Open topics

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

Prof. Ing. Pavel Pechač, Ph.D. (pechac@fel.cvut.cz)

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. (pechac@fel.cvut.cz)

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. (pechac@fel.cvut.cz)

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. (pechac@fel.cvut.cz)

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. (pechac@fel.cvut.cz)

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. (pechac@fel.cvut.cz)

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. 

Propagation of Electromagnetic Waves in Periodic Structures

Prof. Ing. Jan Macháč, DrSc. (machac@fel.cvut.cz)

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. (machac@fel.cvut.cz)

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. (machac@fel.cvut.cz)

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. (machac@fel.cvut.cz)

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.

Za obsah odpovídá: Stanislav Zvánovec (xzvanove@fel.cvut.cz) update:26.8.2015