unlike previously reported MIMO antennas, the proposed designs provide full radiation coverage and polarisation diversity, as well as adequate gain and efficiency values to support several mainboard sides. Apart from sub-6 GHz frequencies, 5G devices are projected to support the centimetre/milli-metre wave spectrum's higher bands. To create linear phased arrays, small antennas can be placed at various locations on a smartphone board. For 5G smartphones, we propose novel linear phased arrays with tiny parts like Dipole and Quasi-Yagi resonators. In comparison to previously published designs, the suggested phased arrays have desirable qualities such as compact size, wide beam-steering, broad bandwidth, end-fire radiation, high gain, and efficiency. With a reduced mutual coupling function, the suggested 5G antennas can provide single-band, multi-band, and broad-band characteristics. Both models and measurements are used to an-alyse the fundamental features of 5G antennas, and good agreement is found. Furthermore, in the presence of the user and the smartphone components, good features are seen due to the small size and superior arrangement of elements. Because of these benefits, the sug-gested antennas are well-suited for usage in 5G smartphone applications.

The main objectives of this research are to investigate and design low profile antennas for mobile handsets applications using the balanced concept. These antennas are considered to cover a wide range of wireless standards such as: DCS (1710-1880 MHz), PCS (1850-1990 MHz), UMTS (1920-2170 MHz), WLAN (2400-2500 MHz and 5000-5800 MHz) and UWB frequency bands. Various antennas are implemented based on built-in planar dipole with a folded arm structure. The performance of several designed antennas in terms of input return loss, radiation patterns, radiation efficiency and power gain are presented and several remarkable results are obtained. The measurements confirm the theoretical design concept and show reasonable agreement with computations. The stability performance of the proposed antenna is also evaluated by analysing the current distribution on the mobile phone ground plane. The specific absorption rate (SAR) performance of the antenna is also studied experimentally by measuring antenna near field exposure. The measurement results are correlated with the calculated ones. A new dual-band balanced antenna using coplanar waveguide structure is also proposed, discussed and tested; this is intended to eliminate the balanced feed network. The predicted and measured results show good agreement, confirming good impedance bandwidth characteristics and excellent dual-band performance. In addition, a hybrid method to model the human body interaction with a dual band balanced antenna structure covering the 2.4 GHz and 5.2 GHz bands is presented. Results for several test cases of antenna locations on the body are presented and discussed. The near and far fields were incorporated to provide a full understanding of the impact on human tissue. The cumulative distribution function of the radiation efficiency and absorbed power are also evaluated.

Actuellement, les fantassins de l'armée française sont équipés d'un système de radiocommunication quand ils sont en intervention sur le terrain. L'antenne utilisée pour émettre et recevoir les signaux radiofréquences (RF) est du type monopole appelée antenne fouet placée parallèlement au corps du fantassin au niveau de la clavicule gauche. Cependant, l'antenne fouet perturbe le champ de vision des fantassins surtout lorsqu'ils tournent leur tête vers la gauche. De plus, la position de l'antenne fouet gêne les fantassins gauchers lorsqu'ils sont en position de tir. Enfin, l'antenne fouet rajoute un poids supplémentaire. Il est évident alors que l'intégration de l'antenne dans les gilets militaires permet de mieux répondre aux besoins des fantassins notamment en termes d'ergonomie. Cependant une telle intégration doit aussi répondre aux besoins d'efficacité de rayonnement, de couverture spatiale et de protection du corps vis-à-vis du rayonnement de l'antenne. De plus les contraintes liées à la technologie de réalisation doivent être prises en compte. La thèse est focalisée sur la conception et la caractérisation d'antennes intégrées aux gilets militaires. Le travail de recherche s'est fait dans le cadre du projet collaboratif GIANTE, soutenu par le dispositif DGA-RAPID, associant les partenaires complémentaires : SAFRAN Sagem, le laboratoire LCIS et ARDEJE. Le travail inclue tous les développements relevant de la conception électromagnétique avec la prise en compte du corps humain et le suivi de la réalisation par impression numérique assurée par ARDEJE qui possède la technologique jet d'encre. Il concerne également la caractérisation RF (adaptation, bande passante, diagramme de rayonnement) des antennes avec un banc expérimental adapté et l'évaluation des performances globales des antennes en environnements fonctionnels (milieu dégagé, milieu urbain, forêt). / Nowadays, the infantrymen of French army are equipped with a radio communication system when they are in field action. The antenna used to transmit and receive Radiofrequency (RF) signals is a monopole antenna called as whip antenna. It is placed parallel to the infantryman's body at the left clavicle. However, the whip antenna disrupts the field of view of infantrymen particularly when they turn their head to the left. Moreover, the position of the whip antenna bothers the left-handed infantrymen when they are in fire position. Finally, the whip antenna adds an additional weight to the infantrymen. Thus, it is obvious that the integration of the antenna into the military jackets allows to better meet the needs of infantrymen particularly in terms of ergonomy. However such an integration must also meet the needs in terms of radiation efficiency, spatial coverage and protection of the body against the antenna radiation. Moreover, the constraints of realization technology must be taken into account. The thesis is focused on the design and characterization of integrated antennas into military jackets. The research work is performed within the collaborative project GIANTE, supported by the DGA-RAPID frameproject, associating complementary partners: SAFRAN Sagem, laboratory LCIS, and ARDEJE. The work includes all the electromagnetic studies required by the environmental constraints by taking account the human body. It also includes the follow-up of the realizations made by ARDEJE that masters inkjet printing technologies. The RF characterization (impedance matching, bandwidth, radiation pattern) of antennas with a suitable bench test and the evaluation of global performances of antennas in functional environments (environment free from obstructions, urban areas, forest) are also part of the thesis work.

Actuellement, les fantassins de l'armée française sont équipés d'un système de radiocommunication quand ils sont en intervention sur le terrain. L'antenne utilisée pour émettre et recevoir les signaux radiofréquences (RF) est du type monopole appelée antenne fouet placée parallèlement au corps du fantassin au niveau de la clavicule gauche. Cependant, l'antenne fouet perturbe le champ de vision des fantassins surtout lorsqu'ils tournent leur tête vers la gauche. De plus, la position de l'antenne fouet gêne les fantassins gauchers lorsqu'ils sont en position de tir. Enfin, l'antenne fouet rajoute un poids supplémentaire. Il est évident alors que l'intégration de l'antenne dans les gilets militaires permet de mieux répondre aux besoins des fantassins notamment en termes d'ergonomie. Cependant une telle intégration doit aussi répondre aux besoins d'efficacité de rayonnement, de couverture spatiale et de protection du corps vis-à-vis du rayonnement de l'antenne. De plus les contraintes liées à la technologie de réalisation doivent être prises en compte. La thèse est focalisée sur la conception et la caractérisation d'antennes intégrées aux gilets militaires. Le travail de recherche s'est fait dans le cadre du projet collaboratif GIANTE, soutenu par le dispositif DGA-RAPID, associant les partenaires complémentaires : SAFRAN Sagem, le laboratoire LCIS et ARDEJE. Le travail inclue tous les développements relevant de la conception électromagnétique avec la prise en compte du corps humain et le suivi de la réalisation par impression numérique assurée par ARDEJE qui possède la technologique jet d'encre. Il concerne également la caractérisation RF (adaptation, bande passante, diagramme de rayonnement) des antennes avec un banc expérimental adapté et l'évaluation des performances globales des antennes en environnements fonctionnels (milieu dégagé, milieu urbain, forêt). / Nowadays, the infantrymen of French army are equipped with a radio communication system when they are in field action. The antenna used to transmit and receive Radiofrequency (RF) signals is a monopole antenna called as whip antenna. It is placed parallel to the infantryman's body at the left clavicle. However, the whip antenna disrupts the field of view of infantrymen particularly when they turn their head to the left. Moreover, the position of the whip antenna bothers the left-handed infantrymen when they are in fire position. Finally, the whip antenna adds an additional weight to the infantrymen. Thus, it is obvious that the integration of the antenna into the military jackets allows to better meet the needs of infantrymen particularly in terms of ergonomy. However such an integration must also meet the needs in terms of radiation efficiency, spatial coverage and protection of the body against the antenna radiation. Moreover, the constraints of realization technology must be taken into account. The thesis is focused on the design and characterization of integrated antennas into military jackets. The research work is performed within the collaborative project GIANTE, supported by the DGA-RAPID frameproject, associating complementary partners: SAFRAN Sagem, laboratory LCIS, and ARDEJE. The work includes all the electromagnetic studies required by the environmental constraints by taking account the human body. It also includes the follow-up of the realizations made by ARDEJE that masters inkjet printing technologies. The RF characterization (impedance matching, bandwidth, radiation pattern) of antennas with a suitable bench test and the evaluation of global performances of antennas in functional environments (environment free from obstructions, urban areas, forest) are also part of the thesis work.

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