This document discusses the analysis and design of a half transverse electromagnetic (HTEM) horn-type antenna for high-power impulse radiation applications. It presents mathematical formulations for calculating key antenna parameters like characteristic impedance that consider the isolation distance between the antenna arm and reflector. Simulation and experimental results are used to determine the optimal geometric design parameters, such as tapering angle and flair angle, that maximize antenna gain. Formulas show how parameters like electric and magnetic fields depend on the antenna geometry, pulse characteristics, and material properties.
Comparative study of slot loaded rectangular and triangular microstrip array ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
STUDY OF ARRAY BI-CONICAL ANTENNA FOR DME APPLICATIONSijwmn
This paper introduces a new configuration of array bi-conical antenna to enhance the gain of an antenna for Distance Measuring Equipment (DME) avionic system. Due to its large size, the antenna can be placed in terrestrials DME stations. The antenna consists of the bi-conical elements placed in a linear configuration. The simulated maximum gain is 10.2dB, the antenna operates in the DME band (960 – 1215 MHz). Al the simulations are performed with CADFEKO a Method of Moments based Solver.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A Leaky Wave Antenna Design Based on Half-mode Substrate Integrated Waveguide...IJECEIAES
A new type of leaky-wave antenna (LWA) using half-mode substrate integrated waveguide (HMSIW) as the base structure is proposed in this paper. The structure consists of an array of slot, antenna designed to operate in X band applications from 8 to 12 GHz. HMSIW preserves nearly all the advantages of SIW whereas its size is nearly reduced by half. The antenna radiates one main beam that can be steered from the backward to the forward direction by changing frequency.
Comparative study of slot loaded rectangular and triangular microstrip array ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
STUDY OF ARRAY BI-CONICAL ANTENNA FOR DME APPLICATIONSijwmn
This paper introduces a new configuration of array bi-conical antenna to enhance the gain of an antenna for Distance Measuring Equipment (DME) avionic system. Due to its large size, the antenna can be placed in terrestrials DME stations. The antenna consists of the bi-conical elements placed in a linear configuration. The simulated maximum gain is 10.2dB, the antenna operates in the DME band (960 – 1215 MHz). Al the simulations are performed with CADFEKO a Method of Moments based Solver.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A Leaky Wave Antenna Design Based on Half-mode Substrate Integrated Waveguide...IJECEIAES
A new type of leaky-wave antenna (LWA) using half-mode substrate integrated waveguide (HMSIW) as the base structure is proposed in this paper. The structure consists of an array of slot, antenna designed to operate in X band applications from 8 to 12 GHz. HMSIW preserves nearly all the advantages of SIW whereas its size is nearly reduced by half. The antenna radiates one main beam that can be steered from the backward to the forward direction by changing frequency.
Aeolian vibrations of overhead transmission line bundled conductors during in...Power System Operation
In part A of this paper, the frequency mobility response
of the excitation technique used to induce vibration on
a quad-bundled conductor rigidly attached indoors was
investigated. Two reference inputs were used to link
the shaker to the quad bundle conductors via a square
rigid block made of welded square hollow steel. The
primary objective was to determine whether there
was interference due to the use of a rigid connection.
In the first instance, restraining the free motion of the
bundle conductors which would be disadvantageous
to the vibration response results. The interference
was evaluated in the form of mobility FRF responses
Side Lobe Level (SLL) Reduction Methods in AntennaDarshan Bhatt
Side Lobe levels are the important aspects in RADAR and navigation engineering and many other real time transmission systems. It is nothing but wastage of transmitted power in undesired direction. So, for reduction of SLL different methods are used for different types of antennas. In this presentation SLL reduction is discussed for Antenna arrays and for microstrip patch antenna arrays.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This paper proposes a flexible compact bowtie antenna for medical application that operates at 2.45 GHz. The proposed antennas are miniaturized using meander technique. Both substrates and conducting material of the antenna are made of flexible material semi-transparent film as the substrate and shieldit fabric as the conducting material which suitable for wearable and on body application. The results show that the total length of the antenna is significantly reduced by up to 38%. However, the gain of the antenna is slightly decreased when the size of the antenna become smaller. The results of this research could provide guidance and has significant implication for future development of wearable electronics especially in medical monitoring application.
Validation of Polarization angles Based Resonance Modes IJERA Editor
The symmetry, tilt and elongation degrees are figures of merit which can be used to describe the radar target
shape once incorporated with the target resonance modes. Through optimization of the second moments of the
quadrature-polarized residues matrix, the angles are determined by the optimum co-null polarization states. The
approach is tested and validated against low signal-to-noise ratio and also the late-time onset selection when
extracting the mode set. A wire plane model is used and the results show that with ensemble averaging it
possible to have robust polarization angle set, even with small number of sample set
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Design and simulation of broadband rectangular microstrip antennaBASIM AL-SHAMMARI
Abstract
In this work, many techniques are suggested and analyses for
rectangular microstrip antenna (RMSA) operating in X-band for 10 GHz
center frequency. These approaches are: lowering quality factor, shifting
feeding point , using reactive loading and modification of the patch shape.
The design of a RMSA is made to several dielectric materials, and the
selection is based upon which material gives a better antenna performance
with reduced surface wave loss. Duroid 5880 and Quartz are the best materials
for proposed design to achieve a broader Bandwidth (BW) and better
mechanical characteristics than using air. The overall antenna BW for RMSA
is increased by 11.6 % with Duroid 5880 with shifted feeding point and with
central shorting pin (Reactive loading) while that for Quartz is 17.4 %.
Modification of patch shape with similar improving techniques gives an
overall increasing VSWR bandwidth of 26.2 % for Duroid 5880 and a
bandwidth of 30.9 % for Quartz. These results are simulated using Microwave
Office package version 3.22, 2000.
Substrate integrated waveguide power divider, circulator and coupler in [10 1...ijistjournal
The Substrate Integrated Waveguide (SIW) technology is an attractive approach for the design of high
performance microwave and millimeter wave components, as it combines the advantages of planar
technology, such as low fabrication costs, with the low loss inherent to the waveguide solution. In this
study, a substrate integrated waveguide power divider, circulator and coupler are conceived and optimized
in [10-15] GHz band by Ansoft HFSS code. Thus, results of this modeling are presented, discussed and
allow to integrate these devices in planar circuits.
T- Shape Antenna Design for Microwave Band Applications IJEEE
It’s been studied fractal antennas shows promising future. There are numerous kinds of antenna, the thirst for excelling in this area is ever increasing. In this paper a Fractal based Antenna is designed to achieve reduced size and multiband. Fractal antenna is simulated using EM wave simulator like HFSS (High frequency structured simulator) and is designed and developed for multiple applications. The proposed antenna is experimentally realized using FR Epoxy substrate with dielectric constant 4.4 and thickness h= 1.56 mm with coaxial feeding. The patch has the dimensions of 2.5 cm 2.5 cm. An experimental result of this antenna shows multiband characteristics having resonances at frequencies such as 2.4 GHz , 6.8 GHz, 8 GHz, 10.8 GHz, 12.2 GHz,15.4 GHz with bandwidth of 230 MHz, 2 GHz, 600 MHz, 870 MHz and 2 GHz respectively. Further VSWR is also studied in this paper.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
An approach to design a rectangular microstrip patch antenna in s band by tlm...prj_publication
In this paper we have designed a rectangular microstrip antenna in ‘S’ band
transmission line model. The S band frequency ranges from 2 GHz to 4GHz for wireless
application. The desired frequency is chosen to be 2.4 GHz at which the patch antenna is
designed to improve the bandwidth. After calculating the various parameters such as width,
effective dielectric constant, effective length and actual length. The antenna impedance is
matched to 50 ohm using inset feed. The results are obtained (Input Impedance, reflection
coefficient, SWR and bandwidth) by using MATLAB software.
Aeolian vibrations of overhead transmission line bundled conductors during in...Power System Operation
In part A of this paper, the frequency mobility response
of the excitation technique used to induce vibration on
a quad-bundled conductor rigidly attached indoors was
investigated. Two reference inputs were used to link
the shaker to the quad bundle conductors via a square
rigid block made of welded square hollow steel. The
primary objective was to determine whether there
was interference due to the use of a rigid connection.
In the first instance, restraining the free motion of the
bundle conductors which would be disadvantageous
to the vibration response results. The interference
was evaluated in the form of mobility FRF responses
Side Lobe Level (SLL) Reduction Methods in AntennaDarshan Bhatt
Side Lobe levels are the important aspects in RADAR and navigation engineering and many other real time transmission systems. It is nothing but wastage of transmitted power in undesired direction. So, for reduction of SLL different methods are used for different types of antennas. In this presentation SLL reduction is discussed for Antenna arrays and for microstrip patch antenna arrays.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This paper proposes a flexible compact bowtie antenna for medical application that operates at 2.45 GHz. The proposed antennas are miniaturized using meander technique. Both substrates and conducting material of the antenna are made of flexible material semi-transparent film as the substrate and shieldit fabric as the conducting material which suitable for wearable and on body application. The results show that the total length of the antenna is significantly reduced by up to 38%. However, the gain of the antenna is slightly decreased when the size of the antenna become smaller. The results of this research could provide guidance and has significant implication for future development of wearable electronics especially in medical monitoring application.
Validation of Polarization angles Based Resonance Modes IJERA Editor
The symmetry, tilt and elongation degrees are figures of merit which can be used to describe the radar target
shape once incorporated with the target resonance modes. Through optimization of the second moments of the
quadrature-polarized residues matrix, the angles are determined by the optimum co-null polarization states. The
approach is tested and validated against low signal-to-noise ratio and also the late-time onset selection when
extracting the mode set. A wire plane model is used and the results show that with ensemble averaging it
possible to have robust polarization angle set, even with small number of sample set
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Design and simulation of broadband rectangular microstrip antennaBASIM AL-SHAMMARI
Abstract
In this work, many techniques are suggested and analyses for
rectangular microstrip antenna (RMSA) operating in X-band for 10 GHz
center frequency. These approaches are: lowering quality factor, shifting
feeding point , using reactive loading and modification of the patch shape.
The design of a RMSA is made to several dielectric materials, and the
selection is based upon which material gives a better antenna performance
with reduced surface wave loss. Duroid 5880 and Quartz are the best materials
for proposed design to achieve a broader Bandwidth (BW) and better
mechanical characteristics than using air. The overall antenna BW for RMSA
is increased by 11.6 % with Duroid 5880 with shifted feeding point and with
central shorting pin (Reactive loading) while that for Quartz is 17.4 %.
Modification of patch shape with similar improving techniques gives an
overall increasing VSWR bandwidth of 26.2 % for Duroid 5880 and a
bandwidth of 30.9 % for Quartz. These results are simulated using Microwave
Office package version 3.22, 2000.
Substrate integrated waveguide power divider, circulator and coupler in [10 1...ijistjournal
The Substrate Integrated Waveguide (SIW) technology is an attractive approach for the design of high
performance microwave and millimeter wave components, as it combines the advantages of planar
technology, such as low fabrication costs, with the low loss inherent to the waveguide solution. In this
study, a substrate integrated waveguide power divider, circulator and coupler are conceived and optimized
in [10-15] GHz band by Ansoft HFSS code. Thus, results of this modeling are presented, discussed and
allow to integrate these devices in planar circuits.
T- Shape Antenna Design for Microwave Band Applications IJEEE
It’s been studied fractal antennas shows promising future. There are numerous kinds of antenna, the thirst for excelling in this area is ever increasing. In this paper a Fractal based Antenna is designed to achieve reduced size and multiband. Fractal antenna is simulated using EM wave simulator like HFSS (High frequency structured simulator) and is designed and developed for multiple applications. The proposed antenna is experimentally realized using FR Epoxy substrate with dielectric constant 4.4 and thickness h= 1.56 mm with coaxial feeding. The patch has the dimensions of 2.5 cm 2.5 cm. An experimental result of this antenna shows multiband characteristics having resonances at frequencies such as 2.4 GHz , 6.8 GHz, 8 GHz, 10.8 GHz, 12.2 GHz,15.4 GHz with bandwidth of 230 MHz, 2 GHz, 600 MHz, 870 MHz and 2 GHz respectively. Further VSWR is also studied in this paper.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
An approach to design a rectangular microstrip patch antenna in s band by tlm...prj_publication
In this paper we have designed a rectangular microstrip antenna in ‘S’ band
transmission line model. The S band frequency ranges from 2 GHz to 4GHz for wireless
application. The desired frequency is chosen to be 2.4 GHz at which the patch antenna is
designed to improve the bandwidth. After calculating the various parameters such as width,
effective dielectric constant, effective length and actual length. The antenna impedance is
matched to 50 ohm using inset feed. The results are obtained (Input Impedance, reflection
coefficient, SWR and bandwidth) by using MATLAB software.
Circularly polarized microstrip antenna with reactive load design for wireles...BASIM AL-SHAMMARI
This paper presents a design of microstrip antenna for IEEE 802.11b and for IEEE 802.11g using a nearly square patch antenna, excited by a standard miniature adapter probe feed line. The patch and ground plain are separated by a substrate; the radiating patch is loaded by a central shorting pin and feeding probe loaded by a series capacitor. This antenna has wide bandwidth in the frequency band of (WLAN) and with a return loss ≤ −10 dB from 2.4 GHz to 2.48 GHz exhibits circularly polarized far field radiation pattern.
The proposed antennas have been simulated and analyzed using method of moments (MoM) based software package Microwave Office 2008 v8.0. The results show that the bandwidth of the antenna increases by using reactive load. The simulated gain of the antenna is over 6 dB.
Circularly polarized microstrip antenna with reactive load design for wireles...BASIM AL-SHAMMARI
Abstract
This paper presents a design of microstrip antenna for IEEE 802.11b and for IEEE 802.11g using a nearly square patch antenna, excited by a standard miniature adapter probe feed line. The patch and ground plain are separated by a substrate; the radiating patch is loaded by a central shorting pin and feeding probe loaded by a series capacitor. This antenna has wide bandwidth in the frequency band of (WLAN) and with a return loss ≤ −10 dB from 2.4 GHz to 2.48 GHz exhibits circularly polarized far field radiation pattern.
The proposed antennas have been simulated and analyzed using method of moments (MoM) based software package Microwave Office 2008 v8.0. The results show that the bandwidth of the antenna increases by using reactive load. The simulated gain of the antenna is over 6 dB.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
A Broadband Rectangular Microstrip Patch Antenna for Wireless Communicationswww.nbtc.go.th
In this paper, a simple design of wideband
rectangular patch antenna is presented by using asymmetrical
feed and a reduction in ground plane with proper gap distance.
The frequency-dependent characteristic impedance included in
the proposed procedure is addressed to eliminate possible
errors in the high-frequency broadband applications. The
antenna proposed in this research provides 2.3GHz bandwidth
(frequency range: 0.9GHz - 3.2GHz) which can be utilized in
various broadband applications such as remote sensing,
biomedical and mobile radio. The proposed procedure in this
research is compatible with CAD applications and is valuable
contribution as it permits quick and easy design for RF
engineers.
Reference : International Journal of Modeling and Optimization, Vol. 4, No. 3, June 2014
http://www.ijmo.org/papers/373-A0002.pdf
Thanks for reading.
Noppadol Tiamnara
Variable radiation pattern from co axial probe fed rectangular patch antenna ...eSAT Journals
Abstract The idea of obtaining variable radiation patterns from the same antenna is important aspect in achieving the adaptive antenna systems. In the EM signal processing the change of radiation signifies the information to be transmitted, its rate of transmission, the geographical changes and direction to transmit etc. i.e. each time when the requirement arises to change the radiation pattern it has to be done to satisfy the conditions. Electronically steerable antennas were used where the antenna radiation will be altered by varying the feed and similar case is applied for shaped patterns from array antenna where the feed to be given will be calculated and given accordingly. In the present concept the metamaterials are used to obtain different radiation patterns occurred at different operating frequencies using the same antenna without changing the antenna physically are varying its feed. Key Words: Inductance, capacitance, operating frequency, variable radiation, enhancement, radiation cancellation.
Microstrip patch antenna for pcs and wlaneSAT Journals
Abstract Due to development in wireless devices, it poses a new challenge for the design of an antenna in wireless communication. Patch antennas are well suited for various wireless application systems due to their low weight, low profile, versatility, conformability, low cost and low sensitivity to manufacturing tolerances. This paper present design, simulation of a rectangular micro strip antenna for WLAN and PCS. The aim of the work is to design reliable broadband, compact patch antenna for wireless devices. Antenna is proposed which is providing circular polarization, dual band, resonant frequencies at 1.9 GHz, 2.4 GHz. Key Words: Patch antenna, co-axial feeding, polarization, dual band, HFSS …
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
2. UMBARKAR et al.: ANALYSIS OF HTEM HORN-TYPE ANTENNA FOR HIGH-POWER IMPULSE RADIATION APPLICATIONS 3289
Fig. 3. Schematic of near field and far field region.
Fig. 4. Side view and top view of antenna.
intensity of half transverse electromagnetic (HTEM) antenna
at the side and back, in order to get a feel of radiation
loss.
To understand the design and analysis of the antenna, an
experiment was conducted using HV pulse generator having
an output pulse of rise time 6.0122 ns connected to a half
TEM horn antenna. The experimental results were used along
with FIT-based software (CST microwave studio) and the
optimum geometrical parameters of the antenna were obtained.
A comparison of the experimental results with simulation has
been shown.
The rest of this paper is organized as follows: 1) the details
of antenna parameter calculation are reported in Section II;
2) the experiment on HTEM antenna is reported in Section III;
3) Section IV compares the experimental and simulation
results; and 4) Section V investigates the optimum geometrical
values of the antenna using the simulation software so as to
obtain maximum gain.
II. ANTENNA PARAMETER CALCULATIONS
An antenna generally consists of a near and far field region
as shown in Fig. 3. The near field region is defined by the
spherical region whose radius is less than R
R =
2L2
ctr
(1)
where L is the total length of the reflector of the antenna,
tr is the rise time of the pulse, and c is speed of light. The
spherical region with radius greater than R is called as the far
field region [13].
The far field region calculations are given in [13]. The
antenna parameters, such as tapering angle (θa), aperture
height (a), flair angle (α), plate width (w), and arc curvature,
are shown in Fig. 4 (for 3-D view, refer Fig. 2).
The various optimal geometrical relationships are given in
(1)–(8) [8]
w = 2L tan(α/2) (2)
a = L sin θa (3)
w
a
=
2 tan(α/2)
sin θa
(4)
α = 2 arctan
w
2a
sin(θa) . (5)
The characteristic impedance (Zc) for w/a > 1 and w/a < 1
are given by (6) and (7), respectively [12]
Zc = 2 ×
377
(w/a) + 2
(6)
Zc = 2 × 138 × log
8
(w/a)
. (7)
It should be noted that w and a have to be chosen such that
Zc = 377 to match the output impedance of antenna to
characteristic impedance of free space.
The geometric impedance ( fg) is then obtained from Zc
and intrinsic impedance Z0 given by (8)
fg =
Zc
Z0
. (8)
Equations (2)–(8) are discussed in [8] and these formulas
need to be rewrite by considering the feeding height. If antenna
has feeding height (Hf ) then its aperture heights will be
a = Hf + L sin θa. (9)
Thus, (w/a) ratio will be
w
a
=
2L tan(α/2)
H f + L sin θa
(10)
α = 2 arctan
1
2L
w
a
(Hf + L sin(θa) . (11)
The characteristic impedance (Zc) for w/a > 1 and w/a < 1
are given by (12) and (13), respectively
Zc =
377(Hf + L sin(θa))
H f + L(sin(α/2) + sin(θa))
(12)
Zc = 2 × 138 × log
8(Hf + L sin θa)
2L sin(α/2)
. (13)
The variation of characteristic impedance for (w/a < 1)
and (w/a > 1) for Hf = 0.33 m, is shown in Figs. 5 and 6,
respectively.
The antenna has been modeled as a transmission line model
[14], [15] and the total radiated E field in bore-sight is
ETOT
y (r, t)=−
Vo
r
a
4πcfg
δ(t)−
c
2L
u(t)−u t−
2L
c
(14)
where r is bore sight distance and δ(t) is the delta function.
Equation (14) is now expressed in terms of tapering angle of
the antenna. Equations (3) and (14) gives
ETOT
y (r, θa, t)
=−
Vo
r
a
4πcfg
⎡
⎣δ(t)−
c sin θa
2a
⎡
⎣
u(t)−
u t− 2
c
a
sin θa
⎤
⎦
⎤
⎦. (15)
3. 3290 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 42, NO. 10, OCTOBER 2014
Fig. 5. Characteristics impedance, Zc, of the HTEM horn antenna as a
function of the angles α and θa for (w/a < 1).
Fig. 6. Characteristics impedance, Zc, of the HTEM horn antenna as a
function of the angles α and θa for (w/a > 1).
Equation (10) shows that the total radiated field depends on
θa, r, f g, and dV/dt. Equation (15) is modified to (17)
θa = sin−1
2
a
w
tan
α
2
(16)
ETOT
y (r, α, t)
= −
Vo
r
a
4πcfg
δ(t)−
c
w
tan(α/2)
u(t)−
u t− w
c
1
tan(α/2)
.
(17)
Orientation of antenna (refer Fig. 4) has tapered length along
z-axis and flared along y-axis. The magnetic vector potential
(Az) is given by
Az =
μL
4π
I t − r
c
r
cos θa cos α (18)
where μ and ε are the permeability and permittivity of free
space, I(t − r/c) is the retarded current for 0° < θa < 90°
and 0° < α < 90°.
Equations (15)–(18), relate the antenna geometric parameter
with the electromagnetic field parameters. Further Maxwell’s
equations and vector magnetic potential equations are used to
obtain the electric and magnetic field equations
Hφ =
μL cos θa cos α sin θ
4π
⎛
⎝
I t − r
c
rc
+
I t − r
c
r2
⎞
⎠ (19)
Fig. 7. Experimental setup.
Eθ =
L sin θ
4πε
⎛
⎝−
I t − r
c
rc2
+
I t − r
c
r2c
+
I t − r
c
r3
⎞
⎠ (20)
Er =
L cos θa sin α cos θ
2πε
⎛
⎝
I t − r
c
r2c
+
I t − r
c
r3
⎞
⎠. (21)
It can be seen from (19)–(21) that Er , Eθ , Hφ are functions
of L, r, α, θa, c, ε and other current related quantity. The gain
of antenna is equal to [r · Efar/V]peak [3].
III. EXPERIMENT
The half TEM antenna has L = 1.5 m, α = 31°,
θa = 30°, which corresponds to width w = 0.83 m, and
a = 1.08 m. It is located on the top of Marx generator at a
height of 1.85 m from the ground. The 20 stage, 64 J, 360 pF,
300 kV Marx generator along with the peaking stage, and
antenna are shown in Fig. 7. The input pulse applied to the
antenna was a pulse with 6.0122-ns rise time and half-width at
full-maximum (FWHM) 150 ns. This is the pulse output of the
Marx generator peaking stage. The experiment described was
conducted to understand the shortcomings of the design and
modify the antenna.
Voltage and current output waveform of the Marx generator
peaking stage is shown in Fig. 8. It is observed that the
output pulse has 264-kV peak voltage and 1.4-kA peak current.
In this experiment, the radiated magnetic field is measured by
PRODYNE magnetic field sensor model B-24 (R) at various
distances and angles from the antenna center.
A. Calculation of the Radiated Magnetic Field
The simplified mathematical equation reported in [20] for
magnetic field measurement is given in
Voscilloscope = Aeq ·
dB
dt
= sensor (Volt) (22)
4. UMBARKAR et al.: ANALYSIS OF HTEM HORN-TYPE ANTENNA FOR HIGH-POWER IMPULSE RADIATION APPLICATIONS 3291
Fig. 8. Output of 20 stages of the Marx generator with peaking stage
(FWHM: 150 ns, Vch: 24 kV, RL: 160 , time/div.: 100 ns, rise time: 3 ns).
Fig. 9. Observed radiated far field, measured at 15-m distance.
where VOscilloscope is the voltage measured on the oscilloscope,
and B is the magnetic flux density. The B-dot sensor (Model
No. B-24-R) has equivalent area (Aeq) = 9 × 10−6 m2.
B. Calculation of the Radiated Electric Field (E)
The relationship of electric field intensity and magnetic field
is given in
E ≈ cB(Volt/meter). (23)
This sensor is connected to the oscilloscope using Bayonet
Neill–Concelman shielding cable, to avoid introduction of
the external field effects. Experimental reading of radiated
field at the 15-m distance is shown in Fig. 9, which gives
the peak amplitude of electric field intensity (5 kV/m). The
antenna feeding pulse has rise time of 6.0122 ns and has peak
amplitude 264 kV. Thus, the maximum rate of rise of voltage
is (dV/dt) = (264 kV/6.0122 ns) = 4.391 × 1013 V/s
(r Efar)peak ∝ (dV/dt) (24)
where r is the bore-sight distance [3].
IV. COMPARISON OF EXPERIMENTAL RESULTS
WITH CST SIMULATION
The FIT software gives 3-D platforms for design and analy-
sis of high-frequency electromagnetic problems. The radiated
free space propagation of the pulse is calculated using transient
analysis solver [19]. The simulation is carried out for different
far field distances and azimuthal angles for the input feeding
Fig. 10. Marx generator output pulse with peaking capacitor.
Fig. 11. Radiated E-field (far field) at 15-m distance for 5-ns rise time input
pulse.
Fig. 12. Scaled up version of Fig. 11.
pulse shown in Fig. 10. This feeding pulse is obtained from
the experiment.
The radiated pulse measured at 15-m bore-sight distance
from the center is shown in Fig. 11. The scaled up version of
the Fig. 11 is shown in Fig. 12 to measure the rise time of
radiated pulse.
The simulated results have first spike of 5.0025-kV/m
amplitude with rise time of 1.84 ns and second spike of
2.9655-kV/m with rise time of 3.16 ns. The 16.7481-ns
delayed second spike is probably due to ground plate reflection
[17]. These two consecutive spikes correspond to the two
dominant frequencies of 32.8 and 81.9 MHz, which can be
observed from Fig. 13 [16], [18].
The experimental results and simulation results for the far
field with respect to azimuthal angle and bore-sight distance
5. 3292 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 42, NO. 10, OCTOBER 2014
Fig. 13. FFT of radiated E-far field for 5-ns rise time pulse at 15-m distance.
Fig. 14. Electric field variation in azimuthal direction.
Fig. 15. Electric field variation with respect to distance.
Fig. 16. Electric field variation with height from ground floor.
are plotted, as shown in Figs. 14 and 15. It is observed that
both the results match. The variation of electric field intensity
with azimuth angle at 15-m distance from HTEM horn and
1.85-m height from ground was recorded as shown in Fig. 16.
Fig. 17. Gaussian pulse with 1.44-ns rise time.
Fig. 18. [r · Efar/V]peak versus antenna length (L).
Fig. 19. [r · Efar/V]peak versus antenna tapering angle (θa) L = 4.5 m,
α = 31°.
V. INVESTIGATION OF HTEM ANTENNA USING CST-MS
It is observed that the gain of the antenna is only 0.3, which
could be improved. Equations (14)–(16) and [8] indicate that
the gain is equal to (r · Efar/V)peak of antenna depends on
the electrical length of antenna (L/λ) and antenna parameters.
To observe the variation of the gain with respect to the antenna
geometry simulation is carried out with a Gaussian input pulse
of tr = 1.44 ns as shown in Fig. 17. Fig. 18 shows the variation
of gain with respect to the length of antenna [8]. It is observed
that as length of antenna increases its gain improves. From
Fig. 18, it is observed that the gain is 0.489 at 4.5-m length
of the antenna. Then, from (2) and (3) width w = 2.4959 m
and height a = 2.25 m. The simulation also shows that loss of
radiation reduces from the back and sides of the antenna for
L ≥ 4.5 m. Similarly the gain for variation of θa, α, and tr
are shown in Figs. 19–21, respectively. It is observed that the
gain is 0.444 at θa and α = 25°. It is to be noted that for this
antenna the maximum gain will be 0.5 as reported in [16].
Thus, the simulation shows that the impulse generator-peaking
6. UMBARKAR et al.: ANALYSIS OF HTEM HORN-TYPE ANTENNA FOR HIGH-POWER IMPULSE RADIATION APPLICATIONS 3293
Fig. 20. [r · Efar/V]peak versus antenna flair angle (α) for L = 4.5 m,
θa = 25°.
Fig. 21. [r · Efar/V]peak versus rise time for L = 4.5 m, θa = 23°, α = 25°.
switch stage output rise time should be modified to 2 ns. The
antenna geometry should be L = 4.5 m, α = 25°, θa = 23°
to obtain an approx gain of 0.5.
VI. CONCLUSION
This paper discusses the salient features of HTEM antenna.
It has modified the existing mathematical formula to include
the isolation distance between HV input arms and the
grounded reflector. The variation of characteristic impedance
with respect to flair angle and tapering angle have been
discussed. The variation of gain for the length, flair angle and
tapering angle of antenna, and rise time has been plotted. The
effects of side and back radiations have also been discussed.
An experiment has been conducted and it has been shown that
the experimental and simulations results match. The simulation
has been used to obtain the parameters of antenna, which can
give optimum gain value of 0.5 pu for the antenna.
ACKNOWLEDGMENT
The authors would like to thank Prof. O. G. Kakde
(Director-VJTI), Dr. L. M. Gantayet (Group Director-BARC),
Dr. N. M. Singh, Dr. W. Sushma, Prof. F. S. Kazi,
Dr. R N. Awale, and D. Aniket of VJTI, Mumbai, and
S. Singh, Dr. A. K. Ray, D. P. Chakravarthy, S. Sandip,
A. Ritu, T. Somesh, and C. S. Reddy, of BARC, Mumbai and
H. Singh of Onus Engineering Group, for their encouragement
and fabrication support.
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Sachin Bhagwat Umbarkar received the B.E.
degree in electronics and telecommunication from
Pravara Engineering College, University of Pune,
Pune, India, in 2009, and the M.Tech. degree from
the Veermata Jijabai Technological Institute (VJTI),
Mumbai, India, in 2011, where he is currently pur-
suing the Ph.D. degree in high-power microwave
application for UWB systems with the Electrical
Engineering Department.
He is currently a Research Fellow at VJTI.
7. 3294 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 42, NO. 10, OCTOBER 2014
Harivittal A. Mangalvedekar (M’14) received the
B.E., M.E., and Ph.D. degrees in electrical engineer-
ing from University of Mumbai, Mumbai, India, in
1979, 1984, and 1995, respectively.
He has been with the Veermata Jijabai Tech-
nological Institute (VJTI), Mumbai, India, for the
last 27 years, where he is currently a Professor
with the Electrical Engineering Department. He has
developed the High Voltage Laboratory at VJTI.
His current research interests include pulsed power
systems, and high-voltage and power systems
Sreedevi Bindu was born in Kerala, India, in 1970.
She received the Degree in electrical and electronics
engineering and the master’s degree in power system
from the University of Mumbai, Mumbai, India, in
1992 and 2001, respectively, where she is currently
pursuing the Ph.D. degree with the Department of
Electrical Engineering, Veermata Jijabai Technolog-
ical Institute.
She is an Associate Professor with the Fr. Conce-
icao Rodrigues Institute of Technology, Navi Mum-
bai, India.
Archana Sharma received the B.E. degree in
electrical engineering from Regional Engineering
College, Bhopal, India, in 1987, and the M.Sc.
(Eng.) and Ph.D. degrees from the Indian Institute
of Science Bangalore, India, in 1994 and 2003,
respectively. Her specialization is in the design and
development of single shot and repetitive pulsed
electron beam generators based on Marx generator
and linear induction accelerators.
She joined the Bhabha Atomic Research Center,
Mumbai, India, as a Scientific Officer, where she
is currently the Head of the Energetics and Pulsed Power Systems Section
with the Accelerator and Pulse Power Division. Her current research inter-
ests include compact pulsed power systems for HPM, FXR, and industrial
applications.
Purnamasi Chotelal Saroj was born in Uttar
Pradesh, India, in 1966. He received the Diploma
degree in industrial electronics and the B.E. degree
in electrical engineering from University of Mumbai,
Mumbai, India, in 1992.
He is currently with the Accelerator and Pulse
Power Division, Bhabha Atomic Research Center,
Mumbai. His current research interests include the
development of high-voltage pulse.
Mr. Saroj is a member of VEDA Society in India.
Kailash Chandra Mittal received the M.Sc. (Hons.)
degree in physics from Punjab University, Chandi-
garh, India, in 1974, and the Ph.D. degree in physics
from the University of Mumbai, Mumbai, India,
in 1986.
He joined the Plasma Physics Division at the
Bhabha Atomic Research Center, Mumbai, as a
Scientific Officer, in 1975. From 1989 to 1991, he
was with Cornell University, Ithaca, NY, USA, as a
Post Doctoral Fellow, the University of New Mex-
ico, Albuquerque, NM, USA, as a Senior Research
Associate, and the University of Paris, Paris, France, as an Invited Professor.
In 2007, he was with Ecole Polytechnique, Paris, as an INSA Fellow. He has
been involved in high-power electron beam generation and its applications to
flash X-ray generation, high-power microwave generation, and pulse neutron
generation for strategic purposes. He is involved in the Industrial Electron
Accelerator Program, where high-power electron beams are employed for
the industrial applications. He is currently involved in the development
of superconducting RF cavities for high-energy proton accelerators. He is
currently the Head of the Accelerator and Pulse Power Division, the Head
of the Particle Beam Generation and Diagnostics Section, and the Project
Manager of the Electron Beam Center. He has more than 175 scientific
publications/presentations in international/national journals/conferences.