Dissertation topics

Microwave Sensors

Prof. Ing. Karel Hoffmann, CSc. ()

A research in the area of microwave sensors for precise distance measurements and thickness measurement of metallic materials has been guided by the supervisor in last several years. A new microwave interferometric measurement method with theoretical distance precision in the order of microns has been developed. There is a great space for further research of calibration and correction algorithms for elimination of systematic errors and also for further circuit improvement of the measurement systems.

Precise Microwave Measurement on Planar Lines

Prof. Ing. Karel Hoffmann, CSc. ()

A research in the area of precise measurements on planar lines is going on at the department of electromagnetic field. A new earlier unknown source of systematic measurement errors has been discovered. It is radiation of the adapter between coaxial line and an open planar line like e.g., microstrip line. Many of significant findings has been discovered. However, a lot of space is still remaining for further research. The problematic of adapter radiations in the area of measurement on differential lines applied namely in digital circuits remains unmapped.

Measurement of Extreme Impedances

Prof. Ing. Karel Hoffmann, CSc. ()

Measurement of extreme impedances, it is impedances with reflection coefficient close to 1, is in microwave frequency range a very new topic. The research was initiated in 2007 by the supervisor. Since that time new measurement systems for these measurements have been developed. Further development of these systems can be expected. Calibrations, measurement test fixtures and correction methods are very topical and yet not solved topics. Further research in this area is necessary for future measurement of perspective components based on carbon nano-tubes, tuning varactors with extremely low capacitance in the order of atto farad. Another applications can be supposed also in scanning microwave microscopy.

Microwave Imaging Systems

Prof. Ing. Karel Hoffmann, CSc. ()

Development of microwave and mm-wave imaging systems is very fast in last years. Current systems are very complicated and expensive. The aim of the research is to find new possible system solutions with simpler construction and acceptable imaging properties.

Hollow-Core Fibers for Ultra-Sensitive and Interferometric Applications in the NIR and MIR Region

Ing. Matěj Komanec, Ph.D. ()

Hollow-core fibers represent the future of optical fiber technology. By guiding light in an air core, they can provide extremely low fiber non-linearity, low and stable signal latency, and the possibility to construct long-length gas cells. Our research group works on a fully international level in cooperation with one of the world-leading institutes in hollow-core fibers, the University of Southampton, in a multitude of research and application topics.

Specialty optical fibers for communication and sensing

Ing. Matěj Komanec, Ph.D. ()

Specialty optical fibers are becoming the state-of-the-art solution in both research and application fields. These fibers bring unprecedented possibilities in many areas ranging from fiber-optic communications, fiber-optic sensing to fiber-based design of interiors and illumination. In our team, we carry out research on a fully international level in cooperation world-leading institutes in specialty optical fibers and their applications, e.g. University of Valencia, and University of Las Palmas Gran Canaria.

Propagation of Electromagnetic Waves in Periodic Structures

Prof. Ing. Jan Macháč, DrSc. ()

The work is aimed at investigation and design of general periodical structures. The periodicity can be in one direction – transmission line/electrical circuits, two or three dimensions – volumetric artificial materials, surfaces. The aim is to obtain effective parameters describing propagation of electromagnetic waves in these structures – tensors of permittivity, permeability. Studied structures can show behavior not known in natural materials – surface impedance, permittivity, permeability, conductivity.

High Frequency Circuits on an Artificial Dielectric Substrate

Prof. Ing. Jan Macháč, DrSc. ()

The work is aimed at investigation and design of high frequency circuits based on a microstrip line designed on a substrate of  artificial dielectric material. This line shows high effective permittivity, so it is possible to substantially reduce circuit dimensions. Such circuits are applicable even in integrated structures.

Leaky Wave Antennas

Prof. Ing. Jan Macháč, DrSc. ()

The work is aimed at investigation and design of antennas working with leaky wave – travelling wave. The antennas are designed on substrate integrated waveguide and are able to steer the main radiating beam by changing frequency.

Metamaterials

Prof. Ing. Jan Macháč, DrSc. ()

The work is aimed at investigation and design of artificial material structures that show properties not known in natural materials. Metamaterials are created by a periodic system, or by a stochastic system of particular elements – resonators. The target is to create material with isotropic response, i.e., material with properties not depending on a propagating wave direction. Next area is an investigation of active metamaterials that are created by particular cells with active transistor circuits. Such structures can compensate material losses or its dispersion.

General system of an antenna arrays

Prof. Ing. Miloš Mazánek, CSc. ()

Properties of an antenna are described by the complex vector of the electromagnetic field in each position over the surrounding sphere. The goal of the study is the distribution of properties (parameters) of radiators including optimization of the limited number of radiated elements. General description oriented towards physical parameters is followed by modelling and measurement using electromagnetic simulators.

Propagation Modeling for Microwave and Millimeter Wave Wireless Systems in Built-Up Areas

Prof. Ing. Pavel Pechač, Ph.D. ()

Focused on research of advanced deterministic signal propagation models of for prospective outdoor and indoor wireless systems. These systems tend to use millimeter waves frequency bands and complex antenna systems.

Radiowave Propagation in Atmospheric Boundary Layer

Prof. Ing. Pavel Pechač, Ph.D. 

()

The topic deals with the radio wave propagation in the troposphere for the needs of wireless links in cm and mm wav bands. The works includes investigations of radiometeorologic properties of the lowest layers of the atmosphere, e.g., monitoring spatial and temporal distribution of refractivity, the impact of hydrometeors etc.

Propagation Modeling for Low Elevation Links

Prof. Ing. Pavel Pechač, Ph.D. ()

The topic is generally focused on research of wireless propagation channel for so called low elevation links, i.e. typically ground-to-air(UAV) links. The work includes investigations of both atmospheric and local environment effects as well as system issues like diversity techniques.

Propagation Modeling for SatCom and SatNav Services

Prof. Ing. Pavel Pechač, Ph.D. ()

The topic is focused on research of propagation channel for satellite communication and navigation services, i.e. high elevation links. The aim is to develop new deterministic propagation models involving the effects of the atmosphere and the terrestrial terminal type (fixed, mobile, nomadic) and environment (terrain, buildings, antennas).

Frequency Selective Planar Structures for Wireless Friendly Buildings

Prof. Ing. Pavel Pechač, Ph.D. ()

The aim is to investigate electromagnetic properties of building structures and materials for the concept of so called wireless friendly buildings.

Sea surface scattering

Prof. Ing. Pavel Pechač, Ph.D. ()

Currently, maritime vessels utilize a variety of wireless communication and navigation systems. Although the corresponding links are well-designed, the presence of conducting sea surface cannot be completely ignored. To solve such problems, approximative methods such as physical optics are more suitable than full wave methods. However, sampling the sea surface at fractions of wavelength is still not feasible and other methods need to be developed. This task is to be carried out in collaboration with University of Vigo and German Aerospace Center.