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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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L-band receiver front-end
Kolář, Jan ; Špaček, Jiří (referee) ; Kasal, Miroslav (advisor)
This Master's Thesis deals with a design of L-band receiver front-end. In the concrete the receiver is designed for receiving signals of frequency band 1,3 GHz. All particular blocks from low noise amplifier to intermediate frequency amplifier and frequency doubler in LO input are described, designed and simulated in program Ansoft. The part of this Master's Thesis is aimed to construct a working front-end receiver and to measure its basic parameters.
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Low-noise S-band amplifier
Potěšil, Dušan ; Vágner, Petr (referee) ; Kasal, Miroslav (advisor)
This work deals with design, simulation and realisation of a receiving systém of an S-band front end for satellite communication. The first part of the project is designed the low noise amplifier (LNA) with high associated gain. The basic point of the design is choice of the active device. In the present time are available the ultra low noise transistors based on the GaAs with high mobility electron. The two-stage LNA has been designed with Agilent ATF-55143. It is pseudomorphic HEMTs ,which work in an enhancement mode.These transistor do not require a negative bias voltage and have extremely good typical noise figure. The design includes an interdigital tuned band pass filter between stages. The second part of the project is search another way design circuit. There are designed two LNA with paralel coupled line filter. The first has been applied on a PTFE substrate Duroid 5880 with relative permitivity 2,2 and tg d = 0,009. The substrate FR-4 (r = 4.34) with the thickness 0.06” was used for the realization.
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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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Novel conformationally locked nucleosides and nucleotides based on bicyclo[3.2.1]octane scaffold as a pseudosugar moiety
Šála, Michal ; Dejmek, Milan ; Procházková, Eliška ; Hřebabecký, Hubert ; Rybáček, Jiří ; Dračínský, Martin ; Novák, Pavel ; Rosenbergová, Šárka ; Fukal, J. ; Sychrovský, Vladimír ; Rosenberg, Ivan ; Nencka, Radim
A route to a series of novel carbocyclic nucleosides locked in North conformation with bicyclo[3.2.1]octane scaffold was developed. Prepared nucleosides served as a starting material for the synthesis of modified oligomers [d(GCATATCAC), r(GCAUAUCAC), and A9]. Biological effects of the prepared nucleosides as well as the hybridization properties of the appropriate duplexes were evaluated.
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