Novel Notched UWB Filter Using Stepped Impedance Stub Loaded

Research ArticleNovel Notched UWB Filter Using Stepped Impedance StubLoaded Microstrip Resonator and Spurlines

Ramkumar Uikey1 Ramanand Sagar Sangam1

Kakumanu Prasadu2 and Rakhesh Singh Kshetrimayum1

1Department of Electronics amp Electrical Engineering IIT Guwahati Assam 781039 India2Ford Motor Pvt Ltd Dr MGR Road Perungundi Chennai 600096 India

Correspondence should be addressed to Rakhesh Singh Kshetrimayum krsiitgernetin

Received 10 June 2015 Revised 15 August 2015 Accepted 19 August 2015

Academic Editor Giancarlo Bartolucci

Copyright copy 2015 Ramkumar Uikey et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

This paper presents a novel ultrawideband (UWB) bandpass filter using stepped impedance stub loaded microstrip resonator(SISLMR) The proposed resonator is so formed to allow its four resonant frequencies in the UWB passband which extends from31 GHz to 106GHz Moreover two spurline sections are employed to create a sharp notched-band filter for suppressing the signalsof 5GHzWLANdevices Experimental results of the fabricated filters are in good agreementwith theHFSS simulations and validatethe design

1 Introduction

Since the release ofUWB spectrumby the Federal Communi-cations Commission for unlicensed commercial applicationsin early 2002 [1] compact size UWB bandpass filters withgood in-band transmission sharp selectivity and flat groupdelays are highly demanded to realize UWB radio systemsA number of methods have been reported in the literature[2ndash8] to design the UWB bandpass filters An early methodreported in [2] is based on cascaded low-pass-high-pass filtersections A hybrid microstripCPW structure with back-to-back transition configuration is used in [3] to achieve theUWB bandpass response In [4] a stepped impedance four-mode resonator is developed on the method of networkanalysis and optimization in Z-domain Today a major classof available UWB filters are based on the multiple-moderesonators (MMR) and are quite popular due to their easydesign methods and simple structures The concept of MMRbasedUWBfilter was initially presented in [5] In this work atriple-modeMMR is integrated with dual-pole overenhancedparallel coupled lines to realize the UWB filter This workis extended in [6] to get a more feasible filter with relaxedfabrication tolerance In [7 8] open ended stub loaded

resonator based UWB filters are designed to widen the upperstopband

In recent years researchers are more attracted towardsfilters with notch bands embedded in the UWB passbandThese notch bands are required to suppress the strongnarrowband emissions in the WLAN and WiMAX bandswhich coincide with the 31 GHz to 106GHzUWB spectrumMany efforts have been put forward by researchers in [9ndash12]to design notched-band UWB filters A Meander line slot isdeveloped in [9] to reject the undesired IEEE 80211a signalsSymmetrical pairs of defected ground structure with embed-ded open stubs are employed to create the WLAN notch[10] In [11] five short circuited stubs are incorporated in thedesign to exhibit highly selective filtering characteristics Inour early work [12] we designed a notched-band bandpassfilter using complementary single split ring resonators in theground plane All abovementioned filters possess good notchband filtering but they are either based on defected groundstructures or suffer from fabrication difficulties due to viaholes Hence emphasis is given to planar structures whichare free from via holes and defected ground structures

In this paper we are proposing a novel quad-modestepped impedance stub loaded microstrip resonator

Hindawi Publishing CorporationInternational Journal of Microwave Science and TechnologyVolume 2015 Article ID 939521 5 pageshttpdxdoiorg1011552015939521

2 International Journal of Microwave Science and Technology

W

W1L5

W3

L4L1

W2L2

L3

L

Figure 1 Basic structure of the proposed stepped impedance stubloaded UWB bandpass filter

(SISLMR) to design the UWB bandpass filters It isconstructed by loading a uniform 50 Ω transmission linewith three symmetrical stepped impedance stubs that isone at the center and two at the symmetrical side locationsThen two symmetrical spurline sections are developedaround the central stepped impedance stub to create asharp notch band for suppressing the WLAN radio systemsoperating in the 5GHz frequency bands Finite elementbased Anosoft HFSS software is used for deriving the filterrsquoselectrical performance later two filter prototypes one withnotch band and one without notch band are fabricatedand measured for experimental verification of the predictedresults

2 Initial UWB Filter Design

Figure 1 depicts the schematic of the proposed resonator Itconsists of a conventional transmission line resonator (50 Ω)

of width 1198821and length 2119871

1+ 1198822in the horizontal plane

and three vertically loaded stepped impedance stubs thatis one stepped impedance stub of width 119882

2 1198823 length

1198714 1198715at the center and the other two stubs of the same

dimensions at the symmetrical sides located at a distance ofabout 120582

1198924 from the central stub In the initial design we

load a 50 Ω transmission line (asymp15120582119892) with single stepped

impedance at the center When impedance ratio for thisstepped impedance stub is set close to 02 we observesome UWB filtering characteristics with two transmissionzeros near 2 and 11 GHz respectively and a pole near65 GHz Later this initial resonator structure is modifiedby introducing two more stepped impedance stubs to havea higher degree of freedom in the design A parametricanalysis is performed using FEM based HFSS software andresonator parameters are optimized to achieve the UWBbandpass response Optimized electrical parameters for theproposed SISLMR are given in Table 1 and HFSS simulatedresults are shown in Figure 2 Simulation results depict thatthe proposed resonator has four resonant frequencies in thedesired passband located at 343 520 740 and 938GHzrespectively Transmission zeros in the lower and upperstopband are located at 217 and 1097GHz respectivelyDesigned filter demonstrates goodUWBfiltering with |119878

21| ge

Table 1 Design parameter values for Figure 1

119871 = 38mm 119882 = 32mm FR4-epoxy substrate1198711

= 1875mm 1198821

= 31mm 120598119903

= 44

1198712

= 775mm 1198822

= 05mm ℎ = 16mm1198713

= 35mm 1198823

= 95mm 119905 = 0035mm1198714

= 65mm tan 120575 = 0002

1198715

= 95mm

0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

minus80

minus70

minus60

minus50

minus40

minus30

minus20

minus10minus30

S11 (dB)S21 (dB)

S11S

21

(dB)

Figure 2 Simulated frequency response of the designed UWBbandpass filter

minus3 dB and |11987811

| le minus10 dB and flat group delay in the desiredUWB spectrum

21 Approximate Theoretical Analysis This section describesan approximate theoretical analysis of the proposed res-onator It considers the case of lossless transmission linesand ignores the effects of step discontinuities frequencydispersion and edge capacitances at the open stubs

Figure 3 shows the transmission line model of the pro-posed resonator The overall ABCD matrix [119877] in Figure 3can be obtained by multiplying the ABCD matrices of theterminal lines connecting lines between stepped impedancestubs and stepped impedance stubs in sequence that is

[119877] = [119860] [119861] [119862] [119861] [119862] [119861] [119860] (1)

where

[119860] =

[[[

[

cos (1205791015840

1)

119895 sin (1205791015840

1)

1198841

1198951198841sin (120579

1015840

1) cos (120579

1015840

1)

]]]

]

[119861] =[[

[

1 0

1198951198842

1198842tan (120579

3) + 1198841tan (120579

2)

1198841

minus 1198842tan (120579

2) tan (120579

3)

1

]]

]

[119862] =[[

[

cos (1205791)

119895 sin (1205791)

1198841

1198951198841sin (1205791) cos (120579

1)

]]

]

(2)

International Journal of Microwave Science and Technology 3

Z1 1205799984001 Z1 1205791

Port 1 Port 2

Z2 1205792

Z3 1205793 T998400

T

Figure 3 Transmission line model of the proposed UWB bandpassfilter

0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

S11

S21

minus150

minus125

minus100

minus75

minus50

minus25

minus100

SimulatedAnalytical

S11S

21

(dB)

Figure 4 Comparison of simulated and analytical results

Using (1) andmatched load condition at port 2 |11987821

| (dB) and|11987811

| (dB) for the resonator in Figure 1 are deduced as100381610038161003816100381611987821

1003816100381610038161003816 = 20

sdot log(2radic11988501

11988502

11987711

+ 11987712

11988502

+ 11987721

11988501

+ 11987722

(11988501

11988502

)) dB

1003816100381610038161003816119878111003816100381610038161003816 = 20

sdot log(11987711

+ 11987712

11988502

minus 11987721

11988501

minus 11987722

(11988501

11988502

)

11987711

+ 11987712

11988502

+ 11987721

11988501

+ 11987722

(11988501

11988502

)) dB

(3)

11988501

and 11988502

in the above equations are source and loadimpedances respectively In Figure 4 analytical results of(3) are plotted in MATLAB and compared with the HFSSsimulated results This plot shows good match between thetwo results and further supports the validity of the proposedSISLMR for designing the UWB bandpass filters

3 Realization of Notched-Band UWB Filter

UWB filter designed in the previous section is modifiedby introducing two symmetrical spurlines to create a sharpnotch function in the UWB passband Figure 5 shows thecircuit of modified UWB filter In the modified filter all theparameters of the initial UWBfilter are kept unchangedwhiledimensions of the two spurlines are set as length (119886) gap (119887)

ab

c

xe

Figure 5 UWB filter with spurlines for realizing WLAN notchband

0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

minus70

minus60

minus50

minus40

minus30

minus20

minus10minus30

S11 (dB)S21 (dB)

S11S

21

(dB)

Figure 6 Simulated 119878-parameter of the notched-band UWB band-pass filter

Table 2 Design parameter values for the spurlines

119886 = 7mm 119887 = 03mm119888 = 1mm 119890 = 03mm119909 = 31mm

and height (119888) respectively These are etched symmetricallyat a distance of 119909 around the central stepped impedancestub Length (119886) and gap (119887) of spurlines play a key role inadjusting the stopband center frequency [13] and thereforethese are properly optimized using HFSS software so thatthe resulting notched-band filter can completely suppress theinterference from WLAN devices operating in the 5GHzband Table 2 lists the optimized parameters of the proposedspurline sections

Figure 6 shows the variation of HFSS simulated 119878-parameters with frequency for the notched-band UWB filterThis filter exhibits a 10 dB stopband from 515 to 66GHzwith minimum |119878

21| of minus39 dB at 56GHz and completely

eliminates the 5GHz WLAN bands Furthermore it has two10 dB passbands in the desired UWB spectrum the firstpassband covers a frequency range extending from 32 to515 GHz while the second passband covers 66 to 108 GHzband


(a) (b)

Figure 7 Fabricated filters (a) Initial UWB bandpass filter and (b) notched-band UWB filter

1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus100

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

15

Gro

up d

elay

(ns)

MeasuredSimulated

(b)

Figure 8 Comparison of simulated and experimental results for the initial UWB filter (a) 119878-parameters and (b) group delay

1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

Gro

up d

elay

(ns)

MeasuredSimulated

(b)

Figure 9 Comparison of simulated and experimental results for the notched-band UWB filter (a) 119878-parameters and (b) group delay

4 Comparison with Experimental Results

After deriving the optimized electrical parameters for theproposed UWB filters the two filter prototypes are fabricatedand measured using VNA for experimental verificationFigure 7 shows the photograph of fabricated filters Simulatedand measured 119878-parameters and group delay for the initiallydesigned UWB filter and notch band UWB filter are plotted

together in Figures 8 and 9 respectively for quantitativecomparison These graphs show a good match betweenthe two results For the initial UWB filter measured 10 dBpassband extends from 31 to 11 GHz while for the notched-band filter measured stopband extends from 55 to 68GHzand the two passbands cover 315ndash55GHz and 68ndash114 GHzbands respectively For both filters maximum group delayvariation is better than 07 ns The two fabricated filters are


compact in size and do not incorporate any defected groundstructures or via hole connections Someminor discrepanciesare observed in the measured results which may be causeddue to unexpected tolerances in fabrication and substrateparameters similar to what has been reported in [14]

5 Conclusion

In this paper we proposed a novel stepped impedance stubloaded microstrip resonator (SISLMR) for designing theUWB bandpass filters Initial UWB filter is designed byloading three double section stepped impedance stubs to themain 50 Ω microstrip line and an approximate theoreticalanalysis is also presented Later on the required WLANnotch band is designed using the spurline method Afteroptimization of filter parameters in HFSS software twocompact size UWB filters were fabricated and measured forexperimental verificationMeasured and simulated results arein good agreement with each other and validate the design

Conflict of Interests

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

References

[1] Federal Communications Commission ldquoRevision of part 15 ofthe commissionrsquos rules regarding ultra-wideband transmissionsystemsrdquo Tech Rep ET-Docket 98-153 FCC02-48 FederalCommunications Commission (FCC) Washington DC USA2002

[2] C-L Hsu F-C Hsu and J-T Kuo ldquoMicrostrip bandpassfilters for Ultra-Wideband (UWB) wireless communicationsrdquoin Proceedings of the IEEE MTT-S International MicrowaveSymposium Digest pp 679ndash682 IEEE Long Beach Calif USAJune 2005

[3] H Wang L Zhu and W Menzel ldquoUltra-wideband bandpassfilter with hybrid microstripCPW structurerdquo IEEE Microwaveand Wireless Components Letters vol 15 no 12 pp 844ndash8462005

[4] P Cai Z Ma X Guan Y Kobayashi T Anada and GHagiwara ldquoA novel compact ultra-wideband bandpass filterusing a microstrip stepped-impedance four-modes resonatorrdquoin Proceedings of the IEEE MTT-S International MicrowaveSymposium (IMS rsquo07) pp 751ndash754 IEEE Honolulu HawaiiUSA June 2007

[5] L Zhu S Sun andW Menzel ldquoUltra-Wideband (UWB) band-pass filters using multiple-mode resonatorrdquo IEEE Microwaveand Wireless Components Letters vol 15 no 11 pp 796ndash7982005

[6] L Zhu and H Wang ldquoUltra-wideband bandpass filter onaperture-backed microstrip linerdquo Electronics Letters vol 41 no18 pp 1015ndash1016 2005

[7] R Li and L Zhu ldquoCompact UWB bandpass filter using stub-loadedmultiple-mode resonatorrdquo IEEEMicrowave andWirelessComponents Letters vol 17 no 1 pp 40ndash42 2007

[8] Q-X Chu and S-T Li ldquoCompact UWB bandpass filter withimproved upper-stopband performancerdquo Electronics Lettersvol 44 no 12 pp 742ndash743 2008

[9] G-M Yang R Jin C Vittoria V G Harris and N X SunldquoSmall Ultra-wideband (UWB) bandpass filter with notchedbandrdquo IEEE Microwave and Wireless Components Letters vol18 no 3 pp 176ndash178 2008

[10] W Zong X Zhu C You and J Wang ldquoDesign and implementof compact UWB bandpass filter with a frequency notch byconsisting of coupled Microstrip line structure DGS and EOSrdquoinProceedings of the International Conference onAdvancedTech-nologies for Communications pp 179ndash182 Haiphong VietnamOctober 2009

[11] H Shaman and J-S Hong ldquoUltra-wideband (UWB) bandpassfilter with embedded band notch structuresrdquo IEEE MicrowaveandWireless Components Letters vol 17 no 3 pp 193ndash195 2007

[12] S S Karthikeyan and R S Kshetrimayum ldquoNotched UWBbandpass filter using complementary single split ring resonatorrdquoIEICE Electronics Express vol 7 no 17 pp 1290ndash1295 2010

[13] R N Bates ldquoDesign of microstrip spur-line band-stop filtersrdquoIEE Journal on Microwaves Optics and Acoustics vol 1 no 6pp 209ndash214 1977

[14] P Cai Z Ma X Guan et al ldquoA compact UWB bandpass filterusing two-section open-circuited stubs to realize transmissionzerosrdquo in Proceedings of the Asia-Pacific Microwave Conference(APMC rsquo05) vol 5 Suzhou China December 2005

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Hindawi Publishing Corporation httpwwwhindawicom

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Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



W

W1L5

W3

L4L1

W2L2

L3

L

Figure 1 Basic structure of the proposed stepped impedance stubloaded UWB bandpass filter

(SISLMR) to design the UWB bandpass filters It isconstructed by loading a uniform 50 Ω transmission linewith three symmetrical stepped impedance stubs that isone at the center and two at the symmetrical side locationsThen two symmetrical spurline sections are developedaround the central stepped impedance stub to create asharp notch band for suppressing the WLAN radio systemsoperating in the 5GHz frequency bands Finite elementbased Anosoft HFSS software is used for deriving the filterrsquoselectrical performance later two filter prototypes one withnotch band and one without notch band are fabricatedand measured for experimental verification of the predictedresults

2 Initial UWB Filter Design

Figure 1 depicts the schematic of the proposed resonator Itconsists of a conventional transmission line resonator (50 Ω)

of width 1198821and length 2119871

1+ 1198822in the horizontal plane

and three vertically loaded stepped impedance stubs thatis one stepped impedance stub of width 119882

2 1198823 length

1198714 1198715at the center and the other two stubs of the same

dimensions at the symmetrical sides located at a distance ofabout 120582

1198924 from the central stub In the initial design we

load a 50 Ω transmission line (asymp15120582119892) with single stepped

impedance at the center When impedance ratio for thisstepped impedance stub is set close to 02 we observesome UWB filtering characteristics with two transmissionzeros near 2 and 11 GHz respectively and a pole near65 GHz Later this initial resonator structure is modifiedby introducing two more stepped impedance stubs to havea higher degree of freedom in the design A parametricanalysis is performed using FEM based HFSS software andresonator parameters are optimized to achieve the UWBbandpass response Optimized electrical parameters for theproposed SISLMR are given in Table 1 and HFSS simulatedresults are shown in Figure 2 Simulation results depict thatthe proposed resonator has four resonant frequencies in thedesired passband located at 343 520 740 and 938GHzrespectively Transmission zeros in the lower and upperstopband are located at 217 and 1097GHz respectivelyDesigned filter demonstrates goodUWBfiltering with |119878

21| ge

Table 1 Design parameter values for Figure 1

119871 = 38mm 119882 = 32mm FR4-epoxy substrate1198711

= 1875mm 1198821

= 31mm 120598119903

= 44

1198712

= 775mm 1198822

= 05mm ℎ = 16mm1198713

= 35mm 1198823

= 95mm 119905 = 0035mm1198714

= 65mm tan 120575 = 0002

1198715

= 95mm

0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

minus80

minus70

minus60

minus50

minus40

minus30

minus20

minus10minus30

S11 (dB)S21 (dB)

S11S

21

(dB)

Figure 2 Simulated frequency response of the designed UWBbandpass filter

minus3 dB and |11987811

| le minus10 dB and flat group delay in the desiredUWB spectrum

21 Approximate Theoretical Analysis This section describesan approximate theoretical analysis of the proposed res-onator It considers the case of lossless transmission linesand ignores the effects of step discontinuities frequencydispersion and edge capacitances at the open stubs

Figure 3 shows the transmission line model of the pro-posed resonator The overall ABCD matrix [119877] in Figure 3can be obtained by multiplying the ABCD matrices of theterminal lines connecting lines between stepped impedancestubs and stepped impedance stubs in sequence that is

[119877] = [119860] [119861] [119862] [119861] [119862] [119861] [119860] (1)

where

[119860] =

[[[

[

cos (1205791015840

1)

119895 sin (1205791015840

1)

1198841

1198951198841sin (120579

1015840

1) cos (120579

1015840

1)

]]]

]

[119861] =[[

[

1 0

1198951198842

1198842tan (120579

3) + 1198841tan (120579

2)

1198841

minus 1198842tan (120579

2) tan (120579

3)

1

]]

]

[119862] =[[

[

cos (1205791)

119895 sin (1205791)

1198841

1198951198841sin (1205791) cos (120579

1)

]]

]

(2)


Z1 1205799984001 Z1 1205791

Port 1 Port 2

Z2 1205792

Z3 1205793 T998400

T


0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

S11

S21

minus150

minus125

minus100

minus75

minus50

minus25

minus100

SimulatedAnalytical

S11S

21

(dB)



| (dB) and|11987811


1003816100381610038161003816 = 20


11988502

11987711

+ 11987712

11988502

+ 11987721

11988501

+ 11987722

(11988501

11988502

)) dB

1003816100381610038161003816119878111003816100381610038161003816 = 20

sdot log(11987711

+ 11987712

11988502

minus 11987721

11988501

minus 11987722

(11988501

11988502

)

11987711

+ 11987712

11988502

+ 11987721

11988501

+ 11987722

(11988501

11988502

)) dB

(3)

11988501

and 11988502




ab

c

xe


0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

minus70

minus60

minus50

minus40

minus30

minus20

minus10minus30

S11 (dB)S21 (dB)

S11S

21

(dB)



119886 = 7mm 119887 = 03mm119888 = 1mm 119890 = 03mm119909 = 31mm






(a) (b)


1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus100

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

15

Gro

up d

elay

(ns)

MeasuredSimulated

(b)


1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

Gro

up d

elay

(ns)

MeasuredSimulated

(b)







5 Conclusion




References

















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Z1 1205799984001 Z1 1205791

Port 1 Port 2

Z2 1205792

Z3 1205793 T998400

T


0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

S11

S21

minus150

minus125

minus100

minus75

minus50

minus25

minus100

SimulatedAnalytical

S11S

21

(dB)



| (dB) and|11987811


1003816100381610038161003816 = 20


11988502

11987711

+ 11987712

11988502

+ 11987721

11988501

+ 11987722

(11988501

11988502

)) dB

1003816100381610038161003816119878111003816100381610038161003816 = 20

sdot log(11987711

+ 11987712

11988502

minus 11987721

11988501

minus 11987722

(11988501

11988502

)

11987711

+ 11987712

11988502

+ 11987721

11988501

+ 11987722

(11988501

11988502

)) dB

(3)

11988501

and 11988502




ab

c

xe


0 1 2 31 4 5 6 7 8 9 106 12 13 14

Frequency (GHz)

minus70

minus60

minus50

minus40

minus30

minus20

minus10minus30

S11 (dB)S21 (dB)

S11S

21

(dB)



119886 = 7mm 119887 = 03mm119888 = 1mm 119890 = 03mm119909 = 31mm






(a) (b)


1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus100

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

15

Gro

up d

elay

(ns)

MeasuredSimulated

(b)


1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

Gro

up d

elay

(ns)

MeasuredSimulated

(b)







5 Conclusion




References

















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










(a) (b)


1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus100

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

15

Gro

up d

elay

(ns)

MeasuredSimulated

(b)


1 2 31 4 5 6 7 8 9 106 12 13

Frequency (GHz)

S11

S21

minus75

minus50

minus25

minus10

0

SimulatedMeasured

S11S

21

(dB)

(a)

1 2 3 4 5 6 7 8 9 10 11 12 13

Frequency (GHz)

minus15

minus10

minus5

0

5

10

Gro

up d

elay

(ns)

MeasuredSimulated

(b)







5 Conclusion




References

















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











5 Conclusion




References

















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









Documents

Novel Notched UWB Filter Using Stepped Impedance Stub Loaded