<p>In wireless communication there is commonly much unnecessary communication made in directions not pointing towards the recipient. Normally omni directional antennas are being used which sends the same amount of energy in all directions equally. This waste of energy reduces the lifetime of battery powered units and causes more traffic collisions than necessary. One way of minimizing this wasted energy and traffic collisions, is to use another type of antenna called “smart antenna”. These antennas can use selectable radiation patterns depending on the situation and thus drastically minimize the unnecessary energy waste. Smart antennas also provide the ability to sense the direction of incoming signals which is favorable for physical layout mapping such as orientation.</p><p>This thesis presents the prototyping of a new type of smart antenna called the SPIDA smart antenna. This antenna is a cheap to produce smart antenna designed for the 2.4 GHz frequency band. The SPIDA smart antenna can use sixty-four different signal patterns with the control of six separate directional modes, amongst these patterns are six single direction patterns, an omni-directional signal pattern and fifty-six combi-direction patterns. The thesis presents complete building instructions, evaluation data and functional drivers for the SPIDA smart antenna.</p>

In wireless communication there is commonly much unnecessary communication made in directions not pointing towards the recipient. Normally omni directional antennas are being used which sends the same amount of energy in all directions equally. This waste of energy reduces the lifetime of battery powered units and causes more traffic collisions than necessary. One way of minimizing this wasted energy and traffic collisions, is to use another type of antenna called “smart antenna”. These antennas can use selectable radiation patterns depending on the situation and thus drastically minimize the unnecessary energy waste. Smart antennas also provide the ability to sense the direction of incoming signals which is favorable for physical layout mapping such as orientation. This thesis presents the prototyping of a new type of smart antenna called the SPIDA smart antenna. This antenna is a cheap to produce smart antenna designed for the 2.4 GHz frequency band. The SPIDA smart antenna can use sixty-four different signal patterns with the control of six separate directional modes, amongst these patterns are six single direction patterns, an omni-directional signal pattern and fifty-six combi-direction patterns. The thesis presents complete building instructions, evaluation data and functional drivers for the SPIDA smart antenna.

<p>In wireless communication there is commonly much unnecessarycommunication made in directions not pointing towards the recipient. Normallyomni directional antennas are being used which sends the same amount ofenergy in all directions equally. This waste of energy reduces the lifetime ofbattery powered units and causes more traffic collisions than necessary. Oneway of minimizing this wasted energy and traffic collisions, is to use anothertype of antenna called “smart antenna”. These antennas can use selectableradiation patterns depending on the situation and thus drastically minimize theunnecessary energy waste. Smart antennas also provide the ability to sense thedirection of incoming signals which is favorable for physical layout mappingsuch as orientation.This thesis presents the prototyping of a new type of smart antenna called theSPIDA smart antenna. This antenna is a cheap to produce smart antennadesigned for the 2.4 GHz frequency band. The SPIDA smart antenna can usesixty-four different signal patterns with the control of six separate directionalmodes, amongst these patterns are six single direction patterns, an omnidirectionalsignal pattern and fifty-six combi-direction patterns. The thesispresents complete building instructions, evaluation data and functional driversfor the SPIDA smart antenna.</p>

In wireless communication there is commonly much unnecessarycommunication made in directions not pointing towards the recipient. Normallyomni directional antennas are being used which sends the same amount ofenergy in all directions equally. This waste of energy reduces the lifetime ofbattery powered units and causes more traffic collisions than necessary. Oneway of minimizing this wasted energy and traffic collisions, is to use anothertype of antenna called “smart antenna”. These antennas can use selectableradiation patterns depending on the situation and thus drastically minimize theunnecessary energy waste. Smart antennas also provide the ability to sense thedirection of incoming signals which is favorable for physical layout mappingsuch as orientation.This thesis presents the prototyping of a new type of smart antenna called theSPIDA smart antenna. This antenna is a cheap to produce smart antennadesigned for the 2.4 GHz frequency band. The SPIDA smart antenna can usesixty-four different signal patterns with the control of six separate directionalmodes, amongst these patterns are six single direction patterns, an omnidirectionalsignal pattern and fifty-six combi-direction patterns. The thesispresents complete building instructions, evaluation data and functional driversfor the SPIDA smart antenna.

Les travaux de cette thèse s’intéressent à un nouveau concept d’antenne reconfigurable offrant un bon compromis entre performances, complexité et coût. Ce concept, qualifié d’hybride, vise à combiner les avantages des réseaux d’antennes lacunaires et des antennes à éléments parasites. Cette hybridation est une alternative à la complexité des réseaux d’antennes conventionnels pour répondre aux exigences d’une architecture modulaire, générique et reconfigurable. L’intérêt majeur de ce concept est de proposer une architecture d’antenne permettant de réduire la complexité du circuit de formation des faisceaux (par la réduction du nombre d’éléments rayonnants à alimenter) tout en adressant les problématiques d’adaptation (TOS actif) des éléments excités. Ceci est permis grâce à la présence d’éléments parasites qui permettent de gérer la diffusion des couplages sur l’antenne. Cette thèse décrit le principe du concept hybride et propose une évaluation de ses potentialités. Par la suite, une définition des éléments à mettre en œuvre pour réaliser une preuve de concept est effectuée, en mettant l’accent sur l’importance de la caractérisation expérimentale. Les performances d’un prototype d’antenne hybride reconfigurable sont ensuite présentées afin de valider les développements et conclure sur cette solution innovante. / The work of this thesis aims to investigate a new concept of reconfigurable antenna allowing a good trade-off between performances, complexity and cost. This concept is called ‘hybrid’ because it is based on the capabilities of thinned arrays and parasitic element antennas. It is an alternative to classical antenna arrays and their complexity. The proposed concept has a modular architecture, and a good versatility for reconfigurable beams. The main advantage of this hybrid antenna is the simplicity of its beam formation network (BFN) which requires only a few number of excited elements. The antenna uses parasitic elements to manage the effects of couplings between the electromagnetic access. The problematic of active VSWR is also solved at the antenna level, avoiding the use of additional components in the BFN. This work details the principle of the reconfigurable hybrid antenna concept. The potentialities are evaluated. The elements required to realize a proof of concept are then defined, using a dedicated experimental setup. A prototype is manufactured and the performances have been checked to validate this innovative concept.

Multiple-Input-Multiple-Output (MIMO) antenna technology refers to an antenna with multiple radiators at both transmitter and receiver ends. It is designed to increase the data rate in wireless communication systems by achieving multiple channels occupying the same bandwidth in a multipath environment. The main drawback associated with this technology is the coupling between the radiating elements. A MIMO antenna system merely acts as an antenna array if the coupling between the radiating elements is high. For this reason, strong decoupling between the radiating elements should be achieved, in order to utilize the benefits of MIMO technology. The main objectives of this thesis are to investigate and implement several printed MIMO antenna geometries with integrated decoupling approaches for WLAN, WiMAX, and 5G applications. The characteristics of MIMO antenna performance have been reported in terms of scattering parameters, envelope correlation coefficient (ECC), total active reflection coefficient (TARC), channel capacity loss (CCL), diversity gain (DG), antenna efficiency, antenna peak gain and antenna radiation patterns. Three new 2×2 MIMO array antennas are proposed, covering dual and multiple spectrum bandwidths for WLAN (2.4/5.2/5.8 GHz) and WiMAX (3.5 GHz) applications. These designs employ a combination of DGS and neutralization line methods to reduce the coupling caused by the surface current in the ground plane and between the radiating antenna elements. The minimum achieved isolation between the MIMO antennas is found to be better than 15 dB and in some bands exceeds 30 dB. The matching impedance is improved and the correlation coefficient values achieved for all three antennas are very low. In addition, the diversity gains over all spectrum bands are very close to the ideal value (DG = 10 dB). The forth proposed MIMO antenna is a compact dual-band MIMO antenna operating at WLAN bands (2.4/5.2/5.8 GHz). The antenna structure consists of two concentric double square rings radiating elements printed symmetrically. A new method is applied which combines the defected ground structure (DGS) decoupling method with five parasitic elements to reduce the coupling between the radiating antennas in the two required bands. A metamaterial-based isolation enhancement structure is investigated in the fifth proposed MIMO antenna design. This MIMO antenna consists of two dual-band arc-shaped radiating elements working in WLAN and Sub-6 GHz 5th generation (5G) bands. The antenna placement and orientation decoupling method is applied to improve the isolation in the second band while four split-ring resonators (SRRs) are added between the radiating elements to enhance the isolation in the first band. All the designs presented in this thesis have been fabricated and measured, with the simulated and measured results agreeing well in most cases. / Higher Committee for Education Development in Iraq (HCED)