Communications, antenna, radar, and microwave engineers must deal with the
generation, transmission, and reception of electromagnetic waves. Device engineers
working on ever-smaller integrated circuits and at ever higher frequencies must take
into account wave propagation effects at the chip and circuit-board levels.
Communication and computer network engineers routinely use waveguiding systems,
such as transmission lines and optical fibers. Novel recent developments in materials,
such as photonic bandgap structures, omnidirectional dielectric mirrors, birefringent
multilayer films, surface plasmons, negative-index metamaterials, slow and fast light,
promise a revolution in the control and manipulation of light and other applications.
These are just some examples of topics discussed in this book.
The book is organized around three main topic areas:
analysis and design of multilayer films.
Waveguiding systems, including metallic, dielectric, and surface
waveguides, transmission lines, impedance matching, and S-parameters.
Linear and aperture antennas, scalar and vector diffraction theory, plane-
array design, numerical methods in antennas, and coupled antennas.
The text emphasizes connections to other subjects. For example, the
mathematical techniques for analyzing wave propagation in multilayer structures,
multisegment transmission lines, and the design of multilayer optical filters are the
same as those used in DSP, such as the lattice structures of linear prediction, the
analysis and synthesis of speech, and geophysical signal processing. Similarly,
antenna array design is related to the problem of spectral analysis of sinusoids and to
digital filter design, and Butler beams are equivalent to the FFT.
Electromagnetic radiation (EM radiation or EMR) is the radiant energy
released by certain electromagneticprocesses. Visible light is an electromagnetic
radiation. Other familiar electromagnetic radiations are invisible to the human eye,
such as radio waves, infrared light and X-rays.
Classically, electromagnetic radiation consists of electromagnetic waves,
which are synchronizedoscillations of electric and magnetic fields that propagate at
the speed of light through a vacuum. The oscillations of the two fields are
perpendicular to each other and perpendicular to the direction of energy andwave
propagation, forming a transverse wave. Electromagnetic waves can be characterized
by either thefrequency or wavelength of their oscillations to form the electromagnetic
spectrum, which includes, in order of increasing frequency and decreasing
wavelength: radio waves, microwaves, infrared radiation, visible light,ultraviolet
radiation, X-rays and gamma rays.
Electromagnetic waves are produced whenever charged particles are
accelerated, and these waves can subsequently interact with any charged particles.
EM waves carry energy, momentum and angular momentum away from their source
particle and can impart those quantities to matter with which they interact. Quanta of
EM waves are called photons, which aremassless, but they are still affected by
gravity. Electromagnetic radiation is associated with those EM waves that are free to
propagate themselves ("radiate") without the continuing influence of the moving
charges that produced them, because they have achieved sufficient distance from
those charges. Thus, EMR is sometimes referred to as the far field. In this language,
the near fieldrefers to EM fields near the charges and current that directly produced
them, specifically, electromagnetic induction and electrostatic induction phenomena.
In the quantum theory of electromagnetism, EMR consists of photons, the
elementary particles responsible for all electromagnetic interactions. Quantum effects
provide additional sources of EMR, such as the transition of electrons to lower
energy levels in an atom and black-body radiation. The energy of an individual
photon is quantized and is greater for photons of higher frequency. This relationship
is given by Planck's equation E = h
ν, where E is the energy per photon, ν is the
frequency of the photon, and h isPlanck's constant. A single gamma ray photon, for
example, might carry ~100,000 times the energy of a single photon of visible light.
The effects of EMR upon biological systems (and also to many other chemical
systems, under standard conditions) depend both upon the radiation's power and its
frequency. For EMR of visible frequencies or lower (i.e., radio, microwave, infrared),
the damage done to cells and other materials is determined mainly by power and
caused primarily by heating effects from the combined energy transfer of many
photons. By contrast, for ultraviolet and higher frequencies (i.e., X-rays and gamma
rays), chemical materials and living cells can be further damaged beyond that done
by simple heating, since individual photons of such high frequency have enough
energy to cause direct molecular damage.
Geometrical optics, or ray optics, describes light propagation in terms of rays.
The ray in geometric optics is an abstraction, or instrument, useful in approximating
the paths along which light propagates in certain classes of circumstances.
The simplifying assumptions of geometrical optics include that light rays:
- propagate in rectilinear paths as they travel in a homogeneous medium
- bend, and in particular circumstances may split in two, at the interface
between two dissimilar media
- follow curved paths in a medium in which the refractive index changes
- may be absorbed or reflected.
Geometrical optics does not account for certain optical effects such as
diffraction and interference. This simplification is useful in practice; it is an excellent
approximation when the wavelength is small compared to the size of structures with
which the light interacts. The techniques are particularly useful in describing
geometrical aspects of imaging, including optical aberrations.
A light ray is a line or curve that is perpendicular to the light's wavefronts (and
is therefore collinear with the wave vector).
A slightly more rigorous definition of a light ray follows from Fermat's
principle, which states that the path taken between two points by a ray of light is the
path that can be traversed in the least time.
Geometrical optics is often simplified by making the paraxial approximation,
allowing optical components and systems to be described by simple matrices. This
leads to the techniques ofGaussian optics and paraxial ray tracing, which are used to
find basic properties of optical systems, such as approximate image and object
positions and magnifications.
A slit that is wider than a single wave will produce interference-like effects
downstream from the slit. It is easier to understand by thinking of the slit not as a
long slit, but as a number of point sources spaced evenly across the width of the slit.
This can be seen in Figure 2 .
Single Slit Diffraction - Four Wavelengths
To examine this effect better, lets consider a single monochromatic
from the slit, the light at any given point is made up of contributions from each of
these point sources. The resulting phase differences are caused by the different in
path lengths that the contributing portions of the rays traveled from the slit.
The variation in wave intensity can be mathematically modeled. From the
center of the slit, the diffracting waves propagate radially. The angle of the minimum
λ) and the slit's width (d) such that:
slit width, wavelength and intensity of the original waves before passing through the
where x is equal to:
In physics, a charged particle is a particle with an electric charge. It may be
an ion, such as a molecule or atom with a surplus or deficit of electrons relative to
protons. It can be the electrons and protons themselves, as well as other elementary
particles, like positrons. It may also be an atomic nucleus devoid of electrons, such as
an alpha particle, ahelium nucleus. Neutrons have no charge, so they are not charged
particles unless they are part of a positively charged nucleus. Plasmas are a collection
of charged particles, atomic nuclei and separated electrons, but can also be a gas
containing a significant proportion of charged particles. Plasma is called the fourth
state of matter because its properties are quite different from solids, liquids and gases.
It is the process of changing in direction of travelling particle due to the
correlation with atom. Conservation of Energy is valid and momentum is preserved.
Rutherford scattering equation
o Elastic collision: sum of momentum is conserved before and after.
o Rutherford scattering equation
2. Inelastic collision
Inelastic collision takes most of the part in energy loss process of charged
particle inside of the matter.
α-particle is called inelastic collision.
α-particle loses momentum corresponding to ionization.
power that interrupts the progress of heavy particle in matter.
Range equation R = Range, E = energy of heavy particle, S = stopping power
o Specific Ionization: the number of ion pairs produced per unit track length.
o Bragg curve: the graph of specific energy loss along the track of a charged
particle. As it loses energy, stopping power value approximately increases along the
1/E then stops. Like this, the peak before its maximum range of stopping power
called Bragg peak.
o Range: distance that heavy charged particle progressed until energy is
completely lost by repeating ionizing and scattering with atom. In case of the particle
that has certain energy, gets certain range. Range is defined as a relation of strength
Quantum mechanics (QM; also known as quantum physics or quantum theory),
including quantum field theory, is a fundamental branch of physics concerned with
processes involving, for example, atoms and photons. Systems such as these which
obey quantum mechanics can be in a quantum superposition of different states, unlike
in classical physics.
Quantum mechanics gradually arose from Max Planck's solution in 1900 to the
black-body radiation problem (reported 1859) and Albert Einstein's 1905 paper which
offered a quantum-based theory to explain the photoelectric effect (reported
1887).Early quantum theory was profoundly reconceived in the mid-1920s.
The reconceived theory is formulated in various specially developed
mathematical formalisms. In one of them, a mathematical function, the wave
function, provides information about the probability amplitude of position,
momentum, and other physical properties of a particle.
Important applications of quantum theory include superconducting magnets,
light-emitting diodes and the laser, the transistorand semiconductors such as the
microprocessor, medical and research imaging such as magnetic resonance imaging
andelectron microscopy, and explanations for many biological and physical
Scientific inquiry into the wave nature of light began in the 17th and 18th
centuries, when scientists such as Robert Hooke, Christiaan Huygens and Leonhard
Euler proposed a wave theory of light based on experimental observations.
that he later described in a paper titled On the nature of light and colours. This
experiment played a major role in the general acceptance of the wave theory of light.
In 1838, Michael Faraday discovered cathode rays. These studies were
followed by the 1859 statement of the black-body radiationproblem by Gustav
Kirchhoff, the 1877 suggestion by Ludwig Boltzmann that the energy states of a
physical system can be discrete, and the 1900 quantum hypothesis of Max Planck.
Planck's hypothesis that energy is radiated and absorbed in discrete "quanta" (or
energy elements) precisely matched the observed patterns of black-body radiation.
In 1896, Wilhelm Wien empirically determined a distribution law of black-
independently arrived at this result by considerations of Maxwell's equations.
However, it was valid only at high frequencies and underestimated the radiance at
low frequencies. Later, Planck corrected this model using Boltzmann's statistical
interpretation of thermodynamics and proposed what is now called Planck's law,
which led to the development of quantum mechanics.
Following Max Planck's solution in 1900 to the black-body radiation problem
(reported 1859), Albert Einstein offered a quantum-based theory to explain the
photoelectric effect(1905, reported 1887). Around 1900-1910, the atomic theory and
the corpuscular theory of light
first came to be widely accepted as scientific fact;
Among the first to study quantum phenomena in nature were Arthur Compton,
C. V. Raman, and Pieter Zeeman, each of whom has a quantum effect named after
him. Robert Andrews Millikan studied the photoelectric effect experimentally, and
Albert Einstein developed a theory for it. At the same time, Niels Bohr developed his
theory of the atomic structure, which was later confirmed by the experiments of
Henry Moseley. In 1913, Peter Debye extended Niels Bohr's theory of atomic
structure, introducing elliptical orbits, a concept also introduced by Arnold
This phase is known as old quantum theory.
Max Planck is considered the father of the quantum theory.
Planck cautiously insisted that this was simply an aspect of the processes of
absorption and emission of radiation and had nothing to do with the physical reality
of the radiation itself.
In fact, he considered his quantum hypothesis a mathematical
Albert Einstein interpreted Planck's quantum hypothesis realistically and used it to
explain the photoelectric effect, in which shining light on certain materials can eject
electrons from the material. He won the 1921 Nobel Prize in Physics for this work.
Einstein further developed this idea to show that an electromagnetic wave such
as light could also be described as a particle (later called the photon), with a discrete
quantum of energy that was dependent on its frequency.
The 1927 Solvay Conference in Brussels.
the 20th century by Max Planck, Niels Bohr, Werner Heisenberg, Louis de Broglie,
Arthur Compton, Albert Einstein,Erwin Schrödinger, Max Born, John von Neumann,
Paul Dirac, Enrico Fermi, Wolfgang Pauli, Max von Laue, Freeman Dyson, David
Hilbert, Wilhelm Wien, Satyendra Nath Bose, Arnold Somerfield, and others. The
Copenhagen interpretation of Niels Bohr became widely accepted.
In the mid-1920s, developments in quantum mechanics led to its becoming the
standard formulation for atomic physics. In the summer of 1925, Bohr and
Heisenberg published results that closed the old quantum theory. Out of deference to
their particle-like behavior in certain processes and measurements, light quanta came
to be called photons (1926). From Einstein's simple postulation was born a flurry of
debating, theorizing, and testing. Thus, the entire field of quantum physics emerged,
leading to its wider acceptance at the Fifth Solvay Conference in 1927.
It was found that subatomic particles and electromagnetic waves are neither
concept of wave–particle duality.
By 1930, quantum mechanics had been further unified and formalized by the
on measurement, the statistical nature of our knowledge of reality, and philosophical
speculation about the 'observer'. It has since permeated many disciplines including
quantum chemistry, quantum electronics, quantum optics, and quantum information
science. Its speculative modern developments include string theory and quantum
gravity theories. It also provides a useful framework for many features of the modern
periodic table of elements, and describes the behaviors of atoms during chemical
bonding and the flow ofelectrons in computer semiconductors, and therefore plays a
crucial role in many modern technologies.
While quantum mechanics was constructed to describe the world of the very
small, it is also needed to explain some macroscopic phenomena such as
The word quantum derives from the Latin, meaning "how great" or "how
In quantum mechanics, it refers to a discrete unit assigned to certain
physical quantities such as the energy of an atom at rest (see Figure 1). The discovery
that particles are discrete packets of energy with wave-like properties led to the
branch of physics dealing with atomic and subatomic systems which is today called
quantum mechanics. It underlies the mathematical framework of many fields of
physics and chemistry, including condensed matter physics, solid-state physics,
atomic physics, molecular physics, computational physics, computational chemistry,
quantum chemistry, particle physics, nuclear chemistry, and nuclear physics. Some
fundamental aspects of the theory are still actively studied.
Quantum mechanics is essential to understanding the behavior of systems at
atomic length scales and smaller. If the physical nature of an atom were solely
described byclassical mechanics, electrons would not orbit the nucleus, since orbiting
electrons emit radiation (due to circular motion) and would eventually collide with
the nucleus due to this loss of energy. This framework was unable to explain the
stability of atoms. Instead, electrons remain in an uncertain, non-deterministic,
assumptions of classical mechanics and electromagnetism.
Quantum mechanics was initially developed to provide a better explanation and
description of the atom, especially the differences in the spectra of light emitted by
differentisotopes of the same chemical element, as well as subatomic particles. In
short, the quantum-mechanical atomic model has succeeded spectacularly in the
realm where classical mechanics and electromagnetism falter.