Design horn-antenna using hfss

1
Design and Implementation of a pair of Horn
antenna for UIU microwave test setup
A thesis project submitted to the Department of Electrical and Electronic Engineering in Partial
Fulfillment of the Requirement for the Degree of
B.Sc. in Electrical and Electronic Engineering (EEE)
Department of Electrical and Electronic Engineering
United International University
Dhaka, Bangladesh
Fall 2010

2
Design and Implementation of a pair of Horn
antenna for UIU microwave test setup
By
Sadia Khandaker Monika Mousume Haque
ID: 021071060 ID: 021071062
Mubina Farhin Kazi Riaz Ullah
ID: 021071066 ID: 021071069
A thesis project submitted to the Department of Electrical and Electronic Engineering in Partial
Fulfillment of the Requirement for the Degree of
B.Sc. in Electrical and Electronic Engineering (EEE)
Supervisor
Mohammad Monir Morshed
Assistant Professor
Dept. of EEE
Fall 2010

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Dedication
To our Parents. . . . .
Thank you for your unconditional support with our studies. Thank you for giving us a
chance to prove and improve ourselves thorough all our walks of life. We love our
parents, thanks to both of you for helping to make us who we are, for teaching us to be
proud of who we are, for showing us how to be strong, for giving us the courage to be
weak, and giving us the strength to always strive for better and giving us the wisdom to
know when to turn away and when to change ahead. Our parents are our rock and
foundation.

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Declaration
It is hereby declared that this thesis is done by ourselves and has not been submitted
elsewhere for the award of any degree or diploma. There is lots of information that are
used from the published and unpublished work of others has been acknowledged in the
text. We have provided the list of references.
Signature of the Supervisor:
Mohammad Monir Morshed
Signature of the Candidates:
Sadia Khandaker Monika
Mousume Haque
Mubina Farhin
Kazi Riaz Ullah

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Acknowledgements
All praises are to the Supreme Being, Creator and Ruler of the universe, whose mercy keeps us
alive and enable to pursue our education in Electrical & Electronics Engineering to complete the
thesis on “Design and Implementation of a pair of Horn antenna for UIU microwave test
setup”.
We also send our salam to the Holy Prophet.
We thank our honorable supervisor Mr. Mohammad Monir Morshed, Assistant professor,
Department of Electronics and Electrical Engineering, United International University, for his
day to day supervision, constructive suggestions, valuable criticism and keen interest to carry
out this work. His scientific integrity and dedication have been inspiring us throughout our
graduate study and his patience and continuous encouragement helped our scientific approaches
during these years.
Cordial thanks to our parents, relatives and all our well wishers for their wholehearted
inspiration throughout the period of the thesis work.

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Abstract
This paper is our report for designing a pair of horn antenna for the UIU microwave test
setup. This work includes designing and implementation of a pair of pyramidal horn
antenna, and simulation of basic parameters using (HFSS). A brief theory on microwave
communication system, antenna basics, software introduction, design and
implementation of horn antenna will be discussed along the result of our design. Our
results and analysis show that the project was within the scope of our ability to design
and test the horn antennas.

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Table of Contents
Acknowledgements .........................................................................................................5
List of figures.…………………………………………………………………………11
CHAPTER-1 INTRODUCTION TO MICROWAVE COMMUNICATION
SYSTEM........................................................................................................................15
1.1 Introduction...............................................................................................................15
1.2 History ......................................................................................................................16
1.3 Why use microwaves................................................................................................17
1.4 Microwave sources ...................................................................................................21
1.5 Microwave Transmitter and Receiver.......................................................................21
1.6 Microwave Link Networks .......................................................................................22
1.7 Forms of microwave communication .......................................................................25
1.7.1 Analog microwave communication ..................................................................25
1.7.2 Digital microwave communication...................................................................25
1.8 Applications..............................................................................................................26
1.8.1 Long distance telephone calls ...........................................................................26
1.8.2 Wireless LAN protocols....................................................................................26
1.8.3 Metropolitan area networks ..............................................................................26
1.8.4 Wide Area Mobile Broadband Wireless Access...............................................26
1.8.5 Satellite communications systems ....................................................................27
1.8.6 Radar.................................................................................................................27
1.8.7 Radio astronomy ...............................................................................................27
1.8.8 Navigation.........................................................................................................27
1.8.9 Power ................................................................................................................28
1.8.10 Spectroscopy...................................................................................................28
1.9 Advantages................................................................................................................29
1.9.1 Able to Transmit Large Quantities of Data.......................................................29
1.9.2 Relatively Low Costs........................................................................................29
1.10 Limitations..............................................................................................................30
1.10.1 Line of Sight Technology ...............................................................................30
1.10.2 Subject to Electromagnetic and Other Interference ........................................30

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Chapter-02 Antenna Basics..........................................................................................32
2.1 Antenna Basics: ........................................................................................................32
2.1.1 What is Antenna? :............................................................................................32
2.1.2 Basic Types of Antenna:...................................................................................32
2.2 Basics Parameter of Antenna:...................................................................................33
2.2.2 Gain:..................................................................................................................34
2.2.3 Directivity: ........................................................................................................34
2.2.4 Beamwidth:.......................................................................................................35
2.2.5 VSWR:..............................................................................................................35
2.2.6 Radiation Intensity:...........................................................................................35
2.2.7 Beam Efficiency:...............................................................................................35
2.3 Antenna Patterns:......................................................................................................36
2.3.1 Antenna Pattern:................................................................................................36
2.3.2 Antenna Field Types:........................................................................................36
2.3.3 Antenna Field Regions:.....................................................................................36
2.3.4 Antenna Pattern Definitions:.............................................................................36
2.3.5 Principal Plane Patterns: ...................................................................................37
2.3.6 Antenna Pattern Parameters..............................................................................37
2.4 Different types of antenna with their radiation patterns & characteristic:...........38
Chapter-03: Introduction of HFSS and Modeling of Dipole antenna......................44
3.1-What is HFSS? .........................................................................................................44
3.2: Installing HFSS software.........................................................................................45
3.2.1-System Requirements .......................................................................................45
3.2.2- Installing the Ansoft HFSS Software ..............................................................45
3.2.3- Starting Ansoft HFSS ......................................................................................45
3.3-Ansoft Terms............................................................................................................45
3.3.1-Project Manager- ..............................................................................................46
3.3.2-Property window...............................................................................................47
3.3.3-Ansoft 3D Modeler-..........................................................................................47
3.3.4-3D Modeler Design Tree ..................................................................................48
3.3.6-Toolbars ............................................................................................................49
3.3.7-Ansoft HFSS Desktop.......................................................................................49

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3.5-Set Solution Type .....................................................................................................50
3.6-Parametric Model Creation: .....................................................................................51
3.6.1-Overview of the 3D Modeler User Interface (Continued)................................51
3.7-The Dipole Antenna simulation by HFSS V.9.........................................................52
3.7.1-Getting started with HFSS 9.1:.........................................................................52
3.7.2-Opening a New Project.....................................................................................53
3.7.3-Creating the 3D Model .....................................................................................54
3.8-Create Dipole............................................................................................................54
3.8.1-Create waveguide..............................................................................................54
3.8.2- Drawing the Dipole..........................................................................................56
3.9- Creating the port......................................................................................................59
3.10- Radiation Boundary...............................................................................................63
3.11- Solution Setup .......................................................................................................65
3.12- Structure Analysis .................................................................................................66
3.13- Create Reports .......................................................................................................67
Chapter 4: Parametric Study: Horn Antenna ...........................................................73
4.1: Types of Horn Antennas..........................................................................................73
4.2: Horn antenna parameters .........................................................................................74
4.3: Modeling of Horn antenna in HFSS ........................................................................74
4.3.1: Getting started with HFSS 9.1:........................................................................74
4.3.2: Opening a New Project ....................................................................................75
4.3.3: Creating the 3D Model.....................................................................................76
4.3.4: Create Horn Top ..............................................................................................77
4.3.5: Create funnel base:...........................................................................................78
4.3.6: Create the funnel:.............................................................................................79
4.3.7: Complete the Horn...........................................................................................79
4.3.8: Create Air Box around the Horn Antenna .......................................................80
4.3.9: Assigning Boundaries and excitations.............................................................81
4.3.10: Create Radiation Boundary............................................................................82
4.3.11: Analysis Setup ...............................................................................................83
4.3.12: Model Validation ...........................................................................................84
4.3.13: Analyze ..........................................................................................................84
4.4: Creating Report........................................................................................................85
4.4.1: Create 3D Polar Far Field Plot.........................................................................85
4.4.2: Creating rectangular plot..................................................................................86

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4.5: Compute Antenna Parameter...................................................................................89
4.6 Create animation of Electric field and Magnetic field..............................................90
4.7 Simulation results of different types of Horn antenna..............................................91
4.7.1 Simulation Results for H-plane sectoral Horn antenna.....................................91
4.7.2 3D Polar plot for H-plane sectoral Horn:..........................................................91
4.7.3 Antenna parameters of H-sectoral Horn: ..........................................................92
4.7.4 Simulation Results for H-plane sectoral Horn antenna.....................................93
4.7.5 3D Polar plot for E-plane sectoral Horn: ..........................................................93
4.7.6 Antenna parameters of H-sectoral Horn: ..........................................................94
4.7.7 Simulation Results for Pyramidal Horn antenna...............................................95
4.7.8 3D Polar plot for E-plane sectoral Horn: ..........................................................95
4.7.9 Antenna parameters of Pyramidal Horn: ..........................................................96
4.7.10 Antenna as impedance matching device .........................................................97
4.7.11 Rectangular plot and radiation pattern of Directivity and Gain......................98
Chapter 5: Implementation of Horn Antenna .........................................................100
5.1 Equipments / Instruments .......................................................................................100
5.2 Diagram of instruments setup.................................................................................100
5.3 Procedure ................................................................................................................101
5.4 Tabular Column......................................................................................................101
5.5 Graphical Representation of the results..................................................................102
5.6 Snap shots of microwave test bench and Horn antenna..........................................102
5.6.1 Microwave test bench .....................................................................................102
5.6.2 Horn antenna...................................................................................................103
Chapter 6 Conclusion.................................................................................................105
References……………………………………………………………………………106
List of Tables
Table 1.1: IEEE Frequency Spectrum ............................................................................19
Table 5.1 Experimental Results....................................................................................101

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List of Figures
Fig 1.1: Microwave Communication System ............................................................16
Fig 1.2: Microwave transmitter and receiver.............................................................22
Fig 2.1: Receiving Antenna .......................................................................................32
Fig 2.2: Transmitting Antenna...................................................................................32
Fig 2.3: Propagation of TEM wave using transmitting & receiving antenna ............33
Fig 2.4: Antenna Pattern Parameters (Normalized Power Pattern) ...........................37
Fig 2.5: Monopole Antenna .......................................................................................38
Fig 2.6(a)&(b): Elevation...........................................................................................38
Fig 2.7: λ/2 Dipole Antenna.......................................................................................39
Fig 2.8(a)&(b): Elevation...........................................................................................39
Fig 2.9: Biconical Antenna ........................................................................................40
Fig 2.10(a): Elevation ................................................................................................40
Fig 2.10(b): Azimuth..................................................................................................40
Fig 2.11: Yagi Antenna..............................................................................................41
Fig 2.12(a)&(b): Elevation.........................................................................................41
Fig 2.13 Horn antenna................................................................................................42
Fig 2.14(a): Elevation (3 dB beamwidth = 56λ/dz) ...................................................42
Fig 2.14(b): Azimuth (3 dBbeamwidth = 70 8E/dx)..................................................42
Fig:3.1Differents terms of ansoft...............................................................................46
Fig:3.2 Differents terms of Project window...............................................................46
Fig:3.2(a) Differents terms of Property window........................................................47
Fig:3.2(b)Different terms of 3D modeler window....................................................47
Fig:3.2(c)Different terms of 3D model......................................................................48
Fig:3.3 Modeler design tree .......................................................................................48
Fig:3.4 Toolbars of ansoft HFSS ...............................................................................49
Fig:3.5 Ansoft desktop design tree. ...........................................................................50
Fig:3.6 Status bar .......................................................................................................51
Fig:3.7Active Cursor..................................................................................................51
Fig:3.8 Project menu window....................................................................................53
Fig: 3.9 Solution type window...................................................................................53
Fig. 3.10 Model Unit window....................................................................................54
Fig. 3.11 set the default material................................................................................54
Fig. 3.12 Property window........................................................................................55
Fig. 3.13 Final variable table ....................................................................................55
Fig. 3.14 Drawing dipole ...........................................................................................56
Fig. 3.15 appeared table by creating the dipole .........................................................57
Fig. 3.16 table from model menu..............................................................................57
Fig. 3.17 form the duplicate dipole in the 180 degree position ................................58
Fig. 3.18 Duplicate Around Axis window................................................................58
Fig. 3.19 Final dipole structure.................................................................................59
Fig:3.20 (a)&(b) Selecting YZ plane.........................................................................59

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Fig. 3.22 View of a 3D modeler window..................................................................60
Fig. 3.24 Port assumption .........................................................................................61
Fig. 3.25 Port assigning window................................................................................62
Fig. 3.26 HFSS window after assigning port.............................................................62
Fig. 3.27 Property window.........................................................................................63
Fig. 3.28 Property window.........................................................................................63
Fig:3.29 Select Face Window...................................................................................64
Fig:3.30 Select Radiation port ..................................................................................64
Fig:3.31 Select Setup window ...................................................................................65
Fig:3.32 Select Setup window ..................................................................................66
Fig:3.33 Validation Check Window ..........................................................................66
Fig. 3.34 Analyzing window......................................................................................67
Fig. 3.35 Select the result patterns .............................................................................67
Fig:3.36 Trace Window .............................................................................................68
Fig. 3.37 Rectangular plot.........................................................................................68
Fig. 3.38 (a) Define the air box as infinite sphere; (b) Compute antenna properties.69
Fig: 3.39 Results of antenna parameters ....................................................................69
Fig: 3.40 Display type................................................................................................70
Fig. 3.41 Traces Window...........................................................................................70
Fig. 3.43 Radiation pattern of Directivity..................................................................71
Fig: 4.1 H-plane sectoral horn....................................................................................73
Fig: 4.2 E-plane sectoral horn....................................................................................73
Fig: 4.3 Pyramidal horn .............................................................................................73
Fig: 4.4 Conical horn .................................................................................................73
Fig: 4.5 Project menu window...................................................................................75
Fig: 4.6 Solution type window...................................................................................75
Fig. 4.7 Model Unit window......................................................................................76
Fig. 4.8 Waveguide....................................................................................................76
Fig. 4.9 Waveguide and Funnel Base ........................................................................78
Fig. 4.10 Project menu...............................................................................................79
Fig. 4.11 Highlight the Horn top and funnel base......................................................79
Fig. 4.12 A complete horn after connection...............................................................80
Fig. 4.13 A complete horn after unite ........................................................................80
Fig. 4.14 An Air box outside the horn .......................................................................81
Fig. 4.15 Select Face window....................................................................................81
Fig. 4.16 Wave Port ...................................................................................................82
Fig. 4.17 Solution setup window ...............................................................................83
Fig: 4.18 Sweep setup window ..................................................................................83
Fig. 4.19 Validation Check Window .........................................................................84
Fig. 4.20 Analyzing window......................................................................................84
Fig. 4.21 3D Polar plot...............................................................................................85

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Fig. 4.22 Trace window .............................................................................................86
Fig. 4.23 Rectangular plot..........................................................................................87
Fig. 4.25 Rectangular plot for real and imaginary impedance of horn antenna.........88
Fig. 4.26 (a) Define the air box as infinite sphere; (b) Compute antenna properties.89
(c) Results of antenna parameters ..............................................................................89
Fig. 4.27(a) Electric field propagation animation (b) Magnetic field propagation
animation....................................................................................................................90
Fig. 4.28 H-plane sectoral horn..................................................................................91
Fig. 4.29 3D polar plot...............................................................................................91
Fig. 4.30 Antenna parameters of H-sectoral Horn.....................................................92
Fig. 4.31 E-plane sectoral horn..................................................................................93
Fig. 4.32 3D polar plot...............................................................................................93
Fig. 4.33 Antenna parameters of E-sectoral Horn .....................................................94
Fig: 4.34 Pyramidal horn ...........................................................................................95
Fig. 4.35 3D polar plot...............................................................................................95
Fig. 4.36 Antenna parameters of Pyramidal Horn .....................................................96
Fig. 4.37 Impedance parameter of waveguide ...........................................................97
Fig. 4.38Impedance parameter of pyramidal horn.....................................................97
Fig. 4.39 Rectangular plot of Directivity...................................................................98
Fig. 4.40 Radiation pattern of Directivity..................................................................98
Fig. 5.1 Measurement of Horn.................................................................................100
Fig. 5.2 Microwave bench set-up to measure the gain of horn antenna ..................100
Fig. 5.3 Gain Vs Distance Graph .............................................................................102
Fig. 5.4 Microwave test bench of UIU lab...............................................................102
Fig. 5.5 Pyramidal Horn antenna .............................................................................103
Fig. 5.6 Microwave test bench when horn antenna is connected.............................103

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Chapter 1
Introduction to
Microwave
Communication
System

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CHAPTER-1
INTRODUCTION TO MICROWAVE
COMMUNICATION SYSTEM
1.1 Introduction
Microwave communication is the transmission of signals via radio using a series of
microwave towers. Microwave communication is known as a form of “line of sight”
communication, because there must be nothing obstructing the transmission of data
between these towers for signals to be properly sent and received.
The term microwave is associated to electromagnetic waves of frequency of the order of
MHz .Since the energy carried by the wave is directly proportional to their frequency
they are of great use in distance communication. For a simple microwave
communication system, a radiator, a reflector and one receiver antenna are essential. As
the wave penetrates through the atmosphere a satellite reflector is usually used.
The objective of microwave communication systems is to transmit information from
one place to another without interruption, and clear reproduction at the receiver. Fig. 1.1
indicates how this is achieved in its simplest form.
Above 100 MHz the waves travel in straight lines and can therefore be narrowly
focused. Concentrating all the energy into a small beam using a parabolic antenna (like
the satellite TV dish) gives a much higher signal to noise ratio, but the transmitting and
receiving antennas must be accurately aligned with each other. Before the advent of
fiber optics, these microwaves formed the heart of the long distance telephone
transmission system.
In its simplest form the microwave link can be one hop, consisting of one pair of
antennas spaced as little as one or two kilometers apart, or can be a backbone, including
multiple hops, spanning several thousand kilometers. A single hop is typically 30 to 60
km in relatively flat regions for frequencies in the 2 to 8 GHz bands. When antennas are
placed between mountain peaks, a very long hop length can be achieved. Hop distances
in excess of 200 km are in existence.
The "line-of-sight" nature of microwaves has some very attractive advantages over
cable systems. Line of sight is a term which is only partially correct when describing
microwave paths. Atmospheric conditions and certain effects modify the propagation of
microwaves so that even if the designer can see from point A to point B (true line of

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sight), it may not be possible to place antennas at those two points and achieve a
satisfactory communication performance.
In order to overcome the problems of line-of-sight and power amplification of weak
signals, microwave systems use repeaters at intervals of about 25 to 30 km in between
the transmitting receiving stations. The first repeater is placed in line-of-sight of the
transmitting station and the last repeater is placed in line-of-sight of the receiving
station. Two consecutive repeaters are also placed in line-of-sight of each other. The
data signals are received, amplified, and re-transmitted by each of these stations.
Figure 1.1: Microwave Communication System
1.2 History
It is necessary in a study of the history of microwave communications to start with the
monumental discoveries and demonstrations in the fields of electrical communication
and the application of the principles of electromagnetic wave propagation to radio.
The history of microwave communications includes major discoveries of Morse,
Maxwell, Hertz, Marconi, and other pioneers of the radio and electronics fields. This
paper traces the early work which led to wireless communications and the long struggle
to achieve practical microwave radio. Even though the first microwave line-of-sight
systems were demonstrated and placed in service during the 1930's, it was not until the
late 1940's and early 1950's that huge transcontinental microwave transmission systems
were implemented. The 1960's and 1970's witnessed significant progress in the
technology and application of line-of-sight microwave communication systems. Other
microwave systems including troposcatter, satellite, and millimeter waveguide
transmission systems were also developed during the 1960's and 1970's. The past 100
Transmitter ReceiverInput Output
Transmission
line
Transmission
line

17
years have witnessed very significant breakthroughs in radio technology, particularly at
microwave frequencies, that have had an enormous impact on the world's societies
through improved communications for the populace, business, and governments.
Enormous strides in the development of microwave technology were made during
World War II, with the bulk of the effort aimed at radar systems. South worth’s
waveguide group at Bell Labs become heavily involved in this effort and invented many
waveguide components for radar, including waveguide lobe switches, rotary joints,
improved filters, waveguide modulators and demodulators, phasing devices, waveguide
hybrids including the magic-tee, directional couplers, attenuators, power measuring
devices and other instruments. While these components were extremely useful for the
radar work, they were also applicable for communication systems.
The technology used for microwave communication was developed in the early 1940’s
by Western Union. The first microwave message was sent in 1945 from towers located
in New York and Philadelphia. Following this successful attempt, microwave
communication became the most commonly used data transmission method for
telecommunications service providers.
1.3 Why use microwaves
Communication using electromagnetic radiation (except for light) began early in this
century, and most early practical systems used very long wavelengths (low frequencies)
which traveled great distances. Eventually, electronics were developed, including the
vacuum tube (or "valve") which allowed controlled frequencies and modulation. This
led to the use of higher frequencies, many channels, and commercial and industrial
radio. During the 1930's and 1940's various experimenters discovered that higher
frequencies could bring other advantages to communications. Some of these
experimenters were government agencies and the military - some were universities, and
some were private individuals.
Among these discoveries were that microwaves are easier to control (than longer
wavelengths) because small antennas could direct the waves very well. One advantage
of such control is that the energy could be easily confined to a tight beam (expressed as
narrow beam width). This beam could be focused on another antenna dozens of miles
away, making it very difficult for someone to intercept the conversation. Another
characteristic is that because of their high frequency, greater amounts of information
could be put on them (expressed as increased modulation bandwidth). Both of these
advantages (narrow beam width and modulation bandwidth) make microwaves very
useful for RADAR as well as communications.
Eventually, these qualities led to the use of microwaves by the telephone companies.
They placed towers every 30 to 60 miles each with antennas, receivers and transmitters.
These would relay hundreds or even thousands of voice conversations across the
country. The ability to modulate with a wide bandwidth permitted so many

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conversations on just one signal, and the reduction in beam width made this reasonably
secure. In the 1950s experiments were conducted that showed the potential to connect
the two coasts of the US via these microwave circuits to produce television
programming on a continental basis, and true television networks were born.
Amateur radio interests in microwaves have mostly been for the challenge of working
with such esoteric frequencies that require specialized techniques in design, fabrication
and testing. Furthermore, in order to reach beyond LOS (line-of-sight) amateurs have
spent countless hours carefully measuring propagation phenomena. Amateurs have
carried on conversations using 10GHz well over 1,000 miles, and have bounced signals
at that frequency off the moon. For more information about amateur radio uses of
microwaves set your browser to www.wa1mba.org, contact a local VHF/Microwave
Amateur radio club, or contact the ARRL.
A photon is a quantum of electromagnetic energy. Physicists think of electromagnetic
energy as having a "dual nature", in that some experiments reveal its nature as a particle
which we call a photon and other experiments reveal its nature as a wave.
When it comes to lower frequencies (longer wavelengths), such as microwaves, VHF,
and the like, it becomes much less convenient to think of energy in the form of photons,
but there is no specific reason to decide that only one nature exists at these longer
wavelengths. Sometimes photons are referred to when describing an RF interaction with
matter. The author does not know of any other word to describe the particulate nature of
a propagating RF energy field except "photon". When the interaction with matter
converts the energy into a mechanical form, we sometimes refer to the energy packets
as "phonons". This is not a propagating Electro-Magnetic (EM) field, but rather a sound
wave, and at the most minute level, even mechanical energy is quantized.
In most antenna, transmission line, waveguide, and quasi-optic formulations, the EM
field is described according to its wave-like nature. When dealing with the interaction
between a microwave field and a molecule of Oxygen (for instance), in order to
understand just why there are specific resonant frequencies of the molecule, a quantized
nature re-appears, and the notion of the field expressed as photons can make sense.
The interactions between matter and EM fields have clearly different properties when
comparing the interaction that causes a change in mechanical vibration with the
interaction that causes a change in electron orbital state. The first occurs in the
microwave and millimeter wave range - such as the serious absorption of 22 GHz
signals by water vapor in the atmosphere. Here the interaction causes vibration and
heat. To cause changes in electron orbital states, infrared, visible and UV range
wavelengths are involved - such as is evidenced by florescence and lasers. In these
cases much more than conversion to heat occurs. We call the second group of
wavelengths "light" and the word "photon" is derived from Greek for light.

19
Here are some frequency bands, exact frequencies, approximate wavelength and their
applications.
Table 1.1: IEEE Frequency Spectrum
SL.
No
Frequency Band Frequency Wavelength Application
1
ELF (Extreme Low
Frequency)
30-300 Hz
10,000-1,000
km
Radio band & radio
communication
2
VF (Voice
Frequency)
300-3,000 Hz
1,000-100
km
Transmits voice signal
3
VLF (Very Low
Frequency)
3-30 kHz 100-10 km
Communicate with
submarines near the
surface, radio navigation
beacons (alpha) and time
signals (beta),
electromagnetic
geophysical surveys
4 LF (Low Frequency) 30-300 kHz 10-1 km
AM broadcasting as the
long wave band, aircraft
beacon, navigation
(LORAN), information,
and weather systems
5
MF (Medium
Frequency)
300-3,000
kHz
1-0.1 km
Non-directional
navigational radio
beacons (NDBs) for
maritime and aircraft
navigation
6
HF (High
Frequency)
3-30 MHz 100-10 m
Amateur radio operators,
who can take advantage
of direct, long-distance
(often inter-continental)
communications and the
"thrill factor" resulting
from making contacts in
variable conditions
7
VHF (Very High
Frequency)
30-300 MHz 10-1 m
Identify faults and
defects in ceramic
insulators
8
UHF (Ultra High
Frequency )
300-3,000
MHz
100-10 cm
Transmission of
television signals

20
9
SHF (Super High
Frequency)
3-30 GHz 10-1 cm
Microwave devices,
WLAN, most modern
radars
10
EHF (Extreme High
Frequency)
30-300 GHz 1-0.1 cm
Radio astronomy and
remote sensing
11 Decimillimeter
300-3,000
GHz
1-0.1 mm
Transmits signal
12 P Band 0.23-1 GHz 130-30 cm
Radar
13 L Band 1-2 GHz 30-15 cm
Satellite
14 S Band 2-4 GHz 15-7.5 cm
Weather radar, surface
ship radar, and some
communications
satellites, especially
those used by NASA to
communicate with the
Space Shuttle and the
International Space
Station
15 C Band 4-8 GHz 7.5-3.75 cm
Long-distance radio
telecommunications
16 X Band 8-12.5 GHz 3.75-2.4 cm
Radar receivers,
electronic counter
measures, decoys,
jammers, and phased
array systems
17 Ku Band 12.5-18 GHz 2.4-1.67 cm
Satellite communications
18 K Band 18-26.5 GHz 1.67-1.13 cm
Conforming bandage to
hold dressings in place
19 Ka Band 26.5-40 GHz 1.13-0.75 cm
Satellite communication
20 Millimeter wave 40-300 GHz 7.5-1 mm
Transmitting large
amounts of computer
data, cellular
communications, and
radar
21 Sub millimeter wave
300-3,000
GHz
1-0.1 mm
Pulsed magnetic field

21
1.4 Microwave sources
Vacuum tube devices operate on the ballistic motion of electrons in a vacuum under the
influence of controlling electric or magnetic fields, and include the magnetron, klystron,
traveling-wave tube (TWT), and gyrotron. These devices work in the density modulated
mode, rather than the current modulated mode. This means that they work on the basis
of clumps of electrons flying ballistically through them, rather than using a continuous
stream.
Cut away view inside a cavity magnetron as used in a microwave oven.
Low power microwave sources use solid-state devices such as the field-effect transistor
(at least at lower frequencies), tunnel diodes, Gunn diodes, and IMPATT diodes.
A maser is a device similar to a laser, which amplifies light energy by stimulating the
emitted radiation. The maser, rather than amplifying light energy, amplifies the lower
frequency, longer wavelength microwaves.
The sun also emits microwave radiation, and most of it is blocked by Earth's
atmosphere.
The Cosmic Microwave Background Radiation (CMBR) is a source of microwaves that
supports the science of cosmology's Big Bang theory of the origin of the Universe.
1.5 Microwave Transmitter and Receiver
Fig.1.2 below shows block diagram of microwave link transmitter and receiver section
The voice, video, or data channels are combined by a technique known as multiplexing
to produce a BB signal. This signal is frequency modulated to an IF and then up
converted (heterodyned) to the RF for transmission through the atmosphere. The reverse
process occurs at the receiver. The microwave transmission frequencies are within the
approximate range 2 to 24 GHz.

22
Figure 1.2: Microwave transmitter and receiver
The frequency bands used for digital microwave radio are recommended by the CCIR.
Each recommendation clearly defines the frequency range, the number of channels that
can be used within that range, the channel spacing the bit rate and the polarization
possibilities.
1.6 Microwave Link Networks
A microwave link is a communications system that uses a beam of radio waves in the
microwave frequency range to transmit information between two fixed locations on the
earth. They are crucial to many forms of communication and impact a broad range of
industries. Broadcasters use microwave links to send programs from the studio to the
transmitter location, which might be miles away. Microwave links carry cellular
telephone calls between cell sites. Wireless Internet service providers use microwave
links to provide their clients with high-speed Internet access without the need for cable
connections. Telephone companies transmit calls between switching centers over
microwave links, although fairly recently they have been largely supplanted by fiber-
optic cables. Companies and government agencies use them to provide communications
networks between nearby facilities within an organization, such as a company with
several buildings within a city.

23
One of the reasons microwave links are so adaptable is that they are broadband. That
means they can move large amounts of information at high speeds. Another important
quality of microwave links is that they require no equipment or facilities between the
two terminal points, so installing a microwave link is often faster and less costly than a
cable connection. Finally, they can be used almost anywhere, as long as the distance to
be spanned is within the operating range of the equipment and there is clear path (that
is, no solid obstacles) between the locations. Microwaves are also able to penetrate rain,
fog, and snow, which mean bad weather doesn’t disrupt transmission.
A simplified rendering of a microwave link. A microwave link is a communications
system that uses a beam of radio waves in the microwave frequency range to transmit
information between two fixed locations on the earth.
A simple one-way microwave link includes four major elements: a transmitter, a
receiver, transmission lines, and antennas. These basic components exist in every radio
communications system, including cellular telephones, two-way radios, wireless
networks, and commercial broadcasting. But the technology used in microwave links
differs markedly from that used at the lower frequencies (longer wavelengths) in the
radio spectrum. Techniques and components that work well at low frequencies are not
useable at the higher frequencies (shorter wavelengths) used in microwave links. For
example, ordinary wires and cables function poorly as conductors of microwave signals.
On the other hand, microwave frequencies allow engineers to take advantage of certain
principles that are impractical to apply at lower frequencies. One example is the use of a
parabolic or “dish” antenna to focus a microwave radio beam. Such antennas can be
designed to operate at much lower frequencies, but they would be too large to be
economical for most purposes.
In a microwave link the transmitter produces a microwave signal that carries the
information to be communicated. That information—the input—can be anything
capable of being sent by electronic means, such as a telephone call, television or radio
programs, text, moving or still images, web pages, or a combination of those media.
The transmitter has two fundamental jobs: generating microwave energy at the required
frequency and power level, and modulating it with the input signal so that it conveys
meaningful information. Modulation is accomplished by varying some characteristic of
the energy in response to the transmitter’s input. Flashing a light to transmit a message
in Morse Code is an example of modulation. The differing lengths of the flashes (the
dots and dashes), and the intervals of darkness between them, convey the information—
in this case a text message.
The second integral part of a microwave link is a transmission line. This line carries the
signal from the transmitter to the antenna and, at the receiving end of the link, from the
antenna to the receiver. In electrical engineering, a transmission line is anything that
conducts current from one point to another. Lamp cord, power lines, telephone wires
and speaker cable are common transmission lines. But at microwave frequencies, those

24
media excessively weaken the signal. In their place, engineers use coaxial cables and,
especially, hollow pipes called waveguides.
The third part of the microwave system is the antennas. On the transmitting end, the
antenna emits the microwave signal from the transmission line into free space. “Free
space” is the electrical engineer’s term for the emptiness or void between the
transmitting and receiving antennas. It is not the same thing as “the atmosphere,”
because air is not necessary for any type of radio transmission (which is why radio
works in the vacuum of outer space). At the receiver site, an antenna pointed toward the
transmitting station collects the signal energy and feeds it into the transmission line for
processing by the receiver.
Antennas used in microwave links are highly directional, which means they tightly
focus the transmitted energy, and receive energy mainly from one specific direction.
This contrasts with antennas used in many other communications systems, such as
broadcasting. By directing the transmitter’s energy where it's needed—toward the
receiver—and by concentrating the received signal, this characteristic of microwave
antennas allows communication over long distances using small amounts of power.
Between the link’s antennas lies another vital element of the microwave link—the path
taken by the signal through the earth’s atmosphere. A clear path is critical to the
microwave link’s success. Since microwaves travel in essentially straight lines, man-
made obstacles (including possible future construction) that might block the signal must
either be overcome by tall antenna structures or avoided altogether. Natural obstacles
also exist. Flat terrain can create undesirable reflections, precipitation can absorb or
scatter some of the microwave energy, and the emergence of foliage in the spring can
weaken a marginally strong signal, which had been adequate when the trees were bare
in the winter. Engineers must take all the existing and potential problems into account
when designing a microwave link.
At the end of the link is the final component, the receiver. Here, information from the
microwave signal is extracted and made available in its original form. To accomplish
this, the receiver must demodulate the signal to separate the information from the
microwave energy that carries it. The receiver must be capable of detecting very small
amounts of microwave energy, because the signal loses much of its strength on its
journey.
This entire process takes place at close to the speed of light, so transmission is virtually
instantaneous even across long distances. With all of their advantages, microwave links
are certain to be important building blocks of the world’s communications infrastructure
for years to come.

25
1.7 Forms of microwave communication
Microwave communication takes place both analog and digital formats. While digital is
the most advanced form of microwave communication, both analog and digital methods
pose certain benefits for users.
1.7.1 Analog microwave communication
Analog microwave communication systems originated in the 1950s and their
development over subsequent decades has witnessed evolution from analog to digital
and from PDH to SDH. Higher modulation efficiency, greater bandwidth, longer
transmission distances, and enhanced reliability denote continual progress that remains
essentially market driven.
Analog microwave communication systems, operated at a frequency of two gigahertz (2
GHz), have been used by railroad companies, power companies, pipeline operators and
state and local governments to support private networks for voice and data
communication.
1.7.2 Digital microwave communication
Digital microwave communication refers to a type of communication mode which uses
microwave (frequency) to carry digital information through the electric wave space,
transmit independent information and conduct regeneration. Microwave is weak in
diffraction and it is only line-of-sight communication, therefore, it has a limited
transmission distance. In long-distance transmission, relay is needed to connect sites.
Thus, it is called microwave relay communication.
Digital microwave communication utilizes more advanced, more reliable technology. It
is much easier to find equipment to support this transmission method because it is the
newer form of microwave communication. Because it has a higher bandwidth, it also
allows transmitting more data using more verbose protocols. The increased speeds will
also decrease the time it takes to poll microwave site equipment. This is more reliable
format provides for more reliable reporting with advanced communication equipment,
while also allowing to bring in LAN connection when it becomes available at the site.

26
1.8 Applications
Microwave communication systems handle a large fraction of the world’s international
and other long haul telephone, data and television transmissions.
Most of the currently developing wireless telecommunications systems, such as direct
broadcast satellite (DBS) television, personal communication systems (PCSs), wireless
local area networks (WLANS), cellular video (CV) systems and global positioning
satellite (GPS) systems rely heavily on microwave technology.
1.8.1 Long distance telephone calls
Before the advent of fiber-optic transmission, most long distance telephone calls were
carried via networks of microwave radio relay links run by carriers such as AT&T Long
Lines. Starting in the early 1950s, frequency division multiplex was used to send up to
5,400 telephone channels on each microwave radio channel, with as many as ten radio
channels combined into one antenna for the hop to the next site, up to 70 km away.
1.8.2 Wireless LAN protocols
Wireless LAN protocols, such as Bluetooth and the IEEE 802.11 specifications, also
use microwaves in the 2.4 GHz ISM band, although 802.11a uses ISM band and U-NII
frequencies in the 5 GHz range. Licensed long-range (up to about 25 km) Wireless
Internet Access services have been used for almost a decade in many countries in the
3.5–4.0 GHz range. The FCC recently carved out spectrum for carriers that wish to
offer services in this range in the U.S. — with emphasis on 3.65 GHz. Dozens of
service providers across the country are securing or have already received licenses from
the FCC to operate in this band. The WIMAX service offerings that can be carried on
the 3.65 GHz band will give business customers another option for connectivity.
1.8.3 Metropolitan area networks
MAN protocols, such as WiMAX (Worldwide Interoperability for Microwave Access)
based in the IEEE 802.16 specification. The IEEE 802.16 specification was designed to
operate between 2 to 11 GHz. The commercial implementations are in the 2.3 GHz, 2.5
GHz, 3.5 GHz and 5.8 GHz ranges.
1.8.4 Wide Area Mobile Broadband Wireless Access
MBWA protocols based on standards specifications such as IEEE 802.20 or
ATIS/ANSI HC-SDMA (e.g. iBurst) are designed to operate between 1.6 and 2.3 GHz
to give mobility and in-building penetration characteristics similar to mobile phones but
with vastly greater spectral efficiency.

27
Some mobile phone networks, like GSM, use the low-microwave/high-UHF
frequencies around 1.8 and 1.9 GHz in the America and elsewhere, respectively. DVB-
SH and S-DMB use 1.452 to 1.492 GHz, while proprietary/incompatible satellite radio
in the U.S. uses around 2.3 GHz for DARS.
Microwave radio is used in broadcasting and telecommunication transmissions because,
due to their short wavelength, highly directional antennas are smaller and therefore
more practical than they would be at longer wavelengths (lower frequencies). There is
also more bandwidth in the microwave spectrum than in the rest of the radio spectrum;
the usable bandwidth below 300 MHz is less than 300 MHz while many GHz can be
used above 300 MHz. Typically, microwaves are used in television news to transmit a
signal from a remote location to a television station from a specially equipped van. See
broadcast auxiliary service (BAS), remote pickup unit (RPU), and studio/transmitter
link (STL).
1.8.5 Satellite communications systems
Most satellite communications systems operate in the C, X, Ka, or Ku bands of the
microwave spectrum. These frequencies allow large bandwidth while avoiding the
crowded UHF frequencies and staying below the atmospheric absorption of EHF
frequencies. Satellite TV either operates in the C band for the traditional large dish
fixed satellite service or Ku band for direct-broadcast satellite. Military communications
run primarily over X or Ku-band links, with Ka band being used for Milstar.
1.8.6 Radar
Radar uses microwave radiation to detect the range, speed, and other characteristics of
remote objects. Development of radar was accelerated during World War II due to its
great military utility. Now radar is widely used for applications such as air traffic
control, weather forecasting, navigation of ships, and speed limit enforcement.
1.8.7 Radio astronomy
Most radio astronomy uses microwaves. Usually the naturally-occurring microwave
radiation is observed, but active radar experiments have also been done with objects in
the solar system, such as determining the distance to the Moon or mapping the invisible
surface of Venus through cloud cover.
1.8.8 Navigation
Global Navigation Satellite Systems (GNSS) including the Chinese Beidou, the
American Global Positioning System (GPS) and the Russian GLONASS broadcast
navigational signals in various bands between about 1.2 GHz and 1.6 GHz.

28
1.8.9 Power
A microwave oven passes (non-ionizing) microwave radiation (at a frequency near 2.45
GHz) through food, causing dielectric heating by absorption of energy in the water, fats
and sugar contained in the food. Microwave ovens became common kitchen appliances
in Western countries in the late 1970s, following development of inexpensive cavity
magnetrons. Water in the liquid state possesses many molecular interactions which
broaden the absorption peak. In the vapor phase, isolated water molecules absorb at
around 22 GHz, almost ten times the frequency of the microwave oven.
Microwave heating is used in industrial processes for drying and curing products.
Many semiconductor processing techniques use microwaves to generate plasma for
such purposes as reactive ion etching and plasma-enhanced chemical vapor deposition
(PECVD).
Microwave frequencies typically ranging from 110 – 140 GHz are used in stellarators
and more notably in tokamak experimental fusion reactors to help heat the fuel into a
plasma state. The upcoming ITER Thermonuclear Reactor is expected to range from
110–170 GHz and will employ Electron Cyclotron Resonance Heating (ECRH).
Microwaves can be used to transmit power over long distances, and post-World War II
research was done to examine possibilities. NASA worked in the 1970s and early 1980s
to research the possibilities of using solar power satellite (SPS) systems with large solar
arrays that would beam power down to the Earth's surface via microwaves.
Less-than-lethal weaponry exists that uses millimeter waves to heat a thin layer of
human skin to an intolerable temperature so as to make the targeted person move away.
A two-second burst of the 95 GHz focused beam heats the skin to a temperature of 130
°F (54 °C) at a depth of 1/64th of an inch (0.4 mm). The United States Air Force and
Marines are currently using this type of Active Denial System.
1.8.10 Spectroscopy
Microwave radiation is used in electron paramagnetic resonance (EPR or ESR)
spectroscopy, typically in the X-band region (~9 GHz) in conjunction typically with
magnetic fields of 0.3 T. This technique provides information on unpaired electrons in
chemical systems, such as free radicals or transition metal ions such as Cu(II). The
microwave radiation can also be combined with electrochemistry, microwave enhanced
electrochemistry.

29
1.9 Advantages
The various advantages of microwave communications are as follows:
• Large bandwidth availability
• Less power requirement with the use of repeaters
• Easily penetrable to the areas like even the ionosphere
• Line of sight propagation
• Reduces the size of the antenna
• Can accommodate more number of channels
• No cabling needed between sites
• Multichannel transmission
• Provides a high data rate
• Cost of purchasing towers for transmission is pretty low
1.9.1 Able to Transmit Large Quantities of Data
According to "Microwave Communication," microwave radio systems have the
capacity to broadcast great quantities of information because of their higher frequencies.
They use repeaters (a device that receives the transmitting signal through one antenna,
converts it into an electrical signal and retransmits it) to transmit large volumes of data
over great distances. Microwave radio communication systems propagate signals
through the earth's atmosphere. These signals are sent between transmitters and
receivers that lie on top of towers. This allows microwave radio systems to transmit
thousands of data channels between two points without relying on a physical
transmitting medium (optical fibers or metallic cables).
1.9.2 Relatively Low Costs
Microwave communication systems have relatively low construction costs compared
with other forms of data transmission, such as wire-line technologies. A microwave
communication system does not require physical cables or expensive attenuation
equipment (devices that maintain signal strength during transmission). Mountains, hills
and rooftops provide inexpensive and accessible bases for microwave transmission
towers.

30
1.10 Limitations
With the development of satellite and cellular technologies, microwave has become less
widely used in the telecommunications industry. Fiber-optic communication is now the
dominant data transmission method. However, microwave communication equipment is
still in use at many remote sites where fiber-optic cabling cannot be economically
installed.
The limitations of microwave communications are as follows:
• Line-of-sight will be disrupted if any obstacle, such as new buildings, are in the
way
• Signal absorption by the atmosphere. Microwaves suffer from attenuation due to
atmospheric conditions
• Towers are expensive to build
1.10.1 Line of Sight Technology
Microwave radio systems are a line of sight technology, meaning the signals will not
pass through objects (e.g., mountains, buildings and airplanes). This drawback limits
microwave communication systems to line of sight operating distances. Signals flow
between one fixed point to another, provided no solid obstacle disrupts the flow.
1.10.2 Subject to Electromagnetic and Other Interference
According to "Rural America at the Crossroads: Networking for the Future," microwave
radio signals are affected by electromagnetic interference (EMI). EMI is any
disturbance that degrades, obstructs or interrupts the performance of microwave signals.
Microwave signal disruption EMI is caused by electric motors, electric power
transmission lines, wind turbines, television/radio stations and cell phone transmission
towers. Wind turbines, for instance, scatter and diffract TV, radio and microwave
signals when placed between signal transmitters and receivers. Microwave radio
communication is also affected by heavy moisture, snow, vapor, rain and fog due to rain
fade (the absorption of microwave signals by ice, snow or rain, causing signal
degradation and distortion).
…………………………………………………………………………………………….

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Chapter-02 Antenna Basics
2.1 Antenna Basics:
2.1.1 What is Antenna? :
An antenna is a conductor that can transmit, send and receive signals such as
microwave, radio or satellite signals. A high-gain antenna increases signal strength,
where a low-gain antenna receives or transmits over a wide angle.
In other words : An antenna is a specialized transducer that converts radio-frequency
(RF) fields into alternating current (AC) or vice-versa or a device used for radiating or
receiving radio waves. Antenna is also known as aerial. Any one of the paired
segmented, and movable sensory appendages occurring on the heads of many
arthropods.There are two basic types: the receiving antenna, which intercepts RF energy
and delivers AC to electronic equipment, and the transmitting antenna, which is fed
with AC from electronic equipment and generates an RF field.
2.1.2 Basic Types of Antenna:
There are two basic types:
1. Receiving antenna
2. Transmitting antenna
Receiving antenna:
This is which intercepts RF energy and delivers AC to electronic equipment.
Fig 2.1: Receiving Antenna
The receiver is represented by its input impedance as seen from the antenna terminals
(i.e. transformed by the transmission line).
Transmitting antenna:
It’s an antenna which is fed with AC from electronic equipment and generates an RF
field.
Fig 2.2: Transmitting Antenna

33
The transmitter is represented by its input impedance (which is frequency-dependent
and is influenced by objects nearby) as seen from the generator.
Fig 2.3: Propagation of TEM wave using transmitting & receiving antenna
Except this basis two types there are many antennas in our communication system. Such
as: Horn antenna, monopole antenna,band antenna,long wire antenna,corner
antenna,refletor antenna,cubical quad antenna,rhombic antenna,plasma antenna,mobile
phone detetor antenna,GPS antenna,groundplane antenna,metal-plate antenna,liquid
metal antenna,yagi antenna.
2.2 Basics Parameter of Antenna:
Basic parameter of antenna includes the radiation patterns, gain, directivity, beam lob,
beam width etc.
2.2.1 Radiation pattern:
The radiation pattern of antenna is a representation (pictorial or mathematical) of the
distribution of the power out-flowing (radiated) from the antenna (in the case of
transmitting antenna), or inflowing (received) to the antenna (in the case of receiving
antenna) as a function of direction angles from the antenna.
• Antenna radiation pattern (antenna pattern):
– is defined for large distances from the antenna, where the spatial (angular) distribution
of the radiated power does not depend on the distance from the radiation source
– is independent on the power flow direction: it is the same when the antenna is used to
transmit and when it is used to receive radio waves
– is usually different for different frequencies and different polarizations of radio wave
radiated/ received
The Basic equation of radiation may be expressed simply as
ÍL=Qú (Ams-1
)

34
Where,
Í=Time-changing current, As-1
L=Length of current element, m
Q=Charge, C
Ú=Time change of velocity which equals the acceleration of the charge, ms-2
2.2.2 Gain:
Antenna gain relates the intensity of an antenna in a given direction to the intensity that
would be produced by a hypothetical ideal antenna that radiates equally in all directions
(isotropically) and has no losses.
The gain is a measure of how much of the input power is concentrated in a particular
direction. It is expressed with respect to a hypothetical isotropic antenna, which radiates
equally in all directions. Thus in the direction (q, f), the gain is
G (q, f) = (dP/dW)/ (Pin /4p)
Where Pin is the total input power and dP is the increment of radiated output power in
solid angle dW. The gain is maximum along the boresight direction.
The input power is Pin = Ea
2
A / h Z0 where Ea is the average electric field over the area
A of the aperture, Z0 is the impedance of free space, and h is the net antenna efficiency.
The output power over solid angle dW is dP = E2
r2
dW/ Z0, where E is the electric field
at distance r. But by the Fraunhofer theory of diffraction, E = Ea A / r l along the
boresight direction, where l is the wavelength. Thus the boresight gain is given in terms
of the size of the antenna by the important relation as
G = h (4 p / l2
) A
This equation determines the required antenna area for the specified gain at a given
wavelength. The net efficiency h is the product of the aperture taper efficiency ha, which
depends on the electric field distribution over the antenna aperture (it is the square of
the average divided by the average of the square), and the total radiation efficiency h *
= P/Pin associated with various losses. These losses include spillover, ohmic heating,
phase nonuniformity, blockage, surface roughness, and cross polarization. Thus h = ha h
*. For a typical antenna, h = 0.55.
2.2.3 Directivity:
Directivity (D): the ratio of the radiation intensity in a given direction from the antenna
to the radiation intensity averaged over all directions.
D (θ,φ) = U(θ,φ)/Uavg = 4πU(θ,φ)/Prad

35
The directivity of an isotropic radiator is D (θ,φ) = 1.
The maximum directivity is defined as [D (θ,φ)]max = Do.
The directivity range for any antenna is 0≤D (θ,φ)≤Do.
Directivity in dB:
D(θ,φ) [dB] = 10log10d(θ,φ)
2.2.4 Beamwidth:
The beamwidth is a measure of how much the frequency can be varied while still
obtaining an acceptable VSWR (2:1 or less) and minimizing losses in unwanted
directions.
Half-power beamwidth (HPBW): Half-power beamwidth is the angle between two
vectors from the pattern’s origin to the points of the major lobe where the radiation
intensity is half its maximum
First-null beamwidth (FNBW): First-null beamwidth is the angle between two
vectors, originating at the pattern’s origin and tangent to the main beam at its base.
Often FNBW ≈ 2*HPB
2.2.5 VSWR:
The Voltage Standing Wave Ratio (VSWR) is an indication of the amount of mismatch
between an antenna and the feed line connecting to it. The range of values for VSWR is
from 1 to ∞. A VSWR value under 2 is considered suitable for most antenna
applications. The antenna can be described as having a good match.
2.2.6 Radiation Intensity:
The power radiated from an antenna per unit solid angle is called the radiation intensity
U (watts per steradian or per square degree). The normalized power pattern can also be
expressed in terms of this parameter as the ratio of the radiation intensity U(θ, φ), as a
function of angle, to its maximum value. Thus,
Pn(θ, φ) = U(θ, φ)/U(θ, φ)max
= S(θ, φ)/S(θ, φ)max
Whereas the Poynting vector S depends on the distance from the antenna (varying
inversely as the square of the distance), the radiation intensity U is independent of the
distance, assuming in both cases that we are in the far field of the antenna.
2.2.7 Beam Efficiency:
The (total) beam area ΩA (or beam solid angle) consists of the main beam area (or solid
angle) ΩM plus the minor-lobe area (or solid angle) Ωm. Thus,
ΩA = ΩM + Ωm

36
The ratio of the main beam area to the (total) beam area is called the (main) beam
efficiency εM. Thus,
Beam efficiency = εM
= ΩM/ΩA (dimensionless)
The ratio of the minor-lobe area (_m) to the (total) beam area is called the stray factor.
Thus,
Stray Factor =ε m
= Ωm/ΩA
It follows that,
ε M + ε m = 1
2.3 Antenna Patterns:
2.3.1 Antenna Pattern:
A graphical representation of the antenna radiation properties as a function of position
(spherical coordinates).
Common Types of Antenna Patterns
• Power Pattern - normalized power vs. spherical coordinate position.
• Field Pattern - normalized /E/ or /H/ vs. spherical coordinate position.
2.3.2 Antenna Field Types:
• Reactive field - the portion of the antenna field characterized by standing
(stationary) waves which represent stored energy.
• Radiation field - the portion of the antenna field characterized by radiating
(propagating) waves which represent transmitted energy.
2.3.3 Antenna Field Regions:
• Reactive Near Field Region - the region immediately surrounding the antenna
where the reactive field (stored energy – standing waves) is dominant.
• Near-Field (Fresnel) Region - the region between the reactive nearfield and the
far-field where the radiation fields are dominant and the field distribution is
dependent on the distance from the antenna.
• Far-Field (Fraunhofer) Region - the region farthest away from the antenna
where the field distribution is essentially independent of the distance from the
antenna (propagating waves).
2.3.4 Antenna Pattern Definitions:
• Isotropic Pattern - an antenna pattern defined by uniform radiation in all
directions, produced by an isotropic radiator (point source, a non-physical
antenna which is the only nondirectional antenna).

37
• Directional Pattern - a pattern characterized by more efficient radiation in one
direction than another (all physically realizable antennas are directional
antennas).
• Omnidirectional Pattern - a pattern which is uniform in a given plane.
2.3.5 Principal Plane Patterns:
The E-plane and H-plane patterns for a linearly polarized antenna:
• E-plane - the plane containing the electric field vector and the direction of
maximum radiation.
• H-plane - the plane containing the magnetic field vector and the direction of
maximum radiation.
2.3.6 Antenna Pattern Parameters
• Radiation Lobe - a clear peak in the radiation intensity surrounded by regions
of weaker radiation intensity.
• Main Lobe (major lobe, main beam) - radiation lobe in the direction of
maximum radiation.
• Minor Lobe - any radiation lobe other than the main lobe.
• Side Lobe - a radiation lobe in any direction other than the direction(s) of
intended radiation.
• Back Lobe - the radiation lobe opposite to the main lobe.
Fig 2.4: Antenna Pattern Parameters (Normalized Power Pattern)

38
2.4 Different types of antenna with their radiation patterns &
characteristic:
Some different types of antenna with their radiation patterns and characteristics are
given below:
1. Monopole Antenna:
Fig 2.5: Monopole Antenna
Radiation Pattern:
Fig 2.6(a): Elevation Fig 2.6(b): Azimuth
Characteristics:
Polarization: Linear, vertical as shown
Typical Half-Power Beamwidth: 45 deg x 360 deg
Typical Gain: 2-6 dB at best
Remarks: Polarization changes to horizontal if rotated to horizontal.

39
2. λ/2 Dipole Antenna:
Fig 2.7: λ/2 Dipole Antenna
Radiation Pattern:
Characteristics:
Polarization: Linear, vertical as shown
Typical Gain: 2 dB
Remarks: Pattern and lobing changes significantly with L/f. Used as a gain reference <
2 GHz.

40
3. Biconical Antenna:
Fig 2.9: Biconical Antenna
Radiation Pattern:
Characteristics:
Polarization: Linear, Vertical as shown
Typical Half-Power Beamwidth:
20-100 deg x 360 deg
Typical Gain: 0-4 dB

41
4. Yagi Antenna:
Fig 2.11: Yagi Antenna
Radiation Pattern:
Characteristics:
Polarization: Linear, horizontal as shown
Typical Half-Power Beamwidth: 50 deg X 50 deg
Typical Gain: 5 to 15 dB

42
5. Horn Antenna:
Fig 2.13 Horn antenna
Radiation Pattern:
Characteristics:
Polarization: Linear
Typical Gain: 5 to 20 dB
………………………………………………………………………………………….....

43
Chapter 3
Introduction of HFSS
and
Modeling of Dipole
antenna

44
Chapter-03: Introduction of HFSS and
Modeling of Dipole antenna
3.1-What is HFSS?
HFSS is a high-performance full-wave electromagnetic (EM) field simulator for
arbitrary 3D volumetric passive device modeling that takes advantage of the familiar
Microsoft Windows graphical user interface. It integrates simulation, visualization,
solid modeling, and automation in an easy-to-learn environment where solutions to your
3D EM problems are quickly and accurately obtained. Ansoft HFSS employs the Finite
Element Method (FEM), adaptive meshing, and brilliant graphics to give you
unparalleled performance and insight to all of your 3D EM problems. Ansoft HFSS can
be used to calculate parameters such as SParameters, Resonant Frequency, and Fields.
Typical uses include:
1. Package Modeling – BGA, QFP, Flip-Chip
2. PCB Board Modeling – Power/Ground planes, Mesh Grid Grounds,
3. Backplanes
4. Silicon/GaAs - Spiral Inductors, Transformers
5. EMC/EMI – Shield Enclosures, Coupling, Near- or Far-Field Radiation
6. Antennas/Mobile Communications – Patches, Dipoles, Horns, Conformal
7. Cell Phone Antennas, Quadrafilar Helix, Specific Absorption Rate(SAR),
8. Infinite Arrays, Radar Cross Section(RCS), Frequency Selective Surfaces(FSS)
9. Connectors – Coax, SFP/XFP, Backplane, Transitions
10. Waveguide – Filters, Resonators, Transitions, Couplers
11. Filters – Cavity Filters, Microstrip, Dielectric
HFSS is an interactive simulation system whose basic mesh element is atetrahedron.
This allows you to solve any arbitrary 3D geometry, especially those with complex
curves and shapes, in a fraction of the time it would take using other techniques. The
name HFSS stands for High Frequency Structure Simulator. Ansoft pioneered the
use of the Finite Element Method (FEM) for EM simulation by
developing/implementing technologies such as tangential vector finite elements,
adaptive meshing, and Adaptive Lanczos-Pade Sweep (ALPS). Today, HFSS continues
to lead the industry with innovations such as Modes-to-Nodes and Full-Wave Spice™.
Ansoft HFSS has evolved over a period of years with input from many users and
industries. In industry, Ansoft HFSS is the tool of choice for high-productivity research,
development, and virtual prototyping.

45
3.2: Installing HFSS software
3.2.1-System Requirements
• Microsoft Windows XP, Windows 2000, or Windows 2003 Server. For
upto-date information, refer to the HFSS Release Notes.
• Pentium –based computer
• 128MB RAM minimum
• 8MB Video Card minimum
• Mouse or other pointing device
• CD-ROM drive.
3.2.2- Installing the Ansoft HFSS Software
For up-to-date information, refer to the HFSS Installation Guide.
3.2.3- Starting Ansoft HFSS
• Click the Microsoft Start button, select Programs, and select the Ansoft, HFSS 9
program group program group. Click HFSS 9.
• Or Double click on the HFSS 9 icon on the Windows Desktop.
3.3-Ansoft Terms
The Ansoft HFSS window has several optional panels:
• A Project Manager which contains a design tree which lists the structure of the
project
• A Message Manager that allows you to view any errors or warnings that occur
before you begin a simulation
• A Property Window that displays and allows you to change model
• Parameters or attributes.
• A Progress Window that displays solution progress.
• A 3D Modeler Window which contains the model and model tree for the
• Active design.

46
Fig:3.1Differents terms of ansoft
3.3.1-Project Manager-
Fig:3.2 Differents terms of Project window

47
Model
Graphics
Area
3D modeler Design
tree Context
menu
3.3.2-Property window
Fig:3.2 Differents terms of Property window
3.3.3-Ansoft 3D Modeler-
Fig:3.2(a)Different terms of 3D modeler window

48
Fig:3.2(b)Different terms of 3D model
3.3.4-3D Modeler Design Tree
(a)Grouped by Materials (b)Object view
Fig:3.3 Modeler design tree

49
3.3.6-Toolbars
• The toolbar buttons are shortcuts for frequently used commands. Most of the
available toolbars are displayed in this illustration of the Ansoft HFSS initial
screen, but your Ansoft HFSS window probably will not be arranged this way.
• You can customize your toolbar display in a way that is convenient for you.
Some toolbars are always displayed; other toolbars display automatically when
you select a document of the related type. For example, when you select a 2D
report from the project tree, the 2D report toolbar displays.
Fig:3.4 Toolbars of ansoft HFSS
3.3.7-Ansoft HFSS Desktop
The Ansoft HFSS Desktop provides an intuitive, easy-to-use interface for
developing passive RF device models. Creating designs, involves the following:
• Parametric Model Generation – creating the geometry, boundaries and
• excitations
• Analysis Setup – defining solution setup and frequency sweeps
• Results – creating 2D reports and field plots
• Solve Loop - the solution process is fully automated
• To understand how these processes co-exist, examine the illustration shown
• Below

50
Design
Solution type
1.Parametric model
Geometry/Materials
2.Analysis
Solution setup
Frequency sweep
3.Results
2D reports
fields
Boundaries
Excitations
Analyze
Update
Mesh operation
Mesh refinement Solve
Converged
Finished
Fig:3.5 Ansoft desktop design tree.
3.5-Set Solution Type
This section describes how to set the Solution Type. The Solution Type defines
the type of results, how the excitations are defined, and the convergence. The
following Solution Types are available:
• Driven Modal - calculates the modal-based S-parameters. The S-matrix
solutions will be expressed in terms of the incident and reflected powers of
waveguide modes.
• Driven Terminal - calculates the terminal-based S-parameters of
multiconductor
transmission line ports. The S-matrix solutions will be expressed
in terms of terminal voltages and currents.
• Eignemode – calculate the eigenmodes, or resonances, of a structure. The
Eigenmode solver finds the resonant frequencies of the structure and the
fields at those resonant frequencies.

51
3.6-Parametric Model Creation:
• The Ansoft HFSS 3D Modeler is designed for ease of use and flexibility.
Thepower of the 3D Modeler is in its unique ability to create fully parametric
designswithout editing complex macros/model history.
• The purpose of this chapter is to provide an overview of the 3D Modeling
capabilities. By understanding the basic concepts outlined here you will
be ableto quickly take advantage of the full feature set offered by the 3D
ParametricModeler.
3.6.1-Overview of the 3D Modeler User Interface (Continued)
When using the 3D Modeler interface you will also interact with two additional
interfaces:
Status Bar/Coordinate Entry – The Status Bar on the Ansoft HFSS Desktop
Window displays the Coordinate Entry fields that can be used to define
points or offsets during the creation of structural objects.
Fig:3.6 Status bar
Grid Plane
To simplify the creation of structural primitives, a grid or drawing plane is used.The
drawing plane does not in any way limit the user to two dimensional coordinates but
instead is used as a guide to simplify the creation of structural primitives. The drawing
plane is represented by the active grid plane (The grid does not have to be visible). To
demonstrate how drawing planes are used, review the following section: Creating and
Viewing Simple Structures.
Active Cursor
• The active cursor refers to the cursor that is available during object creation. The
cursor allows you to graphically change the current position. The position is
displayed on the status bar of the Ansoft HFSS Desktop Window
Fig:3.7Active Cursor

52
• When objects are not being constructed, the cursor remains passive and is set for
dynamic selection. See the Overview of Selecting Objects for more details.
3.7-The Dipole Antenna simulation by HFSS V.9
Dipole antennas are extremely popular in the microwave region. Dipole antennas are
commonly used for broadcasting, cellular phones, and wireless communications due to
their omnidirective property. Thus in this tutorial, a dipole antenna will be constructed
and analyzed using the HFSS in this simulation.
3.7.1-Getting started with HFSS 9.1:
• Launching Ansoft HFSS
To access Ansoft HFSS, click the Microsoft Start button, select Programs, and
select the Ansoft, HFSS 9 program group. Click HFSS 9.
• Setting Tool Options
To set the tool options:
Note: In order to follow the steps outlined in this example, verify that
the following tool options are set:
1. Select the menu item Tools>Options> HFSS Options
2. HFSS Options Window:
1. Click the General tab
Use Wizards for data entry when creating new
boundaries:Checked
Duplicate boundaries with geometry: Checked
2. Click the OK button
3. Select the menu item Tools > Options > 3D Modeler
Options.
4. 3D Modeler Options Window:
1. Click the Operation tab
Automatically cover closed polylines: _ Checked
2. Click the Drawing tab
Edit property of new primitives: _ Checked

53
3.7.2-Opening a New Project
To open a new project:
1. In an Ansoft HFSS window, click the _ On the Standard toolbar, or
select the menu item File > New.
2. From the Project menu, select Insert HFSS Design.
Fig:3.8 Project menu window
Set Solution Type
To set the solution type:
1. Select the menu item HFSS > Solution Type
2. Solution Type Window:
1. Choose Driven Modal
Fig: 3.9 Solution type window

54
3.7.3-Creating the 3D Model
Set Model Units
To set the units:
1. Select the menu item 3D Modeler > Units
2. Set Model Units:
1. Select Units: mm
Fig. 3.10 Model Unit window
Set Default Material
To set the default material:
Using the 3D Modeler Materials toolbar, choose vacuum
Fig. 3.11 set the default material
3.8-Create Dipole
3.8.1-Create waveguide
HFSS relies on variables for any parameterization / optimization within the project.
Variables also hold many other benefits which will make them necessary for all
projects.
• Fixed Ratios (length, width, height) are easily maintained using variables.
• Optimetrics use variables to optimize the design according to user-defined
criteria.

55
• All dimensions can be quickly changed in one window as opposed to altering
each object individually.
This will open the variable table. Add all variables shown below by selecting Add. Be
sure to include units as needed.
Fig. 3.12 Property window
The final variable table should looks like
Fig. 3.13 Final variable table

56
3.8.2- Drawing the Dipole
• We will start to by creating the dipole element using the Draw Cylinder button
from the toolbar.
• By default the proprieties dialog will appear after you have finished drawing an
object. The position and size of objects can be modified from the dialog.
Fig. 3.14 Drawing dipole

57
Fig. 3.15 appeared table by creating the dipole
• Double click to the model menu and this will appear a window like as follow
Fig. 3.16 table from model menu

58
• Follow the format above for structure size. Give the name dip1 to this object.
Assign the material PEC and click OK. PEC (Perfect Electric Conductor) will
create ideal conditions for the element.
The next step is to build the symmetric of dip1. To do that, Right -Click the drawing
area and select Edit -> Duplicate -> Around Axis.
Fig. 3.17 form the duplicate dipole in the 180 degree position
Fig. 3.18 Duplicate Around Axis window

59
The dipole structure is illustrated below:
Fig. 3.19 Final dipole structure
3.9- Creating the port
• In the section you will create a Lumped Gap Source. This will provide an
excitation to the dipole structure. Begin by selecting the YZ plane from the
toolbar. Using the 3D toolbar, click Draw Rectangle and place two arbitrary
points within the model area.
Fig:3.20 (a) Selecting YZ plane Fig: 3.20(b) Draw rectangle

60
Enter the following information
Double click “create rectangle’’ and this will appear a window like below.
Fig. 3.22 View of a 3D modeler window

61
Enter the information below
• With the source geometry in place, the user must provide an excitation. A
lumped port will be used for the dipole model. This excitation is commonly used
when the far field region is of primary interest. In the project explorer, right-
click Excitation -> Assign -> Lumped Port.
Name the port source and leave the default values for impedance.
Name the port source and leave the default values for impedance
Fig. 3.24 Port assumption

62
Click Next and enter the following:
Fig. 3.25 Port assigning window
Using the mouse, position the cursor to the bottom-center of the port. Ansoft's snap
feature should place the pointer when the user approaches the center of any object. Left-
click to define the origin of the E-field vector. Move the cursor to the top-center of the
port. Left-click to terminate the E-field vector. Click finish to complete the port
excitation.
Note: In case you find some difficulties for drawing the lumped port, you can redraw
the rectangular plane, affect the lumped port, then resize the rectangular plane.
Fig. 3.26 HFSS window after assigning port

63
3.10- Radiation Boundary
In this section, a radiation boundary is created so that far field information may be
extracted from the structure. To obtain the best result, a cylindrical air boundary is
defined with a distance of λ/4. From the toolbar, select Draw Cylinder.
Enter the following information:

64
• With the geometry complete, the actual radiation boundary may now be assigned.
• Click and select all faces as
follow:
Fig:3.29 Select Face Window
• With all faces selected, right-click the Boundary icon in the object explorer and
select Boundary -> Assign -> Radiation.
Leave the default name Rad1 and click OK.
Fig:3.30 Select Radiation port

65
3.11- Solution Setup
In this section a solution must be defined to display the desired data. We are primarily
interested in the frequency response of the structure. We will also explore HFSS's
ability to calculate general antenna parameters such as directivity, radiation resistance,
radiation efficiency, etc... .
From the project explorer, select Analysis -> Add Solution Setup.
Enter the following. Click ok when complete.
Fig:3.31 Select Setup window
To view the frequency response of the structure, a frequency sweep must be defined.
From the project explorer select Setup1 -> Add Sweep.

66
Enter the following:
Fig:3.32 Select Setup window
3.12- Structure Analysis
At this point, the user should be ready to analyze the structure. Before running the
analysis, always verify the project by selecting from the 3D toolbar. If everything is
correct the user should see:
Fig:3.33 Validation Check Window

67
Analyze the structure by clicking
Fig. 3.34 Analyzing window
3.13- Create Reports
After completion of the analysis, we will create a report to display both the
resonant frequency and also the radiation pattern. Click on the heading HFSS
and select Results -> Create Reports.
Choose the following in the Create Report window:
Fig. 3.35 Select the result patterns

68
• Select the following highlighted parameters and click Add Trace to load the
options into the Trace window.
Fig:3.36 Trace Window
• Click Done when complete. The graph is displayed below:
Fig. 3.37 Rectangular plot

69
• HFSS has the ability to compute antenna parameters automatically. In order to
produce the calculations, the user must define an infinite sphere for far field
calculations. Right-click the Radiation icon in the project manager window and
select Insert Far Field Setup -> Infinite Sphere.
(a) (b)
Fig. 3.38 (a) Define the air box as infinite sphere; (b) Compute antenna properties
• Accept all default parameters and click Done. Right-click Infinite Sphere1 -
>Compute Antenna Parameters... from the project explorer as shown:
• Select all defaults and results are displayed as follows:
Fig: 3.39 Results of antenna parameters

70
• Next, the far field will be plotted. Create Reports as previously shown. Modify
the following:
Fig: 3.40 Display type
• Enter the following:
Fig. 3.41 Traces Window

71
• Select the Mag and enter the following:
Fig. 3.42 Traces Window
• Select Add Trace and click Done when complete. The radiation pattern is
displayed below:
Fig. 3.43 Radiation pattern of Directivity

72
Chapter 4
Parametric Study
of
Horn Antenna

73
Chapter 4: Parametric Study: Horn Antenna
Horn antennas are extremely popular in the microwave region. An aperture antenna
contains some sort of opening through which electromagnetic waves are transmitted or
received. One of the examples of aperture antenna is horns. The analysis of aperture
antennas is typically quite different than the analysis of wire antennas. Before the
parametric study here we discussed about different types of horn antennas
4.1: Types of Horn Antennas
Generally Horn Antenna is type of waveguide one end of which is flared out. Flared
waveguide, which produces nearly uniform phase front, is larger than the waveguide
itself. However, radiation is poor and non directive pattern results because of mismatch
between the waveguide and free space. The mouth of the waveguide is flared out to
improve the radiation efficiency, directive pattern and directivity.
There are three main basic types of Horn Antennas:
1. Sectoral Horn
2. Pyramidal Horn
3. Conical Horn
• Sectoral Horn is two types:
a. Sectoral H-plane Horn
b. Sectoral E-plane Horn
Fig: 4.1 H-plane sectoral horn Fig: 4.2 E-plane sectoral horn
Fig: 4.3 Pyramidal horn Fig: 4.4 Conical horn

74
The pyramidal horn is the most widely used antenna for feeding large microwave dish
antennas and for calibrating them. That’s why we are simulating a pyramidal horn
antenna here.
4 . 2: Horn antenna parameters
In this simulation, our objective is to analyze a horn antenna resonating at a frequency
of 10 GHz.
Here are the dimensions of Horn Antenna:
• Wave guide dimension: a = 22.86mm & b = 10.16mm
• Horn top: 60mm * 45mm
• Distance from the horn top plane to the bottom is 120mm
• Distance from the top plane to the base of waveguide of the horn is 132mm
• Air box: 145mm * 70mm * 50mm
4.3: Modeling of Horn antenna in HFSS
4.3.1: Getting started with HFSS 9.1:
• Launching Ansoft HFSS
To access Ansoft HFSS, click the Microsoft Start button, select Programs, and
select the Ansoft, HFSS 9 program group. Click HFSS 9.
• Setting Tool Options
• To set the tool options:
Note: In order to follow the steps outlined in this example, verify that
the following tool options are set:
1. Select the menu item Tools>Options> HFSS Options
2. HFSS Options Window:
1. Click the General tab
Use Wizards for data entry when creating new boundaries: Checked
Duplicate boundaries with geometry: Checked

75
3. Select the menu item Tools > Options > 3D Modeler Options.
4. 3D Modeler Options Window:
1. Click the Operation tab
Automatically cover closed poly lines: _ Checked
2. Click the Drawing tab
Edit property of new primitives: _ Checked
4.3.2: Opening a New Project
• To open a new project:
1. In an Ansoft HFSS window, click the On the Standard toolbar,
or select the menu item File > New.
2. From the Project menu, select Insert HFSS Design.
• Set Solution Type
• To set the solution type:
1. Select the menu item HFSS > Solution Type
2. Solution Type Window:
1. Choose Driven Modal
Fig: 4.5 Project menu window Fig: 4.6 Solution type window

76
4.3.3: Creating the 3D Model
• Set Model Units
To set the units:
1. Select the menu item 3D Modeler > Units
2. Set Model Units:
1. Select Units: mm
Fig. 4.7 Model Unit window
• Set Default Material
• To set the default material:
Using the 3D Modeler Materials toolbar, choose vacuum
• Create Rectangular Waveguide
• Create waveguide
1. Select the menu item Draw > Box
2. Using the coordinate entry fields, enter the Box position
X: -11.43, Y: -5.08, Z: 0.0 Press the Enter key
3. Using the coordinate entry fields enter the ‘a’ and ‘b’:
dX: 22.86, dY: 10.16, dZ: 0.0 Press the Enter key
4. Using the coordinate entry fields, enter the height:
Fig. 4.8 Waveguide

77
• To set the name:
1. Select the Attribute tab from the Properties window.
2. For the Value of Name type: Waveguide
• To fit the view:
1. Select the menu item View > Fit All > Active View.
Or press the CTRL+D key
• To make the waveguide transparent:
2. For the Transparent click and type: 0.5 and Click OK.
3. Click the OK button.
4.3.4: Create Horn Top
• Create rectangle:
1. Select the menu item Draw > Rectangle
2. Using the coordinate entry fields, enter the Rectangle position
3. Using the coordinate entry fields, enter the horn top dimension:
2. For the Value of Name type: Horn_top
• To fit the view:
1. Select the menu item View > Fit All > Active View.
Or press the CTRL+D key

78
4.3.5: Create funnel base:
To create the funnel of the horn antenna, draw and connect two rectangles, and then
connect them to create the 3D funnel. First rectangle is horn top. Now place the second
on the top of the waveguide.
• Create Rectangle:
1. Select the menu item Draw > Rectangle
2. Using the coordinate entry fields, enter the Rectangle position
3. Using the coordinate entry fields, enter the horn top dimension:
2. For the Value of Name type: funnel_base
4. To select the Color click Edit.
5. Choose the Green and click Ok.
Fig. 4.9 Waveguide and Funnel Base

79
4.3.6: Create the funnel:
• Connecting 2D Objects:
Now you can connect the 2D objects that make up the base and the top of the
funnel to create the 3D, funnel-shaped object.
1. Choose the Horn_Top and funnel_base from the 3D Modeler design
tree.
2. Select the menu item 3D Modeler > Surface > Connect.
3. Name the object funnel.
Fig. 4.10 Project menu Fig. 4.11 Highlight the Horn top and funnel base
4.3.7: Complete the Horn
• To select the object
Select the menu item Edit > Select All Visible. Or press the CTRL+A
key.

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