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Wideband transimpedance photodiode amplifier
Šťastný, Martin ; Roubal, Zdeněk (referee) ; Drexler, Petr (advisor)
This thesis deals with the design of transimpedance amplifier with high gain. There are described different principles of semiconductor sensors of optical signal. There is also a comparison of different methods of converting the photocurrent to voltage. It also discusses the design of an appropriate feedback capacitor in terms of stability in participation as a transimpedance amplifier. It examines the impact of non-zero currents flowing to the input operational amplifier circuit functionality and output offset compensation. Part of the thesis is a simulation that confirms the calculated values. The thesis also deals with the implementation of the receiver and the method of correct measurement of the cut-off frequency.
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Electrogram processing and analysis
Hanák, Pavel ; Kolářová, Jana (referee) ; Janoušek, Oto (advisor)
The aim of the study was focused on problem of electrograms recording from alive tissue. Study of electrograms recording was extended with noise analysis and its elimination. Elimination of noise and disturption was made in program Matlab; lowpass filtration and wavelet transformation was used. Application for electrograms analysis was developed in latter part of this work.
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Fast optical receiver for measurement application
Žádník, Jakub ; Steinbauer, Miloslav (referee) ; Drexler, Petr (advisor)
This bachelor's thesis analyzes the problem of a detection of analog optical signals on frequencies nearing 100 MHz. The theoretical part describes a principle of the basic photodiode types and their parameters including their equivalent circuit and parasitic characteristics. Next we discuss the ideal circuit selection and its components, especially the photodiode and operational amplifier. In the practical part we simulate the circuit in the software Tina-TI and measure chosen photodiodes. After that, real circuit boards are designed, constructed, soldered, tested and adjusted to achieve the best performance possible.
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Wireless optical link
Haňka, Jiří ; Hudcová, Lucie (referee) ; Poliak, Juraj (advisor)
This thesis is aimed at section of transmission of digital data by using two optical wireless communications realized by two free-space optics transcievers working in full-duplex mode. Generally, the work describes present options of optical connections, their principles and comparison with other connections. Basic components of realized transmitter and receiver are mentioned with their characteristics and wirings. The work describes options of transmission and further deals with various external events, which influence characteristics of transmitted optical signal. Thesis describes the optical part of design and construction free-space optic and it’s ending energy balance of this link. Further, the work treats of basic use of ethernet technology in transmissions, coding and modulations of data transmitted by optical connection.
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Design and implementation of RGB sensor for educational unit
Švehla, Lukáš ; Krejsa, Jiří (referee) ; Spáčil, Tomáš (advisor)
This thesis deals with construction of RGB sensor which will be extension for preparing of the education kit equipped with microcontroller AT Mega on Arduino board. It contains a brief introduction how the photodiodes work. There is also described some chosen RGB sensors, suggestion and realisation of Printed Circuit Board. Next continue with measurement. Then is chosen and completion final product from the best sensors.
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Short path optical wireless link design
Kovář, Ondřej ; Látal, Jan (referee) ; Diblík, Jan (advisor)
This diploma thesis is focused on design and prototyping of wireless optical link for an indoor usage. In the beginning of the thesis frequency spectrums of infrared, visible and ultraviolet light are described by its typical qualities such as values of attenuation or reflection capability. On the basis of this analysis, a proper wavelength has been chosen for usage at the engineered communication system. Next part is devoted to selection of suitable communication components on basis of its declared qualities. In the following chapter this qualities are in carefully measured and after that they are compared with values provided by its manufacturer. The following section is devoted to design schemes of transceiver modules. After completion of the design the manufacturing of PCB, mounting components and the analysis of their distribution was described. The last part of this thesis deals with testing of created prototype in terms of maximum transmission distances and operating frequencies. At the very end of this project, in one small section ways to improve system characteristics was discussed.
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Non-elektricity Quantities Fiber Optic Sensor
Mytyska, Kamil ; Škorpil, Vladislav (referee) ; Filka, Miloslav (advisor)
This diploma thesis deals with an analysis of the method of propagation of optical fiber by two polarization planes. The method of light propagation is mathematically described using Jones and Stokes vectors. The first part describes wave theory of light divided by Fresnel wave theory, polarization ellipse, degenerate polarization states, parameters of polarization ellipse, Poincaré sphere and degenerated states on Poincaré sphere. Then follows Stokes and Jones polarization parameters, their vectors and Mueller matrix. In addition this paper illustrates the principle of the temperature sensor which is carried out with the help of the polarimeter and its computer program. The following is design of temperature sensor, which is composed of polarizer, photodiode, light output meter and digital multimeter. Another part of the thesis shows the measured values using the current measurement solution using polarimeter and proposed photodiode sensor. At the end of the thesis there is a comparison of the measured values for the three different temperatures that were applied to the optical fiber.
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Control and monitoring of parameters in microfluidic systems
Meloun, Jan ; Sekora, Jiří (referee) ; Čmiel, Vratislav (advisor)
This thesis discusses the construction of Microfluidic systems for a microscope. The theoretical part of this thesis deals with light, light’s behaviour and optical spectral analysis in some methods are discussed. Also, the use of the development platform Arduino with wireless data transfer for data visualization is mentioned. Methods for measuring pH are mentioned as well. The practical part is dedicated to the construction of the Microfluidic system with the use of Arduino, smart mobile devices and a developed mobile application including controlling liquid flow with the measured data visualization.
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