Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
Hindawi Publishing CorporationInternational Journal of Antennas and PropagationVolume 2013 Article ID 850489 6 pageshttpdxdoiorg1011552013850489
Research ArticleNew Configuration of Handset MIMO Antenna forLTE 700 Band Applications
Byeonggwi Mun1 Frances J Harackiewicz2 Byeongkwan Kim1 Hyunho Wi1
Jonghyun Lee1 Myun-Joo Park1 Changwon Jung3 and Byungje Lee1
1 Department of Wireless Communications Engineering Kwangwoon University 447-1 Wolgye-Dong Nowon-GuSeoul 139-701 Republic of Korea
2Department of Electrical and Computer Engineering Southern Illinois University Carbondale Carbondale IL 62901 USA3Graduate School of NID Fusion Technology Seoul National University of Technology 172 Gongneung-2 Dong Nowon-GuSeoul 139-743 Republic of Korea
Correspondence should be addressed to Byungje Lee bj leekwackr
Received 15 February 2013 Accepted 12 April 2013
Academic Editor Yuan Yao
Copyright copy 2013 Byeonggwi Mun et alThis is an open access article distributed under theCreativeCommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
A compact handset multiple-input multiple-output (MIMO) antenna for long-term evolution (LTE) 700 band (746sim787MHz)applications is proposed The proposed antenna consists of two symmetrical PIFAs Without the usage of any additional couplingelements between closely mounted antennas a high isolation (gt15 dB) and a low enveloped correlation coefficient (ECC lt 035)are achieved by the optimum location and arrangement of MIMO antenna elements
1 Introduction
The long term evolution (LTE) standard has attracted atten-tion as the fourth generation ofmobile communications tech-nology to provide better mobile broadband and multimediaservices Multiple-input multiple-output (MIMO) operationof the LTE system has become a prerequisite to enhance datareliability channel capacity and network coverage in mul-tipath environments using multiple antennas without addi-tional power [1] Since more than two neighboring antennasshould be designed within the very limited spaces available inthemobile handsets achieving high isolation and a low envel-oped correlation coefficient (ECC) between closely spacedantennas is very important A number of studies has beenconducted on improving isolation by cutting slots or slits inthe ground plane [2 3] and using the ground wall amongradiators and a T-shaped short strip [4] Suspended neutral-ization line or neutralizing structures have been used for theenhancement of isolation as well [5ndash9] However applyingthese techniques to LTE MIMO antennas at 700MHz hasbecome a serious technical challenge because the groundplane requiresmodification and there is no sufficient space to
embed additional elements between closely packed antennasIn this paper we present a promising design of a handsetantenna comprising a main antenna for the GSM850900(824sim960MHz) and DCSPCS (171sim199GHz) bands and anauxiliary antenna covering the LTE 700 (746sim787MHz) bandto perform the MIMO operation High isolation can beachieved by collinearly arranging the E-field directions ofLTE MIMO antennas in the near-field region because acollinearly arranged antenna has a lower mutual impedancethan that of a broadside arranged antenna [10]Moreover lowECC is achieved by the pattern diversity technique with LTEMIMOantennas symmetrically located on the top sides of theground plane
2 LTE MIMO Antenna Simulation
Figure 1 shows the proposed compact LTE MIMO antennaThe overall dimensions of the proposed antenna are 5 times35 times 6mm3 and the size of the ground plane is 60 times110 times 1mm3 As shown in Figure 1(a) the proposed PIFAstructure antennas are printed on FR4 substrate (120576
119903= 44) and
2 International Journal of Antennas and Propagation
A
B C
35
MIMO antenna 1MIMO antenna 2
Ground plane [60 times 110 times
119909
119910 119911
120601
120579
[unit mm]
Folded line
1 mm3]
(a)
FeedShorting
A
B
C
5
53
1
642
6
29
Folded line
(b)
Figure 1 Geometry of the proposed LTE MIMO antenna (a) overall view and (b) detailed view of antenna element
119871=110
mm
119882 = 70mm
Gap = 20mm
(a)
70 mm
10 mm
(b)
50 mm
60 mm
(c)
20 mm
10 mm
(d)
Figure 2 Antenna location and arrangement (a) case 1 (b) case 2 (c) case 3 and (d) case 4
symmetrically arranged on the top sides of the ground planeThe distance between the two PIFAs is 50mm (asymp0013120582
0) To
achieve high isolation and low ECC without any additionalcoupling structures and cancel out the existing mutual cou-pling an optimum antenna location and arrangement areproposed In general when two linearly polarized antennasare located orthogonally to each other they can providepolarization diversity by reducing the mutual coupling sothat high isolation and low ECC can be achieved betweenthem However this technique does not work very well forhandset antennas at lower frequencies such as the LTE 700band (746sim787MHz) because their ground sizes are usually
much smaller than their wavelength (1205820= 429mm) There-
fore it is necessary to apply a novel technique for the LTEMIMO handset antenna design The first step in the LTEMIMO antenna design is deciding the location of antennaelements The top side of the ground plane is an attractiveregion for mobile handset applications because it is relativelyeasy to apply pattern diversity when the size of the groundplane ismuch smaller than the wavelengthThe second step isdeciding how to arrange antenna elements In the near-fieldregion mutual coupling can be suppressed more effectivelywhen the E-field directions of two antennas are arrangedcollinearly with each other compared with the broadside
International Journal of Antennas and Propagation 3
Port 1 (on)
Port 2 (off)
Port 1 (off)
Port 2 (on)
minus125
minus5
minus875
minus125
minus163
minus20
minus238
minus275
minus313
minus35
minus388minus40
0
(dB)
(a)
Port 1 (on) Port 2 (off)
(b)
Port 1 (on) Port 2 (off)
(c)
Port 1 (on)
Port 2 (off)
(d)
Figure 3 119864-field distribution in the near-field region (a) case 1 (b) case 2 (c) case 3 and (d) case 4
arrangement of the E-field directions [10] This proposedmethod is verified by four cases of antenna arrangementsmdashcase 1 perpendicular case 2 broadside and cases 3 and 4collinearmdashas shown in Figure 2 These are divided into theperpendicular broadside and collinear arrangements by theE-field distribution as shown in Figure 3 Figure 4 showsthat the perpendicular (case 1) and collinear arrangements(cases 3 and 4) give higher isolation (magnitude of 119878
21in dB)
than that of the broadside arrangement (case 2) Howeverthe collinearly arranged MIMO antenna in case 3 only givesthe lowest ECC (lt019) which is less than the recommendedvalue [11] of 05 as shown in Table 1This is due to theMIMOantenna in case 3 achieving better pattern diversity in the far-field region than the MIMO antenna in case 1 where the twoantennas are physically perpendicular to each otherThe ECCshown in Table 1 is obtained by using the far-field radiationpatterns [12] as shown in (1) where the incident wave isassumed as a uniform environment (119875(120579 120601) = 1)
ECC (120588119890)
=
1003816
1003816
1003816
1003816
1003816
1003816
int
2120587
0int
120587
0119864
lowast
1(120579 120601) sdot 119864
2(120579 120601) sdot 119875 (120579 120601) sin (120579) 119889120579 119889120601
1003816
1003816
1003816
1003816
1003816
1003816
2
[
(int2120587
0int120587
0119864lowast
1 (120579120601)sdot1198641(120579120601)sdot119875(120579120601)sin(120579)119889120579 119889120601)
sdot(int2120587
0int120587
0119864lowast
2 (120579120601)sdot1198642(120579120601)sdot119875(120579120601)sin(120579)119889120579 119889120601)
]
(1)
where 11986412(120579 120601) is the electric field pattern of antennas 1 and
2 respectively and119875(120579 120601) is the incident field angular densityfunction
3 MainMIMO Antenna Designand Measurement
Based on the simulation results to find the optimum locationand arrangement of the LTE 700 band MIMO antennathe main antenna covering the GSM850900 bands (824sim960MHz) and DCSPCS bands (171sim199GHz) and theMIMO antenna (case 3 in Figure 2(c)) covering the LTE 700band (746sim787MHz) are designed and measured Figure 5shows the structure of the proposed main antenna andMIMO antenna The compact main antenna mounted on aground plane 60 times 110 times 1mm3 in size consists of the PIFAstructure with a capacitively coupled feed [13] Its overalldimensions are 60 times 5 times 6mm3 and it is printed on amultilayer consisting of FR4 (thickness = 1mm) and foam(thickness = 5mm) substrates Each LTEMIMO antenna (5times35 times 6mm3) is located on top sides of the ground plane withcollinearly arranged E-fields in the near-field region
Figure 6 shows the measured 119878-parameters of the pro-posed antenna The proposed antenna (VSWR lt 3) coversthe LTE 700 band (746sim787MHz) GSM850900 bands (824sim960MHz) and DCSPCS bands (171sim199GHz) Althoughthe main antenna and MIMO antennas are embedded in a
4 International Journal of Antennas and Propagation
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987811|
(a)
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987821|
(b)
Figure 4 Simulated 119878-parameters (a) 11987811and (b) 119878
21
35
BA
DC
55
60
MIMO antenna 1 MIMO antenna 2Ground plane [60 times 110 times
119909
119910 119911
120601120579
[unit mm]Folded line
1 mm3]
(a)
C
FeedShorting
D
B A
55 5 25
4
4
245
3
15 6 45
Folded line
(b)
(c)
Figure 5 Geometry of the proposed antenna (a) overall view (b) detailed view of main antenna and (c) fabricated antenna
International Journal of Antennas and Propagation 5
Table 1 Simulated results for each case
Contents Ant typeCase 1 Case 2 Case 3 Case 4
Resonant frequency (119891119903) 0765GHz 0791 GHz 0766GHz 0754GHz
Isolation 118 dB 67 dB 157 dB 103 dBECC (at 119891
119903) 052 078 019 081
Arrangement (gap) Perpendicular (20mm) Broadside (10mm) Collinear (50mm) Collinear (10mm)
LTE GSM850900 DCSPCS
05 075 1 125 15 175 2 225 25minus30
minus25
minus20
minus15
minus10
minus5
0
S-pa
ram
eter
s (dB
)
Frequency (GHz)
VSWR3 1
|11987811|
|11987833|
|11987812|
|11987813|
Figure 6 Measured 119878-parameters
07 075 08 085 09 095 1 18 2Frequency (GHz)
Aver
age g
ain
(dBi
)
0
02
04
06
08
1
Enve
lope
d co
rrel
atio
n co
effici
ent
LTE GSM850900 DCSPCS
Antenna 1 and 2 (gain) Antenna 1 and 2 (ECC) Antenna 3 (gain)
minus12
minus10
minus8
minus6
minus4
minus2
0
ECC lt 035
Figure 7 Measured average gain and ECC
narrow area they operate almost independently The mea-sured isolation between the two MIMO antennas is higherthan 15 dB and this is generally acceptable for practicalMIMO antenna applications in industry Figure 7 shows themeasured average gain and ECC The proposed antenna hasan average gain of more than minus43 dBi in the LTE band and
30
60
120
150180
210
240
270
300
330
Antenna 1Antenna 2
(dB)
minus20
minus15
minus10
minus5
00 [+119911]
90 [+119909]
Figure 8 Measured radiation patterns at 766MHz (119911119909-plane)
more than minus3 dBi in the GSM850900 and DCSPCS bandsMoreover the proposed LTE MIMO antenna shows a lowerECC (lt035) Figure 8 shows themeasured radiation patternsof twoMIMO antennas in the LTE700 band (766MHz)Theyhave been measured with one antenna excited and the otherterminated to a load with 50Ω The polarizations of the twoantennas are orthogonal to each other Since each MIMOantenna element (PIFA) has both the vertical E-field com-ponent (due to current on the radiating element) and thehorizontal E-field component (due to current on the groundplane) the direction of the compositive E-field can be di-agonal In addition to this since the horizontal E-field com-ponent of each MIMO antenna element is in opposite direc-tion the polarizations of the two antennas are diagonallyorthogonal to each other as shown in Figure 8 Thereforethese orthogonal radiation patterns and high isolation(gt15 dB) result in a lower ECC (lt035) which is less than therecommended value of 05 [11]
4 Conclusion
A compact (5 times 35 times 6mm3) handset MIMO antenna forLTE 700 band applications has been proposed and con-structed with two symmetrical PIFAs Closely packedMIMOantennas were designed without any additional couplingstructures to obtain good isolation The proposed antennaachieves high isolation (gt15 dB) and low ECC (lt035) by
6 International Journal of Antennas and Propagation
collinearly arranging the E-fields of two antennas in the near-field region and obtaining diagonally orthogonal radiationpatterns
Acknowledgment
This research was conducted under a Research Grant fromKwangwoon University in 2013 and this work (Grant noC0015229) was supported by Business for Cooperative RampDbetween Industry Academy and Research Institute fundedKorea Small and Medium Business Administration in 2012
References
[1] G J Foschini ldquoLayered space-time architecture for wirelesscommunication in a fading environment when using multi-element antennasrdquo Bell Labs Technical Journal vol 1 no 2 pp41ndash59 1996
[2] C Y Chiu C H Cheng R D Murch and C R RowellldquoReduction ofmutual coupling between closely-packed antennaelementsrdquo IEEE Transactions on Antennas and Propagation vol55 no 6 pp 1732ndash1738 2007
[3] M S Sharawi S S Iqbal and Y S Faouri ldquoAn 800MHz 2x1compactMIMOantenna system for LTE handsetsrdquo IEEE Trans-actions onAntenna and Propagation vol 59 no 8 pp 3128ndash31312011
[4] A C K Mak C R Rowell and R D Murch ldquoIsolation en-hancement between two closely packed antennasrdquo IEEE Trans-actions on Antennas and Propagation vol 56 no 11 pp 3411ndash3419 2008
[5] ADiallo C Luxey P LThuc R Staraj andGKossiavas ldquoStudyand reduction of the mutual coupling between two mobilephonePIFAs operating in theDCS1800 andUMTSbandsrdquo IEEETransactions on Antenna and Propagation vol 54 no 11 pp3063ndash3074
[6] J Byun J H Jo and B Lee ldquoCompact dual-band diversityantenna for mobile handset applicationsrdquoMicrowave and Opti-cal Technology Letters vol 50 no 10 pp 2600ndash2604 2008
[7] B Yu C W Jung H Lee et al ldquoClosely mounted compactwideband diversity antenna for mobile phone applicationsrdquoInternational Journal of Antennas and Propagation vol 2012Article ID 798046 6 pages 2012
[8] H Bae F J Harackiewicz M J Park et al ldquoCompact mobilehandset MIMO antenna for LTE700 applicationsrdquo Microwaveand Optical Technology Letters vol 52 no 11 pp 2419ndash24222010
[9] B Kim Y Park H Wi et al ldquoIsolation enhancement of USBdongle MIMO antenna in LTE 700 band applicationsrdquo IEEEAntennas and Wireless Propagation Letters vol 11 pp 961ndash9642012
[10] N G Alexopoulos and I E Rana ldquoMutual impedance compu-tation between printed dipolesrdquo IEEE Transactions on Antennasand Propagation vol 29 no 1 pp 106ndash111 1981
[11] R G Vaughan and J B Andersen ldquoAntenna diversity in mobilecommunicationsrdquo IEEE Transactions on Vehicular Technologyvol 36 no 4 pp 149ndash172 1987
[12] S Blanch J Romeu and I Corbella ldquoExact representation ofantenna system diversity performance from input parameterdescriptionrdquo Electronics Letters vol 39 no 9 pp 705ndash707 2003
[13] H Rhyu J Byun F J Harackiewicz et al ldquoMulti-band hybridantenna for ultra-thin mobile phone applicationsrdquo ElectronicsLetters vol 45 no 15 pp 773ndash774 2009
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
2 International Journal of Antennas and Propagation
A
B C
35
MIMO antenna 1MIMO antenna 2
Ground plane [60 times 110 times
119909
119910 119911
120601
120579
[unit mm]
Folded line
1 mm3]
(a)
FeedShorting
A
B
C
5
53
1
642
6
29
Folded line
(b)
Figure 1 Geometry of the proposed LTE MIMO antenna (a) overall view and (b) detailed view of antenna element
119871=110
mm
119882 = 70mm
Gap = 20mm
(a)
70 mm
10 mm
(b)
50 mm
60 mm
(c)
20 mm
10 mm
(d)
Figure 2 Antenna location and arrangement (a) case 1 (b) case 2 (c) case 3 and (d) case 4
symmetrically arranged on the top sides of the ground planeThe distance between the two PIFAs is 50mm (asymp0013120582
0) To
achieve high isolation and low ECC without any additionalcoupling structures and cancel out the existing mutual cou-pling an optimum antenna location and arrangement areproposed In general when two linearly polarized antennasare located orthogonally to each other they can providepolarization diversity by reducing the mutual coupling sothat high isolation and low ECC can be achieved betweenthem However this technique does not work very well forhandset antennas at lower frequencies such as the LTE 700band (746sim787MHz) because their ground sizes are usually
much smaller than their wavelength (1205820= 429mm) There-
fore it is necessary to apply a novel technique for the LTEMIMO handset antenna design The first step in the LTEMIMO antenna design is deciding the location of antennaelements The top side of the ground plane is an attractiveregion for mobile handset applications because it is relativelyeasy to apply pattern diversity when the size of the groundplane ismuch smaller than the wavelengthThe second step isdeciding how to arrange antenna elements In the near-fieldregion mutual coupling can be suppressed more effectivelywhen the E-field directions of two antennas are arrangedcollinearly with each other compared with the broadside
International Journal of Antennas and Propagation 3
Port 1 (on)
Port 2 (off)
Port 1 (off)
Port 2 (on)
minus125
minus5
minus875
minus125
minus163
minus20
minus238
minus275
minus313
minus35
minus388minus40
0
(dB)
(a)
Port 1 (on) Port 2 (off)
(b)
Port 1 (on) Port 2 (off)
(c)
Port 1 (on)
Port 2 (off)
(d)
Figure 3 119864-field distribution in the near-field region (a) case 1 (b) case 2 (c) case 3 and (d) case 4
arrangement of the E-field directions [10] This proposedmethod is verified by four cases of antenna arrangementsmdashcase 1 perpendicular case 2 broadside and cases 3 and 4collinearmdashas shown in Figure 2 These are divided into theperpendicular broadside and collinear arrangements by theE-field distribution as shown in Figure 3 Figure 4 showsthat the perpendicular (case 1) and collinear arrangements(cases 3 and 4) give higher isolation (magnitude of 119878
21in dB)
than that of the broadside arrangement (case 2) Howeverthe collinearly arranged MIMO antenna in case 3 only givesthe lowest ECC (lt019) which is less than the recommendedvalue [11] of 05 as shown in Table 1This is due to theMIMOantenna in case 3 achieving better pattern diversity in the far-field region than the MIMO antenna in case 1 where the twoantennas are physically perpendicular to each otherThe ECCshown in Table 1 is obtained by using the far-field radiationpatterns [12] as shown in (1) where the incident wave isassumed as a uniform environment (119875(120579 120601) = 1)
ECC (120588119890)
=
1003816
1003816
1003816
1003816
1003816
1003816
int
2120587
0int
120587
0119864
lowast
1(120579 120601) sdot 119864
2(120579 120601) sdot 119875 (120579 120601) sin (120579) 119889120579 119889120601
1003816
1003816
1003816
1003816
1003816
1003816
2
[
(int2120587
0int120587
0119864lowast
1 (120579120601)sdot1198641(120579120601)sdot119875(120579120601)sin(120579)119889120579 119889120601)
sdot(int2120587
0int120587
0119864lowast
2 (120579120601)sdot1198642(120579120601)sdot119875(120579120601)sin(120579)119889120579 119889120601)
]
(1)
where 11986412(120579 120601) is the electric field pattern of antennas 1 and
2 respectively and119875(120579 120601) is the incident field angular densityfunction
3 MainMIMO Antenna Designand Measurement
Based on the simulation results to find the optimum locationand arrangement of the LTE 700 band MIMO antennathe main antenna covering the GSM850900 bands (824sim960MHz) and DCSPCS bands (171sim199GHz) and theMIMO antenna (case 3 in Figure 2(c)) covering the LTE 700band (746sim787MHz) are designed and measured Figure 5shows the structure of the proposed main antenna andMIMO antenna The compact main antenna mounted on aground plane 60 times 110 times 1mm3 in size consists of the PIFAstructure with a capacitively coupled feed [13] Its overalldimensions are 60 times 5 times 6mm3 and it is printed on amultilayer consisting of FR4 (thickness = 1mm) and foam(thickness = 5mm) substrates Each LTEMIMO antenna (5times35 times 6mm3) is located on top sides of the ground plane withcollinearly arranged E-fields in the near-field region
Figure 6 shows the measured 119878-parameters of the pro-posed antenna The proposed antenna (VSWR lt 3) coversthe LTE 700 band (746sim787MHz) GSM850900 bands (824sim960MHz) and DCSPCS bands (171sim199GHz) Althoughthe main antenna and MIMO antennas are embedded in a
4 International Journal of Antennas and Propagation
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987811|
(a)
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987821|
(b)
Figure 4 Simulated 119878-parameters (a) 11987811and (b) 119878
21
35
BA
DC
55
60
MIMO antenna 1 MIMO antenna 2Ground plane [60 times 110 times
119909
119910 119911
120601120579
[unit mm]Folded line
1 mm3]
(a)
C
FeedShorting
D
B A
55 5 25
4
4
245
3
15 6 45
Folded line
(b)
(c)
Figure 5 Geometry of the proposed antenna (a) overall view (b) detailed view of main antenna and (c) fabricated antenna
International Journal of Antennas and Propagation 5
Table 1 Simulated results for each case
Contents Ant typeCase 1 Case 2 Case 3 Case 4
Resonant frequency (119891119903) 0765GHz 0791 GHz 0766GHz 0754GHz
Isolation 118 dB 67 dB 157 dB 103 dBECC (at 119891
119903) 052 078 019 081
Arrangement (gap) Perpendicular (20mm) Broadside (10mm) Collinear (50mm) Collinear (10mm)
LTE GSM850900 DCSPCS
05 075 1 125 15 175 2 225 25minus30
minus25
minus20
minus15
minus10
minus5
0
S-pa
ram
eter
s (dB
)
Frequency (GHz)
VSWR3 1
|11987811|
|11987833|
|11987812|
|11987813|
Figure 6 Measured 119878-parameters
07 075 08 085 09 095 1 18 2Frequency (GHz)
Aver
age g
ain
(dBi
)
0
02
04
06
08
1
Enve
lope
d co
rrel
atio
n co
effici
ent
LTE GSM850900 DCSPCS
Antenna 1 and 2 (gain) Antenna 1 and 2 (ECC) Antenna 3 (gain)
minus12
minus10
minus8
minus6
minus4
minus2
0
ECC lt 035
Figure 7 Measured average gain and ECC
narrow area they operate almost independently The mea-sured isolation between the two MIMO antennas is higherthan 15 dB and this is generally acceptable for practicalMIMO antenna applications in industry Figure 7 shows themeasured average gain and ECC The proposed antenna hasan average gain of more than minus43 dBi in the LTE band and
30
60
120
150180
210
240
270
300
330
Antenna 1Antenna 2
(dB)
minus20
minus15
minus10
minus5
00 [+119911]
90 [+119909]
Figure 8 Measured radiation patterns at 766MHz (119911119909-plane)
more than minus3 dBi in the GSM850900 and DCSPCS bandsMoreover the proposed LTE MIMO antenna shows a lowerECC (lt035) Figure 8 shows themeasured radiation patternsof twoMIMO antennas in the LTE700 band (766MHz)Theyhave been measured with one antenna excited and the otherterminated to a load with 50Ω The polarizations of the twoantennas are orthogonal to each other Since each MIMOantenna element (PIFA) has both the vertical E-field com-ponent (due to current on the radiating element) and thehorizontal E-field component (due to current on the groundplane) the direction of the compositive E-field can be di-agonal In addition to this since the horizontal E-field com-ponent of each MIMO antenna element is in opposite direc-tion the polarizations of the two antennas are diagonallyorthogonal to each other as shown in Figure 8 Thereforethese orthogonal radiation patterns and high isolation(gt15 dB) result in a lower ECC (lt035) which is less than therecommended value of 05 [11]
4 Conclusion
A compact (5 times 35 times 6mm3) handset MIMO antenna forLTE 700 band applications has been proposed and con-structed with two symmetrical PIFAs Closely packedMIMOantennas were designed without any additional couplingstructures to obtain good isolation The proposed antennaachieves high isolation (gt15 dB) and low ECC (lt035) by
6 International Journal of Antennas and Propagation
collinearly arranging the E-fields of two antennas in the near-field region and obtaining diagonally orthogonal radiationpatterns
Acknowledgment
This research was conducted under a Research Grant fromKwangwoon University in 2013 and this work (Grant noC0015229) was supported by Business for Cooperative RampDbetween Industry Academy and Research Institute fundedKorea Small and Medium Business Administration in 2012
References
[1] G J Foschini ldquoLayered space-time architecture for wirelesscommunication in a fading environment when using multi-element antennasrdquo Bell Labs Technical Journal vol 1 no 2 pp41ndash59 1996
[2] C Y Chiu C H Cheng R D Murch and C R RowellldquoReduction ofmutual coupling between closely-packed antennaelementsrdquo IEEE Transactions on Antennas and Propagation vol55 no 6 pp 1732ndash1738 2007
[3] M S Sharawi S S Iqbal and Y S Faouri ldquoAn 800MHz 2x1compactMIMOantenna system for LTE handsetsrdquo IEEE Trans-actions onAntenna and Propagation vol 59 no 8 pp 3128ndash31312011
[4] A C K Mak C R Rowell and R D Murch ldquoIsolation en-hancement between two closely packed antennasrdquo IEEE Trans-actions on Antennas and Propagation vol 56 no 11 pp 3411ndash3419 2008
[5] ADiallo C Luxey P LThuc R Staraj andGKossiavas ldquoStudyand reduction of the mutual coupling between two mobilephonePIFAs operating in theDCS1800 andUMTSbandsrdquo IEEETransactions on Antenna and Propagation vol 54 no 11 pp3063ndash3074
[6] J Byun J H Jo and B Lee ldquoCompact dual-band diversityantenna for mobile handset applicationsrdquoMicrowave and Opti-cal Technology Letters vol 50 no 10 pp 2600ndash2604 2008
[7] B Yu C W Jung H Lee et al ldquoClosely mounted compactwideband diversity antenna for mobile phone applicationsrdquoInternational Journal of Antennas and Propagation vol 2012Article ID 798046 6 pages 2012
[8] H Bae F J Harackiewicz M J Park et al ldquoCompact mobilehandset MIMO antenna for LTE700 applicationsrdquo Microwaveand Optical Technology Letters vol 52 no 11 pp 2419ndash24222010
[9] B Kim Y Park H Wi et al ldquoIsolation enhancement of USBdongle MIMO antenna in LTE 700 band applicationsrdquo IEEEAntennas and Wireless Propagation Letters vol 11 pp 961ndash9642012
[10] N G Alexopoulos and I E Rana ldquoMutual impedance compu-tation between printed dipolesrdquo IEEE Transactions on Antennasand Propagation vol 29 no 1 pp 106ndash111 1981
[11] R G Vaughan and J B Andersen ldquoAntenna diversity in mobilecommunicationsrdquo IEEE Transactions on Vehicular Technologyvol 36 no 4 pp 149ndash172 1987
[12] S Blanch J Romeu and I Corbella ldquoExact representation ofantenna system diversity performance from input parameterdescriptionrdquo Electronics Letters vol 39 no 9 pp 705ndash707 2003
[13] H Rhyu J Byun F J Harackiewicz et al ldquoMulti-band hybridantenna for ultra-thin mobile phone applicationsrdquo ElectronicsLetters vol 45 no 15 pp 773ndash774 2009
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
International Journal of Antennas and Propagation 3
Port 1 (on)
Port 2 (off)
Port 1 (off)
Port 2 (on)
minus125
minus5
minus875
minus125
minus163
minus20
minus238
minus275
minus313
minus35
minus388minus40
0
(dB)
(a)
Port 1 (on) Port 2 (off)
(b)
Port 1 (on) Port 2 (off)
(c)
Port 1 (on)
Port 2 (off)
(d)
Figure 3 119864-field distribution in the near-field region (a) case 1 (b) case 2 (c) case 3 and (d) case 4
arrangement of the E-field directions [10] This proposedmethod is verified by four cases of antenna arrangementsmdashcase 1 perpendicular case 2 broadside and cases 3 and 4collinearmdashas shown in Figure 2 These are divided into theperpendicular broadside and collinear arrangements by theE-field distribution as shown in Figure 3 Figure 4 showsthat the perpendicular (case 1) and collinear arrangements(cases 3 and 4) give higher isolation (magnitude of 119878
21in dB)
than that of the broadside arrangement (case 2) Howeverthe collinearly arranged MIMO antenna in case 3 only givesthe lowest ECC (lt019) which is less than the recommendedvalue [11] of 05 as shown in Table 1This is due to theMIMOantenna in case 3 achieving better pattern diversity in the far-field region than the MIMO antenna in case 1 where the twoantennas are physically perpendicular to each otherThe ECCshown in Table 1 is obtained by using the far-field radiationpatterns [12] as shown in (1) where the incident wave isassumed as a uniform environment (119875(120579 120601) = 1)
ECC (120588119890)
=
1003816
1003816
1003816
1003816
1003816
1003816
int
2120587
0int
120587
0119864
lowast
1(120579 120601) sdot 119864
2(120579 120601) sdot 119875 (120579 120601) sin (120579) 119889120579 119889120601
1003816
1003816
1003816
1003816
1003816
1003816
2
[
(int2120587
0int120587
0119864lowast
1 (120579120601)sdot1198641(120579120601)sdot119875(120579120601)sin(120579)119889120579 119889120601)
sdot(int2120587
0int120587
0119864lowast
2 (120579120601)sdot1198642(120579120601)sdot119875(120579120601)sin(120579)119889120579 119889120601)
]
(1)
where 11986412(120579 120601) is the electric field pattern of antennas 1 and
2 respectively and119875(120579 120601) is the incident field angular densityfunction
3 MainMIMO Antenna Designand Measurement
Based on the simulation results to find the optimum locationand arrangement of the LTE 700 band MIMO antennathe main antenna covering the GSM850900 bands (824sim960MHz) and DCSPCS bands (171sim199GHz) and theMIMO antenna (case 3 in Figure 2(c)) covering the LTE 700band (746sim787MHz) are designed and measured Figure 5shows the structure of the proposed main antenna andMIMO antenna The compact main antenna mounted on aground plane 60 times 110 times 1mm3 in size consists of the PIFAstructure with a capacitively coupled feed [13] Its overalldimensions are 60 times 5 times 6mm3 and it is printed on amultilayer consisting of FR4 (thickness = 1mm) and foam(thickness = 5mm) substrates Each LTEMIMO antenna (5times35 times 6mm3) is located on top sides of the ground plane withcollinearly arranged E-fields in the near-field region
Figure 6 shows the measured 119878-parameters of the pro-posed antenna The proposed antenna (VSWR lt 3) coversthe LTE 700 band (746sim787MHz) GSM850900 bands (824sim960MHz) and DCSPCS bands (171sim199GHz) Althoughthe main antenna and MIMO antennas are embedded in a
4 International Journal of Antennas and Propagation
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987811|
(a)
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987821|
(b)
Figure 4 Simulated 119878-parameters (a) 11987811and (b) 119878
21
35
BA
DC
55
60
MIMO antenna 1 MIMO antenna 2Ground plane [60 times 110 times
119909
119910 119911
120601120579
[unit mm]Folded line
1 mm3]
(a)
C
FeedShorting
D
B A
55 5 25
4
4
245
3
15 6 45
Folded line
(b)
(c)
Figure 5 Geometry of the proposed antenna (a) overall view (b) detailed view of main antenna and (c) fabricated antenna
International Journal of Antennas and Propagation 5
Table 1 Simulated results for each case
Contents Ant typeCase 1 Case 2 Case 3 Case 4
Resonant frequency (119891119903) 0765GHz 0791 GHz 0766GHz 0754GHz
Isolation 118 dB 67 dB 157 dB 103 dBECC (at 119891
119903) 052 078 019 081
Arrangement (gap) Perpendicular (20mm) Broadside (10mm) Collinear (50mm) Collinear (10mm)
LTE GSM850900 DCSPCS
05 075 1 125 15 175 2 225 25minus30
minus25
minus20
minus15
minus10
minus5
0
S-pa
ram
eter
s (dB
)
Frequency (GHz)
VSWR3 1
|11987811|
|11987833|
|11987812|
|11987813|
Figure 6 Measured 119878-parameters
07 075 08 085 09 095 1 18 2Frequency (GHz)
Aver
age g
ain
(dBi
)
0
02
04
06
08
1
Enve
lope
d co
rrel
atio
n co
effici
ent
LTE GSM850900 DCSPCS
Antenna 1 and 2 (gain) Antenna 1 and 2 (ECC) Antenna 3 (gain)
minus12
minus10
minus8
minus6
minus4
minus2
0
ECC lt 035
Figure 7 Measured average gain and ECC
narrow area they operate almost independently The mea-sured isolation between the two MIMO antennas is higherthan 15 dB and this is generally acceptable for practicalMIMO antenna applications in industry Figure 7 shows themeasured average gain and ECC The proposed antenna hasan average gain of more than minus43 dBi in the LTE band and
30
60
120
150180
210
240
270
300
330
Antenna 1Antenna 2
(dB)
minus20
minus15
minus10
minus5
00 [+119911]
90 [+119909]
Figure 8 Measured radiation patterns at 766MHz (119911119909-plane)
more than minus3 dBi in the GSM850900 and DCSPCS bandsMoreover the proposed LTE MIMO antenna shows a lowerECC (lt035) Figure 8 shows themeasured radiation patternsof twoMIMO antennas in the LTE700 band (766MHz)Theyhave been measured with one antenna excited and the otherterminated to a load with 50Ω The polarizations of the twoantennas are orthogonal to each other Since each MIMOantenna element (PIFA) has both the vertical E-field com-ponent (due to current on the radiating element) and thehorizontal E-field component (due to current on the groundplane) the direction of the compositive E-field can be di-agonal In addition to this since the horizontal E-field com-ponent of each MIMO antenna element is in opposite direc-tion the polarizations of the two antennas are diagonallyorthogonal to each other as shown in Figure 8 Thereforethese orthogonal radiation patterns and high isolation(gt15 dB) result in a lower ECC (lt035) which is less than therecommended value of 05 [11]
4 Conclusion
A compact (5 times 35 times 6mm3) handset MIMO antenna forLTE 700 band applications has been proposed and con-structed with two symmetrical PIFAs Closely packedMIMOantennas were designed without any additional couplingstructures to obtain good isolation The proposed antennaachieves high isolation (gt15 dB) and low ECC (lt035) by
6 International Journal of Antennas and Propagation
collinearly arranging the E-fields of two antennas in the near-field region and obtaining diagonally orthogonal radiationpatterns
Acknowledgment
This research was conducted under a Research Grant fromKwangwoon University in 2013 and this work (Grant noC0015229) was supported by Business for Cooperative RampDbetween Industry Academy and Research Institute fundedKorea Small and Medium Business Administration in 2012
References
[1] G J Foschini ldquoLayered space-time architecture for wirelesscommunication in a fading environment when using multi-element antennasrdquo Bell Labs Technical Journal vol 1 no 2 pp41ndash59 1996
[2] C Y Chiu C H Cheng R D Murch and C R RowellldquoReduction ofmutual coupling between closely-packed antennaelementsrdquo IEEE Transactions on Antennas and Propagation vol55 no 6 pp 1732ndash1738 2007
[3] M S Sharawi S S Iqbal and Y S Faouri ldquoAn 800MHz 2x1compactMIMOantenna system for LTE handsetsrdquo IEEE Trans-actions onAntenna and Propagation vol 59 no 8 pp 3128ndash31312011
[4] A C K Mak C R Rowell and R D Murch ldquoIsolation en-hancement between two closely packed antennasrdquo IEEE Trans-actions on Antennas and Propagation vol 56 no 11 pp 3411ndash3419 2008
[5] ADiallo C Luxey P LThuc R Staraj andGKossiavas ldquoStudyand reduction of the mutual coupling between two mobilephonePIFAs operating in theDCS1800 andUMTSbandsrdquo IEEETransactions on Antenna and Propagation vol 54 no 11 pp3063ndash3074
[6] J Byun J H Jo and B Lee ldquoCompact dual-band diversityantenna for mobile handset applicationsrdquoMicrowave and Opti-cal Technology Letters vol 50 no 10 pp 2600ndash2604 2008
[7] B Yu C W Jung H Lee et al ldquoClosely mounted compactwideband diversity antenna for mobile phone applicationsrdquoInternational Journal of Antennas and Propagation vol 2012Article ID 798046 6 pages 2012
[8] H Bae F J Harackiewicz M J Park et al ldquoCompact mobilehandset MIMO antenna for LTE700 applicationsrdquo Microwaveand Optical Technology Letters vol 52 no 11 pp 2419ndash24222010
[9] B Kim Y Park H Wi et al ldquoIsolation enhancement of USBdongle MIMO antenna in LTE 700 band applicationsrdquo IEEEAntennas and Wireless Propagation Letters vol 11 pp 961ndash9642012
[10] N G Alexopoulos and I E Rana ldquoMutual impedance compu-tation between printed dipolesrdquo IEEE Transactions on Antennasand Propagation vol 29 no 1 pp 106ndash111 1981
[11] R G Vaughan and J B Andersen ldquoAntenna diversity in mobilecommunicationsrdquo IEEE Transactions on Vehicular Technologyvol 36 no 4 pp 149ndash172 1987
[12] S Blanch J Romeu and I Corbella ldquoExact representation ofantenna system diversity performance from input parameterdescriptionrdquo Electronics Letters vol 39 no 9 pp 705ndash707 2003
[13] H Rhyu J Byun F J Harackiewicz et al ldquoMulti-band hybridantenna for ultra-thin mobile phone applicationsrdquo ElectronicsLetters vol 45 no 15 pp 773ndash774 2009
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
4 International Journal of Antennas and Propagation
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987811|
(a)
06 065 07 075 08 085 09 095 1minus30
minus25
minus20
minus15
minus10
minus5
0
Frequency (GHz)
Case 1Case 2
Case 3Case 4
(dB)
|11987821|
(b)
Figure 4 Simulated 119878-parameters (a) 11987811and (b) 119878
21
35
BA
DC
55
60
MIMO antenna 1 MIMO antenna 2Ground plane [60 times 110 times
119909
119910 119911
120601120579
[unit mm]Folded line
1 mm3]
(a)
C
FeedShorting
D
B A
55 5 25
4
4
245
3
15 6 45
Folded line
(b)
(c)
Figure 5 Geometry of the proposed antenna (a) overall view (b) detailed view of main antenna and (c) fabricated antenna
International Journal of Antennas and Propagation 5
Table 1 Simulated results for each case
Contents Ant typeCase 1 Case 2 Case 3 Case 4
Resonant frequency (119891119903) 0765GHz 0791 GHz 0766GHz 0754GHz
Isolation 118 dB 67 dB 157 dB 103 dBECC (at 119891
119903) 052 078 019 081
Arrangement (gap) Perpendicular (20mm) Broadside (10mm) Collinear (50mm) Collinear (10mm)
LTE GSM850900 DCSPCS
05 075 1 125 15 175 2 225 25minus30
minus25
minus20
minus15
minus10
minus5
0
S-pa
ram
eter
s (dB
)
Frequency (GHz)
VSWR3 1
|11987811|
|11987833|
|11987812|
|11987813|
Figure 6 Measured 119878-parameters
07 075 08 085 09 095 1 18 2Frequency (GHz)
Aver
age g
ain
(dBi
)
0
02
04
06
08
1
Enve
lope
d co
rrel
atio
n co
effici
ent
LTE GSM850900 DCSPCS
Antenna 1 and 2 (gain) Antenna 1 and 2 (ECC) Antenna 3 (gain)
minus12
minus10
minus8
minus6
minus4
minus2
0
ECC lt 035
Figure 7 Measured average gain and ECC
narrow area they operate almost independently The mea-sured isolation between the two MIMO antennas is higherthan 15 dB and this is generally acceptable for practicalMIMO antenna applications in industry Figure 7 shows themeasured average gain and ECC The proposed antenna hasan average gain of more than minus43 dBi in the LTE band and
30
60
120
150180
210
240
270
300
330
Antenna 1Antenna 2
(dB)
minus20
minus15
minus10
minus5
00 [+119911]
90 [+119909]
Figure 8 Measured radiation patterns at 766MHz (119911119909-plane)
more than minus3 dBi in the GSM850900 and DCSPCS bandsMoreover the proposed LTE MIMO antenna shows a lowerECC (lt035) Figure 8 shows themeasured radiation patternsof twoMIMO antennas in the LTE700 band (766MHz)Theyhave been measured with one antenna excited and the otherterminated to a load with 50Ω The polarizations of the twoantennas are orthogonal to each other Since each MIMOantenna element (PIFA) has both the vertical E-field com-ponent (due to current on the radiating element) and thehorizontal E-field component (due to current on the groundplane) the direction of the compositive E-field can be di-agonal In addition to this since the horizontal E-field com-ponent of each MIMO antenna element is in opposite direc-tion the polarizations of the two antennas are diagonallyorthogonal to each other as shown in Figure 8 Thereforethese orthogonal radiation patterns and high isolation(gt15 dB) result in a lower ECC (lt035) which is less than therecommended value of 05 [11]
4 Conclusion
A compact (5 times 35 times 6mm3) handset MIMO antenna forLTE 700 band applications has been proposed and con-structed with two symmetrical PIFAs Closely packedMIMOantennas were designed without any additional couplingstructures to obtain good isolation The proposed antennaachieves high isolation (gt15 dB) and low ECC (lt035) by
6 International Journal of Antennas and Propagation
collinearly arranging the E-fields of two antennas in the near-field region and obtaining diagonally orthogonal radiationpatterns
Acknowledgment
This research was conducted under a Research Grant fromKwangwoon University in 2013 and this work (Grant noC0015229) was supported by Business for Cooperative RampDbetween Industry Academy and Research Institute fundedKorea Small and Medium Business Administration in 2012
References
[1] G J Foschini ldquoLayered space-time architecture for wirelesscommunication in a fading environment when using multi-element antennasrdquo Bell Labs Technical Journal vol 1 no 2 pp41ndash59 1996
[2] C Y Chiu C H Cheng R D Murch and C R RowellldquoReduction ofmutual coupling between closely-packed antennaelementsrdquo IEEE Transactions on Antennas and Propagation vol55 no 6 pp 1732ndash1738 2007
[3] M S Sharawi S S Iqbal and Y S Faouri ldquoAn 800MHz 2x1compactMIMOantenna system for LTE handsetsrdquo IEEE Trans-actions onAntenna and Propagation vol 59 no 8 pp 3128ndash31312011
[4] A C K Mak C R Rowell and R D Murch ldquoIsolation en-hancement between two closely packed antennasrdquo IEEE Trans-actions on Antennas and Propagation vol 56 no 11 pp 3411ndash3419 2008
[5] ADiallo C Luxey P LThuc R Staraj andGKossiavas ldquoStudyand reduction of the mutual coupling between two mobilephonePIFAs operating in theDCS1800 andUMTSbandsrdquo IEEETransactions on Antenna and Propagation vol 54 no 11 pp3063ndash3074
[6] J Byun J H Jo and B Lee ldquoCompact dual-band diversityantenna for mobile handset applicationsrdquoMicrowave and Opti-cal Technology Letters vol 50 no 10 pp 2600ndash2604 2008
[7] B Yu C W Jung H Lee et al ldquoClosely mounted compactwideband diversity antenna for mobile phone applicationsrdquoInternational Journal of Antennas and Propagation vol 2012Article ID 798046 6 pages 2012
[8] H Bae F J Harackiewicz M J Park et al ldquoCompact mobilehandset MIMO antenna for LTE700 applicationsrdquo Microwaveand Optical Technology Letters vol 52 no 11 pp 2419ndash24222010
[9] B Kim Y Park H Wi et al ldquoIsolation enhancement of USBdongle MIMO antenna in LTE 700 band applicationsrdquo IEEEAntennas and Wireless Propagation Letters vol 11 pp 961ndash9642012
[10] N G Alexopoulos and I E Rana ldquoMutual impedance compu-tation between printed dipolesrdquo IEEE Transactions on Antennasand Propagation vol 29 no 1 pp 106ndash111 1981
[11] R G Vaughan and J B Andersen ldquoAntenna diversity in mobilecommunicationsrdquo IEEE Transactions on Vehicular Technologyvol 36 no 4 pp 149ndash172 1987
[12] S Blanch J Romeu and I Corbella ldquoExact representation ofantenna system diversity performance from input parameterdescriptionrdquo Electronics Letters vol 39 no 9 pp 705ndash707 2003
[13] H Rhyu J Byun F J Harackiewicz et al ldquoMulti-band hybridantenna for ultra-thin mobile phone applicationsrdquo ElectronicsLetters vol 45 no 15 pp 773ndash774 2009
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
International Journal of Antennas and Propagation 5
Table 1 Simulated results for each case
Contents Ant typeCase 1 Case 2 Case 3 Case 4
Resonant frequency (119891119903) 0765GHz 0791 GHz 0766GHz 0754GHz
Isolation 118 dB 67 dB 157 dB 103 dBECC (at 119891
119903) 052 078 019 081
Arrangement (gap) Perpendicular (20mm) Broadside (10mm) Collinear (50mm) Collinear (10mm)
LTE GSM850900 DCSPCS
05 075 1 125 15 175 2 225 25minus30
minus25
minus20
minus15
minus10
minus5
0
S-pa
ram
eter
s (dB
)
Frequency (GHz)
VSWR3 1
|11987811|
|11987833|
|11987812|
|11987813|
Figure 6 Measured 119878-parameters
07 075 08 085 09 095 1 18 2Frequency (GHz)
Aver
age g
ain
(dBi
)
0
02
04
06
08
1
Enve
lope
d co
rrel
atio
n co
effici
ent
LTE GSM850900 DCSPCS
Antenna 1 and 2 (gain) Antenna 1 and 2 (ECC) Antenna 3 (gain)
minus12
minus10
minus8
minus6
minus4
minus2
0
ECC lt 035
Figure 7 Measured average gain and ECC
narrow area they operate almost independently The mea-sured isolation between the two MIMO antennas is higherthan 15 dB and this is generally acceptable for practicalMIMO antenna applications in industry Figure 7 shows themeasured average gain and ECC The proposed antenna hasan average gain of more than minus43 dBi in the LTE band and
30
60
120
150180
210
240
270
300
330
Antenna 1Antenna 2
(dB)
minus20
minus15
minus10
minus5
00 [+119911]
90 [+119909]
Figure 8 Measured radiation patterns at 766MHz (119911119909-plane)
more than minus3 dBi in the GSM850900 and DCSPCS bandsMoreover the proposed LTE MIMO antenna shows a lowerECC (lt035) Figure 8 shows themeasured radiation patternsof twoMIMO antennas in the LTE700 band (766MHz)Theyhave been measured with one antenna excited and the otherterminated to a load with 50Ω The polarizations of the twoantennas are orthogonal to each other Since each MIMOantenna element (PIFA) has both the vertical E-field com-ponent (due to current on the radiating element) and thehorizontal E-field component (due to current on the groundplane) the direction of the compositive E-field can be di-agonal In addition to this since the horizontal E-field com-ponent of each MIMO antenna element is in opposite direc-tion the polarizations of the two antennas are diagonallyorthogonal to each other as shown in Figure 8 Thereforethese orthogonal radiation patterns and high isolation(gt15 dB) result in a lower ECC (lt035) which is less than therecommended value of 05 [11]
4 Conclusion
A compact (5 times 35 times 6mm3) handset MIMO antenna forLTE 700 band applications has been proposed and con-structed with two symmetrical PIFAs Closely packedMIMOantennas were designed without any additional couplingstructures to obtain good isolation The proposed antennaachieves high isolation (gt15 dB) and low ECC (lt035) by
6 International Journal of Antennas and Propagation
collinearly arranging the E-fields of two antennas in the near-field region and obtaining diagonally orthogonal radiationpatterns
Acknowledgment
This research was conducted under a Research Grant fromKwangwoon University in 2013 and this work (Grant noC0015229) was supported by Business for Cooperative RampDbetween Industry Academy and Research Institute fundedKorea Small and Medium Business Administration in 2012
References
[1] G J Foschini ldquoLayered space-time architecture for wirelesscommunication in a fading environment when using multi-element antennasrdquo Bell Labs Technical Journal vol 1 no 2 pp41ndash59 1996
[2] C Y Chiu C H Cheng R D Murch and C R RowellldquoReduction ofmutual coupling between closely-packed antennaelementsrdquo IEEE Transactions on Antennas and Propagation vol55 no 6 pp 1732ndash1738 2007
[3] M S Sharawi S S Iqbal and Y S Faouri ldquoAn 800MHz 2x1compactMIMOantenna system for LTE handsetsrdquo IEEE Trans-actions onAntenna and Propagation vol 59 no 8 pp 3128ndash31312011
[4] A C K Mak C R Rowell and R D Murch ldquoIsolation en-hancement between two closely packed antennasrdquo IEEE Trans-actions on Antennas and Propagation vol 56 no 11 pp 3411ndash3419 2008
[5] ADiallo C Luxey P LThuc R Staraj andGKossiavas ldquoStudyand reduction of the mutual coupling between two mobilephonePIFAs operating in theDCS1800 andUMTSbandsrdquo IEEETransactions on Antenna and Propagation vol 54 no 11 pp3063ndash3074
[6] J Byun J H Jo and B Lee ldquoCompact dual-band diversityantenna for mobile handset applicationsrdquoMicrowave and Opti-cal Technology Letters vol 50 no 10 pp 2600ndash2604 2008
[7] B Yu C W Jung H Lee et al ldquoClosely mounted compactwideband diversity antenna for mobile phone applicationsrdquoInternational Journal of Antennas and Propagation vol 2012Article ID 798046 6 pages 2012
[8] H Bae F J Harackiewicz M J Park et al ldquoCompact mobilehandset MIMO antenna for LTE700 applicationsrdquo Microwaveand Optical Technology Letters vol 52 no 11 pp 2419ndash24222010
[9] B Kim Y Park H Wi et al ldquoIsolation enhancement of USBdongle MIMO antenna in LTE 700 band applicationsrdquo IEEEAntennas and Wireless Propagation Letters vol 11 pp 961ndash9642012
[10] N G Alexopoulos and I E Rana ldquoMutual impedance compu-tation between printed dipolesrdquo IEEE Transactions on Antennasand Propagation vol 29 no 1 pp 106ndash111 1981
[11] R G Vaughan and J B Andersen ldquoAntenna diversity in mobilecommunicationsrdquo IEEE Transactions on Vehicular Technologyvol 36 no 4 pp 149ndash172 1987
[12] S Blanch J Romeu and I Corbella ldquoExact representation ofantenna system diversity performance from input parameterdescriptionrdquo Electronics Letters vol 39 no 9 pp 705ndash707 2003
[13] H Rhyu J Byun F J Harackiewicz et al ldquoMulti-band hybridantenna for ultra-thin mobile phone applicationsrdquo ElectronicsLetters vol 45 no 15 pp 773ndash774 2009
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
6 International Journal of Antennas and Propagation
collinearly arranging the E-fields of two antennas in the near-field region and obtaining diagonally orthogonal radiationpatterns
Acknowledgment
This research was conducted under a Research Grant fromKwangwoon University in 2013 and this work (Grant noC0015229) was supported by Business for Cooperative RampDbetween Industry Academy and Research Institute fundedKorea Small and Medium Business Administration in 2012
References
[1] G J Foschini ldquoLayered space-time architecture for wirelesscommunication in a fading environment when using multi-element antennasrdquo Bell Labs Technical Journal vol 1 no 2 pp41ndash59 1996
[2] C Y Chiu C H Cheng R D Murch and C R RowellldquoReduction ofmutual coupling between closely-packed antennaelementsrdquo IEEE Transactions on Antennas and Propagation vol55 no 6 pp 1732ndash1738 2007
[3] M S Sharawi S S Iqbal and Y S Faouri ldquoAn 800MHz 2x1compactMIMOantenna system for LTE handsetsrdquo IEEE Trans-actions onAntenna and Propagation vol 59 no 8 pp 3128ndash31312011
[4] A C K Mak C R Rowell and R D Murch ldquoIsolation en-hancement between two closely packed antennasrdquo IEEE Trans-actions on Antennas and Propagation vol 56 no 11 pp 3411ndash3419 2008
[5] ADiallo C Luxey P LThuc R Staraj andGKossiavas ldquoStudyand reduction of the mutual coupling between two mobilephonePIFAs operating in theDCS1800 andUMTSbandsrdquo IEEETransactions on Antenna and Propagation vol 54 no 11 pp3063ndash3074
[6] J Byun J H Jo and B Lee ldquoCompact dual-band diversityantenna for mobile handset applicationsrdquoMicrowave and Opti-cal Technology Letters vol 50 no 10 pp 2600ndash2604 2008
[7] B Yu C W Jung H Lee et al ldquoClosely mounted compactwideband diversity antenna for mobile phone applicationsrdquoInternational Journal of Antennas and Propagation vol 2012Article ID 798046 6 pages 2012
[8] H Bae F J Harackiewicz M J Park et al ldquoCompact mobilehandset MIMO antenna for LTE700 applicationsrdquo Microwaveand Optical Technology Letters vol 52 no 11 pp 2419ndash24222010
[9] B Kim Y Park H Wi et al ldquoIsolation enhancement of USBdongle MIMO antenna in LTE 700 band applicationsrdquo IEEEAntennas and Wireless Propagation Letters vol 11 pp 961ndash9642012
[10] N G Alexopoulos and I E Rana ldquoMutual impedance compu-tation between printed dipolesrdquo IEEE Transactions on Antennasand Propagation vol 29 no 1 pp 106ndash111 1981
[11] R G Vaughan and J B Andersen ldquoAntenna diversity in mobilecommunicationsrdquo IEEE Transactions on Vehicular Technologyvol 36 no 4 pp 149ndash172 1987
[12] S Blanch J Romeu and I Corbella ldquoExact representation ofantenna system diversity performance from input parameterdescriptionrdquo Electronics Letters vol 39 no 9 pp 705ndash707 2003
[13] H Rhyu J Byun F J Harackiewicz et al ldquoMulti-band hybridantenna for ultra-thin mobile phone applicationsrdquo ElectronicsLetters vol 45 no 15 pp 773ndash774 2009
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of