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Circuit Parameters Measurement by S parameters - Laboratory Experiment
Karniš, David ; Láčík, Jaroslav (referee) ; Urbanec, Tomáš (advisor)
Bachelor thesis describes a method of measuring impedance suitable for determining the properties of RF and microwave circuits. The main objective is to get acquainted with S parameters, method of measuring them with vector analysis and with equivalent circuits of passive elements. Further is discussed the issue of calibration and its parts. The following section describes the product design process, concluded by verification of measuring method and design.
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Periodic structure design for directivity enhancement of dielectric resonator antennas
Slavíček, Radek ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
The thesis deals with linearly polarized dielectric rectangular resonator antenna (DRA) operating in the basic mode TEy11 and higher order mode TEy131 at f0 = 10GHz surrounded by an electromagnetic band gap structure (EBG). The dielectric resonator antennas, the EBG structure were designed and a method of integration of both components was developed. The simulated results show a significant improvement of the radiation pattern in the E-plane radiation pattern (narrower main beam, lower level of side lobes, higher directivity) in comparison to a conventional DRA. This was verified by the TEy11 measurement.
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Coaxial probes for permittivity measurement of materials
Hub, Michal ; Urbanec, Tomáš (referee) ; Láčík, Jaroslav (advisor)
This bachelor thesis deals with the measuring complex permittivity of dielectrics using a coaxial probe with an open end in the frequency range of 300 MHz to 3 GHz. It is non-invasive measurement method can be widely used during the research of dielectrics. There are describe various approaches to coaxial probe design with respect to the expected size of complex permitivity in this work. Based on the studies available materials was proposed several probes with a focus on the method of measuring the low-loss dielectrics with help reflective plate. The probes were simulated to measure the reflectance in Design CST MICROWAVE STUDIO. Thereof can calculate the value of complex permittivity. This document lists only those probes that show good results and are prerequisite for the realization of practical measurement.
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Computer design of primary surveillance radar siting on airport
Krajíček, Antonín ; Urbanec, Tomáš (referee) ; Láčík, Jaroslav (advisor)
This semestral thesis deals with the application of the principles of site selection for surveillance radar designed for air traffic control in MATLAB. The thesis describes processing of maps and implementation of waypoints for air traffic control support. Another objective is to create a script for the calculation of the radar range by using the Radar Equation. The thesis concludes with addressing the issue of radio wave propagation over irregular terrain using the Split-step parabolic Equation.
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Measure antennas for GSM and Wi-Fi bands
Hurt, Martin ; Láčík, Jaroslav (referee) ; Mikulášek, Tomáš (advisor)
This bachelor’s thesis deals with the design of the measure antennas for GSM900, GSM1800 and Wi-Fi bands. In the first step, the work is focused on the design of two antennas for GSM900/GSM1800 bands and for Wi-Fi band in the CST Microwave Studio. In the second step, both antennas are fabricated and validated by the measurements. The measured results of the realized antennas are affected by asymmetric currents. In the work, the possibilities of the eliminating of the currents are discussed in detail.
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Dielectric resonator antenna
Štarha, Michal ; Pokorný, Michal (referee) ; Láčík, Jaroslav (advisor)
This project deals with using of dielectric resonators as antennas. There are discussed possibilities feed of these antennas, as feed probe, feed of microstrip line, aperture coupling, or coplanar waveguide. Then there is a simple example design dielectric resonator antenna and its modeling in CST Microwave Studio. The designed antenna is fabricated and measured.
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Modeling of planar coupling circuits
Valošek, Josef ; Puskely, Jan (referee) ; Láčík, Jaroslav (advisor)
This master’s thesis deals with modelling of the planar coupling circuits, namely type of the wideband couplers and the ultra-wideband couplers. The purpose of this thesis is an analysis, a synthesis, a numerical modelling and a fabrication (only chosen types) of the presented couplers. All of the couplers works on medium frequency f0 = 7 GHz with coupling C = 3 dB. Types of the substrate are Arlon 25N and Arlon AD600. EM simulator IE3D and circuit simulator in program Ansoft Designer are used for the numerical modelling. The realized wideband couplers were measuring by the vector analyzer Agilent E3864B.
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3D printed antenna with dielectric lens for free-space material characterization method
Horník, Milan ; Láčík, Jaroslav (referee) ; Kaděra, Petr (advisor)
This bachelor´s thesis deals with the free space setup for material permittivity characterization. The workplace includes two horn antennas, two dielectric lenses and sample holder. The work deals with the characteristic properties of materials such as permittivity and permeability. Further, the methods used to determine permittivity are discussed. The next part of the work is focused on a theoretical analysis of the design of a broadband horn antenna with a dielectric lens. The chapter 3D printing and surface treatment deals with the issue of 3D printing and the possibility of applying a conductive layer on the plastic components. The following section presents the calculated and simulated results performed in CST Microwave Studio. In the next chapter, mechanical construction and measurement setup fabrication are discussed. In the end, the achieved results are evaluated.
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Patch antenna array for IFF band
Mička, Josef ; Pítra, Kamil (referee) ; Láčík, Jaroslav (advisor)
This master thesis deals with designing and implementing an antenna array for the IFF band. The design includes an antenna element simulation and a feeding network design for the antenna array. The antenna element is designed as broadband and has an SWR of less than 1.5 in each band. Two stacked patches are used to achieve the required bandwidth. The patches are fed through a slot. An asymmetric stripline line is used for the feeding network. The simulated antenna array shows good impedance matching and gain properties. The final part of the master thesis compares the measured results with the simulated results. Finally, an attempt is made to improve the SWR of the manufactured antenna array.
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Circuit Parameters Measurement by S parameters - Laboratory Experiment
Karniš, David ; Láčík, Jaroslav (referee) ; Urbanec, Tomáš (advisor)
Bachelor thesis describes a method of measuring impedance suitable for determining the properties of RF and microwave circuits. The main objective is to get acquainted with S parameters, method of measuring them with vector analysis and with equivalent circuits of passive elements. Further is discussed the issue of calibration and its parts. The following section describes the product design process, concluded by verification of measuring method and design.
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