design of rhombus-shaped slot patch antenna for wireless...

Research ArticleDesign of Rhombus-Shaped Slot Patch Antenna forWireless Communications

Manavalan Saravanan and Madihally Janardhana Srinivasa Rangachar

Department of Electronics and Communication Engineering Hindustan Institute of Technology and Science Chennai India

Correspondence should be addressed to Manavalan Saravanan msarawinsgmailcom

Received 23 August 2018 Accepted 29 October 2018 Published 10 January 2019

Academic Editor Rui Zhang

Copyright copy 2019Manavalan Saravanan andMadihally Janardhana Srinivasa Rangachar)is is an open access article distributedunder the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in anymedium provided the original work is properly cited

A single feed circularly polarized patch antenna is presented )e antenna consists of a rhombus-shaped slot incorporated in theradiating patch at its center )e antenna is designed to operate at 23GHz band )e antenna achieves left-hand polarization orright-hand polarization based on the orientation of the slot in the radiating patch)e antenna parameters are synthesized using ahigh-frequency structure simulator and its characteristics are validated by the Agilent network analyzer (N9925A) and antennatest systems )e measured results obtained agree with simulated results and show that the antenna achieves minus10 dB impedancebandwidth of 85MHz (227GHzndash2355GHz) for left-hand polarization and 85MHz (226GHzndash2345GHz) for right-handpolarization )e antenna gives a 3 dB axial ratio beamwidth of 95deg(minus35deg le AR le 60deg) for both left-hand polarization and right-hand polarization along with better 3 dB axial ratio bandwidth of 140deg in the operating band )e antenna also achieves a goodcross-polarization isolation of minus17 dBic for both left-hand and right-hand polarization at its operating frequency Hence theantenna is best suited for modern wireless communication systems

1 Introduction

Compact circular polarized patch antennas play a vital rolein satellite communications and airborne communicationdue to their low profile and lightweight )ese antennasrequire low cross-polarization isolation in order to mitigatemultipath interference and wider axial ratio beamwidthto provide a wide coverage area However 3 dB axialratio beamwidth of the antenna suffers from a narrowbeamwidth and cannot meet the required practical appli-cations A lot of researchers have been proposed to improveaxial ratio beamwidth and to reduce cross-polarizationisolation One way of improving the beamwidth is toemploy a 3D ground structure as in [1 2] )ese structuresutilize a multilayer stacked structure which diffracts theelectromagnetic waves from the ground plane therebyaltering the radiation pattern of the antenna Howeverthese structures increase the overall width of the antennaIn [3] the beamwidth of the antenna is improved by al-tering the spacing between the two crossed dipoles placed

in a square-shaped contour However it results in a bi-directional radiation pattern and thus results in power lossin the undesired direction Another way of improving thebeamwidth is by exciting surface waves through substratesextended on the ground plane as given in [4] )is tech-nique significantly produces backward radiations therebyinterfering with other circuit elements

A popular technique to improve the beamwidth is byintroducing parasitic elements around the patch Howeverthe space required for these patch elements are higher andhence increases the overall length of the antenna [5] A 3Dcircularly polarized patch is presented in [6] )e antennauses a crossed slot in the radiating patch and a triangularfeed structure is made to improve the bandwidth of theantenna )ough the techniques discussed increase the axialratio beamwidth of the antenna the technique fails tosuppress the cross-polarization isolation especially at lowelevation angles [7 8] One more technique to improve thebeamwidth is by introducing lumped elements in the ra-diating patch In [9] PIN diodes are placed along diagonals

HindawiJournal of Computer Networks and CommunicationsVolume 2019 Article ID 5149529 7 pageshttpsdoiorg10115520195149529

of the square patch and the beamwidth is fully controlled bythe shunt inductive load )e antenna uses the dual feed toexcite two orthogonal modes In [10 11] a circularly po-larized antenna with an improved axial ratio beamwidth isproved However it suffers from poor cross-polarizationisolation In [12] parasitic stubs are used to perturb thesurface fields on the radiating patch to achieve circularpolarization with an improved axial ratio beamwidth Re-cently a slot of appropriate shape is etched in the circularradiating patch is used to achieve circular polarization[13ndash15]

In this paper a rhombus-shaped slot patch antennaoperating at 23GHz band is presented )e antenna isfabricated on FR4 substrate and its performance is mea-sured using the Agilent network analyzer and antenna testsystems)emeasured results are compared with simulationresults and show that the antenna is best suited for airbornewireless communication systems

2 Geometry of Proposed Antenna

)e geometry of the proposed antenna is illustrated inFigure 1 )e antenna is fabricated on fire retardant di-electric substrate (FR4) having a relative permittivity ofεr 44 and dielectric loss tangent of ζ 002 In order tohave low profile thickness the substrate is chosen to have athickness of 16mm A rhombus-shaped slot is etched in theradiating element in order to excite two orthogonal modes)is perturbs the surface current over the patch elementthereby generating circular polarization )e orientation ofthe slot determines the nature of polarization)e antenna isfed by 50Ω SMA connector A quarter wave transformerhaving an impedance of 50Ω is used for impedancematching

21 Surface Current Distribution )e surface current dis-tribution over the radiating patch is simulated and is shownin Figure 2 Figure 2(a) shows surface current distributioncorresponding to left-hand circular polarization (LHCP)Here surface current in the right half plane along X-axisperturbs near the corner of the slot in advance whencompared to the left half plane)is adds a 90deg phase delay inthe surface current between both the half planes whichresults in LHCP Figure 2(b) shows surface current distri-bution corresponds to right-hand circularly polarization(RHCP) Here surface current in the left half plane along X-axis perturbs near the corner of the slot in advance whencompared to the right half plane )is adds a 90deg phase delayin the surface current between both the half planes whichresults in LHCP )us based on the orientation of the slotthe antenna achieves either left-hand or right-handpolarization

3 Antenna Design Considerations

A circular shape is considered as the basic antenna geometryshape for the proposed antenna model Hence the radius ofthe circular patch [16] is calculated from the followingequation

a 18412lowast c

2πlowastfr lowastεr

radic (1)

where a radius of the patch (m) c velocity of light invacuum 3lowast108ms fr resonant frequency (GHz) andεr relative permittivity 44 (no unit)

)e introduction of the slot in the radiating elementincreases the electrical length of the antenna and it shifts theoperating frequency )erefore an offset length introducedin the radial length of the patch is needed and is given in thefollowing equation

R aminus 00134lowastλεr

radic1113888 1113889 (2)

where R effective radius of the antennaSince slot dimensions greatly affect the purity of po-

larization the dimension of the slot has to be carefullychosen for the antenna to radiate circular polarization )efollowing equation gives optimal slot dimension of theproposed model

L R47

SlotX 2L

radic

SlotY 32

L

(3)

Table 1 gives overall dimensions of the proposed antennamodel operating at the 23GHz band

4 Results and Discussions

To verify the feasibility of the presented circular polarizedantenna a prototype is fabricated on FR4 substrate having athickness of 16mm A 50Ω SMA connector is used to feedthe model

In order to analyze the characteristics of the proposedantenna the prototype is tested using the network analyzerN9924A as shown in Figure 3 and its radiation charac-teristics are measured using the antenna test setup shown inFigure 4 A 50Ω N-type adapter is used to couple thenetwork analyzer with the model

)e impedance curve measured using a network an-alyzer is shown in Figure 5 and is compared with simu-lation results It is observed that the antenna resonates at23 GHz band and achieves a minus10 dB impedance band-width of 85MHz (227 GHzndash2355 GHz) for left-handpolarization and 85MHz (226 GHzndash2345 GHz) forright-hand polarization In order to validate the radiationcharacteristics the fabricated model is tested under theantenna test system )e measured radiation character-istics are compared with simulation results and are shownin Figure 6

A standard pyramidal horn antenna having a gain of9 dB is used as a reference antenna )e distance betweentwo antennas (R) is measured and the gain is calculatedusing the Friis transmission equation given below

2 Journal of Computer Networks and Communications

Pr

Ptλ

4πR( )

2

GtGr (4)

Figure 6(a) shows measured radiation characteristicscorresponding to antenna geometry shown in Figures 1(a)

and 6(b) and measured radiation characteristics corre-sponding to antenna geometry shown in Figure 1(b) esimulation results agree with measured results and theantenna gives symmetrical radiation pattern around zenithe antenna achieves a good cross-polarization isolation of

Slot_Y

Slot_X

Patch

Q_Y Q_X

Feed_Y

Feed

_X

R

ZY

X

(a)

Slot_Y

Slot_X

Patch

Q_Y Q_X

Feed_Y

Feed

_X

R

ZY

X

(b)

Figure 1 Antenna geometry (a) LHCP (b) RHCP

(A) t = 0 amp T (B) t = T4 (C) t = 2T4 (D) t = 3T4

(a)

(E) t = 0 amp T (F) t = T4 (G) t = 2T4 (H) t = 3T4

(b)

Figure 2 Simulated surface current distribution (a) LHCP (b) RHCP

Journal of Computer Networks and Communications 3

minus17 dBic for both LHCP and RHCP congurations at itsoperating frequency

Figure 7 shows a variation of axial ratio against fre-quencies for both LHCP and RHCP congurations It isobserved from Figure 7 that the antenna gives minimumaxial ratio at the 23GHz operating frequency for both thecongurations and achieves a measured wide 3 dB axial ratiobandwidth of 140MHz in the operating band

Figure 8 shows measured E plane and H plane radiationcharacteristics of both LHCP and RHCP congurations It isobserved that the antenna achieves a good axial ratio (AR)

over a wide beam angle ratio beamwidth of 95deg(minus35deg le AR le60deg) for left-hand polarization and 95deg(minus35deg le AR le 60deg) forright-hand polarization e measured gain is calculatedusing the gain comparison method A standard pyramidalhorn antenna having a gain of 9 dB is used as a referenceantenna as shown in Figure 4 e distance between twoantennas (R) is measured and the gain is calculated usingFriis transmission equation

e gain characteristics of the proposed antenna withrespect to operating band are given in Figure 9 It is observedthat the antenna gives a nearly at gain over the operatingbandemeasured gain for LHCP is 516 dBic and RHCP is482 dBic at the boresight of the antenna is small dif-ference in gain results is due to fabrication loss and antennaalignment losses

Table 2 gives performance comparison of proposed an-tenna with traditional antenna models It is observed that theproposed model achieves better axial ratio bandwidth whencompared to the traditional antenna model given in Table 2Moreover the cross-polarization isolation is better in theproposed antenna and is not studied in conventional antennasgiven in Table 2 In addition to this the proposed antenna issimple and ismodelled on the single layer instead of multilayersubstrate as in Ref [14] which makes it easy to integrate withother high-frequency circuits ough the antenna has limi-tation of narrow 3dB axial ratio bandwidth when compared toother traditional antennas the 3 dB axial ratio beamwidthachieved by the proposed antenna is sucient to cover onecomplete sector of a mobile cell network and also suitable formany wireless applications including MIMO application

5 Conclusion

is paper introduces a novel circularly polarized patchantenna operating at 23GHz A rhombus-shaped slot isetched in radiating patch located at its centere dimensionof the slot is tuned to achieve minimum axial ratio at itsoperating frequency e antenna radiates either left-handor right-hand polarization based on the orientation of theslot e measured radiation characteristics show that theproposed antenna attains 516 dBic for LHCP and 482 dBic

Table 1 Antenna design specications

Parameters SpecicationsOperating frequency 23GHzR 1739mmL 370mmSlot_X lowast Slot_Y 523mm lowast 555mmQ_X lowast Q_Y 12mm lowast 096mmFeed_X lowast Feed_Y 8mm lowast 24mm

Figure 3 Testing of antenna

Figure 4 Radiation pattern measurement setup

ndash25

ndash20

ndash15

ndash10

ndash5

0

5

Refle

ctio

n co

effic

ient

(dB)

Frequency (GHz)

LHCP (measured)RHCP (measured)

21 22 23 24 25 262

Figure 5 Reection coecient (dB)


X-Pol (measured)X-Pol (simulated)

Co-Pol (measured)Co-Pol (simulated)

E-plane H-plane

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

(a)



E-plane H-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)

Figure 6 Simulated and measured radiation pattern of (a) LHCP and (b) RHCP

0

1

2

3

4

5

222 227 232 237 242

Axia

l rat

io (d

B)

Freq (GHz)


LHCP (simulated)RHCP (simulated)

Figure 7 Axial ratio vs frequency


for RHCP at the boresight of the antenna e antennaachieves good cross-polarization isolation of minus17 dBic andwider 3 dB axial ratio beamwidth of 95deg(minus35deg le AR le 60deg) forboth left-hand polarization and right-hand polarization atoperating frequency along with better 3 dB axial ratiobandwidth of 140deg in the operating band which best suitedfor airborne communication

Data Availability

No data were used to support this study

Conflicts of Interest

e authors declare that they have no conicts of interest

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

E-planeH-plane

(a)

E-planeH-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)

Figure 8 Radiation pattern measured at the minimum axial ratio (a) LHCP (b) RHCP

ndash20ndash18ndash16ndash14ndash12ndash10

ndash8ndash6ndash4ndash2

0246

22 222 224 226 228 23 232 234 236 238 24

Gai

n (d

Bic) Freq (GHz)

LHCP_Co (simulated)RHCP_Co (simulated)LHCP_X (simulated)RHCP_X (simulated)

LHCP_Co (measured)RHCP_Co (measured)LHCP_X (measured)RHCP_X (measured)

Figure 9 Variation of frequency (GHz) with respect to gain (dB)

Table 2 Performance comparison of the proposed model with the traditional antenna model

Parameter Ref [12] Ref [13] Ref [14] Ref [15] Proposed modelReection coecient (dB) minus21 dB minus13 dB minus20 dB minus25 dB minus206 dB

Maximum gain (dB) 45 dB 53 dBic 68 dBic 61 dBic 516 dBic (LHCP)482 dBic (RHCP)

3 dB axial ratio bandwidth (dB) 55MHz 40MHz 100MHz 40MHz 140MHz3 dB axial ratio beamwidth (dB) 176deg 140deg 100deg 180deg 95degCross-polarization isolation (dB) NA NA NA NA minus17 dB


References

[1] C-L Tang J-Y Chiou and K-L Wong ldquoBeamwidth en-hancement of a circularly polarized microstrip antennamounted on a three-dimensional ground structurerdquo Micro-wave and Optical Technology Letters vol 32 no 2 pp 149ndash153 2001

[2] H Jiang Z Xue W Li and W Ren ldquoBroad beamwidthstacked patch antenna with wide circularly polarised band-widthrdquo Electronics Letters vol 51 no 1 pp 10ndash12 2015

[3] Y Luo Q-X Chu and L Zhu ldquoA low-profile wide-beamwidth circularly-polarized antenna via two pairs ofparallel dipoles in a square contourrdquo IEEE Transactions onAntennas and Propagation vol 63 no 3 pp 931ndash936 2015

[4] N-W Liu W-W Choi and L Zhu ldquoLow-profile wide-beamwidth circularly-polarised patch antenna on a sus-pended substraterdquo IET Microwaves Antennas and Propaga-tion vol 10 no 8 pp 885ndash890 2016

[5] K Ding C Gao D Qu and Q Yin ldquoCompact broadbandcircularly polarized antenna with parasitic patchesrdquo IEEETransactions on Antennas and Propagation vol 65 no 9pp 4854ndash4857 2017

[6] X Chen Z Wei D Wu L Yang and G Fu ldquoLow-cost andcompact 3D circularly polarized microstrip antenna with highefficiency and wide beamwidthrdquo International Journal ofMicrowave and Wireless Technologies vol 9 no 7 pp 1ndash82017

[7] X Chen L Yang J-y Zhao and G Fu ldquoHigh-Efficiencycompact circularly polarized microstrip antenna with widebeamwidth for airborne communicationrdquo IEEE Antennas andWireless Propagation Letters vol 15 pp 1518ndash1521 2016

[8] J-H Lu and H-S Huang ldquoPlanar compact dual-bandmonopole antenna with circular polarization for WLANapplicationsrdquo International Journal of Microwave and Wire-less Technologies vol 8 no 1 pp 81ndash87 2014

[9] X Zhang L Zhu and N-W Liu ldquoPin-loaded circularly-polarized patch antennas with wide 3-dB axial ratio beam-widthrdquo IEEE Transactions on Antennas and Propagationvol 65 no 2 pp 521ndash528 2017

[10] K M Mak and K M Luk ldquoA circularly polarized antennawith wide axial ratio beamwidthrdquo IEEE Transactions onAntennas and Propagation vol 57 no 10 pp 3309ndash33122009

[11] G Massie M Caillet M Clenet and Y M M Antar ldquoA newwideband circularly polarized hybrid dielectric resonatorantennardquo IEEE Antennas and Wireless Propagation Lettersvol 9 pp 347ndash350 2010

[12] S B Vignesh N Nasimuddin and A Alphones ldquoStubs-integrated-microstrip antenna design for wide coverage ofcircularly polarised radiationrdquo IETMicrowaves Antennas andPropagation vol 11 no 4 pp 444ndash449 2017

[13] L B K Bernard Nasimuddin and A Alphones ldquoANe-shaped slotted-circular-patch antenna for circularly polar-ized radiation and radiofrequency energy harvestingrdquo Mi-crowave and Optical Technology Letters vol 58 no 4pp 868ndash875 2016

[14] L B K Bernard Nasimuddin and A Alphones ldquoTeo-shaped slotted-circular-patch antenna for circularly polar-ized radiation and RF energy harvestingrdquo Microwave andOptical Technology Letters vol 57 no 12 pp 2752ndash27582015

[15] A M Jie Nasimuddin M F Karim L Bin F Chin andM Ong ldquoA proximity-coupled circularly polarized slotted-circular patch antenna for RF energy harvesting applicationsrdquo

in Proceedings of 2016 IEEE Region 10 Conference (TENCON)pp 2027ndash2030 Jeju Island Korea November 2016

[16] C A Balanis Antenna 4eory Analysis and Design Wiley-Interscience Hoboken NJ USA 3rd edition 2005


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Submit your manuscripts atwwwhindawicom

of the square patch and the beamwidth is fully controlled bythe shunt inductive load )e antenna uses the dual feed toexcite two orthogonal modes In [10 11] a circularly po-larized antenna with an improved axial ratio beamwidth isproved However it suffers from poor cross-polarizationisolation In [12] parasitic stubs are used to perturb thesurface fields on the radiating patch to achieve circularpolarization with an improved axial ratio beamwidth Re-cently a slot of appropriate shape is etched in the circularradiating patch is used to achieve circular polarization[13ndash15]

In this paper a rhombus-shaped slot patch antennaoperating at 23GHz band is presented )e antenna isfabricated on FR4 substrate and its performance is mea-sured using the Agilent network analyzer and antenna testsystems)emeasured results are compared with simulationresults and show that the antenna is best suited for airbornewireless communication systems

2 Geometry of Proposed Antenna

)e geometry of the proposed antenna is illustrated inFigure 1 )e antenna is fabricated on fire retardant di-electric substrate (FR4) having a relative permittivity ofεr 44 and dielectric loss tangent of ζ 002 In order tohave low profile thickness the substrate is chosen to have athickness of 16mm A rhombus-shaped slot is etched in theradiating element in order to excite two orthogonal modes)is perturbs the surface current over the patch elementthereby generating circular polarization )e orientation ofthe slot determines the nature of polarization)e antenna isfed by 50Ω SMA connector A quarter wave transformerhaving an impedance of 50Ω is used for impedancematching

21 Surface Current Distribution )e surface current dis-tribution over the radiating patch is simulated and is shownin Figure 2 Figure 2(a) shows surface current distributioncorresponding to left-hand circular polarization (LHCP)Here surface current in the right half plane along X-axisperturbs near the corner of the slot in advance whencompared to the left half plane)is adds a 90deg phase delay inthe surface current between both the half planes whichresults in LHCP Figure 2(b) shows surface current distri-bution corresponds to right-hand circularly polarization(RHCP) Here surface current in the left half plane along X-axis perturbs near the corner of the slot in advance whencompared to the right half plane )is adds a 90deg phase delayin the surface current between both the half planes whichresults in LHCP )us based on the orientation of the slotthe antenna achieves either left-hand or right-handpolarization

3 Antenna Design Considerations

A circular shape is considered as the basic antenna geometryshape for the proposed antenna model Hence the radius ofthe circular patch [16] is calculated from the followingequation

a 18412lowast c

2πlowastfr lowastεr

radic (1)

where a radius of the patch (m) c velocity of light invacuum 3lowast108ms fr resonant frequency (GHz) andεr relative permittivity 44 (no unit)

)e introduction of the slot in the radiating elementincreases the electrical length of the antenna and it shifts theoperating frequency )erefore an offset length introducedin the radial length of the patch is needed and is given in thefollowing equation

R aminus 00134lowastλεr

radic1113888 1113889 (2)

where R effective radius of the antennaSince slot dimensions greatly affect the purity of po-

larization the dimension of the slot has to be carefullychosen for the antenna to radiate circular polarization )efollowing equation gives optimal slot dimension of theproposed model

L R47

SlotX 2L

radic

SlotY 32

L

(3)

Table 1 gives overall dimensions of the proposed antennamodel operating at the 23GHz band

4 Results and Discussions

To verify the feasibility of the presented circular polarizedantenna a prototype is fabricated on FR4 substrate having athickness of 16mm A 50Ω SMA connector is used to feedthe model

In order to analyze the characteristics of the proposedantenna the prototype is tested using the network analyzerN9924A as shown in Figure 3 and its radiation charac-teristics are measured using the antenna test setup shown inFigure 4 A 50Ω N-type adapter is used to couple thenetwork analyzer with the model

)e impedance curve measured using a network an-alyzer is shown in Figure 5 and is compared with simu-lation results It is observed that the antenna resonates at23 GHz band and achieves a minus10 dB impedance band-width of 85MHz (227 GHzndash2355 GHz) for left-handpolarization and 85MHz (226 GHzndash2345 GHz) forright-hand polarization In order to validate the radiationcharacteristics the fabricated model is tested under theantenna test system )e measured radiation character-istics are compared with simulation results and are shownin Figure 6

A standard pyramidal horn antenna having a gain of9 dB is used as a reference antenna )e distance betweentwo antennas (R) is measured and the gain is calculatedusing the Friis transmission equation given below


Pr

Ptλ

4πR( )

2

GtGr (4)



Slot_Y

Slot_X

Patch

Q_Y Q_X

Feed_Y

Feed

_X

R

ZY

X

(a)

Slot_Y

Slot_X

Patch

Q_Y Q_X

Feed_Y

Feed

_X

R

ZY

X

(b)



(a)


(b)









5 Conclusion






ndash25

ndash20

ndash15

ndash10

ndash5

0

5

Refle

ctio

n co

effic

ient

(dB)

Frequency (GHz)


21 22 23 24 25 262





E-plane H-plane

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

(a)



E-plane H-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)


0

1

2

3

4

5

222 227 232 237 242

Axia

l rat

io (d

B)

Freq (GHz)






Data Availability




ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

E-planeH-plane

(a)

E-planeH-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)




0246

22 222 224 226 228 23 232 234 236 238 24

Gai

n (d

Bic) Freq (GHz)









References





















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia


Pr

Ptλ

4πR( )

2

GtGr (4)



Slot_Y

Slot_X

Patch

Q_Y Q_X

Feed_Y

Feed

_X

R

ZY

X

(a)

Slot_Y

Slot_X

Patch

Q_Y Q_X

Feed_Y

Feed

_X

R

ZY

X

(b)



(a)


(b)









5 Conclusion






ndash25

ndash20

ndash15

ndash10

ndash5

0

5

Refle

ctio

n co

effic

ient

(dB)

Frequency (GHz)


21 22 23 24 25 262





E-plane H-plane

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

(a)



E-plane H-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)


0

1

2

3

4

5

222 227 232 237 242

Axia

l rat

io (d

B)

Freq (GHz)






Data Availability




ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

E-planeH-plane

(a)

E-planeH-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)




0246

22 222 224 226 228 23 232 234 236 238 24

Gai

n (d

Bic) Freq (GHz)









References





















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia








5 Conclusion






ndash25

ndash20

ndash15

ndash10

ndash5

0

5

Refle

ctio

n co

effic

ient

(dB)

Frequency (GHz)


21 22 23 24 25 262





E-plane H-plane

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

(a)



E-plane H-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)


0

1

2

3

4

5

222 227 232 237 242

Axia

l rat

io (d

B)

Freq (GHz)






Data Availability




ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

E-planeH-plane

(a)

E-planeH-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)




0246

22 222 224 226 228 23 232 234 236 238 24

Gai

n (d

Bic) Freq (GHz)









References





















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia




E-plane H-plane

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

0

105

30

60

90

120

150

180210

240

270

300

330

360

(a)



E-plane H-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)


0

1

2

3

4

5

222 227 232 237 242

Axia

l rat

io (d

B)

Freq (GHz)






Data Availability




ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

E-planeH-plane

(a)

E-planeH-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)




0246

22 222 224 226 228 23 232 234 236 238 24

Gai

n (d

Bic) Freq (GHz)









References





















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



Data Availability




ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

E-planeH-plane

(a)

E-planeH-plane

ndash40

ndash30

ndash20

ndash10

010

530

60

90

120

150

180210

240

270

300

330

360

(b)




0246

22 222 224 226 228 23 232 234 236 238 24

Gai

n (d

Bic) Freq (GHz)









References





















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia


References





















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia




RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia


design of rhombus-shaped slot patch antenna for wireless...

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