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Design of system for indication of gas leakage by ultrasonic microphone
Bohuš, Michal ; Kovář, Jan (referee) ; Šotner, Roman (advisor)
The aim of this project is detection of gass leak based on the ultrasound sensing. Work introduces ultrasound, mechanism of its propagation and attenuation. From all of the available microphones, the piezoelectric microphone was chosen. Project continues with description of the device, which can be capable of detection of the ultrasound leakage in dangerous, explosive environment. This type of device must meet requirements of SIL 2 standard and ATEX directive for zone 2. Project discusses LNA (Low Noise Amplifier), filters and detection circuits design. The device is modular what means that each module can be freely replaced. The role of these modules is to convert analog signal to digital form suitable for microcontroller HERCULES TSM57012.
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Low-noise amplifier for 145 MHz band
Pivoňka, Rostislav ; Vágner, Petr (referee) ; Baran, Ondřej (advisor)
This work contains a description of low noise amplifier (LNA) working on 145 MHz. This amplifier consists of three parts. They are input circuit, active device and output circuit. The amplifier is designed with transistor BF 998 on substrate FR4. The design and simulations are performed by means of software Ansoft Serenade. The design was completed with the help of design equations and Smith chart methods. The input of amplifier is noisy matched and output of amplifier is matched on impedance 50 ohms. The noise factor in frequency band 144 – 146 MHz is about 0,85 dB. The amplifier gain is in this band circa 16dB.
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Antenna a LNA for multiband GNSS receiver
Ondráš, Michal ; Baran, Ondřej (referee) ; Záplata, Filip (advisor)
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.
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Design of system for indication of gas leakage by ultrasonic microphone
Bohuš, Michal ; Kovář, Jan (referee) ; Šotner, Roman (advisor)
The aim of this project is detection of gass leak based on the ultrasound sensing. Work introduces ultrasound, mechanism of its propagation and attenuation. From all of the available microphones, the piezoelectric microphone was chosen. Project continues with description of the device, which can be capable of detection of the ultrasound leakage in dangerous, explosive environment. This type of device must meet requirements of SIL 2 standard and ATEX directive for zone 2. Project discusses LNA (Low Noise Amplifier), filters and detection circuits design. The device is modular what means that each module can be freely replaced. The role of these modules is to convert analog signal to digital form suitable for microcontroller HERCULES TSM57012.
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Low Noise Amplifiers for frequency range 1-3 GHz
Klegová, Hana ; Zamazal, Michal (referee) ; Kasal, Miroslav (advisor)
This masters thesis deals with low noise amplifier design for frequency range 1 GHz - 3 GHz. There is a short theoretical introduction in the first part of the thesis. There are described parameters and properties of transistors and general two-ports. Description of the noise characteristics two-ports follows. The next capture contains design of two-stage amplifiers. One of them is with a microstrip filter between stages and the second one is with combline filter on input of the amplifier. The amplifiers and the microstrip filter were designed in program ANSOFT Designer. The design of combline filter was realised in program CST Microwave Studio. Both amplifiers ware made and their properties ware compared with simulations.
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LNA for Amateur Radio Bands
Děcký, Miroslav ; Pospíšil, Martin (referee) ; Povalač, Aleš (advisor)
The thesis deals with a draft and inclusion of a low noise preamplifier – LNA in a signal route of a radioamateur stage. It also deals with measuring, comparing and subsequently choosing suitable relays for HF application. For the resulting LNA system are designed bandpass filters and also sequencer for correct and safe timing.
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LNA for the APT signals receiver
Žúrek, Dan ; Urbanec, Tomáš (referee) ; Baran, Ondřej (advisor)
This bachelor thesis is dealing with design, realization and optimization of the LNA (Lownoise amplifier) for receiving of APT signals from the NOAA weather satellites in 137 MHz – 138 MHz frequency band. The first part of this work is aimed on critical parameters of the amplifier and the filter circuits especially on a noise figure and a high selectivity. The next part of this project is about the particular concept and simulation of LNA by using the Ansoft Designer software. The printed circuit board is realized in the Cadsoft Eagle. The final part of this bachelor thesis is dealing with a production of such amplifier together with its measurement and testing in a real operation of receiving APT signals.
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GPS Two-Stage Low Noise Amplifier
Šindler, Pavel ; Kasal, Miroslav (referee) ; Baran, Ondřej (advisor)
This work deals with a design of a low noise amplifier for the GPS band. The first part shortly describes properties of GPS signals and possible jamming sources. In the next chapter, basic parameters of low noise amplifiers, ways of the amplifier stability determination and stabilization are described. A summary of methods of a narrowband amplifier design follows. The next chapter contains a short description of filters usable in the designed amplifier. The next part deals with the design of the two-stage low noise amplifier with the help of Ansoft Designer software. The following part deals with the amplifier realization and its parameters measuring. At the end of this work, some experience with GPS signals reception with the realized low noise amplifier, a passive antenna and two different types of GPS receivers are mentioned.
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Low Noise amplifier for 8,4 GHz
Svoboda, Libor ; Vágner, Petr (referee) ; Kasal, Miroslav (advisor)
This project deals with methods of design and realization of low noise microwave amplifier for X-band. The first part describes this issue at a theoretical level. Thus it contains a detailed analysis of microstrip line and its circuit components. It is followed by some specifics of microstrip filters and with mention of microwave heterojunction transistors. The last chapter of the theoretical part describes design of small-signal amplifier with focus on low noise figure. The second part, practical, shows a concrete procedure of two-stage LNA design with HEMTs, using CAD tool Ansoft Designer. This section, as well as the bachelor’s thesis, is finished with realization of amplifier and analysis of its properties.
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Application possibilities of LNVGA programmable amplifier
Sobotka, Josef ; Hanák, Pavel (referee) ; Jeřábek, Jan (advisor)
This thesis deals with the theoretical description of the qualitative characteristics and parameters of some modern active elements, also discusses the theory of signal flow graphs at the level applicable for the following frequency filter design methods. The thesis is also generally discussed the issue with the circuit simulator PSpice modeling theory and voltage amplifiers on the basic 6-levels. The practical part of the work is divided into two parts. The first practical part is dedicated to design four levels of simulation model of components LNVGA element. The second practical part contains detailed theoretical proposals for three circuit structures implementing the frequency filters 2nd order (based on the basic structure of the OTA-C) using signal flow graphs with configuration options of Q and fm based on the parameters of active elements in the peripheral structure and their verification with prepared LNVGA model layers.
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