Zobrazeno 1 - 10
of 363
pro vyhledávání: '"P. Hazdra"'
Publikováno v:
Radioengineering, Vol 27, Iss 4, Pp 956-960 (2018)
This paper describes the application of the theory of characteristic modes to excite a conducting cylinder representing the chassis of a rocket. Mode excitation is achieved by cutting H-shaped slots on the cylinder at specific locations where the max
Externí odkaz:
https://doaj.org/article/9b1f5946152946e5a2d4aad22645f4b8
Autor:
M. Cerveny, P. Hazdra
Publikováno v:
Radioengineering, Vol 26, Iss 4, Pp 968-971 (2017)
In classic antenna analysis, there exist several methods of calculating input impedance when the source distribution of an antenna is known. The well-known induced EMF method, based on spatially distributed currents, is typically applied for this pur
Externí odkaz:
https://doaj.org/article/26448f7f385643c48fa014dabf475487
Publikováno v:
Radioengineering, Vol 25, Iss 1, Pp 12-17 (2016)
Antenna parameters particularly relevant to electrically small antenna design are reviewed in this paper. Source current definitions are accentuated leading to the introduction of the source concept which advantageously utilize only spatially bounded
Externí odkaz:
https://doaj.org/article/a631bf76515e4d8bb9f29a0abbd1cdad
Publikováno v:
Radioengineering, Vol 18, Iss 4, Pp 407-412 (2009)
In this paper, we demonstrate the possibility to strongly modify the radiated fields of a UMTS handset by using a phased two-element PIFA array. The structure is composed of a 100x40 mm2 metallic ground plane acting as the Printed Circuit Board (PCB)
Externí odkaz:
https://doaj.org/article/9ce1179c32c346cc8d5623203ee8de62
Autor:
P. Hazdra, R. Galuscak
Publikováno v:
Radioengineering, Vol 17, Iss 3, Pp 33-37 (2008)
This paper is aimed on specific problems of electrically small and deep dish parabolic antennas. Since these antennas may suffer with low efficiency authors describe design and optimization of simple dual-band loop prime-focus feed achieving good eff
Externí odkaz:
https://doaj.org/article/f97b36cb545344f8bccc1be58b445af8
Publikováno v:
Radioengineering, Vol 17, Iss 3, Pp 42-46 (2008)
This paper shows an interesting sight on the correspondence between total current solution obtained by the Method of Moments and by the Characteristic modes respectively. Derivation is based on representation of a matrix in its spectral form. Detaile
Externí odkaz:
https://doaj.org/article/e5d99bba3eeb49bdbce825a0dc80442b
Publikováno v:
Radioengineering, Vol 17, Iss 1, Pp 20-27 (2008)
Physically large dimensional dish antennas in Cassegrain configuration have played an important role in satellite communications during the past several decades. Recently, however, emerging new technologies have begun to displace these elegant antenn
Externí odkaz:
https://doaj.org/article/87d50e8a5c504b00991fea09764c6f5c
Publikováno v:
Radioengineering, Vol 16, Iss 3, Pp 37-41 (2007)
Paper focuses on so-called L-probe feeding technique suitable for wideband (30% relative bandwidth) driving of microstrip patch antennas. Physical explanation, simulation and measurement are presented. Further modification for improvement of radiatio
Externí odkaz:
https://doaj.org/article/1df6ab2201774c20bca5bd2d3d300a39
Autor:
Michal Pokorny, Ivo Vertat, David Panek, Pavel Hazdra, Milan Svanda, Jan Kracek, Milos Mazanek, Jiri Masopust, Pavel Karban
Publikováno v:
IEEE Access, Vol 12, Pp 11458-11469 (2024)
Contemporary beam-forming antenna arrays often use a large number of individual elements, sometimes hundreds or more, to achieve high gain for advanced applications like radar, space communication, and next-gen cellular networks. These arrays are com
Externí odkaz:
https://doaj.org/article/132bf374bdca4c7e9f798d0ff84f9b1a
Autor:
M. Mazanek, P. Hazdra
Publikováno v:
Radioengineering, Vol 15, Iss 2, Pp 18-21 (2006)
An L-System (Lindenmayer system) is a scheme primarily developed in the area of the computer science for simulating the development of biological structures. It has also been found very useful for generating the geometry of various fractal antennas.
Externí odkaz:
https://doaj.org/article/c019374bc2a2434a9a26b96980f82e10