research article development of a semielliptical partial ...a theoretical and experimental...

Research ArticleDevelopment of a Semielliptical Partial GroundPlane Antenna for RFID and GSM-900

M R Zaman1 R Azim1 N Misran1 M F Asillam2 and T Islam1

1 Institute of Space Science (ANGKASA) Level 2 Faculty of Engineering and Built Environment BuildingUniversiti Kebangsaan Malaysia 43600 UKM Bangi Selangor Malaysia

2 National Space Agency of Malaysia 62100 Putrajaya Selangor Malaysia

Correspondence should be addressed to M R Zaman robelhkyahoocom

Received 24 October 2013 Accepted 11 November 2013 Published 9 April 2014

Academic Editor J S Mandeep

Copyright copy 2014 M R Zaman et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

A novel compact broadband patch antenna for UHF (ultrahigh frequency) RFID (radio frequency identification) and GSM-900(global system for mobile communications) band is shown in this paper The antenna is composed of an ellipse shape annular ringat the patchThe ground plane of the planar antenna ismodified with a semiellipse shape slotThe structure can generate substantialamount of current at the feed-line The geometry of the antenna is evaluated by using HFSS simulation software and deliberatedacross the paper Parametric study is exhibited to delineate the response change of the antenna The antenna has a physical widthof 024 120582 and length of 03 120582 It covers a frequency starting from 09GHz to 108GHz A fractional bandwidth of 182 has beenachieved from 09GHz till 108GHz An average gain of 55 dBi is achieved at the resonance frequencyThe simulated andmeasuredresults have good agreement

1 Introduction

Microstrip antennas are becoming more popular in commu-nication systems day by day With the help of cost effectivesubstrates and different copper shapes over and under thesubstrate researchers are getting new bands of interest withcomparatively less complexity than other types of antennaeRecent advances in radio communications have increased thedemand in the antenna technology

A RFID reader antenna using metamaterial is shown in[1] Coupled branch-line is used to attain dual frequencyperformance However the measured S

21response of the

antenna falls below minus5 dB by introducing loss to the coupledline A rectangular slot is introduced in the ground planewitha circular ring at the patch in [2] to enhance the impedancebandwidth Another near field RFID reader antenna isexhibited in [3] to have a reading performance of about7 cm Despite that the antenna has a bulky dimension of882mm times 80mm A compact rectangular planar antenna isproposed in [4] with a small size and wideband performanceIn [5] an antenna is presented for mobile RFID readerThough the antenna evaluates quadrifilar spiral antenna

(QSA) technology for RFID application nevertheless theantenna gain is as low as 006 dBic An S-shaped impedancematching network is used in designing a mobile RFID readerfor 245GHz in [6] Although the antenna has a gain of6 dBi at the operating frequency nonetheless the antennathickness is 11mm which gives a drawback for portableapplications A RFID reader antenna with L-shaped groundplane is displayed in [7] The antenna has a dimension of250mm times 1055mm which is sizable in RFID applicationCircular slot is introduced to have dual frequency responsein [8 9] by using FR4 substrate This RFID reader antennahas a measured gain of 35 dBi at the operating frequency Ahalf ellipse shape antenna is designed in [10] for vital signdetection at 400MHz frequency In the paper the ellipseshape antenna is compared with a bowtie shape antennaTheimpedance characteristics of the ellipse shape antenna jumpover 150Ω at the claimed frequency with an imaginary valueof ndashj20Ω Another half ellipse shape antenna with differentheight of backed cavity above ground is shown in [11] Theantenna shows an improvement over popular bowtie shapeUWB antenna However the VSWR of the proposed antennais greater than 2 at the claimed frequency An ellipse-loaded

Hindawi Publishing CorporationInternational Journal of Antennas and PropagationVolume 2014 Article ID 693412 7 pageshttpdxdoiorg1011552014693412

2 International Journal of Antennas and Propagation

q

p

b

a

c

R

(a)

e

f

a998400

b998400

(b)

Figure 1 Proposed antenna dimensions (a) patch and (b) ground plane

circular slot array for millimetre-wave WPAN applicationsis presented in [12] Liquid crystal polymer (LCP) is usedfor the antenna design In the design a metallic reflector isused to make the radiation limited which makes the antennasize bulky and bigger in dimension In [13] a design ofellipticalmicrostrip patch antenna is presented using artificialneural networks to gain circular polarizationNonetheless theantenna return loss at the target frequency is minus625 dB whichis not acceptable in minus10 dB return loss scale A theoreticaland experimental investigation of an elliptical annular ringshape antenna is shown in [14] The analysis is carriedout using generalized transmission line model A planarmonopole antenna fed by an offset-microstrip line is shownin [15] A circular ring is used to achieve the dimensionAnother antenna is proclaimed in [16] with coplanar groundplane The antenna is compact and one sided Broadbandand multiband antenna designs are shown in [17] usingellipses shape with the help of genetic algorithm to createamorphous shape Nevertheless the results presented donot include any result showing gain of the antenna Curvefitting technique is shown in [18] for patch antenna usingparticle swarm optimization (PSO) A compact dual ellipsesmonopole antenna is printed in FR4 substrate [19] No resulton the gain of the antenna is demonstrated In [20] anellipse shape crescent slot broadband microstrip antenna isshown Parametric studies are shown for different substratethickness However the antenna results are simulated and notvalidated using fabricated antenna results Different structureof the antenna is presented in finding different frequenciesthroughout the research of microstrip antenna design FR4substrate is being used widely for different applications ofantenna nowadays due to its low price and durability Groundplanemodifiedwideband antenna is shown in [21] which usesFR4 substrate Fromhere it can be seen that FR4 substrate canbe used to have wideband performance

In this paper an elliptical shape antenna is shown withmodified ground plane The antenna is designed for a fre-quency starting from 09GHz to 108GHz The proposed

antenna is compact in size with a length width and heightof 100mm 80mm and 16mm respectively The measuredresults of the antenna are shown to have good agreement withthe simulated result

2 Methodology

The antenna is designed using FR4 substrate with dielectricconstant of 120576

119903= 455 The thickness of the FR4 substrate

is 119867 = 16mm Figure 1 shows the proposed microstripantenna designThe antenna patch is shaped as an ellipsewitha major radius of 30mm with a ratio of 15 with the minorradius of the ellipse This is the outer border of the annularshaped ellipse The inner part of the annular ellipse is cutusing another ellipse with a major radius of 25 with a ratioof 14 with the minor radius Both ellipses are centered at theorigin so that the elliptic slot produced in the middle of theellipse shaped patch has equal distance from all the sides ofthe antenna A feed-line of width 119888 = 8mm is attached withthe annular elliptical patch and extended to the edge of theFR4 PCB The whole structure makes a ldquoTrdquo shaped junctionA semicircle is introduced at the ldquoTrdquo shaped junction tomatch the impedance of the feed-line First the semicircle isdrawn which overlaps both the annular elliptical ring and thefeed-line Then all three structures are merged to have onebasic structureThe semicircle overlaps the feed-line which isunited with each other A rectangular is drawn with a widthand length of 45mm and 100mm respectively at the groundplane It is modified with the cutting edge of a semiellipsewhich has a major radius of 30mm with 15 ratios with theminor radius

The effective relative permittivity of the patch antenna canbe calculated as

120576119890=120576119903+ 1

2+

120576119903minus 1

2 (radic(12ℎ119883) + 1) (1)

Here 119867 is the thickness of the substrate 120576119903is FR4 relative

permittivity and119883 is strip width

International Journal of Antennas and Propagation 3

Frequency (GHz)

Ratio 12Ratio 13

Ratio 15Ratio 16

20171410070401

0

S11

(dB)

minus10

minus8

minus6

minus4

minus2

Figure 2 S11response for the change in radius ratio of the inner elliptical shape of the annular ring at patch

Frequency (GHz)20171410070401

0

minus10

minus8

minus6

minus4

minus2

23mm24mm

26mm27mm

S11

(dB)

Figure 3 S11response for the change in major radius (ratio = 14) of the inner elliptical shape of the annular ring at patch

For the annular ellipse shape patch the effective semi-minor of the outer and inner axis is given by [22]

1198871198902= 1198872[1 +2119889

1205761199031205871198872

ln( 11988722119889) + (141120576

119903+ 177)

+119889

1198872

(0268120576119903+ 165)]

12

1198871198901= 1198871[1 minus2119889

1205761199031205871198871

ln( 11988712119889) + (141120576

119903+ 177)

+119889

1198871

(0268120576119903+ 165)]

12

(2)

3 Parametric Studies

In Figures 2 and 3 parametric studies are shown by changingthe ratio and major radius of the inner ellipse respectivelyWhile changing the radius and ratio of the ellipse there are

some limitations If the radius ratio is taken bigger than 16the inner slot of the patch becomes bigger and narrows theside lines of the annular ellipse resulting in narrow currentdistribution Again the ratios lower than 12 result in a verysmall circle in the middle of the patch The results are shownin Figure 2 due to the changes in radius ratio The resonanceresponse tends to decrease with the increment in ratio InFigure 3 the radius of the major axis is changed withoutchanging the ratio = 14 The radius is changed from 23mmto 27mm and the response is shown in Figure 3 With theincrement in the major radius the resonance response tendsto narrow down centering at the frequency of 1 GHz Themajor radius increment results in more narrowed microstripline at the top of the annular elliptical ring resulting innarrowed current distribution at the region

4 Results and Discussion

Figure 4 shows the fabricated antenna in FR4 substrate Theproposed antenna is simulated using the electromagnetic


(a) (b)

Figure 4 Prototype of the proposed antenna

Frequency (GHz)

SimulatedMeasured

2015100500

0

minus5

minus10

minus15

minus20

minus25

S11

(dB)

Figure 5 Measured S11response of the proposed antenna

CopolarizationCross-polarization

0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus10

minus20

minus30

45∘

1355∘

15∘

000000000

minus10110

minus200

minusminusminus30030

E-plane

(a)


0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus20

minus30

minus10

H-plane

(b)

Figure 6 Measured normalized radiation pattern of the proposed antenna


Frequency (GHz)

Gai

n (d

B)20151005

2

1

0

3

4

5

6

7

Figure 7 Measured gain of the proposed antenna

(a)

33110e + 001

28979e + 001

20717e + 001

16586e + 001

41939e + 000

10390e + 001

21285e + 000

(b)

Figure 8 Simulated current distribution of the (a) antenna patch and (b) ground plane

Table 1 Design specification of the antenna

Dimension Value (mm)Patch ellipse major radius 119886 30Patch ellipse minor radius 119887 20Ground ellipse major radius 1198861015840 30Ground ellipse minor radius 1198871015840 20Feed-line width 119888 8Semicircle radius 119877 9Ground plane width 119890 45Ground plane length 119891 100Antenna length 119901 100Antenna width 119902 80

simulating software Ansoft HFSS The software is based onfinite elementmethod (FEM)The antenna is measured usinga power network analyser of model number E8358A A hornantenna of model number SAS 571 is used to measure theradiation pattern and gain of the antenna The antenna patchand ground are fed by a 50Ω SMA connector The antennawidth is 80mm and length is 100mm 182 fractionalbandwidth of the antenna is achieved in the measurementresult A minus10 dB return loss bandwidth of 180MHz is foundat the UHF band with center frequency of 099GHz (09GHzto 108GHz) The measured resonance response of the pro-posed antenna is shown in Figure 5 and compared with thesimulated result Two resonance responses almost overlap

each other Though there is a small resonance at 300MHzin the simulation result the resonance cannot be seen inthe measured result Also due to environmental effect themeasured resonance response shows more oscillation thanthe simulated result The radiation patterns at the E-planeand H-plane are shown in Figure 6 The co- and cross-polarization of the antenna show omnidirectional radiationpattern at 945MHz frequency The measured gain of theantenna is shown in Figure 7 A peak gain of 65 dBi isachieved at 1 GHz resonance frequency The average gain atthe resonance band is 55 dBi Figure 8 shows the simulatedcurrent distribution at the patch and ground plane of theantenna at 1 GHz From the current distribution it can beseen that at 1 GHz the feed-line at the patch is showinga dense current distribution with a peak at both edgesA coupling with the ground plane is made by the patchfeed-line which can be seen in Figure 8(b) The couplingcontinues throughout the edge of the ground plane and outerboundary of the elliptical shape annular ring at the patchThedimensions of the proposed antenna are tabulated in Table 1

5 Conclusion

Anovel elliptical shaped annular ring patched planar antennais shown in this paper for RFID and GSM-900 applicationsA semielliptical partial ground plane is introduced at thebottom of the proposed antenna The antenna has a minus10 dB


Table 2 Dimension and gain comparison between UHF RFID reader antennas

Antenna name Picture Dimension Peak gain

Proposed ellipse shaped antenna 100mm times 80mm times 16mm 65 dBi

[1] 1015mm times 220mm times 326mm 66 dBic

[3] 882mm times 80mm times 15mm minus161 dBi (simulated)


[7] 250mm times 250mm times 36mm 73 dBi

[8] (for this dual band antennaonly the UHF band is consideredfor comparison)

108mm times 108mm times 16mm 35 dBi

resonance response starting from 09GHz to 108GHz cov-ering the band for UHF RFID and GSM-900 application(Table 2) The measured average gain is 55 dBi with a peakgain of 65 dBi at 1 GHz The measured results agree with thesimulated resultsThe antenna is compact in size and suitablefor RFID and GSM-900 applications

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The authors would like to thank the Institute of Space Science(ANGKASA) UKM for the assistance in every aspect whileconducting this research

References

[1] J Youn-Kwon and B Lee ldquoDual-band circularly polarizedmicrostrip RFID reader antenna using metamaterial branch-line couplerrdquo IEEE Transactions on Antennas and Propagationvol 60 no 2 pp 786ndash791 2012

[2] R Azim M T Islam and N Misran ldquoA planar monopoleantenna for UWB applicationsrdquo International Review of Electri-cal Engineering vol 5 no 4 pp 1848ndash1852 2010

[3] R Ankang W Changying G Yao and Y Yong ldquoA robustUHF near-field RFID reader antennardquo IEEE Transactions onAntennas and Propagation vol 60 no 4 pp 1690ndash1697 2012

[4] R Azim M T Islam and N Misran ldquoPrinted planar antennafor wideband applicationsrdquo Journal of Infrared Millimeter andTerahertz Waves vol 31 no 8 pp 969ndash978 2010

[5] L Soo-Ji L Dong-Jin J Hyeong-Seok T Hyun-Sung and YJong-Won ldquoPlanar square quadrifilar spiral antenna for mobile


RFID readerrdquo in Proceedings of the 42nd European MicrowaveConference (EuMC rsquo12) pp 944ndash947 2012

[6] W Tingqiang S Hua G Liyun C Huizhu H Jingyao and ZHuaiwu ldquoA compact and broadband microstrip stacked patchantenna with circular polarization for 245-GHz mobile RFIDreaderrdquo IEEE Antennas andWireless Propagation Letters vol 12pp 623ndash626 2013

[7] Y Pan L Zheng H J Liu J YWang and R L Li ldquoDirectly-fedsingle-layerwidebandRFID reader antennardquoElectronics Lettersvol 48 pp 607ndash608 2012

[8] J J Tiang M T Islam N Misran and J S Mandeep ldquoCircularmicrostrip slot antenna for dual-frequency RFID applicationrdquoProgress in Electromagnetics Research vol 120 pp 499ndash512 2011

[9] J J Tiang M T Islam N Misran and J S Mandeep ldquoSlotloaded circular microstrip antenna with meandered slitsrdquo Jour-nal of Electromagnetic Waves and Applications vol 25 no 13pp 1851ndash1862 2011

[10] J J Shao C Chen J Chen Y C Ji G Y Fang and HJ Yin ldquoStudy of UWB half-ellipse antenna with a shallowbacked cavity in vital sign detectionrdquo in Proceedings of the 14thInternational Conference on Ground Penetrating Radar (GPRrsquo12) pp 89ndash92 2012

[11] B Wu Y Ji and G Fang ldquoAnalysis of GPR UWB half-ellipseantennas with different heights of backed cavity above groundrdquoIEEE Antennas andWireless Propagation Letters vol 9 pp 130ndash133 2010

[12] A R Weily and Y J Guo ldquoCircularly polarized ellipse-loadedcircular slot array for millimeter-wave WPAN applicationsrdquoIEEE Transactions on Antennas and Propagation vol 57 no 10pp 2862ndash2870 2009

[13] A Agrawal D Vakula and N V S N Sarma ldquoDesign ofelliptical microstrip patch antenna using ANNrdquo in Proceedingsof the Progress in Electromagnetics Research Symposium (PIERSrsquo11) pp 264ndash268 September 2011

[14] A K Bhattacharyya and L Shafai ldquoTheoretical and experimen-tal investigation of the elliptical annular ring antennardquo IEEETransactions on Antennas and Propagation vol 36 no 11 pp1526ndash1530 1988

[15] L Liu S W Cheung R Azim and M T Islam ldquoA com-pact circular-ring antenna for ultra-wideband applicationsrdquoMicrowave and Optical Technology Letters vol 53 no 10 pp2283ndash2288 2011

[16] A TMobashsherM T Islam andNMisran ldquoWideband com-pact antenna with partially radiating coplanar ground planerdquoApplied Computational Electromagnetics Society Newsletter vol26 no 1 pp 73ndash81 2011

[17] L A Griffiths C Furse and Y C Chung ldquoBroadband andmultiband antenna design using the genetic algorithm tocreate amorphous shapes using ellipsesrdquo IEEE Transactions onAntennas and Propagation vol 54 no 10 pp 2776ndash2782 2006

[18] M T Islam M Moniruzzaman N Misran and M N ShakibldquoCurve fitting based particle swarm optimization for uwb patchAntennardquo Journal of Electromagnetic Waves and Applicationsvol 23 no 17-18 pp 2421ndash2432 2009

[19] Y Xia Z Duan and D Edwards ldquoCompact printed dualellipses monopole antenna for UWB systemrdquo in Proceedings ofthe 4th International Conference on Wireless CommunicationsNetworking and Mobile Computing (WiCOM rsquo08) pp 1ndash3October 2008

[20] M M Sharma V Agrawal S Kumawat N C Bajia S Guptaand R P Yadav ldquoEllipse shape crescent slot compact broadband

microstrip antennardquo in Proceedings of the International Confer-ence of Recent Advances in Microwave Theory and Applications(MICROWAVE rsquo08) pp 868ndash870 November 2008

[21] R Azim M T Islam N Misran S W Cheung and YYamada ldquoPlanar UWB antenna with multi-slotted groundplanerdquo Microwave and Optical Technology Letters vol 53 no5 pp 966ndash968 2011

[22] F Alhargan and S Judah ldquoMode charts for confocal annularelliptic resonatorsrdquo IEE Proceedings Microwaves Antennas andPropagation vol 143 no 4 pp 358ndash360 1996

International Journal of

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RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



q

p

b

a

c

R

(a)

e

f

a998400

b998400

(b)

Figure 1 Proposed antenna dimensions (a) patch and (b) ground plane

circular slot array for millimetre-wave WPAN applicationsis presented in [12] Liquid crystal polymer (LCP) is usedfor the antenna design In the design a metallic reflector isused to make the radiation limited which makes the antennasize bulky and bigger in dimension In [13] a design ofellipticalmicrostrip patch antenna is presented using artificialneural networks to gain circular polarizationNonetheless theantenna return loss at the target frequency is minus625 dB whichis not acceptable in minus10 dB return loss scale A theoreticaland experimental investigation of an elliptical annular ringshape antenna is shown in [14] The analysis is carriedout using generalized transmission line model A planarmonopole antenna fed by an offset-microstrip line is shownin [15] A circular ring is used to achieve the dimensionAnother antenna is proclaimed in [16] with coplanar groundplane The antenna is compact and one sided Broadbandand multiband antenna designs are shown in [17] usingellipses shape with the help of genetic algorithm to createamorphous shape Nevertheless the results presented donot include any result showing gain of the antenna Curvefitting technique is shown in [18] for patch antenna usingparticle swarm optimization (PSO) A compact dual ellipsesmonopole antenna is printed in FR4 substrate [19] No resulton the gain of the antenna is demonstrated In [20] anellipse shape crescent slot broadband microstrip antenna isshown Parametric studies are shown for different substratethickness However the antenna results are simulated and notvalidated using fabricated antenna results Different structureof the antenna is presented in finding different frequenciesthroughout the research of microstrip antenna design FR4substrate is being used widely for different applications ofantenna nowadays due to its low price and durability Groundplanemodifiedwideband antenna is shown in [21] which usesFR4 substrate Fromhere it can be seen that FR4 substrate canbe used to have wideband performance

In this paper an elliptical shape antenna is shown withmodified ground plane The antenna is designed for a fre-quency starting from 09GHz to 108GHz The proposed

antenna is compact in size with a length width and heightof 100mm 80mm and 16mm respectively The measuredresults of the antenna are shown to have good agreement withthe simulated result

2 Methodology

The antenna is designed using FR4 substrate with dielectricconstant of 120576

119903= 455 The thickness of the FR4 substrate

is 119867 = 16mm Figure 1 shows the proposed microstripantenna designThe antenna patch is shaped as an ellipsewitha major radius of 30mm with a ratio of 15 with the minorradius of the ellipse This is the outer border of the annularshaped ellipse The inner part of the annular ellipse is cutusing another ellipse with a major radius of 25 with a ratioof 14 with the minor radius Both ellipses are centered at theorigin so that the elliptic slot produced in the middle of theellipse shaped patch has equal distance from all the sides ofthe antenna A feed-line of width 119888 = 8mm is attached withthe annular elliptical patch and extended to the edge of theFR4 PCB The whole structure makes a ldquoTrdquo shaped junctionA semicircle is introduced at the ldquoTrdquo shaped junction tomatch the impedance of the feed-line First the semicircle isdrawn which overlaps both the annular elliptical ring and thefeed-line Then all three structures are merged to have onebasic structureThe semicircle overlaps the feed-line which isunited with each other A rectangular is drawn with a widthand length of 45mm and 100mm respectively at the groundplane It is modified with the cutting edge of a semiellipsewhich has a major radius of 30mm with 15 ratios with theminor radius

The effective relative permittivity of the patch antenna canbe calculated as

120576119890=120576119903+ 1

2+

120576119903minus 1

2 (radic(12ℎ119883) + 1) (1)

Here 119867 is the thickness of the substrate 120576119903is FR4 relative

permittivity and119883 is strip width


Frequency (GHz)

Ratio 12Ratio 13

Ratio 15Ratio 16

20171410070401

0

S11

(dB)

minus10

minus8

minus6

minus4

minus2



0

minus10

minus8

minus6

minus4

minus2

23mm24mm

26mm27mm

S11

(dB)



1198871198902= 1198872[1 +2119889

1205761199031205871198872

ln( 11988722119889) + (141120576

119903+ 177)

+119889

1198872

(0268120576119903+ 165)]

12

1198871198901= 1198871[1 minus2119889

1205761199031205871198871

ln( 11988712119889) + (141120576

119903+ 177)

+119889

1198871

(0268120576119903+ 165)]

12

(2)







(a) (b)


Frequency (GHz)

SimulatedMeasured

2015100500

0

minus5

minus10

minus15

minus20

minus25

S11

(dB)



0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus10

minus20

minus30

45∘

1355∘

15∘

000000000

minus10110

minus200


E-plane

(a)


0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus20

minus30

minus10

H-plane

(b)



Frequency (GHz)

Gai

n (d

B)20151005

2

1

0

3

4

5

6

7


(a)

33110e + 001

28979e + 001

20717e + 001

16586e + 001

41939e + 000

10390e + 001

21285e + 000

(b)






5 Conclusion















Acknowledgment


References




























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Frequency (GHz)

Ratio 12Ratio 13

Ratio 15Ratio 16

20171410070401

0

S11

(dB)

minus10

minus8

minus6

minus4

minus2



0

minus10

minus8

minus6

minus4

minus2

23mm24mm

26mm27mm

S11

(dB)



1198871198902= 1198872[1 +2119889

1205761199031205871198872

ln( 11988722119889) + (141120576

119903+ 177)

+119889

1198872

(0268120576119903+ 165)]

12

1198871198901= 1198871[1 minus2119889

1205761199031205871198871

ln( 11988712119889) + (141120576

119903+ 177)

+119889

1198871

(0268120576119903+ 165)]

12

(2)







(a) (b)


Frequency (GHz)

SimulatedMeasured

2015100500

0

minus5

minus10

minus15

minus20

minus25

S11

(dB)



0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus10

minus20

minus30

45∘

1355∘

15∘

000000000

minus10110

minus200


E-plane

(a)


0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus20

minus30

minus10

H-plane

(b)



Frequency (GHz)

Gai

n (d

B)20151005

2

1

0

3

4

5

6

7


(a)

33110e + 001

28979e + 001

20717e + 001

16586e + 001

41939e + 000

10390e + 001

21285e + 000

(b)






5 Conclusion















Acknowledgment


References




























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










(a) (b)


Frequency (GHz)

SimulatedMeasured

2015100500

0

minus5

minus10

minus15

minus20

minus25

S11

(dB)



0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus10

minus20

minus30

45∘

1355∘

15∘

000000000

minus10110

minus200


E-plane

(a)


0∘

45∘

90∘

135∘

180∘

225∘

270∘

315∘

0

minus20

minus30

minus10

H-plane

(b)



Frequency (GHz)

Gai

n (d

B)20151005

2

1

0

3

4

5

6

7


(a)

33110e + 001

28979e + 001

20717e + 001

16586e + 001

41939e + 000

10390e + 001

21285e + 000

(b)






5 Conclusion















Acknowledgment


References




























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Frequency (GHz)

Gai

n (d

B)20151005

2

1

0

3

4

5

6

7


(a)

33110e + 001

28979e + 001

20717e + 001

16586e + 001

41939e + 000

10390e + 001

21285e + 000

(b)






5 Conclusion















Acknowledgment


References




























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation






















Acknowledgment


References




























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









research article development of a semielliptical partial ...a theoretical and experimental...

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