SlideShare a Scribd company logo
IOSR Journal of Electronics and Communication Engineering (IOSR-JECE)
e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 11, Issue 1, Ver. III (Jan. - Feb .2016), PP 36-39
www.iosrjournals.org
DOI: 10.9790/2834-11123639 www.iosrjournals.org 36 | Page
Frequency Tuning OF Inverted F Antenna
Amin H. Al Ka’bi
Australian College of Kuwait, Kuwait
Abstract: Internal antennas are widely used in mobile wireless communication devices like smart phones,
which have been a major incentive of internal antenna research and design during the last decade, where new
designs with wider frequency bands have been introduced; single-band devices have developed into
multiband and multimode terminals. Although the average terminal size has decreased drastically, the
internal antennas have been designed into standard solutions, to meet the new design requirements, taking
into consideration the strict limitations set on the energy absorbed by the users of mobile devices. In this
paper, a model for frequency tunable ferrite-based Inverted F Antenna is proposed by altering the
permeability of the ferrite material.
I. Introduction
There are different techniques that can be possibly used for changing the operating frequency of the
antenna. They are mainly categorized as: mechanical techniques, using tunable electronic circuits, and
alteration of the properties of the antenna material. In this paper we will focus on the alteration of the
electrical properties (permittivity, permeability, and conductivity) of the antenna material.
The mechanical techniques, which include changing the shape or dimensions of the antenna, have a
disadvantage of lack of reliability to time delay, and short life time due to mechanical movements. On the
other hand the alteration of the antenna material does not require a mechanical movement of the antenna as
suitable material is incorporated into the antenna such that changing its electrical properties lead to change in
the antenna operating frequency[1].
Alteration of Ferrites permeability
Ferrites are magnetic materials made from a mixture of metal oxides. Due to their electrical
characteristics; they can be used many applications like antennas, electronic and communication devices,
inductors, transformers, and many other applications. Ferrites have high permeability at low frequencies,
and a dielectric constant of 10 or more, besides its high resistivity. The behavior of ferrites at high
frequencies is well studied in many research publications e.g. [2] & [3]. In this section a brief overview of
ferrites characteristics is presented.
The magnetic dipole moment is primarily responsible for the magnetic properties of the ferrites,
where it is produced by the spin of electrons in the material. Fig. 1 depicts this process where a constant
magnetic field , is applied to the ferrite, and the electrons start to spin about the axis of the magnetic field
at a frequency of (called Larmor frequency), where . When the magnetic
field is intense, the electron spins causing the dipole moments are aligned together and form one large dipole
moment. This case is called magnetization saturation , which can be used as an indicator of the density of
magnetic flux that is needed to align all the electron spins of the ferrite.
Fig. 1 Spin of electron about the constant field .
In conjunction with the constant magnetic field , a tiny magnitude alternating magnetic field at a
radio frequency , can be used to produce a forced spin of magnetic moment. In this case, the Polder
permeability tensor [4] is produced such as
The Effect of Electromagnetic Polarization on the Performance of Adaptive Array Antennas
DOI: 10.9790/2834-11123639 www.iosrjournals.org 37 | Page
[ ] (1)
where and are given as:-
(2)
(3)
where , and .
Ferrites are commercially obtainable including nickel, lithium, and magnesium ferrites, with
different shapes including bars and sheets. The magnetization saturations of these ferrites have ranges
from , and a resonance width from . As
we are dealing with radio frequencies, the frequencies are measured in MHz, where ,
, and .
If the polarization of the applied magnetic field and the density of the magnetic flux is circular,
where (+) denotes clockwise and (-) denotes anticlockwise polarizations, then can be expressed in terms of
as:-
[ ] [ ] [ ] (4)
where , and .
Fig. 2 depicts a characteristic performance of and versus the frequency of the RF magnetic field. It
can be seen that the clockwise waves resonates at where of exhibits a significant peak can be observed
at that frequency. This indicates a significant reduction in the magnitude of the clockwise waves, in
contradiction with case of anticlockwise waves, where there is no attenuation. Moreover, the waves do not
propagate if the frequency of the RF magnetic field lies in the range as the real part ( of
the ferrites permeability is negative in this case.
Fig. 2 Ferrites permeability as a function of the frequency of RF magnetic field.
This change in the magnetic field intensity when a radio frequency magnetic field propagates
through the ferrites can be employed in designing frequency tunable antennas. In order to investigate this
case, the effective permeability can is used to estimate the range of frequency tuning of the ferrite
material. The magnitude of depends on the direction of the static field and on the radio frequency
magnetic field . Here, we have three scenarios: parallel bias with , transverse bias with
⁄ , and longitudinal bias with . In the transverse bias case will be negative, and
the waves will not propagate when the frequency of the RF magnetic field lies in the range √
.
In the saturation phase of the ferrites, the following approximations hold and
, where indicates the remaining magnetization in the ferrite after the static magnetic field
is turned off [3]. Figure 3 illustrates versus the frequency of the RF magnetic field.
The Effect of Electromagnetic Polarization on the Performance of Adaptive Array Antennas
DOI: 10.9790/2834-11123639 www.iosrjournals.org 38 | Page
Fig. 3 Maximum range of frequency tuning of a ferrite antenna vs. frequency of RF magnetic field[1].
Fig. 4 Resonant frequency vs. the static magnetic field (Magnetic bias), for a rectangular ferrite micro-strip batch
antenna[5].
As the maximum range of frequency tuning of the ferrite antenna (including micro-strip and
dielectric resonator antennas) depends on , it can be seen from Figure 3 that the maximum frequency tuning
range declines by increasing the frequency of the RF magnetic field. The static field can be produced
either by a permanent magnet or by an electromagnet with dc current. Therefore, the resonant frequency of a
ferrite micro-strip batch antenna can be controlled by varying the current in the electromagnet that produces
the static magnetic field , as shown in Fig. 4[5]
Proposed model for Ferrite-based Inverted F Antenna
In this section a model for a ferrite-based Inverted F antenna is proposed. Figure 5 shows a typical
2.4GHz micro-strip Inverted F antenna, and Fig. 6 shows a typical radiation pattern of the antenna with
vertical polarization. The reflection at the feed-point of the antenna in dB is depicted in Fig.7, where it can
be seen clearly that the resonant frequency of the antenna occurs at around 2.41GH.
Fig. 5 Typical 2.4GHz Inverted F antenna Fig. 6 Typical radiation pattern of 2.4 GHz
Inverted F antennas with vertical polarization [6]
The Effect of Electromagnetic Polarization on the Performance of Adaptive Array Antennas
DOI: 10.9790/2834-11123639 www.iosrjournals.org 39 | Page
Fig. 7 Reflection at the feed-point of the 2.4GHz Inverted F antenna [6].
Fig. 8 Resonant frequency vs. the static magnetic field (Magnetic bias), for 2.4GHz Inverted F antenna.
Based on the explanations presented in section 1 and 2, the resonant frequency is expected to follow
the curve shown in Fig. 8. From this figure it can be seen that the resonant frequency of the inverted F
antenna can be significantly shifted from 2.41GHz to 3.15GHz by increasing the bias frequency from
0.2KOrested to 6.0KOersted, with a shift percentage of around 31%. This leads to a significant enhancement
in the performance of the antenna and hence the communication systems over wide range of frequencies
II. Conclusions
In this paper a model for frequency tunable ferrite-based Inverted F antenna is proposed. The
resonant frequency of the antenna can be significantly shifted by altering the permeability of the ferrite
material in the antenna, and without changing the physical dimensions of the antenna. The resonant
frequency shift gives flexibility to operate the antenna over wide range of frequencies which leads a overall
enhancement of the communication systems.
References
[1] Petosa, Aldo, “Frequency-Agile Antennas for Wireless Communications,” Published by Artech House, ISBN
9781608077694, December 2013.
[2] Uchino, K., Ferroelectric Devices, New York, NY: Marel Dekker, 2000.
[3] Martienssen, W., H. Warlimont, (eds.), "Ferroelectrics and Antiferroelectrics." In Springer Handbook of Condensed Matter
and Materials Data, pp. 903- 915, Berlin, Germany: Springer, 2005.
[4] Pozar, D., Microwave Engineering, Boston, MA: Addison- Wesley, 1990, pp. 529- 578.
[5] Mishra, R. K., S. S. Pattnaik, and N. Das, "Tuning of Microstrip Antenna on Ferrite Substrate," IEEE Transaction on
Antennas and Propagation, Vol. 41 No. 2, February 1993, 230- 233.
http://www.ti.com/lit/an/swru120b/swru120b.pdf

More Related Content

What's hot

Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN Operation
Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN OperationVery-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN Operation
Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN Operation
Saou-Wen Su
 
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...
IJEEE
 
Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...
Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...
Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...
jmicro
 
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...
Saou-Wen Su
 
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...
Saou-Wen Su
 
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.
IOSR Journals
 
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN Applications
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN ApplicationsA Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN Applications
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN Applications
Saou-Wen Su
 
Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...
Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...
Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...
IOSR Journals
 
Ch 1 microwave fundamentals
Ch 1  microwave fundamentalsCh 1  microwave fundamentals
Ch 1 microwave fundamentalszarinamdamin
 
Analysis of propagation of modulated optical signal in an integrated optic envi
Analysis of propagation of modulated optical signal in an integrated optic enviAnalysis of propagation of modulated optical signal in an integrated optic envi
Analysis of propagation of modulated optical signal in an integrated optic enviIAEME Publication
 
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN Operation
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN OperationCompact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN Operation
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN Operation
Saou-Wen Su
 
Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...
Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...
Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...
Saou-Wen Su
 
OFC notes Unit -8 VTU
OFC notes Unit -8 VTUOFC notes Unit -8 VTU
OFC notes Unit -8 VTU
Jagadish M
 
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...
Saou-Wen Su
 
Seminar
SeminarSeminar
Novel band microstrip antenna
Novel band microstrip antennaNovel band microstrip antenna
Novel band microstrip antenna
Raghuvardhan Kumar
 

What's hot (18)

Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN Operation
Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN OperationVery-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN Operation
Very-Low-Cost Copper-Wire Antenna for 2.4-GHz WLAN Operation
 
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...
A Review of Multi Resonant Slotted Micro Strip Patch Antenna (MPA) for IMT, W...
 
Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...
Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...
Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics...
 
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...
2008 IEEE AP-S-Internal Wideband Monopole Antenna For MIMO Access-Point Appli...
 
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...
Integration of Internal 700 MHz and WLAN/WiMAX Antennas for Palm-Sized Mobile...
 
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities.
 
01.08030501
01.0803050101.08030501
01.08030501
 
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN Applications
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN ApplicationsA Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN Applications
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN Applications
 
Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...
Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...
Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler...
 
Ch 1 microwave fundamentals
Ch 1  microwave fundamentalsCh 1  microwave fundamentals
Ch 1 microwave fundamentals
 
Analysis of propagation of modulated optical signal in an integrated optic envi
Analysis of propagation of modulated optical signal in an integrated optic enviAnalysis of propagation of modulated optical signal in an integrated optic envi
Analysis of propagation of modulated optical signal in an integrated optic envi
 
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN Operation
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN OperationCompact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN Operation
Compact Paper-Clip-Shaped Wire Antenna for 2.4 and 5.2 GHz WLAN Operation
 
Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...
Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...
Printed Coplanar Two-Antenna Element for 2.4/5 GHz WLAN Operation in a MIMO S...
 
OFC notes Unit -8 VTU
OFC notes Unit -8 VTUOFC notes Unit -8 VTU
OFC notes Unit -8 VTU
 
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...
Hybrid of Monopole and Dipole Antennas for Concurrent 2.4- and 5-GHz WLAN Acc...
 
Seminar
SeminarSeminar
Seminar
 
Patch antenna
Patch antenna Patch antenna
Patch antenna
 
Novel band microstrip antenna
Novel band microstrip antennaNovel band microstrip antenna
Novel band microstrip antenna
 

Viewers also liked

Presentación Jaime Solorzano
Presentación Jaime SolorzanoPresentación Jaime Solorzano
Presentación Jaime Solorzano
Jaime Solorzano
 
Optical transmission technique
Optical transmission techniqueOptical transmission technique
Optical transmission technique
Online
 
Chronicle Tmba online - 6jan2016
Chronicle Tmba online - 6jan2016Chronicle Tmba online - 6jan2016
Chronicle Tmba online - 6jan2016Kerry White
 
Lissy reference letter signed
Lissy reference letter signedLissy reference letter signed
Lissy reference letter signedMelissa O'Brien
 
Anna Jankowska, Portfolio
Anna Jankowska, PortfolioAnna Jankowska, Portfolio
Anna Jankowska, PortfolioAnna Jankowska
 
Agile product
Agile productAgile product
Agile product
Gunther Gerlach
 
Design & Assessment for KB (Teacher workshop) (23-3-2007)
Design & Assessment for KB (Teacher workshop) (23-3-2007)Design & Assessment for KB (Teacher workshop) (23-3-2007)
Design & Assessment for KB (Teacher workshop) (23-3-2007)KBTNHKU
 
Valuation and capital budgeting for the levered firm
Valuation and capital budgeting for the levered firmValuation and capital budgeting for the levered firm
Valuation and capital budgeting for the levered firm
Online
 
Landme Pitch Deck (Apr 2015)
Landme Pitch Deck (Apr 2015)Landme Pitch Deck (Apr 2015)
Landme Pitch Deck (Apr 2015)Brett Hartmann
 
Optical Spatial Modulation OFDM using Micro LEDs
Optical Spatial Modulation OFDM using Micro LEDsOptical Spatial Modulation OFDM using Micro LEDs
Optical Spatial Modulation OFDM using Micro LEDs
Basil Jacob
 
Tips for Workshop Facilitation
Tips for Workshop FacilitationTips for Workshop Facilitation
Tips for Workshop Facilitation
Jennifer Cham
 
Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...
Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...
Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...
IOSR Journals
 
G017154852
G017154852G017154852
G017154852
IOSR Journals
 
Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...
Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...
Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...
IOSR Journals
 
A Study On Psychological Variables On Women Sports Participation Levels In Un...
A Study On Psychological Variables On Women Sports Participation Levels In Un...A Study On Psychological Variables On Women Sports Participation Levels In Un...
A Study On Psychological Variables On Women Sports Participation Levels In Un...
IOSR Journals
 
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...
IOSR Journals
 
A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...
A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...
A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...
IOSR Journals
 

Viewers also liked (20)

NARASIMHULU
NARASIMHULUNARASIMHULU
NARASIMHULU
 
Presentación Jaime Solorzano
Presentación Jaime SolorzanoPresentación Jaime Solorzano
Presentación Jaime Solorzano
 
Optical transmission technique
Optical transmission techniqueOptical transmission technique
Optical transmission technique
 
Chronicle Tmba online - 6jan2016
Chronicle Tmba online - 6jan2016Chronicle Tmba online - 6jan2016
Chronicle Tmba online - 6jan2016
 
Lissy reference letter signed
Lissy reference letter signedLissy reference letter signed
Lissy reference letter signed
 
1.2.1 Materials1
1.2.1 Materials11.2.1 Materials1
1.2.1 Materials1
 
Investor Day
Investor DayInvestor Day
Investor Day
 
Anna Jankowska, Portfolio
Anna Jankowska, PortfolioAnna Jankowska, Portfolio
Anna Jankowska, Portfolio
 
Agile product
Agile productAgile product
Agile product
 
Design & Assessment for KB (Teacher workshop) (23-3-2007)
Design & Assessment for KB (Teacher workshop) (23-3-2007)Design & Assessment for KB (Teacher workshop) (23-3-2007)
Design & Assessment for KB (Teacher workshop) (23-3-2007)
 
Valuation and capital budgeting for the levered firm
Valuation and capital budgeting for the levered firmValuation and capital budgeting for the levered firm
Valuation and capital budgeting for the levered firm
 
Landme Pitch Deck (Apr 2015)
Landme Pitch Deck (Apr 2015)Landme Pitch Deck (Apr 2015)
Landme Pitch Deck (Apr 2015)
 
Optical Spatial Modulation OFDM using Micro LEDs
Optical Spatial Modulation OFDM using Micro LEDsOptical Spatial Modulation OFDM using Micro LEDs
Optical Spatial Modulation OFDM using Micro LEDs
 
Tips for Workshop Facilitation
Tips for Workshop FacilitationTips for Workshop Facilitation
Tips for Workshop Facilitation
 
Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...
Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...
Comparative Analysis of the Different Brassica OleraceaVarieties Grown on Jos...
 
G017154852
G017154852G017154852
G017154852
 
Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...
Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...
Batch Thermodynamics and Kinetic Study for Removal of Cationic Dye from Aqueo...
 
A Study On Psychological Variables On Women Sports Participation Levels In Un...
A Study On Psychological Variables On Women Sports Participation Levels In Un...A Study On Psychological Variables On Women Sports Participation Levels In Un...
A Study On Psychological Variables On Women Sports Participation Levels In Un...
 
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...
 
A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...
A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...
A Fossil Gymnospermous Leaf Gnetalophyllum deccanii gen. et sp.nov. From The ...
 

Similar to E011133639

H010134956
H010134956H010134956
H010134956
IOSR Journals
 
A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...
A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...
A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...
IJECEIAES
 
T- Shape Antenna Design for Microwave Band Applications
T- Shape Antenna Design for Microwave  Band Applications T- Shape Antenna Design for Microwave  Band Applications
T- Shape Antenna Design for Microwave Band Applications
IJEEE
 
Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)
Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)
Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)
IOSR Journals
 
C1103031822
C1103031822C1103031822
C1103031822
IOSR Journals
 
Es4301871876
Es4301871876Es4301871876
Es4301871876
IJERA Editor
 
Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.
Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.
Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.
IOSR Journals
 
Microstrip patch antenna for pcs and wlan
Microstrip patch antenna for pcs and wlanMicrostrip patch antenna for pcs and wlan
Microstrip patch antenna for pcs and wlan
eSAT Journals
 
An Analysis of Dual Band bandpass Filters using with Arbitrary Band Ratios
An Analysis of Dual Band bandpass Filters using with Arbitrary Band RatiosAn Analysis of Dual Band bandpass Filters using with Arbitrary Band Ratios
An Analysis of Dual Band bandpass Filters using with Arbitrary Band Ratios
ijtsrd
 
E010242430
E010242430E010242430
E010242430
IOSR Journals
 
Multiband Microstrip Antenna for Wi-MAX Application-A study
Multiband Microstrip Antenna for Wi-MAX Application-A studyMultiband Microstrip Antenna for Wi-MAX Application-A study
Multiband Microstrip Antenna for Wi-MAX Application-A study
IJERA Editor
 
Copper nanofilm antenna for wlan applications
Copper nanofilm antenna for wlan applicationsCopper nanofilm antenna for wlan applications
Copper nanofilm antenna for wlan applications
IAEME Publication
 
Planar Inverted-F Antenna for GPS Application - A study
Planar Inverted-F Antenna for GPS Application - A studyPlanar Inverted-F Antenna for GPS Application - A study
Planar Inverted-F Antenna for GPS Application - A study
IJERA Editor
 
H010124449
H010124449H010124449
H010124449
IOSR Journals
 
Dual band antenna using reactive loading
Dual band antenna using reactive loadingDual band antenna using reactive loading
Dual band antenna using reactive loadingPrathamesh Bhat
 
Octa-band reconfigurable monopole antenna frequency diversity 5G wireless
Octa-band reconfigurable monopole antenna frequency diversity 5G wirelessOcta-band reconfigurable monopole antenna frequency diversity 5G wireless
Octa-band reconfigurable monopole antenna frequency diversity 5G wireless
IJECEIAES
 
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities
Optimization of Complete Monopole Antennato Exhibit Wideband CapabilitiesOptimization of Complete Monopole Antennato Exhibit Wideband Capabilities
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities
IOSR Journals
 
LAB File
LAB FileLAB File
LAB File
kishoreajay
 

Similar to E011133639 (20)

H010134956
H010134956H010134956
H010134956
 
7 4-1-7-11
7 4-1-7-117 4-1-7-11
7 4-1-7-11
 
A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...
A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...
A Compact Dual Band Elliptical Microstrip Antenna for Ku/K Band Satellite App...
 
T- Shape Antenna Design for Microwave Band Applications
T- Shape Antenna Design for Microwave  Band Applications T- Shape Antenna Design for Microwave  Band Applications
T- Shape Antenna Design for Microwave Band Applications
 
Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)
Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)
Magnetic Femtotesla Inductor Coil Sensor for ELF Noise Signals-( 0.1Hz to3.0 Hz)
 
C1103031822
C1103031822C1103031822
C1103031822
 
Es4301871876
Es4301871876Es4301871876
Es4301871876
 
Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.
Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.
Characteristic Comparison of U-Shaped Monopole and Complete Monopole Antenna.
 
Microstrip patch antenna for pcs and wlan
Microstrip patch antenna for pcs and wlanMicrostrip patch antenna for pcs and wlan
Microstrip patch antenna for pcs and wlan
 
An Analysis of Dual Band bandpass Filters using with Arbitrary Band Ratios
An Analysis of Dual Band bandpass Filters using with Arbitrary Band RatiosAn Analysis of Dual Band bandpass Filters using with Arbitrary Band Ratios
An Analysis of Dual Band bandpass Filters using with Arbitrary Band Ratios
 
E010242430
E010242430E010242430
E010242430
 
Multiband Microstrip Antenna for Wi-MAX Application-A study
Multiband Microstrip Antenna for Wi-MAX Application-A studyMultiband Microstrip Antenna for Wi-MAX Application-A study
Multiband Microstrip Antenna for Wi-MAX Application-A study
 
Copper nanofilm antenna for wlan applications
Copper nanofilm antenna for wlan applicationsCopper nanofilm antenna for wlan applications
Copper nanofilm antenna for wlan applications
 
Planar Inverted-F Antenna for GPS Application - A study
Planar Inverted-F Antenna for GPS Application - A studyPlanar Inverted-F Antenna for GPS Application - A study
Planar Inverted-F Antenna for GPS Application - A study
 
H010124449
H010124449H010124449
H010124449
 
Dual band antenna using reactive loading
Dual band antenna using reactive loadingDual band antenna using reactive loading
Dual band antenna using reactive loading
 
Conference
ConferenceConference
Conference
 
Octa-band reconfigurable monopole antenna frequency diversity 5G wireless
Octa-band reconfigurable monopole antenna frequency diversity 5G wirelessOcta-band reconfigurable monopole antenna frequency diversity 5G wireless
Octa-band reconfigurable monopole antenna frequency diversity 5G wireless
 
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities
Optimization of Complete Monopole Antennato Exhibit Wideband CapabilitiesOptimization of Complete Monopole Antennato Exhibit Wideband Capabilities
Optimization of Complete Monopole Antennato Exhibit Wideband Capabilities
 
LAB File
LAB FileLAB File
LAB File
 

More from IOSR Journals

A011140104
A011140104A011140104
A011140104
IOSR Journals
 
M0111397100
M0111397100M0111397100
M0111397100
IOSR Journals
 
L011138596
L011138596L011138596
L011138596
IOSR Journals
 
K011138084
K011138084K011138084
K011138084
IOSR Journals
 
J011137479
J011137479J011137479
J011137479
IOSR Journals
 
I011136673
I011136673I011136673
I011136673
IOSR Journals
 
G011134454
G011134454G011134454
G011134454
IOSR Journals
 
H011135565
H011135565H011135565
H011135565
IOSR Journals
 
F011134043
F011134043F011134043
F011134043
IOSR Journals
 
D011132635
D011132635D011132635
D011132635
IOSR Journals
 
C011131925
C011131925C011131925
C011131925
IOSR Journals
 
B011130918
B011130918B011130918
B011130918
IOSR Journals
 
A011130108
A011130108A011130108
A011130108
IOSR Journals
 
I011125160
I011125160I011125160
I011125160
IOSR Journals
 
H011124050
H011124050H011124050
H011124050
IOSR Journals
 
G011123539
G011123539G011123539
G011123539
IOSR Journals
 
F011123134
F011123134F011123134
F011123134
IOSR Journals
 
E011122530
E011122530E011122530
E011122530
IOSR Journals
 
D011121524
D011121524D011121524
D011121524
IOSR Journals
 
C011121114
C011121114C011121114
C011121114
IOSR Journals
 

More from IOSR Journals (20)

A011140104
A011140104A011140104
A011140104
 
M0111397100
M0111397100M0111397100
M0111397100
 
L011138596
L011138596L011138596
L011138596
 
K011138084
K011138084K011138084
K011138084
 
J011137479
J011137479J011137479
J011137479
 
I011136673
I011136673I011136673
I011136673
 
G011134454
G011134454G011134454
G011134454
 
H011135565
H011135565H011135565
H011135565
 
F011134043
F011134043F011134043
F011134043
 
D011132635
D011132635D011132635
D011132635
 
C011131925
C011131925C011131925
C011131925
 
B011130918
B011130918B011130918
B011130918
 
A011130108
A011130108A011130108
A011130108
 
I011125160
I011125160I011125160
I011125160
 
H011124050
H011124050H011124050
H011124050
 
G011123539
G011123539G011123539
G011123539
 
F011123134
F011123134F011123134
F011123134
 
E011122530
E011122530E011122530
E011122530
 
D011121524
D011121524D011121524
D011121524
 
C011121114
C011121114C011121114
C011121114
 

Recently uploaded

Search and Society: Reimagining Information Access for Radical Futures
Search and Society: Reimagining Information Access for Radical FuturesSearch and Society: Reimagining Information Access for Radical Futures
Search and Society: Reimagining Information Access for Radical Futures
Bhaskar Mitra
 
Key Trends Shaping the Future of Infrastructure.pdf
Key Trends Shaping the Future of Infrastructure.pdfKey Trends Shaping the Future of Infrastructure.pdf
Key Trends Shaping the Future of Infrastructure.pdf
Cheryl Hung
 
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...
DanBrown980551
 
Accelerate your Kubernetes clusters with Varnish Caching
Accelerate your Kubernetes clusters with Varnish CachingAccelerate your Kubernetes clusters with Varnish Caching
Accelerate your Kubernetes clusters with Varnish Caching
Thijs Feryn
 
Assuring Contact Center Experiences for Your Customers With ThousandEyes
Assuring Contact Center Experiences for Your Customers With ThousandEyesAssuring Contact Center Experiences for Your Customers With ThousandEyes
Assuring Contact Center Experiences for Your Customers With ThousandEyes
ThousandEyes
 
FIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdf
FIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdfFIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdf
FIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdf
FIDO Alliance
 
To Graph or Not to Graph Knowledge Graph Architectures and LLMs
To Graph or Not to Graph Knowledge Graph Architectures and LLMsTo Graph or Not to Graph Knowledge Graph Architectures and LLMs
To Graph or Not to Graph Knowledge Graph Architectures and LLMs
Paul Groth
 
FIDO Alliance Osaka Seminar: Passkeys at Amazon.pdf
FIDO Alliance Osaka Seminar: Passkeys at Amazon.pdfFIDO Alliance Osaka Seminar: Passkeys at Amazon.pdf
FIDO Alliance Osaka Seminar: Passkeys at Amazon.pdf
FIDO Alliance
 
FIDO Alliance Osaka Seminar: Overview.pdf
FIDO Alliance Osaka Seminar: Overview.pdfFIDO Alliance Osaka Seminar: Overview.pdf
FIDO Alliance Osaka Seminar: Overview.pdf
FIDO Alliance
 
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...
Jeffrey Haguewood
 
De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...
De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...
De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...
Product School
 
Essentials of Automations: Optimizing FME Workflows with Parameters
Essentials of Automations: Optimizing FME Workflows with ParametersEssentials of Automations: Optimizing FME Workflows with Parameters
Essentials of Automations: Optimizing FME Workflows with Parameters
Safe Software
 
GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...
GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...
GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...
Sri Ambati
 
AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...
AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...
AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...
Product School
 
ODC, Data Fabric and Architecture User Group
ODC, Data Fabric and Architecture User GroupODC, Data Fabric and Architecture User Group
ODC, Data Fabric and Architecture User Group
CatarinaPereira64715
 
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...
James Anderson
 
Neuro-symbolic is not enough, we need neuro-*semantic*
Neuro-symbolic is not enough, we need neuro-*semantic*Neuro-symbolic is not enough, we need neuro-*semantic*
Neuro-symbolic is not enough, we need neuro-*semantic*
Frank van Harmelen
 
UiPath Test Automation using UiPath Test Suite series, part 4
UiPath Test Automation using UiPath Test Suite series, part 4UiPath Test Automation using UiPath Test Suite series, part 4
UiPath Test Automation using UiPath Test Suite series, part 4
DianaGray10
 
When stars align: studies in data quality, knowledge graphs, and machine lear...
When stars align: studies in data quality, knowledge graphs, and machine lear...When stars align: studies in data quality, knowledge graphs, and machine lear...
When stars align: studies in data quality, knowledge graphs, and machine lear...
Elena Simperl
 
Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...
Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...
Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...
Thierry Lestable
 

Recently uploaded (20)

Search and Society: Reimagining Information Access for Radical Futures
Search and Society: Reimagining Information Access for Radical FuturesSearch and Society: Reimagining Information Access for Radical Futures
Search and Society: Reimagining Information Access for Radical Futures
 
Key Trends Shaping the Future of Infrastructure.pdf
Key Trends Shaping the Future of Infrastructure.pdfKey Trends Shaping the Future of Infrastructure.pdf
Key Trends Shaping the Future of Infrastructure.pdf
 
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...
 
Accelerate your Kubernetes clusters with Varnish Caching
Accelerate your Kubernetes clusters with Varnish CachingAccelerate your Kubernetes clusters with Varnish Caching
Accelerate your Kubernetes clusters with Varnish Caching
 
Assuring Contact Center Experiences for Your Customers With ThousandEyes
Assuring Contact Center Experiences for Your Customers With ThousandEyesAssuring Contact Center Experiences for Your Customers With ThousandEyes
Assuring Contact Center Experiences for Your Customers With ThousandEyes
 
FIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdf
FIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdfFIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdf
FIDO Alliance Osaka Seminar: The WebAuthn API and Discoverable Credentials.pdf
 
To Graph or Not to Graph Knowledge Graph Architectures and LLMs
To Graph or Not to Graph Knowledge Graph Architectures and LLMsTo Graph or Not to Graph Knowledge Graph Architectures and LLMs
To Graph or Not to Graph Knowledge Graph Architectures and LLMs
 
FIDO Alliance Osaka Seminar: Passkeys at Amazon.pdf
FIDO Alliance Osaka Seminar: Passkeys at Amazon.pdfFIDO Alliance Osaka Seminar: Passkeys at Amazon.pdf
FIDO Alliance Osaka Seminar: Passkeys at Amazon.pdf
 
FIDO Alliance Osaka Seminar: Overview.pdf
FIDO Alliance Osaka Seminar: Overview.pdfFIDO Alliance Osaka Seminar: Overview.pdf
FIDO Alliance Osaka Seminar: Overview.pdf
 
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...
 
De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...
De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...
De-mystifying Zero to One: Design Informed Techniques for Greenfield Innovati...
 
Essentials of Automations: Optimizing FME Workflows with Parameters
Essentials of Automations: Optimizing FME Workflows with ParametersEssentials of Automations: Optimizing FME Workflows with Parameters
Essentials of Automations: Optimizing FME Workflows with Parameters
 
GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...
GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...
GenAISummit 2024 May 28 Sri Ambati Keynote: AGI Belongs to The Community in O...
 
AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...
AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...
AI for Every Business: Unlocking Your Product's Universal Potential by VP of ...
 
ODC, Data Fabric and Architecture User Group
ODC, Data Fabric and Architecture User GroupODC, Data Fabric and Architecture User Group
ODC, Data Fabric and Architecture User Group
 
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...
 
Neuro-symbolic is not enough, we need neuro-*semantic*
Neuro-symbolic is not enough, we need neuro-*semantic*Neuro-symbolic is not enough, we need neuro-*semantic*
Neuro-symbolic is not enough, we need neuro-*semantic*
 
UiPath Test Automation using UiPath Test Suite series, part 4
UiPath Test Automation using UiPath Test Suite series, part 4UiPath Test Automation using UiPath Test Suite series, part 4
UiPath Test Automation using UiPath Test Suite series, part 4
 
When stars align: studies in data quality, knowledge graphs, and machine lear...
When stars align: studies in data quality, knowledge graphs, and machine lear...When stars align: studies in data quality, knowledge graphs, and machine lear...
When stars align: studies in data quality, knowledge graphs, and machine lear...
 
Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...
Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...
Empowering NextGen Mobility via Large Action Model Infrastructure (LAMI): pav...
 

E011133639

  • 1. IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 11, Issue 1, Ver. III (Jan. - Feb .2016), PP 36-39 www.iosrjournals.org DOI: 10.9790/2834-11123639 www.iosrjournals.org 36 | Page Frequency Tuning OF Inverted F Antenna Amin H. Al Ka’bi Australian College of Kuwait, Kuwait Abstract: Internal antennas are widely used in mobile wireless communication devices like smart phones, which have been a major incentive of internal antenna research and design during the last decade, where new designs with wider frequency bands have been introduced; single-band devices have developed into multiband and multimode terminals. Although the average terminal size has decreased drastically, the internal antennas have been designed into standard solutions, to meet the new design requirements, taking into consideration the strict limitations set on the energy absorbed by the users of mobile devices. In this paper, a model for frequency tunable ferrite-based Inverted F Antenna is proposed by altering the permeability of the ferrite material. I. Introduction There are different techniques that can be possibly used for changing the operating frequency of the antenna. They are mainly categorized as: mechanical techniques, using tunable electronic circuits, and alteration of the properties of the antenna material. In this paper we will focus on the alteration of the electrical properties (permittivity, permeability, and conductivity) of the antenna material. The mechanical techniques, which include changing the shape or dimensions of the antenna, have a disadvantage of lack of reliability to time delay, and short life time due to mechanical movements. On the other hand the alteration of the antenna material does not require a mechanical movement of the antenna as suitable material is incorporated into the antenna such that changing its electrical properties lead to change in the antenna operating frequency[1]. Alteration of Ferrites permeability Ferrites are magnetic materials made from a mixture of metal oxides. Due to their electrical characteristics; they can be used many applications like antennas, electronic and communication devices, inductors, transformers, and many other applications. Ferrites have high permeability at low frequencies, and a dielectric constant of 10 or more, besides its high resistivity. The behavior of ferrites at high frequencies is well studied in many research publications e.g. [2] & [3]. In this section a brief overview of ferrites characteristics is presented. The magnetic dipole moment is primarily responsible for the magnetic properties of the ferrites, where it is produced by the spin of electrons in the material. Fig. 1 depicts this process where a constant magnetic field , is applied to the ferrite, and the electrons start to spin about the axis of the magnetic field at a frequency of (called Larmor frequency), where . When the magnetic field is intense, the electron spins causing the dipole moments are aligned together and form one large dipole moment. This case is called magnetization saturation , which can be used as an indicator of the density of magnetic flux that is needed to align all the electron spins of the ferrite. Fig. 1 Spin of electron about the constant field . In conjunction with the constant magnetic field , a tiny magnitude alternating magnetic field at a radio frequency , can be used to produce a forced spin of magnetic moment. In this case, the Polder permeability tensor [4] is produced such as
  • 2. The Effect of Electromagnetic Polarization on the Performance of Adaptive Array Antennas DOI: 10.9790/2834-11123639 www.iosrjournals.org 37 | Page [ ] (1) where and are given as:- (2) (3) where , and . Ferrites are commercially obtainable including nickel, lithium, and magnesium ferrites, with different shapes including bars and sheets. The magnetization saturations of these ferrites have ranges from , and a resonance width from . As we are dealing with radio frequencies, the frequencies are measured in MHz, where , , and . If the polarization of the applied magnetic field and the density of the magnetic flux is circular, where (+) denotes clockwise and (-) denotes anticlockwise polarizations, then can be expressed in terms of as:- [ ] [ ] [ ] (4) where , and . Fig. 2 depicts a characteristic performance of and versus the frequency of the RF magnetic field. It can be seen that the clockwise waves resonates at where of exhibits a significant peak can be observed at that frequency. This indicates a significant reduction in the magnitude of the clockwise waves, in contradiction with case of anticlockwise waves, where there is no attenuation. Moreover, the waves do not propagate if the frequency of the RF magnetic field lies in the range as the real part ( of the ferrites permeability is negative in this case. Fig. 2 Ferrites permeability as a function of the frequency of RF magnetic field. This change in the magnetic field intensity when a radio frequency magnetic field propagates through the ferrites can be employed in designing frequency tunable antennas. In order to investigate this case, the effective permeability can is used to estimate the range of frequency tuning of the ferrite material. The magnitude of depends on the direction of the static field and on the radio frequency magnetic field . Here, we have three scenarios: parallel bias with , transverse bias with ⁄ , and longitudinal bias with . In the transverse bias case will be negative, and the waves will not propagate when the frequency of the RF magnetic field lies in the range √ . In the saturation phase of the ferrites, the following approximations hold and , where indicates the remaining magnetization in the ferrite after the static magnetic field is turned off [3]. Figure 3 illustrates versus the frequency of the RF magnetic field.
  • 3. The Effect of Electromagnetic Polarization on the Performance of Adaptive Array Antennas DOI: 10.9790/2834-11123639 www.iosrjournals.org 38 | Page Fig. 3 Maximum range of frequency tuning of a ferrite antenna vs. frequency of RF magnetic field[1]. Fig. 4 Resonant frequency vs. the static magnetic field (Magnetic bias), for a rectangular ferrite micro-strip batch antenna[5]. As the maximum range of frequency tuning of the ferrite antenna (including micro-strip and dielectric resonator antennas) depends on , it can be seen from Figure 3 that the maximum frequency tuning range declines by increasing the frequency of the RF magnetic field. The static field can be produced either by a permanent magnet or by an electromagnet with dc current. Therefore, the resonant frequency of a ferrite micro-strip batch antenna can be controlled by varying the current in the electromagnet that produces the static magnetic field , as shown in Fig. 4[5] Proposed model for Ferrite-based Inverted F Antenna In this section a model for a ferrite-based Inverted F antenna is proposed. Figure 5 shows a typical 2.4GHz micro-strip Inverted F antenna, and Fig. 6 shows a typical radiation pattern of the antenna with vertical polarization. The reflection at the feed-point of the antenna in dB is depicted in Fig.7, where it can be seen clearly that the resonant frequency of the antenna occurs at around 2.41GH. Fig. 5 Typical 2.4GHz Inverted F antenna Fig. 6 Typical radiation pattern of 2.4 GHz Inverted F antennas with vertical polarization [6]
  • 4. The Effect of Electromagnetic Polarization on the Performance of Adaptive Array Antennas DOI: 10.9790/2834-11123639 www.iosrjournals.org 39 | Page Fig. 7 Reflection at the feed-point of the 2.4GHz Inverted F antenna [6]. Fig. 8 Resonant frequency vs. the static magnetic field (Magnetic bias), for 2.4GHz Inverted F antenna. Based on the explanations presented in section 1 and 2, the resonant frequency is expected to follow the curve shown in Fig. 8. From this figure it can be seen that the resonant frequency of the inverted F antenna can be significantly shifted from 2.41GHz to 3.15GHz by increasing the bias frequency from 0.2KOrested to 6.0KOersted, with a shift percentage of around 31%. This leads to a significant enhancement in the performance of the antenna and hence the communication systems over wide range of frequencies II. Conclusions In this paper a model for frequency tunable ferrite-based Inverted F antenna is proposed. The resonant frequency of the antenna can be significantly shifted by altering the permeability of the ferrite material in the antenna, and without changing the physical dimensions of the antenna. The resonant frequency shift gives flexibility to operate the antenna over wide range of frequencies which leads a overall enhancement of the communication systems. References [1] Petosa, Aldo, “Frequency-Agile Antennas for Wireless Communications,” Published by Artech House, ISBN 9781608077694, December 2013. [2] Uchino, K., Ferroelectric Devices, New York, NY: Marel Dekker, 2000. [3] Martienssen, W., H. Warlimont, (eds.), "Ferroelectrics and Antiferroelectrics." In Springer Handbook of Condensed Matter and Materials Data, pp. 903- 915, Berlin, Germany: Springer, 2005. [4] Pozar, D., Microwave Engineering, Boston, MA: Addison- Wesley, 1990, pp. 529- 578. [5] Mishra, R. K., S. S. Pattnaik, and N. Das, "Tuning of Microstrip Antenna on Ferrite Substrate," IEEE Transaction on Antennas and Propagation, Vol. 41 No. 2, February 1993, 230- 233. http://www.ti.com/lit/an/swru120b/swru120b.pdf