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The book comprises a new method of solving the integral equation of
Leontovich, the most rigorous and most effective equation for the
current in thin linear antennas. The book describes the features of
the new method in its application in various types of antennas. It
considers new ways of analyzing antennas, in particular in the
calculation of an antenna gain based on main radiation patterns and
the calculation of the directional characteristics of radiators
with known distribution of current amplitude. The method of
electrostatic analogy proposed by the author, provides the base for
comparison of electromagnetic fields of high-frequency currents and
electrostatic charges located on linear conductors to improve the
directional characteristics of log-periodic and director-type
antennas. A new approach to the analysis of the electrical
characteristics of a microstrip antenna, which allows expansion of
its operation range, is substantiated and developed. New results of
antenna synthesis are obtained. The second part of the book is
devoted to specific types of antennas (the author had a significant
role in their creation). Particular attention is given to ship
antennas for different frequency ranges. The book is intended for
professionals, working in electrodynamics and those working on
development, placement and exploitation of antennas. It will be
useful for lecturers (university-level professors), teachers,
students of radio engineering and researchers working in various
fields of radio electronics and interested in an in-depth study of
theoretical problems and designs f antennas. It can also be used
for short university courses.
The book deals with theoretical and experimental research of
antennas. The presentation is based on the electromagnetic theory.
It begins with the theory of thin antennas. Thin antennas represent
one of the main types of radiators, thus the theory of thin
antennas is the basis of the antennas analysis. Special attention
is paid to the integral equation of Leontovich-Levin for a current
along a straight thin-walled metal cylinder, which is equivalent to
the equation of Hallen with a precise kernel. Together with the
analysis of various types of antennas, the book deals with the
problems of synthesis including the creation a wide-band radiator
by means of determining of the types and the magnitudes of
concentrated loads, which are connected along a linear radiator and
create in a given frequency band high electrical performance.
Problems of antenna engineering are discussed in the second half of
the book, including the results of application of a compensation
method for the protection of humans against irradiation and
structural features of ship antennas.
The book comprises a new method of solving the integral equation of
Leontovich, the most rigorous and most effective equation for the
current in thin linear antennas. The book describes the features of
the new method in its application in various types of antennas. It
considers new ways of analyzing antennas, in particular in the
calculation of an antenna gain based on main radiation patterns and
the calculation of the directional characteristics of radiators
with known distribution of current amplitude. The method of
electrostatic analogy proposed by the author, provides the base for
comparison of electromagnetic fields of high-frequency currents and
electrostatic charges located on linear conductors to improve the
directional characteristics of log-periodic and director-type
antennas. A new approach to the analysis of the electrical
characteristics of a microstrip antenna, which allows expansion of
its operation range, is substantiated and developed. New results of
antenna synthesis are obtained. The second part of the book is
devoted to specific types of antennas (the author had a significant
role in their creation). Particular attention is given to ship
antennas for different frequency ranges. The book is intended for
professionals, working in electrodynamics and those working on
development, placement and exploitation of antennas. It will be
useful for lecturers (university-level professors), teachers,
students of radio engineering and researchers working in various
fields of radio electronics and interested in an in-depth study of
theoretical problems and designs f antennas. It can also be used
for short university courses.
The book deals with theoretical and experimental research of
antennas. The presentation is based on the electromagnetic theory.
It begins with the theory of thin antennas. Thin antennas represent
one of the main types of radiators, thus the theory of thin
antennas is the basis of the antennas analysis. Special attention
is paid to the integral equation of Leontovich-Levin for a current
along a straight thin-walled metal cylinder, which is equivalent to
the equation of Hallen with a precise kernel. Together with the
analysis of various types of antennas, the book deals with the
problems of synthesis including the creation a wide-band radiator
by means of determining of the types and the magnitudes of
concentrated loads, which are connected along a linear radiator and
create in a given frequency band high electrical performance.
Problems of antenna engineering are discussed in the second half of
the book, including the results of application of a compensation
method for the protection of humans against irradiation and
structural features of ship antennas.
Expanding the range of antenna frequency is the main objective of
this book. Solutions proposed are based on the development of new
theoretical methods for analyzing and synthesizing antennas. The
book shows that concentrated capacitive loads connected along
linear and V-antennas provide a high level of matching with a cable
over a wide frequency range and improves directional
characteristics of antennas, i.e. increases the communication
distance. New theoretical methods are proposed for analysis and
synthesis of antennas under consideration: 1) method of calculating
directional characteristics of radiators with a given current
distribution, and 2) method of electrostatic analogy for
calculating mutual and total fields of complex multi-element
radiating structures. These methods allow us to obtain optimal
directional characteristics for director-type antennas (arrays of
Yagi-Uda) and log-periodic antennas with concentrated capacitances
and show that use of capacitors makes it possible to extend the
frequency range of the director antennas and to decrease dimensions
of the log-periodic antennas Multi-element (flat and
three-dimensional) self-complementary antennas with different
variants of connecting generator poles and cable wires to antenna
elements are proposed, which improves the matching with a cable.
Characteristics of flat structures are compared with
characteristics of volume structures: conical, parabolic, and
located on a pyramid edges. The book describes new versions of
transparent antennas, antennas for cellular communication,
multi-tier and multi-radiator antennas, and much more.
Expanding the range of antenna frequency is the main objective of
this book. Solutions proposed are based on the development of new
theoretical methods for analyzing and synthesizing antennas. The
book shows that concentrated capacitive loads connected along
linear and V-antennas provide a high level of matching with a cable
over a wide frequency range and improves directional
characteristics of antennas, i.e. increases the communication
distance. New theoretical methods are proposed for analysis and
synthesis of antennas under consideration: 1) method of calculating
directional characteristics of radiators with a given current
distribution, and 2) method of electrostatic analogy for
calculating mutual and total fields of complex multi-element
radiating structures. These methods allow us to obtain optimal
directional characteristics for director-type antennas (arrays of
Yagi-Uda) and log-periodic antennas with concentrated capacitances
and show that use of capacitors makes it possible to extend the
frequency range of the director antennas and to decrease dimensions
of the log-periodic antennas Multi-element (flat and
three-dimensional) self-complementary antennas with different
variants of connecting generator poles and cable wires to antenna
elements are proposed, which improves the matching with a cable.
Characteristics of flat structures are compared with
characteristics of volume structures: conical, parabolic, and
located on a pyramid edges. The book describes new versions of
transparent antennas, antennas for cellular communication,
multi-tier and multi-radiator antennas, and much more.
Till the very end of the twentieth century tsunami waves (or 'waves
in a harbour', translated from Japanese) were considered an
extremely rare and exotic natural p- nomenon, originating in the
ocean and unexpectedly falling upon the seaside as gigantic waves.
The 26th of December 2004, when tsunami waves wiped out, in a
single day, more than 250,000 human lives, mourned in many
countries, turned out to be a tragic date for all mankind. The
authors of this book, who have studied tsunami waves for many
years, - tended it to be a systematic exposition of modern ideas
concerning * The mechanisms of tsunami wave generation * The
peculiarities of tsunami wave propagation in the open ocean and of
how waves run-up beaches * Methods for tsunami wave registration
and the operation of a tsunami warning system * The mechanisms of
other catastrophic processes in the ocean related to the se- mic
activity of our planet The authors considered their main goal to be
the creation of book prese- ing modern knowledge of tsunami waves
and of other catastrophes in the ocean to scienti?c researchers and
specialists in geophysics, oceanography, seismology,
hydroacoustics, geology, geomorphology, civil and seaside
engineering, postgr- uate students and students of relevant
professions.
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