Hindawi Publishing CorporationActive and Passive Electronic ComponentsVolume 2013 Article ID 192018 5 pageshttpdxdoiorg1011552013192018
Research ArticleA Design of a Terahertz Microstrip Bandstop Filter withDefected Ground Structure
Arjun Kumar and M V Kartikeyan
Millimeter Wave Laboratory Department of Electronics and Computer Engineering Indian Institute of TechnologyRoorkee 247 667 India
Correspondence should be addressed to Arjun Kumar akdeciitrgmailcom
Received 22 February 2013 Accepted 18 September 2013
Academic Editor Krishnamachar Prasad
Copyright copy 2013 A Kumar and M V Kartikeyan This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited
A planarmicrostrip terahertz (THz) bandstop filter has been proposed with defected ground structure with high insertion loss (S21)
in a stopband of minus258 dB at 1436 THz The parameters of the circuit model have been extracted from the EM simulation resultsA dielectric substrate of Benzocyclobutene (BCB) is used to realize a compact bandstop filter using modified hexagonal dumbbell-shape defected ground structure (DB-DGS) In this paper a defected ground structure topology is used in a 1205824 50Ω microstripline at THz frequency range for compactness No article has been reported on the microstrip line at terahertz frequency regimeusing DGS topology The proposed filter can be used for sensing and detection in biomedical instruments in DNA testing Allthe simulationscosimulations are carried out using a full-wave EM simulator CST V9 Microwave Studio HFSS V10 and AgilentDesign Suite (ADS)
1 Introduction
THz frequency range spans from 01 to 100 THz in theelectromagnetic spectrumThis THz regime of EM spectrumhas been effectively exploited in a variety of applications suchas medical spectroscopy security space imaging and mea-surement of overlaid dielectric substrate [1 2] New trendsemerging in the development of technology in optical com-munication systems motivate the requirement of terahertztransmission lines and components [3] The THz technologyis slowly unfolding to mature to meet needs and applica-tion specific requirements Defected ground structures offercompact solutions for the design of microstrip antennas andother passive microwavemillimeter wave components [4]A lot of literature is available based on defected groundstructures for the size reduction of the microstrip filters [4ndash14] However at terahertz frequencies no considerable workhas been reported for the filter design using the defectedground structure (DGS) In this paper a modified hexagonaldumbbell-shaped DGSslot in the ground plane is employedin microstrip line at terahertz frequency regime to achievebandstop characteristics In this work a Benzocyclobuten(BCB) substrate is used for the filter design [15]
2 Properties of BCB Dielectric
BCB is a promising organic material which is showing stablepermittivity values and low loss over a broad frequencyrange [15]Themanufacturer [16] claims a dielectric constant120576
119903= 265 with a few percent variations between 10GHz
and 15 THz and the loss tangent of the dielectric BCB isalso varying between 00008 and 0002 within the frequencyinterval from 1MHz to 10GHz Additional data are also avail-able [16] in the frequency range from 400GHz to 1500GHzwhich confirm a stable dielectric behavior of the BCB on abroad frequency range However no specific electrical valuesare provided in the middle microwave range below 400GHz[17]
3 DGS Design Studies of THz Bandstop Filter
Various dumbbell-shaped defected ground structures (DB-DGS) are shown in Figure 1 in this paper various DB-DGShave been developed on a BCB substrate with height (ℎ) of11 120583m and the permittivity (120576
119903) of the substrate is 26 There
are two reasons for selecting BCB as the substrate [18] Firstit is because that BCB can maintain the value of relative
2 Active and Passive Electronic Components
L
Silver conducting strip
W
(a)
a a
g d
a
(b)
a
a
g d
a
a
(c)
r
dg
(d)
dg
r998400
(e)
k
dg
r998400
r998400998400
(f)
Figure 1 Various configurations of DB-DGS (a) top view of microstrip line (b) triangular DB-DGS (c) square DB-DGS (d) circular DB-DGS (e) hexagonal DB-DGS and (f) modified hexagonal DB-DGS
800 1000 1200 1400 1600minus30
minus25
minus20
minus15
minus10
minus5
0
S-parameter
(dB)
Frequency (GHz)
Modified hexagonal DB-DGSCircular DB-DGSTriangular DB-DGS
Square DB-DGSHexagonal DB-DGS
S21
Figure 2 Comparison of simulated S-parameter of all DB-DGS[22]
permittivity in THz and optical radiation frequency bandSecond the dielectric loss (the part of the insertion loss)of BCB can be considered as zero due to almost zero valueof the corresponding loss tangent (tan 120575) In this paper thedimensions of all the DB-DGS are mentioned in Table 1with the modified hexagonal DB-DGS with 50Ω microstripline having width of 29 120583m and thickness of 002 120583m Here
the silver is used for the ground plane and the conductingstrip [19]
4 A Comparative Bandstop Characteristics ofDB-DGS with the Proposed Modified Design
All the DB-DGS that have been simulated in the CSTMicrowave Studio EM full-wave simulator are shown inFigure 2 The modified hexagonal indicates a more sharptransition in comparison to all other DB-DGS It is clearfrom Table 2 that if the effective capacitance will increase thesharpness of filter will increase The 3-dB cut-off frequenciesfor all the DB-DGS are the same only the resonant peakwill change as per configuration of DB-DGS In Table 2 themodified hexagonal design has a more effective capacitancein comparison to other DB-DGS This effective capacitanceis responsible for the sharpness of the filter
The values of effective inductance and effective capaci-tance are calculated by the circuit extraction techniques usingthe following formulas [5ndash7]
119862 =
5119891
119888
120587 [119891
2
119900minus 119891
2
119888]
119901119891 (1)
119871 =
250
119862(120587119891
119900)
2119899119867 (2)
Sharpness factor =119891
119888
119891
119900
(3)
Active and Passive Electronic Components 3
S-parameters
S paramSP1Start = 800 GHzStop = 1600 GHzStep = 10 GHz
PortP1Num = 1
TermTerm1Num = 1Z = 50Ohm
LL1L = 820pHR =
CC1C = 150 fF
TermPort Term2
Num = 2P2
Num = 2 Z = 50Ohm+
+ +
minus minus
(a)
0
minus10
minus20
minus30
minus40
minus50
minus60
minus70
minus80
minus90
08 09 10 11 12 13 14 15 16Frequency (THz)
dB (S
(1 1
))dB
(S(2
1))
m2 m1
m2
m1
Freq = 1000 THz Freq = 1435 THzdB (S(2 1)) =minus80208dB (S(2 1)) =minus3017
(b)
Figure 3 (a) 119871-119862 equivalent circuit model (b) S-parameter characteristics by co-simulation in ADS [23]
5 Calculation of Various Losses for theProposed Design DB-DGS
As the frequency increases the losses also increase Herein this paper various losses are calculated for studying thebehavior of microstrip terahertz filter using a BCB substratewith height (ℎ) = 11 120583m permittivity (120576
119903) = 26 width of the
silver metal strip conductor (119882) = 29 120583m thickness of strip(119905)= 002120583m and length of the conducting strip (119871) = 50 120583mThese losses are conductor loss dielectric loss and radiationloss which are calculated by using the formulas given belowConductor Loss (see [20]) For the proposed DB-DGS inFigure 1(f) the conductor loss is 100 (nepersmeter) or20 dBmeter This is conductor loss is calculated by using (4)to (7) [20]
120572
119888=
119877
1015840
2 sdot 119885
119900
(4)
119877
1015840=
119877sh119882
(5)
119877sh =120588
120575
(6)
120575 =radic
2120588
2120587119891120583
0120583
119903
(7)
where 120572
119888is conductor loss 1198771015840 is the resistance of entire
strip 119877sh is sheet resistance of silver metal conductor 119882 isthe width of the silver metal conductor 119885
119900is characteristic
impedance of line 120575 is skin depth and 120588 is resistivity ofmetalDielectric Loss and Loss Tangent (see [15 21]) The attenuation120572 at 14 THz is calculated directly that is minus258 dB from thesimulated S-parameter and 120572
119888is calculated from (4) for silver
metal For the BCB at 14 THz the dielectric loss is 58 dB andthe loss tangent is 00002 which is calculated by using (8)
120572
119889= 120572 minus 120572
119888
tan 120575 =120582
119900
120587
sdot
120572
119889radic120576eff
120576
119903
sdot
120576
119903minus 1
120576eff minus 1
120576eff =120576
119903+ 1
2
+
120576
119903minus 1
2
[1 + 10
ℎ
119882
]
minus05
(8)
Here 120572119889is dielectric loss tan 120575 is loss tangent 120576
119903is relative
permittivity 120576eff is effective permittivity and ℎ is height of thesubstrateRadiation Loss at 14 THz (see [8]) The radiation loss iscalculated using simulated S-parameter of the proposed DB-DGS that is shown in Figure 1(f) The area of the proposedfilter is 87 times 50 120583m2 Consider
120578 = 1 minus
1003816
1003816
1003816
1003816
119878
11
1003816
1003816
1003816
1003816
2
minus
1003816
1003816
1003816
1003816
119878
21
1003816
1003816
1003816
1003816
2
(9)
Here at 14 THz the radiation loss is 022 or minus65 dB
6 119871-119862 Modelling and Cosimulation ofProposed DB-DGS
The 119871-119862 parallel resonator circuit has been designed for themodified defect in the ground plane by the circuit extractiontechniques [20] The extracted value of inductance (119871) is820times 10minus3 nH and the capacitance (119862) is 150 times 10minus3 pF calcu-lated by the formulas given in (1)-(2) which have been shownin Table 2This 119871-119862model is cosimulated in ADS2006AThesimulated results are shown in Figure 3 which are in goodagreement with the simulated results in CST MW Studio inFigure 4 for the modified hexagonal DB-DGS
7 Results and Discussion
The extracted value of inductor and the capacitance of thesimulation S-parameter results the equivalent circuit model
4 Active and Passive Electronic Components
Table 1 Dimensions of various design configurations
S no Design configuration of DB-DGS 119886 (120583m) 119892 (120583m) 119889 (120583m) 119903 or 1199031015840 (120583m) 119903
10158401015840 (120583m) 119896 (120583m)1 Circular mdash 2 12 46 mdash mdash2 Hexagonal mdash 2 12 31 mdash mdash3 Triangular 131 2 12 mdash mdash mdash4 Square 82 2 11 mdash mdash mdash5 Modified hexagonal DGS mdash 2 11 52 26 17
Table 2 Dimensions of various design configurations
S no Design configurationof DB-DGS
119891
119888= 3-dB
cut-off (GHz)119891
119900resonant
frequency (GHz)Inductance(119871) in nH
Capacitance(119862) in pF
Sharpnessfactor
1 Circular 1000 14586 843 times 10minus3 141 times 10minus3 0662 Hexagonal 1000 14479 834 times 10minus3 145 times 10minus3 073 Triangular 1000 14461 830 times 10minus3 146 times 10minus3 0714 Square 1000 14488 833 times 10minus3 144 times 10minus3 0725 Modified Hexagonal 1000 14362 820 times 10minus3 150 times 10minus3 077
800 1000 1200 1400 1600minus30
minus25
minus20
minus15
minus10
minus5
0
S-parameter
(dB)
Frequency (GHz)
S21
S21 in dB for modified DGS
Figure 4 Simulated S-parameter of modified hexagonal DB-DGS[22]
of DGS is designed in ADS and again it is simulatedthe simulated results of this equivalent circuit show betteragreement between the simulation results of S-parameters ofproposed design as shown in Figure 4 in both cases theresults are almost same In both the CST Microwave StudioV9 and Agilent ADS2006A the simulated results show thesame cut-off frequency which is approximately 1000 THz Atthis cut-off frequency the size of filter is in 120583m so the sizeof the proposed filter is very small and the total area of thisfilter is 87 times 50 120583m2 The various losses have been calculatedas insertion loss (119878
21) in stopband minus258 dB dielectric loss
is 58 dB conductor loss or attenuation is 20 dBmeter andradiation loss is 022
In Figure 5 the proposed modified hexagonal DB-DGSbandstop filter is cosimulated in various electromagnetic
800 1000 1200 1400 1600
0
Modified DGS simulated in CSTModified DGS simulated in HFSSCircuit simulated in ADS
Frequency (GHz)
minus80
minus60
minus40
minus20
S 21-parameter
(dB)
Figure 5 Comparison of the proposedmodifiedDB-DGS bandstopfilter in various EM simulated tools
(EM) simulation tools for the verification and validation ofthe proposed filter In all the cases the cuto-ff frequency andresonant frequencies are almost the same In case of HFSSsimulation the S-parameter is a little bit distorted But inall the way all results in EM simulation tools are in goodagreement For the simulation of proposed filter absorbingboundary condition has been used to reduce the radiationeffect
8 Conclusions
Many researchers are working on THz filter but no workis reported on filter design on THz frequency with DGS
Active and Passive Electronic Components 5
using microstrip An approach is developed in this paperand a microstrip bandstop filter has been designed at thecut-off frequency of 1000 THz with the insertion loss ofminus258 dB at 14 THz in a stopband no stub or stepped-impedance structure is used Only 50 ohm1205824microstrip linewith modified hexagonal-shaped DGS shows the bandstopcharacteristics at 1000 THz The simulated S-parameter isin excellent agreement with the calculated one especially inreflection coefficient and insertion loss in both simulator CSTMicrowave Studio V9 and ADS200A All the basic DB-DGShave been studied for terahertz frequency and their sharpnessis compared which is shown in Table 2 The modified DB-DGS is sharper than the other DB-DGS In the literature sofar no fabrication has been reported on microstrip filter atterahertz frequency For the validation the proposed filter issimulated in various EMwave simulators like CSTHFSS andADS After comparsion of all simulated results it was foundthat the results are in good agreement
References
[1] C F Kane and R R Krchnavek ldquoBenzocyclobutene opticalwaveguidesrdquo IEEE Photonics Technology Letters vol 7 no 5 pp535ndash537 1995
[2] C Wood J Cunningham C K Tiang et al ldquoMeasurementand simulation of the sensitivity of terahertz frequency rangepassive filter elements to overlaid dielectricsrdquo in Proceedingsof the 31st International Conference on Infrared and MillimeterWaves and 14th International Conference on Terahertz Electron-ics (IRMMW-THz rsquo06) p 423 Sanghai China September 2006
[3] K R Jha and G Singh ldquoAnalysis of narrow terahertz microstriptransmission-line onmultilayered substraterdquo Journal of Compu-tational Electronics vol 10 no 1-2 pp 186ndash194 2011
[4] A K Arya M V Kartikeyan and A Patnaik ldquoDefected groundstructure in the perspective of microstrip antennas a reviewrdquoFrequenz vol 64 no 5-6 pp 79ndash84 2010
[5] C-S Kim J-S Park D Ahn and J-B Lim ldquoA novel 1-Dperiodic defected ground structure for planar circuitsrdquo IEEEMicrowave and Wireless Components Letters vol 10 no 4 pp131ndash133 2000
[6] J S Lim C S Kim Y T Lee D Ahn and SNam ldquoAnew type oflow pass filter with defected ground structurerdquo in Proceedings ofthe 32nd EuropeanMicrowave Conference pp 32ndash36 September2002
[7] V Radisic YQian RCoccioli andT Itoh ldquoNovel 2-Dphotonicbandgap structure for microstrip linesrdquo IEEE Microwave andGuided Wave Letters vol 8 no 2 pp 69ndash71 1998
[8] H-M Kim and B Lee ldquoAnalysis of T-shaped Defected groundstructure (DGS) using closed-form expressionsrdquo in Proceedingsof the 3rd International Conference on Computational Elec-tromagnetics and Its Applications (ICCEA rsquo04) pp 496ndash499November 2004
[9] D Ahn J-S Park C-S Kim J Kim Y Qian and T Itoh ldquoAdesign of the low-pass filter using the novel microstrip defectedground structurerdquo IEEE Transactions on MicrowaveTheory andTechniques vol 49 no 1 pp 86ndash93 2001
[10] J-S Lim C-S Kim Y-T Lee D Ahn and S Nam ldquoDesignof lowpass filters using defected ground structure and compen-sated microstrip linerdquo Electronics Letters vol 38 no 22 pp1357ndash1358 2002
[11] A B Abdel-Rahman A K Verma A Boutejdar and A SOmar ldquoControl of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground planerdquo IEEE Transactions onMicrowave Theory and Techniques vol 52 no 3 pp 1008ndash10132004
[12] A Kumar and A K Verma ldquoDesign of compact seven poleslow pass filter using defected ground structurerdquo in Proceedingsof the International Conference on Emerging Trends in Electronicand Photonic Devices amp Systems (ELECTRO rsquo09) pp 349ndash352December 2009
[13] P Kumar RMahmood J Kishor andA K Shrivastav ldquoControlof band stop responses of very compact size microstrip filterof improved Q factor amp sharp transition by using hexagonaltransmetal DGSrdquo in Proceedings of the International Conferenceon Emerging Trends in Electronic and Photonic Devices ampSystems (ELECTRO rsquo09) pp 383ndash386 December 2009
[14] L H Weng Y C Guo X W Shi and X Q Chen ldquoAnoverview of defected ground structurerdquo Progress in Electromag-netic Research B vol 7 pp 173ndash189 2008
[15] S Costanzo I Venneri G D Massa and A Borgia ldquoBenzo-cyclobutene as Substrate Material for planar millimeter-wavestructures dielectric characterization and applicationrdquo Journalof Infrared Millimeter and Terahertz Waves vol 31 no 1 pp66ndash77 2010
[16] Dow Chemical Cyclotene 3000 Series Advanced ElectronResins httpwwwdowcomcyclotene
[17] S Costanzo A Borgia I Venneri and G Di Massa ldquoMilli-meter-Waves structures on benzocyclobutene dielectric sub-straterdquo Radioengineering vol 20 no 4 pp 785ndash789 2011
[18] L-M Si Y Yong H-J Sun and L Xin ldquoCharacterizationand application of planar terahertz narrow bandpass filter withmetamaterial resonatorsrdquo in Proceedings of the InternationalWorkshop on Metamaterials (META rsquo08) pp 351ndash354 Novem-ber 2008
[19] A Hosseini H Nejati and Y Massoud ldquoDesign of opticalrange third-order chebychev low-pass filter using plasmonicnanostrip waveguidesrdquo in Proceedings of the 50th MidwestSymposium on Circuits and Systems (MWSCAS rsquo07) pp 1245ndash1248 August 2007
[20] E J Denlinger ldquoLosses of microstrip linesrdquo IEEE TransactionsonMicrowaveTheory and Techniques vol 28 no 6 pp 513ndash5221980
[21] M V Schneider ldquoMicrostrip lines for microwave integratedcircuitsrdquo The Bell System Technical Journal vol 48 pp 1421ndash1444 1969
[22] Agilent ADS 2006[23] Microwave Studio V9
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2 Active and Passive Electronic Components
L
Silver conducting strip
W
(a)
a a
g d
a
(b)
a
a
g d
a
a
(c)
r
dg
(d)
dg
r998400
(e)
k
dg
r998400
r998400998400
(f)
Figure 1 Various configurations of DB-DGS (a) top view of microstrip line (b) triangular DB-DGS (c) square DB-DGS (d) circular DB-DGS (e) hexagonal DB-DGS and (f) modified hexagonal DB-DGS
800 1000 1200 1400 1600minus30
minus25
minus20
minus15
minus10
minus5
0
S-parameter
(dB)
Frequency (GHz)
Modified hexagonal DB-DGSCircular DB-DGSTriangular DB-DGS
Square DB-DGSHexagonal DB-DGS
S21
Figure 2 Comparison of simulated S-parameter of all DB-DGS[22]
permittivity in THz and optical radiation frequency bandSecond the dielectric loss (the part of the insertion loss)of BCB can be considered as zero due to almost zero valueof the corresponding loss tangent (tan 120575) In this paper thedimensions of all the DB-DGS are mentioned in Table 1with the modified hexagonal DB-DGS with 50Ω microstripline having width of 29 120583m and thickness of 002 120583m Here
the silver is used for the ground plane and the conductingstrip [19]
4 A Comparative Bandstop Characteristics ofDB-DGS with the Proposed Modified Design
All the DB-DGS that have been simulated in the CSTMicrowave Studio EM full-wave simulator are shown inFigure 2 The modified hexagonal indicates a more sharptransition in comparison to all other DB-DGS It is clearfrom Table 2 that if the effective capacitance will increase thesharpness of filter will increase The 3-dB cut-off frequenciesfor all the DB-DGS are the same only the resonant peakwill change as per configuration of DB-DGS In Table 2 themodified hexagonal design has a more effective capacitancein comparison to other DB-DGS This effective capacitanceis responsible for the sharpness of the filter
The values of effective inductance and effective capaci-tance are calculated by the circuit extraction techniques usingthe following formulas [5ndash7]
119862 =
5119891
119888
120587 [119891
2
119900minus 119891
2
119888]
119901119891 (1)
119871 =
250
119862(120587119891
119900)
2119899119867 (2)
Sharpness factor =119891
119888
119891
119900
(3)
Active and Passive Electronic Components 3
S-parameters
S paramSP1Start = 800 GHzStop = 1600 GHzStep = 10 GHz
PortP1Num = 1
TermTerm1Num = 1Z = 50Ohm
LL1L = 820pHR =
CC1C = 150 fF
TermPort Term2
Num = 2P2
Num = 2 Z = 50Ohm+
+ +
minus minus
(a)
0
minus10
minus20
minus30
minus40
minus50
minus60
minus70
minus80
minus90
08 09 10 11 12 13 14 15 16Frequency (THz)
dB (S
(1 1
))dB
(S(2
1))
m2 m1
m2
m1
Freq = 1000 THz Freq = 1435 THzdB (S(2 1)) =minus80208dB (S(2 1)) =minus3017
(b)
Figure 3 (a) 119871-119862 equivalent circuit model (b) S-parameter characteristics by co-simulation in ADS [23]
5 Calculation of Various Losses for theProposed Design DB-DGS
As the frequency increases the losses also increase Herein this paper various losses are calculated for studying thebehavior of microstrip terahertz filter using a BCB substratewith height (ℎ) = 11 120583m permittivity (120576
119903) = 26 width of the
silver metal strip conductor (119882) = 29 120583m thickness of strip(119905)= 002120583m and length of the conducting strip (119871) = 50 120583mThese losses are conductor loss dielectric loss and radiationloss which are calculated by using the formulas given belowConductor Loss (see [20]) For the proposed DB-DGS inFigure 1(f) the conductor loss is 100 (nepersmeter) or20 dBmeter This is conductor loss is calculated by using (4)to (7) [20]
120572
119888=
119877
1015840
2 sdot 119885
119900
(4)
119877
1015840=
119877sh119882
(5)
119877sh =120588
120575
(6)
120575 =radic
2120588
2120587119891120583
0120583
119903
(7)
where 120572
119888is conductor loss 1198771015840 is the resistance of entire
strip 119877sh is sheet resistance of silver metal conductor 119882 isthe width of the silver metal conductor 119885
119900is characteristic
impedance of line 120575 is skin depth and 120588 is resistivity ofmetalDielectric Loss and Loss Tangent (see [15 21]) The attenuation120572 at 14 THz is calculated directly that is minus258 dB from thesimulated S-parameter and 120572
119888is calculated from (4) for silver
metal For the BCB at 14 THz the dielectric loss is 58 dB andthe loss tangent is 00002 which is calculated by using (8)
120572
119889= 120572 minus 120572
119888
tan 120575 =120582
119900
120587
sdot
120572
119889radic120576eff
120576
119903
sdot
120576
119903minus 1
120576eff minus 1
120576eff =120576
119903+ 1
2
+
120576
119903minus 1
2
[1 + 10
ℎ
119882
]
minus05
(8)
Here 120572119889is dielectric loss tan 120575 is loss tangent 120576
119903is relative
permittivity 120576eff is effective permittivity and ℎ is height of thesubstrateRadiation Loss at 14 THz (see [8]) The radiation loss iscalculated using simulated S-parameter of the proposed DB-DGS that is shown in Figure 1(f) The area of the proposedfilter is 87 times 50 120583m2 Consider
120578 = 1 minus
1003816
1003816
1003816
1003816
119878
11
1003816
1003816
1003816
1003816
2
minus
1003816
1003816
1003816
1003816
119878
21
1003816
1003816
1003816
1003816
2
(9)
Here at 14 THz the radiation loss is 022 or minus65 dB
6 119871-119862 Modelling and Cosimulation ofProposed DB-DGS
The 119871-119862 parallel resonator circuit has been designed for themodified defect in the ground plane by the circuit extractiontechniques [20] The extracted value of inductance (119871) is820times 10minus3 nH and the capacitance (119862) is 150 times 10minus3 pF calcu-lated by the formulas given in (1)-(2) which have been shownin Table 2This 119871-119862model is cosimulated in ADS2006AThesimulated results are shown in Figure 3 which are in goodagreement with the simulated results in CST MW Studio inFigure 4 for the modified hexagonal DB-DGS
7 Results and Discussion
The extracted value of inductor and the capacitance of thesimulation S-parameter results the equivalent circuit model
4 Active and Passive Electronic Components
Table 1 Dimensions of various design configurations
S no Design configuration of DB-DGS 119886 (120583m) 119892 (120583m) 119889 (120583m) 119903 or 1199031015840 (120583m) 119903
10158401015840 (120583m) 119896 (120583m)1 Circular mdash 2 12 46 mdash mdash2 Hexagonal mdash 2 12 31 mdash mdash3 Triangular 131 2 12 mdash mdash mdash4 Square 82 2 11 mdash mdash mdash5 Modified hexagonal DGS mdash 2 11 52 26 17
Table 2 Dimensions of various design configurations
S no Design configurationof DB-DGS
119891
119888= 3-dB
cut-off (GHz)119891
119900resonant
frequency (GHz)Inductance(119871) in nH
Capacitance(119862) in pF
Sharpnessfactor
1 Circular 1000 14586 843 times 10minus3 141 times 10minus3 0662 Hexagonal 1000 14479 834 times 10minus3 145 times 10minus3 073 Triangular 1000 14461 830 times 10minus3 146 times 10minus3 0714 Square 1000 14488 833 times 10minus3 144 times 10minus3 0725 Modified Hexagonal 1000 14362 820 times 10minus3 150 times 10minus3 077
800 1000 1200 1400 1600minus30
minus25
minus20
minus15
minus10
minus5
0
S-parameter
(dB)
Frequency (GHz)
S21
S21 in dB for modified DGS
Figure 4 Simulated S-parameter of modified hexagonal DB-DGS[22]
of DGS is designed in ADS and again it is simulatedthe simulated results of this equivalent circuit show betteragreement between the simulation results of S-parameters ofproposed design as shown in Figure 4 in both cases theresults are almost same In both the CST Microwave StudioV9 and Agilent ADS2006A the simulated results show thesame cut-off frequency which is approximately 1000 THz Atthis cut-off frequency the size of filter is in 120583m so the sizeof the proposed filter is very small and the total area of thisfilter is 87 times 50 120583m2 The various losses have been calculatedas insertion loss (119878
21) in stopband minus258 dB dielectric loss
is 58 dB conductor loss or attenuation is 20 dBmeter andradiation loss is 022
In Figure 5 the proposed modified hexagonal DB-DGSbandstop filter is cosimulated in various electromagnetic
800 1000 1200 1400 1600
0
Modified DGS simulated in CSTModified DGS simulated in HFSSCircuit simulated in ADS
Frequency (GHz)
minus80
minus60
minus40
minus20
S 21-parameter
(dB)
Figure 5 Comparison of the proposedmodifiedDB-DGS bandstopfilter in various EM simulated tools
(EM) simulation tools for the verification and validation ofthe proposed filter In all the cases the cuto-ff frequency andresonant frequencies are almost the same In case of HFSSsimulation the S-parameter is a little bit distorted But inall the way all results in EM simulation tools are in goodagreement For the simulation of proposed filter absorbingboundary condition has been used to reduce the radiationeffect
8 Conclusions
Many researchers are working on THz filter but no workis reported on filter design on THz frequency with DGS
Active and Passive Electronic Components 5
using microstrip An approach is developed in this paperand a microstrip bandstop filter has been designed at thecut-off frequency of 1000 THz with the insertion loss ofminus258 dB at 14 THz in a stopband no stub or stepped-impedance structure is used Only 50 ohm1205824microstrip linewith modified hexagonal-shaped DGS shows the bandstopcharacteristics at 1000 THz The simulated S-parameter isin excellent agreement with the calculated one especially inreflection coefficient and insertion loss in both simulator CSTMicrowave Studio V9 and ADS200A All the basic DB-DGShave been studied for terahertz frequency and their sharpnessis compared which is shown in Table 2 The modified DB-DGS is sharper than the other DB-DGS In the literature sofar no fabrication has been reported on microstrip filter atterahertz frequency For the validation the proposed filter issimulated in various EMwave simulators like CSTHFSS andADS After comparsion of all simulated results it was foundthat the results are in good agreement
References
[1] C F Kane and R R Krchnavek ldquoBenzocyclobutene opticalwaveguidesrdquo IEEE Photonics Technology Letters vol 7 no 5 pp535ndash537 1995
[2] C Wood J Cunningham C K Tiang et al ldquoMeasurementand simulation of the sensitivity of terahertz frequency rangepassive filter elements to overlaid dielectricsrdquo in Proceedingsof the 31st International Conference on Infrared and MillimeterWaves and 14th International Conference on Terahertz Electron-ics (IRMMW-THz rsquo06) p 423 Sanghai China September 2006
[3] K R Jha and G Singh ldquoAnalysis of narrow terahertz microstriptransmission-line onmultilayered substraterdquo Journal of Compu-tational Electronics vol 10 no 1-2 pp 186ndash194 2011
[4] A K Arya M V Kartikeyan and A Patnaik ldquoDefected groundstructure in the perspective of microstrip antennas a reviewrdquoFrequenz vol 64 no 5-6 pp 79ndash84 2010
[5] C-S Kim J-S Park D Ahn and J-B Lim ldquoA novel 1-Dperiodic defected ground structure for planar circuitsrdquo IEEEMicrowave and Wireless Components Letters vol 10 no 4 pp131ndash133 2000
[6] J S Lim C S Kim Y T Lee D Ahn and SNam ldquoAnew type oflow pass filter with defected ground structurerdquo in Proceedings ofthe 32nd EuropeanMicrowave Conference pp 32ndash36 September2002
[7] V Radisic YQian RCoccioli andT Itoh ldquoNovel 2-Dphotonicbandgap structure for microstrip linesrdquo IEEE Microwave andGuided Wave Letters vol 8 no 2 pp 69ndash71 1998
[8] H-M Kim and B Lee ldquoAnalysis of T-shaped Defected groundstructure (DGS) using closed-form expressionsrdquo in Proceedingsof the 3rd International Conference on Computational Elec-tromagnetics and Its Applications (ICCEA rsquo04) pp 496ndash499November 2004
[9] D Ahn J-S Park C-S Kim J Kim Y Qian and T Itoh ldquoAdesign of the low-pass filter using the novel microstrip defectedground structurerdquo IEEE Transactions on MicrowaveTheory andTechniques vol 49 no 1 pp 86ndash93 2001
[10] J-S Lim C-S Kim Y-T Lee D Ahn and S Nam ldquoDesignof lowpass filters using defected ground structure and compen-sated microstrip linerdquo Electronics Letters vol 38 no 22 pp1357ndash1358 2002
[11] A B Abdel-Rahman A K Verma A Boutejdar and A SOmar ldquoControl of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground planerdquo IEEE Transactions onMicrowave Theory and Techniques vol 52 no 3 pp 1008ndash10132004
[12] A Kumar and A K Verma ldquoDesign of compact seven poleslow pass filter using defected ground structurerdquo in Proceedingsof the International Conference on Emerging Trends in Electronicand Photonic Devices amp Systems (ELECTRO rsquo09) pp 349ndash352December 2009
[13] P Kumar RMahmood J Kishor andA K Shrivastav ldquoControlof band stop responses of very compact size microstrip filterof improved Q factor amp sharp transition by using hexagonaltransmetal DGSrdquo in Proceedings of the International Conferenceon Emerging Trends in Electronic and Photonic Devices ampSystems (ELECTRO rsquo09) pp 383ndash386 December 2009
[14] L H Weng Y C Guo X W Shi and X Q Chen ldquoAnoverview of defected ground structurerdquo Progress in Electromag-netic Research B vol 7 pp 173ndash189 2008
[15] S Costanzo I Venneri G D Massa and A Borgia ldquoBenzo-cyclobutene as Substrate Material for planar millimeter-wavestructures dielectric characterization and applicationrdquo Journalof Infrared Millimeter and Terahertz Waves vol 31 no 1 pp66ndash77 2010
[16] Dow Chemical Cyclotene 3000 Series Advanced ElectronResins httpwwwdowcomcyclotene
[17] S Costanzo A Borgia I Venneri and G Di Massa ldquoMilli-meter-Waves structures on benzocyclobutene dielectric sub-straterdquo Radioengineering vol 20 no 4 pp 785ndash789 2011
[18] L-M Si Y Yong H-J Sun and L Xin ldquoCharacterizationand application of planar terahertz narrow bandpass filter withmetamaterial resonatorsrdquo in Proceedings of the InternationalWorkshop on Metamaterials (META rsquo08) pp 351ndash354 Novem-ber 2008
[19] A Hosseini H Nejati and Y Massoud ldquoDesign of opticalrange third-order chebychev low-pass filter using plasmonicnanostrip waveguidesrdquo in Proceedings of the 50th MidwestSymposium on Circuits and Systems (MWSCAS rsquo07) pp 1245ndash1248 August 2007
[20] E J Denlinger ldquoLosses of microstrip linesrdquo IEEE TransactionsonMicrowaveTheory and Techniques vol 28 no 6 pp 513ndash5221980
[21] M V Schneider ldquoMicrostrip lines for microwave integratedcircuitsrdquo The Bell System Technical Journal vol 48 pp 1421ndash1444 1969
[22] Agilent ADS 2006[23] Microwave Studio V9
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
Active and Passive Electronic Components 3
S-parameters
S paramSP1Start = 800 GHzStop = 1600 GHzStep = 10 GHz
PortP1Num = 1
TermTerm1Num = 1Z = 50Ohm
LL1L = 820pHR =
CC1C = 150 fF
TermPort Term2
Num = 2P2
Num = 2 Z = 50Ohm+
+ +
minus minus
(a)
0
minus10
minus20
minus30
minus40
minus50
minus60
minus70
minus80
minus90
08 09 10 11 12 13 14 15 16Frequency (THz)
dB (S
(1 1
))dB
(S(2
1))
m2 m1
m2
m1
Freq = 1000 THz Freq = 1435 THzdB (S(2 1)) =minus80208dB (S(2 1)) =minus3017
(b)
Figure 3 (a) 119871-119862 equivalent circuit model (b) S-parameter characteristics by co-simulation in ADS [23]
5 Calculation of Various Losses for theProposed Design DB-DGS
As the frequency increases the losses also increase Herein this paper various losses are calculated for studying thebehavior of microstrip terahertz filter using a BCB substratewith height (ℎ) = 11 120583m permittivity (120576
119903) = 26 width of the
silver metal strip conductor (119882) = 29 120583m thickness of strip(119905)= 002120583m and length of the conducting strip (119871) = 50 120583mThese losses are conductor loss dielectric loss and radiationloss which are calculated by using the formulas given belowConductor Loss (see [20]) For the proposed DB-DGS inFigure 1(f) the conductor loss is 100 (nepersmeter) or20 dBmeter This is conductor loss is calculated by using (4)to (7) [20]
120572
119888=
119877
1015840
2 sdot 119885
119900
(4)
119877
1015840=
119877sh119882
(5)
119877sh =120588
120575
(6)
120575 =radic
2120588
2120587119891120583
0120583
119903
(7)
where 120572
119888is conductor loss 1198771015840 is the resistance of entire
strip 119877sh is sheet resistance of silver metal conductor 119882 isthe width of the silver metal conductor 119885
119900is characteristic
impedance of line 120575 is skin depth and 120588 is resistivity ofmetalDielectric Loss and Loss Tangent (see [15 21]) The attenuation120572 at 14 THz is calculated directly that is minus258 dB from thesimulated S-parameter and 120572
119888is calculated from (4) for silver
metal For the BCB at 14 THz the dielectric loss is 58 dB andthe loss tangent is 00002 which is calculated by using (8)
120572
119889= 120572 minus 120572
119888
tan 120575 =120582
119900
120587
sdot
120572
119889radic120576eff
120576
119903
sdot
120576
119903minus 1
120576eff minus 1
120576eff =120576
119903+ 1
2
+
120576
119903minus 1
2
[1 + 10
ℎ
119882
]
minus05
(8)
Here 120572119889is dielectric loss tan 120575 is loss tangent 120576
119903is relative
permittivity 120576eff is effective permittivity and ℎ is height of thesubstrateRadiation Loss at 14 THz (see [8]) The radiation loss iscalculated using simulated S-parameter of the proposed DB-DGS that is shown in Figure 1(f) The area of the proposedfilter is 87 times 50 120583m2 Consider
120578 = 1 minus
1003816
1003816
1003816
1003816
119878
11
1003816
1003816
1003816
1003816
2
minus
1003816
1003816
1003816
1003816
119878
21
1003816
1003816
1003816
1003816
2
(9)
Here at 14 THz the radiation loss is 022 or minus65 dB
6 119871-119862 Modelling and Cosimulation ofProposed DB-DGS
The 119871-119862 parallel resonator circuit has been designed for themodified defect in the ground plane by the circuit extractiontechniques [20] The extracted value of inductance (119871) is820times 10minus3 nH and the capacitance (119862) is 150 times 10minus3 pF calcu-lated by the formulas given in (1)-(2) which have been shownin Table 2This 119871-119862model is cosimulated in ADS2006AThesimulated results are shown in Figure 3 which are in goodagreement with the simulated results in CST MW Studio inFigure 4 for the modified hexagonal DB-DGS
7 Results and Discussion
The extracted value of inductor and the capacitance of thesimulation S-parameter results the equivalent circuit model
4 Active and Passive Electronic Components
Table 1 Dimensions of various design configurations
S no Design configuration of DB-DGS 119886 (120583m) 119892 (120583m) 119889 (120583m) 119903 or 1199031015840 (120583m) 119903
10158401015840 (120583m) 119896 (120583m)1 Circular mdash 2 12 46 mdash mdash2 Hexagonal mdash 2 12 31 mdash mdash3 Triangular 131 2 12 mdash mdash mdash4 Square 82 2 11 mdash mdash mdash5 Modified hexagonal DGS mdash 2 11 52 26 17
Table 2 Dimensions of various design configurations
S no Design configurationof DB-DGS
119891
119888= 3-dB
cut-off (GHz)119891
119900resonant
frequency (GHz)Inductance(119871) in nH
Capacitance(119862) in pF
Sharpnessfactor
1 Circular 1000 14586 843 times 10minus3 141 times 10minus3 0662 Hexagonal 1000 14479 834 times 10minus3 145 times 10minus3 073 Triangular 1000 14461 830 times 10minus3 146 times 10minus3 0714 Square 1000 14488 833 times 10minus3 144 times 10minus3 0725 Modified Hexagonal 1000 14362 820 times 10minus3 150 times 10minus3 077
800 1000 1200 1400 1600minus30
minus25
minus20
minus15
minus10
minus5
0
S-parameter
(dB)
Frequency (GHz)
S21
S21 in dB for modified DGS
Figure 4 Simulated S-parameter of modified hexagonal DB-DGS[22]
of DGS is designed in ADS and again it is simulatedthe simulated results of this equivalent circuit show betteragreement between the simulation results of S-parameters ofproposed design as shown in Figure 4 in both cases theresults are almost same In both the CST Microwave StudioV9 and Agilent ADS2006A the simulated results show thesame cut-off frequency which is approximately 1000 THz Atthis cut-off frequency the size of filter is in 120583m so the sizeof the proposed filter is very small and the total area of thisfilter is 87 times 50 120583m2 The various losses have been calculatedas insertion loss (119878
21) in stopband minus258 dB dielectric loss
is 58 dB conductor loss or attenuation is 20 dBmeter andradiation loss is 022
In Figure 5 the proposed modified hexagonal DB-DGSbandstop filter is cosimulated in various electromagnetic
800 1000 1200 1400 1600
0
Modified DGS simulated in CSTModified DGS simulated in HFSSCircuit simulated in ADS
Frequency (GHz)
minus80
minus60
minus40
minus20
S 21-parameter
(dB)
Figure 5 Comparison of the proposedmodifiedDB-DGS bandstopfilter in various EM simulated tools
(EM) simulation tools for the verification and validation ofthe proposed filter In all the cases the cuto-ff frequency andresonant frequencies are almost the same In case of HFSSsimulation the S-parameter is a little bit distorted But inall the way all results in EM simulation tools are in goodagreement For the simulation of proposed filter absorbingboundary condition has been used to reduce the radiationeffect
8 Conclusions
Many researchers are working on THz filter but no workis reported on filter design on THz frequency with DGS
Active and Passive Electronic Components 5
using microstrip An approach is developed in this paperand a microstrip bandstop filter has been designed at thecut-off frequency of 1000 THz with the insertion loss ofminus258 dB at 14 THz in a stopband no stub or stepped-impedance structure is used Only 50 ohm1205824microstrip linewith modified hexagonal-shaped DGS shows the bandstopcharacteristics at 1000 THz The simulated S-parameter isin excellent agreement with the calculated one especially inreflection coefficient and insertion loss in both simulator CSTMicrowave Studio V9 and ADS200A All the basic DB-DGShave been studied for terahertz frequency and their sharpnessis compared which is shown in Table 2 The modified DB-DGS is sharper than the other DB-DGS In the literature sofar no fabrication has been reported on microstrip filter atterahertz frequency For the validation the proposed filter issimulated in various EMwave simulators like CSTHFSS andADS After comparsion of all simulated results it was foundthat the results are in good agreement
References
[1] C F Kane and R R Krchnavek ldquoBenzocyclobutene opticalwaveguidesrdquo IEEE Photonics Technology Letters vol 7 no 5 pp535ndash537 1995
[2] C Wood J Cunningham C K Tiang et al ldquoMeasurementand simulation of the sensitivity of terahertz frequency rangepassive filter elements to overlaid dielectricsrdquo in Proceedingsof the 31st International Conference on Infrared and MillimeterWaves and 14th International Conference on Terahertz Electron-ics (IRMMW-THz rsquo06) p 423 Sanghai China September 2006
[3] K R Jha and G Singh ldquoAnalysis of narrow terahertz microstriptransmission-line onmultilayered substraterdquo Journal of Compu-tational Electronics vol 10 no 1-2 pp 186ndash194 2011
[4] A K Arya M V Kartikeyan and A Patnaik ldquoDefected groundstructure in the perspective of microstrip antennas a reviewrdquoFrequenz vol 64 no 5-6 pp 79ndash84 2010
[5] C-S Kim J-S Park D Ahn and J-B Lim ldquoA novel 1-Dperiodic defected ground structure for planar circuitsrdquo IEEEMicrowave and Wireless Components Letters vol 10 no 4 pp131ndash133 2000
[6] J S Lim C S Kim Y T Lee D Ahn and SNam ldquoAnew type oflow pass filter with defected ground structurerdquo in Proceedings ofthe 32nd EuropeanMicrowave Conference pp 32ndash36 September2002
[7] V Radisic YQian RCoccioli andT Itoh ldquoNovel 2-Dphotonicbandgap structure for microstrip linesrdquo IEEE Microwave andGuided Wave Letters vol 8 no 2 pp 69ndash71 1998
[8] H-M Kim and B Lee ldquoAnalysis of T-shaped Defected groundstructure (DGS) using closed-form expressionsrdquo in Proceedingsof the 3rd International Conference on Computational Elec-tromagnetics and Its Applications (ICCEA rsquo04) pp 496ndash499November 2004
[9] D Ahn J-S Park C-S Kim J Kim Y Qian and T Itoh ldquoAdesign of the low-pass filter using the novel microstrip defectedground structurerdquo IEEE Transactions on MicrowaveTheory andTechniques vol 49 no 1 pp 86ndash93 2001
[10] J-S Lim C-S Kim Y-T Lee D Ahn and S Nam ldquoDesignof lowpass filters using defected ground structure and compen-sated microstrip linerdquo Electronics Letters vol 38 no 22 pp1357ndash1358 2002
[11] A B Abdel-Rahman A K Verma A Boutejdar and A SOmar ldquoControl of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground planerdquo IEEE Transactions onMicrowave Theory and Techniques vol 52 no 3 pp 1008ndash10132004
[12] A Kumar and A K Verma ldquoDesign of compact seven poleslow pass filter using defected ground structurerdquo in Proceedingsof the International Conference on Emerging Trends in Electronicand Photonic Devices amp Systems (ELECTRO rsquo09) pp 349ndash352December 2009
[13] P Kumar RMahmood J Kishor andA K Shrivastav ldquoControlof band stop responses of very compact size microstrip filterof improved Q factor amp sharp transition by using hexagonaltransmetal DGSrdquo in Proceedings of the International Conferenceon Emerging Trends in Electronic and Photonic Devices ampSystems (ELECTRO rsquo09) pp 383ndash386 December 2009
[14] L H Weng Y C Guo X W Shi and X Q Chen ldquoAnoverview of defected ground structurerdquo Progress in Electromag-netic Research B vol 7 pp 173ndash189 2008
[15] S Costanzo I Venneri G D Massa and A Borgia ldquoBenzo-cyclobutene as Substrate Material for planar millimeter-wavestructures dielectric characterization and applicationrdquo Journalof Infrared Millimeter and Terahertz Waves vol 31 no 1 pp66ndash77 2010
[16] Dow Chemical Cyclotene 3000 Series Advanced ElectronResins httpwwwdowcomcyclotene
[17] S Costanzo A Borgia I Venneri and G Di Massa ldquoMilli-meter-Waves structures on benzocyclobutene dielectric sub-straterdquo Radioengineering vol 20 no 4 pp 785ndash789 2011
[18] L-M Si Y Yong H-J Sun and L Xin ldquoCharacterizationand application of planar terahertz narrow bandpass filter withmetamaterial resonatorsrdquo in Proceedings of the InternationalWorkshop on Metamaterials (META rsquo08) pp 351ndash354 Novem-ber 2008
[19] A Hosseini H Nejati and Y Massoud ldquoDesign of opticalrange third-order chebychev low-pass filter using plasmonicnanostrip waveguidesrdquo in Proceedings of the 50th MidwestSymposium on Circuits and Systems (MWSCAS rsquo07) pp 1245ndash1248 August 2007
[20] E J Denlinger ldquoLosses of microstrip linesrdquo IEEE TransactionsonMicrowaveTheory and Techniques vol 28 no 6 pp 513ndash5221980
[21] M V Schneider ldquoMicrostrip lines for microwave integratedcircuitsrdquo The Bell System Technical Journal vol 48 pp 1421ndash1444 1969
[22] Agilent ADS 2006[23] Microwave Studio V9
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 Active and Passive Electronic Components
Table 1 Dimensions of various design configurations
S no Design configuration of DB-DGS 119886 (120583m) 119892 (120583m) 119889 (120583m) 119903 or 1199031015840 (120583m) 119903
10158401015840 (120583m) 119896 (120583m)1 Circular mdash 2 12 46 mdash mdash2 Hexagonal mdash 2 12 31 mdash mdash3 Triangular 131 2 12 mdash mdash mdash4 Square 82 2 11 mdash mdash mdash5 Modified hexagonal DGS mdash 2 11 52 26 17
Table 2 Dimensions of various design configurations
S no Design configurationof DB-DGS
119891
119888= 3-dB
cut-off (GHz)119891
119900resonant
frequency (GHz)Inductance(119871) in nH
Capacitance(119862) in pF
Sharpnessfactor
1 Circular 1000 14586 843 times 10minus3 141 times 10minus3 0662 Hexagonal 1000 14479 834 times 10minus3 145 times 10minus3 073 Triangular 1000 14461 830 times 10minus3 146 times 10minus3 0714 Square 1000 14488 833 times 10minus3 144 times 10minus3 0725 Modified Hexagonal 1000 14362 820 times 10minus3 150 times 10minus3 077
800 1000 1200 1400 1600minus30
minus25
minus20
minus15
minus10
minus5
0
S-parameter
(dB)
Frequency (GHz)
S21
S21 in dB for modified DGS
Figure 4 Simulated S-parameter of modified hexagonal DB-DGS[22]
of DGS is designed in ADS and again it is simulatedthe simulated results of this equivalent circuit show betteragreement between the simulation results of S-parameters ofproposed design as shown in Figure 4 in both cases theresults are almost same In both the CST Microwave StudioV9 and Agilent ADS2006A the simulated results show thesame cut-off frequency which is approximately 1000 THz Atthis cut-off frequency the size of filter is in 120583m so the sizeof the proposed filter is very small and the total area of thisfilter is 87 times 50 120583m2 The various losses have been calculatedas insertion loss (119878
21) in stopband minus258 dB dielectric loss
is 58 dB conductor loss or attenuation is 20 dBmeter andradiation loss is 022
In Figure 5 the proposed modified hexagonal DB-DGSbandstop filter is cosimulated in various electromagnetic
800 1000 1200 1400 1600
0
Modified DGS simulated in CSTModified DGS simulated in HFSSCircuit simulated in ADS
Frequency (GHz)
minus80
minus60
minus40
minus20
S 21-parameter
(dB)
Figure 5 Comparison of the proposedmodifiedDB-DGS bandstopfilter in various EM simulated tools
(EM) simulation tools for the verification and validation ofthe proposed filter In all the cases the cuto-ff frequency andresonant frequencies are almost the same In case of HFSSsimulation the S-parameter is a little bit distorted But inall the way all results in EM simulation tools are in goodagreement For the simulation of proposed filter absorbingboundary condition has been used to reduce the radiationeffect
8 Conclusions
Many researchers are working on THz filter but no workis reported on filter design on THz frequency with DGS
Active and Passive Electronic Components 5
using microstrip An approach is developed in this paperand a microstrip bandstop filter has been designed at thecut-off frequency of 1000 THz with the insertion loss ofminus258 dB at 14 THz in a stopband no stub or stepped-impedance structure is used Only 50 ohm1205824microstrip linewith modified hexagonal-shaped DGS shows the bandstopcharacteristics at 1000 THz The simulated S-parameter isin excellent agreement with the calculated one especially inreflection coefficient and insertion loss in both simulator CSTMicrowave Studio V9 and ADS200A All the basic DB-DGShave been studied for terahertz frequency and their sharpnessis compared which is shown in Table 2 The modified DB-DGS is sharper than the other DB-DGS In the literature sofar no fabrication has been reported on microstrip filter atterahertz frequency For the validation the proposed filter issimulated in various EMwave simulators like CSTHFSS andADS After comparsion of all simulated results it was foundthat the results are in good agreement
References
[1] C F Kane and R R Krchnavek ldquoBenzocyclobutene opticalwaveguidesrdquo IEEE Photonics Technology Letters vol 7 no 5 pp535ndash537 1995
[2] C Wood J Cunningham C K Tiang et al ldquoMeasurementand simulation of the sensitivity of terahertz frequency rangepassive filter elements to overlaid dielectricsrdquo in Proceedingsof the 31st International Conference on Infrared and MillimeterWaves and 14th International Conference on Terahertz Electron-ics (IRMMW-THz rsquo06) p 423 Sanghai China September 2006
[3] K R Jha and G Singh ldquoAnalysis of narrow terahertz microstriptransmission-line onmultilayered substraterdquo Journal of Compu-tational Electronics vol 10 no 1-2 pp 186ndash194 2011
[4] A K Arya M V Kartikeyan and A Patnaik ldquoDefected groundstructure in the perspective of microstrip antennas a reviewrdquoFrequenz vol 64 no 5-6 pp 79ndash84 2010
[5] C-S Kim J-S Park D Ahn and J-B Lim ldquoA novel 1-Dperiodic defected ground structure for planar circuitsrdquo IEEEMicrowave and Wireless Components Letters vol 10 no 4 pp131ndash133 2000
[6] J S Lim C S Kim Y T Lee D Ahn and SNam ldquoAnew type oflow pass filter with defected ground structurerdquo in Proceedings ofthe 32nd EuropeanMicrowave Conference pp 32ndash36 September2002
[7] V Radisic YQian RCoccioli andT Itoh ldquoNovel 2-Dphotonicbandgap structure for microstrip linesrdquo IEEE Microwave andGuided Wave Letters vol 8 no 2 pp 69ndash71 1998
[8] H-M Kim and B Lee ldquoAnalysis of T-shaped Defected groundstructure (DGS) using closed-form expressionsrdquo in Proceedingsof the 3rd International Conference on Computational Elec-tromagnetics and Its Applications (ICCEA rsquo04) pp 496ndash499November 2004
[9] D Ahn J-S Park C-S Kim J Kim Y Qian and T Itoh ldquoAdesign of the low-pass filter using the novel microstrip defectedground structurerdquo IEEE Transactions on MicrowaveTheory andTechniques vol 49 no 1 pp 86ndash93 2001
[10] J-S Lim C-S Kim Y-T Lee D Ahn and S Nam ldquoDesignof lowpass filters using defected ground structure and compen-sated microstrip linerdquo Electronics Letters vol 38 no 22 pp1357ndash1358 2002
[11] A B Abdel-Rahman A K Verma A Boutejdar and A SOmar ldquoControl of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground planerdquo IEEE Transactions onMicrowave Theory and Techniques vol 52 no 3 pp 1008ndash10132004
[12] A Kumar and A K Verma ldquoDesign of compact seven poleslow pass filter using defected ground structurerdquo in Proceedingsof the International Conference on Emerging Trends in Electronicand Photonic Devices amp Systems (ELECTRO rsquo09) pp 349ndash352December 2009
[13] P Kumar RMahmood J Kishor andA K Shrivastav ldquoControlof band stop responses of very compact size microstrip filterof improved Q factor amp sharp transition by using hexagonaltransmetal DGSrdquo in Proceedings of the International Conferenceon Emerging Trends in Electronic and Photonic Devices ampSystems (ELECTRO rsquo09) pp 383ndash386 December 2009
[14] L H Weng Y C Guo X W Shi and X Q Chen ldquoAnoverview of defected ground structurerdquo Progress in Electromag-netic Research B vol 7 pp 173ndash189 2008
[15] S Costanzo I Venneri G D Massa and A Borgia ldquoBenzo-cyclobutene as Substrate Material for planar millimeter-wavestructures dielectric characterization and applicationrdquo Journalof Infrared Millimeter and Terahertz Waves vol 31 no 1 pp66ndash77 2010
[16] Dow Chemical Cyclotene 3000 Series Advanced ElectronResins httpwwwdowcomcyclotene
[17] S Costanzo A Borgia I Venneri and G Di Massa ldquoMilli-meter-Waves structures on benzocyclobutene dielectric sub-straterdquo Radioengineering vol 20 no 4 pp 785ndash789 2011
[18] L-M Si Y Yong H-J Sun and L Xin ldquoCharacterizationand application of planar terahertz narrow bandpass filter withmetamaterial resonatorsrdquo in Proceedings of the InternationalWorkshop on Metamaterials (META rsquo08) pp 351ndash354 Novem-ber 2008
[19] A Hosseini H Nejati and Y Massoud ldquoDesign of opticalrange third-order chebychev low-pass filter using plasmonicnanostrip waveguidesrdquo in Proceedings of the 50th MidwestSymposium on Circuits and Systems (MWSCAS rsquo07) pp 1245ndash1248 August 2007
[20] E J Denlinger ldquoLosses of microstrip linesrdquo IEEE TransactionsonMicrowaveTheory and Techniques vol 28 no 6 pp 513ndash5221980
[21] M V Schneider ldquoMicrostrip lines for microwave integratedcircuitsrdquo The Bell System Technical Journal vol 48 pp 1421ndash1444 1969
[22] Agilent ADS 2006[23] Microwave Studio V9
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
Active and Passive Electronic Components 5
using microstrip An approach is developed in this paperand a microstrip bandstop filter has been designed at thecut-off frequency of 1000 THz with the insertion loss ofminus258 dB at 14 THz in a stopband no stub or stepped-impedance structure is used Only 50 ohm1205824microstrip linewith modified hexagonal-shaped DGS shows the bandstopcharacteristics at 1000 THz The simulated S-parameter isin excellent agreement with the calculated one especially inreflection coefficient and insertion loss in both simulator CSTMicrowave Studio V9 and ADS200A All the basic DB-DGShave been studied for terahertz frequency and their sharpnessis compared which is shown in Table 2 The modified DB-DGS is sharper than the other DB-DGS In the literature sofar no fabrication has been reported on microstrip filter atterahertz frequency For the validation the proposed filter issimulated in various EMwave simulators like CSTHFSS andADS After comparsion of all simulated results it was foundthat the results are in good agreement
References
[1] C F Kane and R R Krchnavek ldquoBenzocyclobutene opticalwaveguidesrdquo IEEE Photonics Technology Letters vol 7 no 5 pp535ndash537 1995
[2] C Wood J Cunningham C K Tiang et al ldquoMeasurementand simulation of the sensitivity of terahertz frequency rangepassive filter elements to overlaid dielectricsrdquo in Proceedingsof the 31st International Conference on Infrared and MillimeterWaves and 14th International Conference on Terahertz Electron-ics (IRMMW-THz rsquo06) p 423 Sanghai China September 2006
[3] K R Jha and G Singh ldquoAnalysis of narrow terahertz microstriptransmission-line onmultilayered substraterdquo Journal of Compu-tational Electronics vol 10 no 1-2 pp 186ndash194 2011
[4] A K Arya M V Kartikeyan and A Patnaik ldquoDefected groundstructure in the perspective of microstrip antennas a reviewrdquoFrequenz vol 64 no 5-6 pp 79ndash84 2010
[5] C-S Kim J-S Park D Ahn and J-B Lim ldquoA novel 1-Dperiodic defected ground structure for planar circuitsrdquo IEEEMicrowave and Wireless Components Letters vol 10 no 4 pp131ndash133 2000
[6] J S Lim C S Kim Y T Lee D Ahn and SNam ldquoAnew type oflow pass filter with defected ground structurerdquo in Proceedings ofthe 32nd EuropeanMicrowave Conference pp 32ndash36 September2002
[7] V Radisic YQian RCoccioli andT Itoh ldquoNovel 2-Dphotonicbandgap structure for microstrip linesrdquo IEEE Microwave andGuided Wave Letters vol 8 no 2 pp 69ndash71 1998
[8] H-M Kim and B Lee ldquoAnalysis of T-shaped Defected groundstructure (DGS) using closed-form expressionsrdquo in Proceedingsof the 3rd International Conference on Computational Elec-tromagnetics and Its Applications (ICCEA rsquo04) pp 496ndash499November 2004
[9] D Ahn J-S Park C-S Kim J Kim Y Qian and T Itoh ldquoAdesign of the low-pass filter using the novel microstrip defectedground structurerdquo IEEE Transactions on MicrowaveTheory andTechniques vol 49 no 1 pp 86ndash93 2001
[10] J-S Lim C-S Kim Y-T Lee D Ahn and S Nam ldquoDesignof lowpass filters using defected ground structure and compen-sated microstrip linerdquo Electronics Letters vol 38 no 22 pp1357ndash1358 2002
[11] A B Abdel-Rahman A K Verma A Boutejdar and A SOmar ldquoControl of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground planerdquo IEEE Transactions onMicrowave Theory and Techniques vol 52 no 3 pp 1008ndash10132004
[12] A Kumar and A K Verma ldquoDesign of compact seven poleslow pass filter using defected ground structurerdquo in Proceedingsof the International Conference on Emerging Trends in Electronicand Photonic Devices amp Systems (ELECTRO rsquo09) pp 349ndash352December 2009
[13] P Kumar RMahmood J Kishor andA K Shrivastav ldquoControlof band stop responses of very compact size microstrip filterof improved Q factor amp sharp transition by using hexagonaltransmetal DGSrdquo in Proceedings of the International Conferenceon Emerging Trends in Electronic and Photonic Devices ampSystems (ELECTRO rsquo09) pp 383ndash386 December 2009
[14] L H Weng Y C Guo X W Shi and X Q Chen ldquoAnoverview of defected ground structurerdquo Progress in Electromag-netic Research B vol 7 pp 173ndash189 2008
[15] S Costanzo I Venneri G D Massa and A Borgia ldquoBenzo-cyclobutene as Substrate Material for planar millimeter-wavestructures dielectric characterization and applicationrdquo Journalof Infrared Millimeter and Terahertz Waves vol 31 no 1 pp66ndash77 2010
[16] Dow Chemical Cyclotene 3000 Series Advanced ElectronResins httpwwwdowcomcyclotene
[17] S Costanzo A Borgia I Venneri and G Di Massa ldquoMilli-meter-Waves structures on benzocyclobutene dielectric sub-straterdquo Radioengineering vol 20 no 4 pp 785ndash789 2011
[18] L-M Si Y Yong H-J Sun and L Xin ldquoCharacterizationand application of planar terahertz narrow bandpass filter withmetamaterial resonatorsrdquo in Proceedings of the InternationalWorkshop on Metamaterials (META rsquo08) pp 351ndash354 Novem-ber 2008
[19] A Hosseini H Nejati and Y Massoud ldquoDesign of opticalrange third-order chebychev low-pass filter using plasmonicnanostrip waveguidesrdquo in Proceedings of the 50th MidwestSymposium on Circuits and Systems (MWSCAS rsquo07) pp 1245ndash1248 August 2007
[20] E J Denlinger ldquoLosses of microstrip linesrdquo IEEE TransactionsonMicrowaveTheory and Techniques vol 28 no 6 pp 513ndash5221980
[21] M V Schneider ldquoMicrostrip lines for microwave integratedcircuitsrdquo The Bell System Technical Journal vol 48 pp 1421ndash1444 1969
[22] Agilent ADS 2006[23] Microwave Studio V9
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