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Antennas for energy transmission along the car roof
Škoda, Adam ; Hebelka, Vladimír (referee) ; Vélim, Jan (advisor)
The presented master’s thesis deals with antennas transmitting energy along conductive materials. Surface waves are used for energy transmission. According to its properties, the horn antenna was chosen for the problem solution. This thesis includes the theoretical analysis of surface waves, waveguides and horn antennas. The concept of antennas includes the comparison of two different materials and two different frequencies. From the set of 8GHz antennas, the structure of two antennas where one wearing the other was chosen as the most suitable. The FoamClad material was also selected due to achievement of better parameters and properties then material CuClad. This structure was designed by two identical horn antennas where the energy between them is transmitted via slot. The suitable feeding and parallel plates were designed, and further the current structure was modified to SIW structure. The designed antenna was manufactured and its properties were measured for further comparison with simulation results. Furthermore, achieved differences between simulated and real antenna are discussed.
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Textil Integrated Horn Antenna
Jaroš, Ondřej ; Pokorný, Michal (referee) ; Vélim, Jan (advisor)
This diploma thesis describes the corrugated substrate integrated horn antenna designed to surface wave’s excitation in the UWB band groups 3, 4, 5 and 6 (6 – 10 GHz). The antenna is integrated into 3,4 mm thick textile with relative permittivity r = 1,195. The coaxial cable is connected via the SMA connector that is attached to the aluminum bracket. From the microstrip line transition the corrugated substrate integrated waveguide is excited. Two strip lines are placed in front of the aperture for improvement of the impedance matching. The directivity of the antenna is 12 dBi at 8 GHz. At the same frequency, the antenna efficiency is 70%.
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Electrical properties of anisotropic dielectric material
Příkazský, David ; Štumpf, Martin (referee) ; Vélim, Jan (advisor)
This work is focused on finding the dielectric properties of unknown material. Especially those we affect the behavior of electrical energy in the material, this feature describes parameter permittivity of material. In this work will be used multiple methods to determine values of permittivity. These measured values of different measurement methods will subsequently compared to each other. Then be discussed in the conclusion reached values and comparing used measurement methods.
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Textile electrodes in ECG measurement
Kocum, Filip ; Vélim, Jan (referee) ; Cupal, Miroslav (advisor)
This semestral thesis deals with the issue of electrocardiogram measurement and heart rate detection using textile electrodes placed on the body. One of the main tasks was to design the possibilities of attaching the sensors to the body in order to ensure the best possible adhesion to the skin. The work focuses on the design of suitable electrode placement in terms of functionality and stability of measurement. Furthermore, the work focuses on the comparison of textile and Ag / AgCl electrodes. The last point was the design of a preamplifier for measurement and its subsequent implementation.
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Monitoring system for small power plants
Vélim, Jan ; Šebesta, Jiří (referee) ; Fedra, Zbyněk (advisor)
he paper describes the design of a monitoring system for small power plants. The rotational speed of the mechanical drive of the generator is measured with an ATtiny2313 microcontroller which evaluates the speed and decides whether to connect or disconnect the coupling driver. Behind the generator voltage and current values are measured which the ATmeta8 microcontroller converts into digital data and sends through a serial link to the main unit. The data are processed in the main unit, displayed on a graphic LCD screen and saved in an external EEPROM memory.
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Sound source localization
Vélim, Jan ; Brejl, Milan (referee) ; Fedra, Zbyněk (advisor)
The paper discusses a possibility of localization of a sound source inside a wooden beam. The method is based on measuring signals from two microphones, assuming the sound source lies between the microphones. The position of the sound source is calculated from the delay between the signals. The calculation of the delay is done by correlation of the signals in the frequency range. ARM architecture microcontroller is used to for the calculations.
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Textile electrodes in ECG measurement
Kocum, Filip ; Vélim, Jan (referee) ; Cupal, Miroslav (advisor)
This semestral thesis deals with the issue of electrocardiogram measurement and heart rate detection using textile electrodes placed on the body. One of the main tasks was to design the possibilities of attaching the sensors to the body in order to ensure the best possible adhesion to the skin. The work focuses on the design of suitable electrode placement in terms of functionality and stability of measurement. Furthermore, the work focuses on the comparison of textile and Ag / AgCl electrodes. The last point was the design of a preamplifier for measurement and its subsequent implementation.
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Relative Permittivity Measurement of 3D-textile
Vélim, Jan
The paper deals with the relative permittivity determination of the 3D-textile by a transmission line method (TLM). Measuring points are shifted to avoid inaccuracies caused by transitions between a coaxial cable and a microstrip line. A substrate where the microstrip line is designed is composed of three layers where one layer (3D-textile) has unknown permittivity. The relative permittivity of the 3D-textile is calculated from effective permittivity by a conformal mapping method.
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Textil Integrated Horn Antenna
Jaroš, Ondřej ; Pokorný, Michal (referee) ; Vélim, Jan (advisor)
This diploma thesis describes the corrugated substrate integrated horn antenna designed to surface wave’s excitation in the UWB band groups 3, 4, 5 and 6 (6 – 10 GHz). The antenna is integrated into 3,4 mm thick textile with relative permittivity r = 1,195. The coaxial cable is connected via the SMA connector that is attached to the aluminum bracket. From the microstrip line transition the corrugated substrate integrated waveguide is excited. Two strip lines are placed in front of the aperture for improvement of the impedance matching. The directivity of the antenna is 12 dBi at 8 GHz. At the same frequency, the antenna efficiency is 70%.
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Electrical properties of anisotropic dielectric material
Příkazský, David ; Štumpf, Martin (referee) ; Vélim, Jan (advisor)
This work is focused on finding the dielectric properties of unknown material. Especially those we affect the behavior of electrical energy in the material, this feature describes parameter permittivity of material. In this work will be used multiple methods to determine values of permittivity. These measured values of different measurement methods will subsequently compared to each other. Then be discussed in the conclusion reached values and comparing used measurement methods.
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