|
|
RF power meter
Hlaváč, Štěpán ; Jedlička,, Petr (referee) ; Drexler, Petr (advisor)
This master’s thesis describes various principles of measurement of electromagnetic waves in a free space and on a line. Used sensors and their real parameters are given for every method. The analysis of protections of high-frequency inputs of measuring instruments is done here and the most suitable method and protections of input for realization are chosen. The analysis of design of secondary protection of high-frequency input is done in this project. The protection of input is realized and measured. The suitable method of measurement is chosen as well as the sensor for measurement of power. The block diagram and circuit diagram of the meter of power are designed. According to designed conception the measuring instrument for measurement of power is realized and its single qualities are measured during the realization. In the final part its precision is measured and the evaluation of results is done.
|
|
|
Audio Pre-Amplifier for Laboratory Measurements
Friml, Vilém ; Hanák, Pavel (referee) ; Kratochvíl, Tomáš (advisor)
This thesis deals with a design of audio pre-amplifier with fixed frequency filters and a choice between amplification using integrated circuits and solidstate circuit. The thesis includes a design of attenuation circuit, an amplifier with an integrated circuit, an amplifier with transistors, a RIAA filter, a speech filter, a physiological filter, a rock preset filter and a power supply circuit. The thesis describes design of the circuit board, solution of oscillations of the amplifier with transistors and a measurement of the constructed device. The aim of the thesis is the design and construction of laboratory equipment.
|
|
|
Analysis and construction of an optical fibre tunable attenuator for telecommunication applications
Prokop, Daniel ; Eliáš, Josef (referee) ; Urban, František (advisor)
This paper deals with the possibilities of designing the module for control of the attenuation of the optical signal. The paper describes basics of ber optic transmission and beam e ects. Variants of attenuation cells are characterized in this paper and based on the ndings a solution of the module for control of the attenuation of the optical signal is proposed. Practical section of the thesis deals with the design and physical construction of module for control of the attenuation of the optical signal using MEMS variable optical attenuator.
|
|
|
Optical amplifier in laboratory practice
Šustr, Pavel ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The aim of this thesis is to introduce to reader the application and use of optical EDFA amplifiers in optical transmission and to show wiring and practical test, including measurements on amplifier. The aim of this thesis is to propose the use of optical amplifier in laboratory practice for subject Optical networks. The thesis briefly introduces the problems of data transmissions through optical fibers with a focus on the use of optical amplifiers. The basic characteristic of optical transmission paths and the reasons for the use of optical amplifiers are described here. One entire chapter is devoted to distinction of optical amplifiers. Amplifiers can be divided according to location in the transmission path to the booster, in-line and pre-amplifiers and according to the used of amplifying technology to optical amplifiers with subsidies, semiconductor optical amplifiers and Raman optical amplifiers. The factors affecting the efficiency of optical amplifiers, such as noise and the level of saturated power are mentioned here too. The different types of optical amplifiers from the two producers are also described. From these amplifiers was chosen EDFA CzechLight Amplifier from Optokon to be used for the laboratory exercise in the subject of Optical networks. The use of EDFA optical amplifiers in optical transmission lines is mentioned here too. These amplifiers can be used in telecommunications transmission systems and for data transmission over long distances. They will find use in WDM transmission systems and cable TV distribution through the optical fiber to the end users. Practical measurements were performed on optical amplifier CLA-PB01F. In the transmission route was located attenuator and the dependence of output power to input signal power was measured. The amplification course was linear in the range of input values provided by the manufacturer. Laboratory exercise for the subject of Optical networks is aimed at preacquaintance of students with problems EDFA optical amplifiers and practical measurements with the optical amplifier CLA-PB01F. Students acquire basic theoretical knowledge of the issue and verify the functionality of optical amplifiers on a specific exercise. This work is destined for all who wish to get basic knowledge of optical amplifiers, their characteristics and possibilities of their use in optical transmission lines.
|
|
|
Pure tone audiometry
Maršálková, Leona ; Harabiš, Vratislav (referee) ; Chmelař, Milan (advisor)
The presented master’s thesis deals with the acoustics, specifically with the selected characteristics of the sound. It focuses on the anatomy of the auditory system and its function. The work describes the testing approaches for an evaluation of the auditory organ function and introduces modern methods used for the hearing tests, especially pure tone audiometry. A part of the thesis is dedicated to a concept of an audiometer for pure tone audiometry, which is presented in a detailed block diagram along with a description of its working components. Included chapters describe the partial circuits of the audiometer supplemented by the calcuations of its individual elements. The concluding part of the thesis deals with the evaluation of the device’s functionality.
|
|
|
Noise reducing of aircraft engines
Čirka, Martin ; Kaddour, Mirvat (referee) ; Šplíchal, Miroslav (advisor)
Nowadays, aircraft transportation influences everyday life in our society, but not only by its advantages of efective traveling, but also by its negative impact on environment, therefore us, people. Due to this reason, I decided to concern myself about noise reducing of aircraft engines in this thesis. Research in this field helps to develop comfort of traveling, but also very important fact is noise impact on people living in surroundings near airports. To understand problem to the roots, first we need to know how is noise actually defined. First part of my bachelor’s thesis contains describtion of sound and noise. I’m also focusing on methods for noise measurement and actions, which are used for noise reduction. Greatest success have been made with Variable Geometry Chevrons, which can adjust to different flying conditions and not just reduce noise, but also can keep thrust of the engine at the same level and is also reducing fuel consumtion during level flight. In fourth chapter, you’ll come to know about regulations, which were made to adopt standards and recommended practices concerning aircraft polution. Also very important factor for setting up new standards is process of aircraft testing, so I summed up principles and procedures, which are usedby aviation organizations.
|
|
|
RF Unit for Portable Monitoring Station
Rokos, Lukáš ; Urbanec, Tomáš (referee) ; Záplata, Filip (advisor)
The thesis describes methods for spectrum monitoring, which are used by the Czech telecommunication office. The thesis describes a design of an RF unit for a portable monitoring station and its potential use. The RF unit consists of several devices, which are connected. Devices like an antenna, a rotator, a rotator control unit, coaxial switches, an amplifier and attenuator were chosen as commercially available devices. It is also described, why were these devices chosen. Other devices such as filters, a control unit for the RF unit and a power supply were designed. The RF unit is controlled by a computer. A software for spectrum monitoring contains a graphical user interface for the RF unit control.
|
|
|
System for control of high-frequency power source with reflected power measurement
Zoufalý, Ondřej ; Drexler, Petr (referee) ; Juřík, Karel (advisor)
This thesis briefly describes the function of the selected high-frequency technology and its use. Furthermore, the thesis contains a discussion of the method of designing a system for control of high-frequency power source with reflected power measurement, after which the selection of suitable components is carried out based on pre-selected parameters. Subsequently, the method of powering and cooling the system is proposed. This is followed by the actual assembly of the system and testing of its functionality and measurement of system parameters. In the last part, selected parts of the printed circuit board of this system are described and justified.
|
|
|
RF Unit for Portable Monitoring Station
Rokos, Lukáš ; Urbanec, Tomáš (referee) ; Záplata, Filip (advisor)
The thesis describes methods for spectrum monitoring, which are used by the Czech telecommunication office. The thesis describes a design of an RF unit for a portable monitoring station and its potential use. The RF unit consists of several devices, which are connected. Devices like an antenna, a rotator, a rotator control unit, coaxial switches, an amplifier and attenuator were chosen as commercially available devices. It is also described, why were these devices chosen. Other devices such as filters, a control unit for the RF unit and a power supply were designed. The RF unit is controlled by a computer. A software for spectrum monitoring contains a graphical user interface for the RF unit control.
|
|
|
Audio Pre-Amplifier for Laboratory Measurements
Friml, Vilém ; Hanák, Pavel (referee) ; Kratochvíl, Tomáš (advisor)
This thesis deals with a design of audio pre-amplifier with fixed frequency filters and a choice between amplification using integrated circuits and solidstate circuit. The thesis includes a design of attenuation circuit, an amplifier with an integrated circuit, an amplifier with transistors, a RIAA filter, a speech filter, a physiological filter, a rock preset filter and a power supply circuit. The thesis describes design of the circuit board, solution of oscillations of the amplifier with transistors and a measurement of the constructed device. The aim of the thesis is the design and construction of laboratory equipment.
|
guest ::
