The main goal of the masters project is to design a dual band antenna for receiving DVB-T signal in the area of the city of Brno. The antenna will be designed and detaily adjusted for receiving multiplex 1 and 3, exactly for frequencies of 538 MHz and 778 MHz. The designed antenna will be deeply tested in 4nec2 and CST Microwave Studio programs.

Although small spacecraft are small in size and light in weight compared to the conventional satellites, they can offer lots of possibilities for space exploration, scientific observation, data collection and telecommunication. Also, they cost a lot less money than the conventional satellites, and the scientific missions can be planned in a relatively short period of time by using the COTS (Commercial Off-The-Shelf) materials. However, there is a big challenge for the small spacecraft that is the limited surface area of the small spacecraft and the outnumbered components to be mounted on the surface of the small spacecraft. The most obvious one is that the competition for the limited real estate between the antenna and solar cells. UAVs, also known as drones, have become so popular that it is not only used for military and scientific applications, but also they are available for recreational use for ordinary people. Although they are getting smaller in size so that one can put them in his pocket or on his palm, they are becoming multifunctional, which requires more sensors to be mounted on the surface of the drone to achieve its multifunctionality. For example, a recreational drone can not only take pictures and videos, but also it can transmit the picture or video in real time to the operator, which needs a camera to take the picture or videos and needs an antenna to transmit the recorded data to the operator. This requires that the limited surface area needs to be efficiently used in order to accommodate the multiple needed components. This thesis presented a faster, better and cheaper way of inkjet printing conformal antennas on the cover glass of the solar cells of the small spacecraft or on the wing or other parts of the UAV body to integrate the antenna with the solar panels of the CubeSats or with or directly printing the antenna on the UAV body to efficiently use the limited real estate. Several meshed and solid patch antennas printed on a space certified AF32 glass substrate using the printing procedure outlined in this thesis and measured to verify the effectiveness of the inkjet printing procedures. A high gain reflectarray with optical transparency of 95% was inkjet printed on space certified AF32 glass and BOROFLOAT glass and measured to verify the antenna performance and solar panel efficiency. Measurement results showed that the inkjet printed reflectarray integrated on top of the solar panel has a gain of 21.5 dB. The solar panel efficiency was dropped by around 6% due to the inkjet printed reflectarray on glass. A simple conformal dual-band antenna for UAV application was designed with ANSYS HFSS and fabricated in the lab using a foam substrate. The measured antenna performances agreed well with the simulation results. This dual-band antenna also can be inkjet printed directly on the wing or other parts of the UAVs using the printing techniques discussed in this thesis.

Yes / This paper describes a hybrid computational method which efficiently models the interaction between a small antenna placed in proximity with the human body. Results for several test cases of placed in different locations on the body are presented and discussed. The near and far fields were incorporated into the study to provide a full understanding of the impact on human tissue. The cumulative distribution function of the radiation efficiency and absorbed power is also provided. The antennas are assumed to be operating over the 2.4 GHz and 5.2 GHz WLAN frequencies.

Yes / A four-element compact dual-band patch antenna having a common ground plane operating at 28/38 GHz is proposed for millimeter-wave communication systems in this paper. The multiple-input-multiple-output (MIMO) antenna geometry consists of a slotted ellipse enclosed within a hollow circle which is orthogonally rotated with a connected partial ground at the back. The overall size of the four elements MIMO antenna is 2.24λ × 2.24λ (at 27.12 GHz). The prototype of four-element MIMO resonator is designed and printed using Rogers RT Duroid 5880 with εr = 2.2 and loss tangent = 0.0009 and having a thickness of 0.8 mm. It covers dual-band having a fractional bandwidth of 15.7% (27.12–31.34 GHz) and 4.2% (37.21–38.81 GHz) for millimeter-wave applications with a gain of more than 4 dBi at both bands. The proposed antenna analysis in terms of MIMO diversity parameters (Envelope Correlation Coefficient (ECC) and Diversity Gain (DG)) is also carried out. The experimental result in terms of reflection coefficient, radiation pattern, gain and MIMO diversity parameter correlates very well with the simulated ones that show the potential of the proposed design for MIMO applications at millimeter-wave frequencies. / This work is supported by the Moore4Medical Project, funded within ECSEL JU in collaboration with the EU H2020 Framework Programme (H2020/2014-2020) under Grant Agreement H2020-ECSEL-2019-IA-876190, and Fundação para a Ciência e Tecnologia (ECSEL/0006/2019). This work is also funded by the FCT/MEC through national funds and when applicable co-financed by the ERDF, under the PT2020 Partnership Agreement under the UID/EEA/50008/2020 Project.

This project describesa microwave antenna for GNSS and low noise amplifier. Mikrostrip antenna is a modern type of antenna. This mikrostrip antenna is Dual – band antenna with circual polarization. The thesis describes how to make anantenna, what a circular polarization is, whata patch antenna is and what GNSS is. Low noise amplifier amplifies the antenna output signal.

This master’s thesis is focused on the properties and types of helical antennas. The helical antenna work in the different modes. These modes are described in this thesis. There are also discussed possibility for design a dual-band helical antennas. The main aim of this work is the selection of a suitable solution and design a dual-band helical antenna for the WiFi band working at resonance frequencies of 2,4 GHz and 5 GHz. The simulation of this antenna was performed in the program CST Microwave studio.

No description available.

This master’s thesis introduces to the reader with a modern antenna type the microstrip patch antennas. The most common types of microstrip antennas and their parameters and feeding methods are introduced in the theoretical section of this master’s thesis. This section deals with the circularly polarized microstrip antennas. Design of an active dual-band circularly polarized antenna for global navigation satellite application in the AWR Microwave Office is presented in the practical section. The proposed single-fed dual-band circularly polarized design is achieved using two stacked square microstrip patches. The antenna operates at the L1 + E1 and L5 + E5a frequency bands. Antenna preamplifier consists of a low-noise transistor and a dual-band band-pass filter. The thesis describes realization and measurement results of the dual-band antenna performance in the anechoic chamber. Measured results of the preamplifier performance are presented.

This master’s thesis deals with user influence on miniature antennas in mobile application. Electrically small antennas including fundamental performance properties and limitations are introduced in the theoretical section of this thesis. This section also deals with microstrip antennas and their common types. The accent is on PIFA antennas, their typical constructions and methods of miniaturization. In the practical section, dual-band PIFA antenna for operation at frequencies of systems GSM900 and GSM1800 is designed with the assistance of electromagnetic field simulator CST Microwave Studio. On this type of antenna, the user influence on impedance matching and radiation pattern in data mode (the user is typing message or browsing with the phone) is investigated. For this purpose the hand phantom, corresponding to author’s right hand, was made from agar based material. For typical position of human hand is designed matching network, which eliminate the user influence and ensure correct function of antenna.

Un développement technologique rapide dans le domaine de télécommunication, qu'il s'agisse de la téléphonie mobile, des réseaux sans fils, de la télévision par satellites, ou des applications radar (civiles ou militaires)...etc. est observé. Cet essor considérable a engendré d'énormes besoins et entraîne une évolution technologique majeure au niveau des antennes. Ces dernières doivent faire face aux différentes exigences, à savoir l'augmentation du gain, l'élargissement de la bande passante… et aux différents problèmes existant, à savoir le coût, l’encombrement…etc. Notre objectif est donc de concevoir des topologies d’antennes simples, à faible encombrement et à gain relativement élevé avec un fonctionnement multibande et/ou ultra large bande. Pour cela nous nous sommes orientés vers des antennes à résonateur diélectrique (ARD) dans les bandes UHF et SHF. Récemment, elles ont fait l’objet de plusieurs recherches et ont acquis un grand intérêt du monde académique et industriel. Les ARDs, par leurs simples et diverses géométries, peuvent être alimentées par différentes usuelles techniques. En outre, leurs tailles peuvent être plus petites que leurs homologues à savoir les antennes imprimées. Une première partie de ce travail s’est concentré sur l’étude des ARDs de forme cylindrique, puis une validation de l’outil de simulation par comparaison avec la mesure. En vue d’une utilisation multistandards, d’un élargissement des bandes de fonctionnement ou d’une modification de la fréquence, une seconde partie a été consacrée à l’étude de nouvelles topologies de résonateurs basées sur un empilement vertical et radial de deux cylindres, une topologie en multicouche et en anneau. Les résultats obtenus trouvent leurs applications dans le GSM900-DSC1800, UMTS, WIFI… / A fast technological development in the telecommunications domain, as mobile telephony, wireless networks, TV over Satellite, Radar Applications (civil or military)…etc, is observed. This considerable growth has led to enormous needs and caused a major technological evolution in antennas. These have to face different needs such as gain improvement, bandwidth enlargement, and different existing problems, such as cost and overcrowding…etc. Though, our goal is to design antenna topologies that are simple, having Low overcrowding and relatively with high gain operating in multiband and/or ultra large. To achieve this we headed to Dielectric Resonator Antennas (DRA) in UHF and SHF bands. Recently they have been the subject of several studies and have gained great interest from both academic and industrial sectors. Due to their diverse and simple geometries, they can be fed with different usual techniques. Furthermore, they can be smaller than patch antennas. The first part of this work has focused on the study of cylindrical DRAs, and then a validation of the simulating tool has been done after comparison with measurement results. For a multi-standard utilization, enlargement antennas’ operating bands, to have bi-band behaviour, get a modification of the resonant frequency and also a reduction of the overcrowding, the second part is dedicated to the study of new resonator topologies based on a vertical and radial stack of two cylinders, and then a multilayer and ring topologies. The obtained results found their applications in GSM900-DCS1800-UMTS-WiFi…