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Four Channel Active Antenna Switch for UHF Band Satellite Reception
Kubeš, Václav ; Povalač, Aleš (referee) ; Urbanec, Tomáš (advisor)
The goal of this bachelor’s thesis is to design and implement a complex device known as an antenna switch, which allows receiving a high-frequency signal in the UHF band from satellites via one of five directional antennas at a given time. With a suitable choice of antennas, this device is to be an alternative to motorized directional antennas used for satellite signal reception. The device is able to determine the correct antenna switching order using satellite position data. It is also able to filter and amplify the selected high-frequency signal for further transmission via coaxial cable to the receiver. The switch is controlled by an ATmega328PB microcontroller, which ensures the control of the integrated switching element itself, simple current and temperature diagnostics, and bidirectional communication with the control computer using the UART protocol over the LIN bus physical layer. The whole device consists of an external unit, which is to be placed near the antennas and ensures the switching itself, and an internal unit placed inside the building, which ensures the power supply and the distribution of diplexed signals. The user can display diagnostic data and control the external unit using a program with a graphical interface.
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Exploatation of VHF, UHF, SHF, and EHF frequency bands in civil & military aeronautic radars (handbook)
Jasimová, Rafah ; Šplíchal, Miroslav (referee) ; Vosecký, Slavomír (advisor)
VHF, UHF, SHF, EHF, radar, wave propagation, electromagnetic wave, active radiolocators, passive radar system
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UHF band front-end of quadrature receiver
Tiller, Jakub ; Špaček, Jiří (referee) ; Kasal, Miroslav (advisor)
The object of this master's thessis is study and description of RF circuits, which are used for receiveing. This work is also aimed to design this circuits and their simulation in Ansoft Designer software. Focus is placed to the standard parameters of receiving technology. The description of amplifier design is presented in this work. Parameters of this amplifier are optimalized to low noise figure. Frequency multiplier designs are included in this project.
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Methods for localization of pulsed broadband signal source
Machala, Petr ; Hadinec, Michal (referee) ; Drexler, Petr (advisor)
The topic of this barchelor’s thesis is the analysis of problems regarding localization of partial discharges (PD) and related PD recording, processing and interpretation in time and frequency domain. In majority of cases the occurrence of partial discharges refers to a certain defect in the measured device, therefore in practice (eg large equipment such as oil transformers) it appears to be very useful and economical to determine the exact position, where PDs are formed. To address these complex issues, it is necessary to design the entire measuring chain from PD detection to measured data processing and localization itself. In terms of data processing and PD localization many different localization and detection methods can be applied, some of them are presented in this documentation. These methods are gradually studied, implemented and afterwards tested using the input data of the experiment.
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Experimental tags for UHF RFID applications
Pacholík, Vladimír ; Holek, Karel (referee) ; Lukeš, Zbyněk (advisor)
This thesis deals with RFID tags design. It comprises an overview of the RDIF technology while focusing upon the passive tags in UHF band. The CST Microwave studio software has been used for draft simulations. The resulting tags have been subjected to parameter measuring – the reflection coefficient, the minimum capacity needed to switch on the tag, the maximum reading distance. The influence of the proximity of metal objects and other materials has also been examined.
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Identification and authentication technologies
Miklánková, Zuzana ; Lieskovan, Tomáš (referee) ; Dzurenda, Petr (advisor)
The bachelor thesis deals with the analysis of currently available RFID technologies and smart cards. Summarized are types of identification and authentication radio or contact systems. The practical part compares measured RFID functional outputs and describes the implementation of multi-attribute authentication system using RFID technology and smart cards. For example, the authentication system can provide employees with access to the building, necessarily demonstrated by both the smart card and RFID tags.The system also includes user privacy elements, where identity of the user cannot be detected by captured communication.
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Algorithms for analysis and processing of RFID signals in FPGA
Harvánek, Michal ; Kováč, Michal (referee) ; Derbek, Vojtěch (advisor)
The result of this thesis is the architecture design for a software-defined radio, which is used to analyze the signal emitted by RFID tags in real time. The aim of this analysis is to measure the frequency characteristics of the RFID tag. The main means for achieving the objective of optimizing signal processing algorithms and reduce the time needed to control the hardware compared to the classical concept of SW radio USRP. It is described how to obtain and display digitally sampled signals using a graphical programming language LabVIEW and subsequent processing of these data in MATLAB. Further described is the skeleton of the proposed solution.
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Dual-band directional antenna for receiving DVB-T signal
Matyáš, Petr ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
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.
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Design of meander RFID antenna
Horák, David ; Šebesta, Jiří (referee) ; Lukeš, Zbyněk (advisor)
This thesis deals with RFID tags. In the first part of the thesis, the general overviews of the present-day RFID systems are presented. This part of the thesis is focused on the passive back-scatter UHF tags and the advantages of their application in supply chain usage. Subsequently, the electromagnetic simulators CST Microwave Studio and IE3D Zeland are described. These simulators were used to design loaded meander antennas. The antennas were designed for different materials and frequency bands of 867 MHz and 2.4 GHz. The designed antennas were made without as well as with the reflector which allows using the antennas in the vicinity of metals. Produced antennas were experimentally tested in the company METRA Blansko Inc, where one of the most significant characteristics of passive RFID tags – the read range was observed.
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