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Hindawi Publishing CorporationInternational Journal of Microwave Science and TechnologyVolume 2013 Article ID 328406 6 pageshttpdxdoiorg1011552013328406

Research ArticleCMOS Ultra-Wideband Low Noise Amplifier Design

K Yousef1 H Jia2 R Pokharel3 A Allam1 M Ragab1 H Kanaya3 and K Yoshida3

1 Electronics and Communications Engineering Department Egypt-Japan University of Science and TechnologyNew Borg Al-Arab 21934 Alexandria Egypt

2 E-JUST Center Kyushu University Nishi-ku Fukuoka 819-0395 Japan3 Graduate School of ISSE Kyushu University Nishi-ku Fukuoka 819-0395 Japan

Correspondence should be addressed to K Yousef khalilyousefejustedueg

Received 29 November 2012 Accepted 26 March 2013

Academic Editor Mohammad S Hashmi

Copyright copy 2013 K Yousef et alThis is an open access article distributed under the Creative CommonsAttribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

This paper presents the design of ultra-wideband low noise amplifier (UWB LNA) The proposed UWB LNA whose bandwidthextends from 25GHz to 16GHz is designed using a symmetric 3D RF integrated inductorThis UWB LNA has a gain of 11 plusmn 10 dBand aNF less than 33 dBGood input and output impedancematching and good isolation are achieved over the operating frequencybandThe proposed UWB LNA is driven from a 18 V supplyThe UWB LNA is designed and simulated in standard TSMC 018 120583mCMOS technology process

1 Introduction

CMOS technology is one of the most prevailing technologiesused for the implementation of radio frequency integratedcircuits (RFICs) due to its reduced cost and its compat-ibility with silicon-based system on chip [1] The use ofultra-wideband (UWB) frequency range (31ndash106GHz) forcommercial applications was approved in February 2002by the Federal Communications Commission Low costreduced power consumption and transmission of data athigh rates are the advantages of UWB technology UWBtechnology has many applications such as wireless sensorand personal area networks ground penetrating radars andmedical applications [2]

Low noise amplifier is considered the backbone of theUWB front-end RF receiver It is responsible for signalreception and amplification over the UWB frequency rangeLNA has many desired design specifications such as low andflat noise figure high and flat power gain good input andoutput wide impedancematching high reverse isolation andreduced DC power consumption [1 3]

Nowadays one of the most suitable configurationssuggested for LNA implementation is current reuse cascaded

amplifier This LNA configuration can attain low DC powerconsumption high flattened gain minimized NF and excel-lent reverse isolation while achieving wide input and outputimpedance matching [1ndash3]

Radio frequency integrated inductors play a significantrole in radio frequency integrated circuits (RFICs) imple-mentation Design development and performance improve-ment of RF integrated inductors represent a challengingwork Achieving high integration level and costminimizationof RFICs are obstructed because of the difficulties facingthe RF integrated inductors designers which are related toobtaining high quality factors [4ndash6]

In this paper the implementation of LNAs using 3Dintegrated inductors will be investigated A symmetric 3Dstructure is proposed as a new structure of integrated induc-tors for RFICs

This paper discusses the design procedure of currentreuse cascaded UWB LNA and its bandwidth expansionIn addition the employment of suggested symmetric 3DRF integrated inductor will be demonstrated This paperis organized as follows Section 2 introduces the suggestedUWB LNA circuit Section 3 gives simulation results anddiscussion Conclusion is driven in Section 4

2 International Journal of Microwave Science and Technology

2 Circuit Description

As shown in Figure 1 the proposed UWB LNA is a currentreuse cascaded core based on a common source topologywitha shunt resistive feedback technique implemented over theinput stage

This current reuse cascaded amplifier achieved goodwideband input impedance matching through the use ofsource degeneration input matching technique Figure 2shows the small signal equivalent circuit of this LNA inputstage The input port of this UWB LNA is desired tomatch source impedance 119877

119904at resonance frequency 120596

119900 This

matching circuit bandwidth is defined through the qualityfactors of source degeneration and gain-peaking inductors(119871119904and 119871

119892) where the input impedance is given by

119885in = 119895120596 (119871 119904 + 119871119892) +1

119895120596119862gs+ 120596119879119871119904

= 119895120596 (119871119904+ 119871119892) +

1

119895120596119862gs+ 119877119904

(1)

where 119885in is the UWB LNA input impedance and 120596119879is the

current-gain cut-off frequency where 120596119879= 119892119898119862gs and 119892119898

and119862gs are the input stage transconductance and gate-sourcecapacitance respectively 119881

119904represents the RF signal source

119877119904is the output impedance of 119881

119904

Although the shunt resistive feedback loop leads toLNA noise performance degradation [7] it is widely usedin recently proposed LNAs due to its superior widebandcharacteristics Shunt capacitive-resistive feedback techniqueis employed to widen the input-matching bandwidth andincrease the LNA stability

Shunt-peaked amplifiers are known to have wide gainbandwidth and high low frequency power gain [8] To havea high flattened gain of the proposed UWB LNA shunt-peaking technique is used In addition the gate-peaking tech-nique is used to enhance the LNA gain at high frequenciesBesides the shunt- and gate-peaking techniques the shuntresistive feedback loop is used in gain flattening [2 8] TheLNA approximate gain is given by

119860 cong119881out119881119904

cong

11989211989811198921198982[119877119871 (1198771198892+ 1198781198711198892)] [119878119871

1198891]

2 sdot 119878119862gs1 [119878 (119871 1199041 + 1198711198921) + 1119878119862gs1]

(2)

Ultra-wideband applications require good noise perfor-mance in addition to high and flat gain Low noise designtechniques which are suitable for narrowband applicationscannot be used for wideband applicationsMain contributionof cascaded matched stages noise figure is due to first stage[9]The reduction of noise figure of input stagewill lead to thereduction of the overall noise figure of the proposed designOptimization and control of factors affecting the NF willimprove this UWB LNA noise performance An equivalentcircuit of the input stage for noise factor calculation is shownin Figure 3 [1]

An estimated value of the noise figure (NF = 10 log10119891)

of this topology is given in [1] where 119891 is the noise factor ofthe UWB LNAThe noise factor 119891 can be given by

119891 = 1 +

119877119892+ 119877lg + 119877ss + 119877ls

119877119904

+

1205751205721205962

1198622

gs1119877119904

51198921198981

+

119877FB ((1198711198921 + 119871 1199041) 119862gs1)2

119877119904(1198921198981119877FB minus 1)

2

sdot

10038161003816100381610038161003816100381610038161003816

1199042

+ 119904 (

120596119900rfbn

119876rfbn) + 120596

2

119900rfbn

10038161003816100381610038161003816100381610038161003816

2

+

1205741198921198981(119877FB + 119877119904)

2

((1198711198921+ 1198711199041) 119862gs1)

2

120572119877119904(1198921198981119877FB minus 1)

2

sdot

10038161003816100381610038161003816100381610038161003816

1199042

+ 119904 (

120596119900dn

119876dn) + 120596

2

119900dn

10038161003816100381610038161003816100381610038161003816

2

(3)

119891 = 1 +

119877119892+ 119877lg + 119877ss + 119877ls

119877119904

+ 119891gn + 119891rfbn + 119891dn (4)

where

120596119900rfbn = radic

1 + 1198921198981119877119904

(1198711198921+ 1198711199041) 119862gs1

119876rfbn =1

119877119904+ 12059611987911198711199041

sdot radic(1 + 119892

1198981119877119904) (1198711198921+ 1198711199041)

119862gs1

120596119900rfbn = radic

1

(1198711198921+ 1198711199041) 119862gs1

119876dn =1

(119877119904|| 119877FB) + 1205961198791119871 1199041

sdot radic(1198711198921+ 1198711199041)

119862gs1

(5)

where119891gn119891dn and119891rfbn are gate drain and feedback resistornoise factors respectively and 120572 120575 and 120574 are constants equalto 085 41 and 221 respectively

It is clear from (4) that to reduce the noise figure highquality factors of 119871

1199041and 119871

1198921are desired It can also be noted

that the noise factor is inversely proportional to feedbackresistor119877

119891 In otherwords weak feedback topology decreases

the noise factor value while strong feedback implementationdegrades the noise performance of the suggested UWB LNA

In addition the noise factor formula given by (4) statesthat the noise figure is also inversely proportional to thetransconductance of the input stage (119892

1198981) This goes along

with the known fact that noise performance trades off withpower consumption

For output matching the series resonance of the shuntpeaking technique is used to match the proposed UWB LNAto the load impedance119877

119871while the series drain resistance119877

1198892

is used to extend the output matching bandwidthThis proposedUWBLNA (LNA1) has an operating band-

width of 31ndash106GHzThe proposed LNA2 whose schematic

International Journal of Microwave Science and Technology 3

1198711199041

1198711198891

1198711198892

1198711198921

1198711198922

11986211198622

119877119891119862119891

1198771198662

119881in

1198771198661

1198811198661

119881119889119889

119881out1198722

1198721

1198771198892

119877119871

Figure 1 Current reuse UWB LNA (LNA1)

119871119904

119871119892

119885in

119877119904

119881119904

119903119900119862 119892119898119881gs gs

Figure 2 Input stage small signal equivalent circuit

119877

1198942

1198902119904

119877119878

1198711198661 119877 1198902 1198902

1198942119892119862 1

119881 1

119877119904

1198902

1198711199041

119877

1198902

1198921198981119881 1 1198942

119889 1198942119899out

119877

+

minus

FB

rfb

119892 rg

gs

rs

ls

lg lg

gs

ls

gs

Figure 3 Equivalent circuit of the fisrt stage for noise calculation[1]

1198711199041

1198711198891

1198711198892

1198711198921

1198711198922

1198621

1198622

119877119891119862119891

1198771198662

119881in

1198771198661

1198811198661

119881119889119889

1198623

1198711199043

1198771198893119862out

119871out

119877out

119881out

1198722

1198721

1198723

1198811198663

Figure 4 Schematic circuit of LNA2

Metal 6

Port 2(Metal 6)

Metal 2

Port 1(Metal 6)

Metal 4

Figure 5 3D view of the symmetric 3D proposed structure

25 35 45 55 65 75 85 95 105 115Frequency (GHz)

200

180

160

140

120

100

80

60

40

20

00

Gai

n an

d N

F (d

B)

GainNoise figure

Figure 6 11987821(dB) and NF (dB) of LNA1


20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

150

100

50

0

minus50

minus100

Gai

n (d

B)

LNA2 (planar Ind)LNA2 (3D Ind)

Figure 7 11987821(dB) of LNA2

20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

60

50

40

30

20

10

00

Noi

se fi

gure

(dB)


119878-parameter response

Figure 8 NF (dB) of LNA2

circuit is shown in Figure 4 is an extended version of LNA1 Ithas a wider operating band of frequency which extends from25GHz to 16GHz

Input impedance match has a special importance andconsideration especially in wideband sensitive circuitsdesign Input impedance matching bandwidth is broadenedby the use of a weaker shunt capacitive-resistive feedbackloop which mainly leads to quality factor reduction of theinput matching circuit Weakness of shunt feedback strengthnot only reduces the input reflection coefficient over thiswide bandwidth but it also reduces the input side injectedthermal noise which decreases the proposed LNA2 noise

25 35 45 55 65 75 85 95 105 115Frequency (GHz)

0

minus50

minus100

minus150

minus200

minus250

minus300

minus350

Refle

ctio

n co

effici

ents

(dB)

11987811

11987822

Figure 9 11987811(dB) and 119878

22(dB) of LNA1

20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175


11987811

(dB)


figure indicating the enhanced noise performance of thesuggested design

Shunt-peaking technique increases the low frequencygain and hence decreases the gain flatnesswhile having awideoperating bandwidth In spite of shunt-peaking drawbacks itmainly facilitates LNA output impedance to load matchingLNA2 bandwidth extension and gain flatness over its operat-ing band of frequency are achieved through the removal ofshunt peaking Moreover the control of gate peaking is usedto enhance the current reuse amplifier core gain

For wideband output impedance matching a unity com-mon gate (CG) matching topology in addition to series


20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175

minus200


11987822

(dB)


resonance circuit consisting of capacitor 119862out and inductor119871out is used to match the LNA2 output impedance to its load(succeeding RF stage) The resistive termination 119877out is usedto control the load-output impedance match bandwidth

A planar RF on-chip spiral inductor (1198711198891) having an

inductance of 145 nH and a maximum quality factor of 80 isneeded as a load of the input CS stage to improve the currentreuse stages matching This RF integrated inductor occupiesan area of 428 120583m times 425 120583m which represents a considerablepart of the UWB LNA total die area

One of the well-known difficulties facing the develop-ment of RFICs is inductors large area relative to other passiveand active components This area problem becomes moresevere with the recent intensive shrinking of active devicesand competitive reduction of fabrication cost [10]

Inductors quality factor (119876) reduction is another limitingfactor of RFICs performance enhancement The reduction ofinductor119876 factor is due to ohmic and substrate losses Ohmiclosses can be decreased by using a high conductive metalfor inductor implementation On the other hand placing ahigh resistive layer underneath the inductor can minimizethe substrate losses Lately optimized 3D structures andimplementations of RF integrated inductors are suggestedto overcome all of these limitations and improve the RFintegrated inductors performance [4 5]

For LNA2 circuit area reduction and RF inductor char-acteristics improvement a symmetric 3D structure for RFintegrated inductor implementation is suggested to replacethe planar RF integrated inductor (119871

1198891) Similar to the design

of planar RF inductor 3D metallic structure layout shouldbe drawn on a substrate to design and test a 3D integratedinductor [11] 3D RF inductors structures are mainly consist-ing of serially connected different metal layers spirals havingthe same current flowdirectionThis 3D structure inductance

is dependent on these different spirals inductances and thepositive mutual coupling they have [11]

For 1P6M CMOS technology which has six differentmetal layers the proposed symmetric 3D RF integratedinductor has a complete spiral inductor on the highest metallayer (1198726) Half of the lower spiral is implemented usingfourth metal layer (1198724) to increase its inductance value dueto the increased mutual coupling The second metal layer(1198722)which is distant from the topmetal layer is employed toimplement the lower spiral other half to reduce the parasiticcomponents of that 3D metal structure and increase itsquality factor The suggested symmetric 3D inductor has aninductance of 145 nH a quality factor of 85 and an areaof 185 120583m times 165 120583m 80 of planar inductor area is savedthrough this symmetric 3D structure while achieving thesame inductance value and higher quality factor Figure 5shows a 3D view of the proposed symmetric RF integratedinductor

3 Simulation Results and Discussion

The proposed UWB LNA (LNA1 and LNA2) circuits aredesigned in TSMC CMOS 018 120583m technology process usingAgilent Advanced Design System (ADS) Electromagneticsimulation is verified by the post-layout simulation resultswhich are obtained using the Cadence design environmentThe suggested symmetric 3D structure is designed and testedusing Momentum simulation software and verified usingCadence design environment The LNAs simulation resultsare given below

31 Power Gain and Noise Figure LNA1 has a gain of 17 plusmn15 dB as shown in Figure 6 It also has a noise figure less than23 dB over its operating band of frequency (31ndash106GHz)11987821(dB) of LNA2 is higher than 10 dB with a maximum

value of 12 dB over the desired band of frequency (25ndash16GHz) This high and flat gain is due to the use of inductivegain-peaking technique in addition to the control of the unitygain current cut-off frequencies of LNA2 Figure 7 showsthat the proposed LNA2 employing the symmetric 3D RFintegrated inductor achieves a gain of 11 plusmn 10 dB

The proposed UWB LNA2 has an enhanced LNA noiseperformance LNA2 NF ranges from 25 dB to 33 dB overthe operating bandwidth (25ndash16GHz) This NF reduction isaccomplished due to the optimization of the LNAnoise factorgiven by (4) and the use of weak shunt capacitive-resistivefeedback implemented over the input stage LNA2 achievesa NF less than 33 dB over the operating band of frequency asshown in Figure 8

32 Input and Output Impedance Matching LNA1 input andoutput ports have good matching conditions to its sourceand load respectively Simulation results of input and outputreflection coefficients of LNA1 are shown in Figure 9 LNA1has 11987811and 11987822less than minus11 dB and minus10 dB respectively over

the UWB range of frequenciesThe proposed UWB LNA2 achieves good input im-

pedance matching as shown in Figure 10 Good impedance


Table 1 Proposed UWB LNA performance summery in compari-son to recently published UWB LNAs

Reference BW(GHz)

Gain(dB)

NF(dB)

11987811

(dB)11987822

(dB)This work (LNA2)lowast 25sim16 11 plusmn 10 lt33 ltminus7 ltminus725This work (LNA1)lowast 31sim106 17 plusmn 15 lt23 ltminus11 ltminus10LNA-1 [1] 17sim59 112 plusmn 23 lt47 ltminus118 ltminus127LNA-2 [1] 15sim117 122 plusmn 06 lt48 ltminus86 ltminus10[2] 3sim106 15 lt44 ltminus7 NA[12] 31sim106 108 plusmn 17 lt6 ltminus10 ltminus93[13] 1sim5 127 plusmn 02 lt35 ltminus8 NAlowastPost-layout simulation results

match between LNA2 and its source is obtained using theseries-resonant input matching technique The input returnloss (119878

11) is less thanminus70 dB over this wide range of frequency

(25ndash16GHz)Figure 11 shows that better output impedance matching is

obtained using the planar integrated inductor while simulat-ing LNA2 Good output impedance matching of LNA2 overits operating band of frequency (25ndash16GHz) is accomplisheddue to the optimization of the CG outputmatching stage withthe aid of the output LC resonant circuit 119877out termination isused to widen the matching bandwidth The output returnloss (119878

22) shown in Figure 11 is less than minus725 dB for LNA2

using the planar inductor while it is less than minus60 dB forLNA2 employing the proposed 3D inductor over the desiredfrequency band (25ndash16GHz)

33 DC Power Reverse Isolation and Stability LNA1 andLNA2 consume DC power of 128mW and 20mW respec-tively froma 18Vpower sourceThe increasedDCconsump-tion of LNA2 is due to having enough driving bias for the CGoutput match stage

Both of the proposed UWB LNA1 and LNA2 have areverse isolation factor (119878

12) less thanminus28 dBover each design

bandwidthThe proposed UWB LNAs (LNA1 and LNA2) areunconditionally stable over their bandwidths

Table 1 shows a summary of the proposed UWB LNAsperformance in comparison to other recently publishedUWBLNAs implemented in 018120583m CMOS technology

4 Conclusion

In this paper two different UWBLNAswere presented LNA1has high gain minimized noise figure and good impedancematch over the UWB range of frequencies LNA2 has awide range of operating frequency (25 GHzndash16GHz) UWBLNA2 consists of a current reuse cascaded amplifier withshunt resistive feedback followed by a CG output stage withresistive termination LNA2 input stage use series-resonantimpedancematching technique and employs a symmetric 3DRF integrated inductor as a load The post-layout simulationresults of LNA1 and LNA2 demonstrate the performanceimprovement achieved through theses designs The next step

is to implement these UWB LNAs to have a comparisonbetween post-layout simulation results andmeasured results

References

[1] Y S Lin C Z Chen H Y Yang et al ldquoAnalysis and designof a CMOS UWB LNA with dual-RLC-branch wideband inputmatching networkrdquo IEEE Transactions on Microwave Theoryand Techniques vol 58 no 2 pp 287ndash296 2010

[2] A I A Galal R K Pokharel H Kanay and K Yoshida ldquoUltra-wideband low noise amplifier with shunt resistive feedbackin 018 120583m CMOS processrdquo in Proceedings of the 10th TopicalMeeting on Silicon Monolithic Integrated Circuits in RF Systems(SiRF rsquo10) pp 33ndash36 January 2010

[3] K Yousef H Jia R Pokharel A Allam M Ragab and KYoshida ldquoA 2ndash16GHz CMOS current reuse cascaded ultra-wideband low noise amplifierrdquo in Proceedings of the Saudi Inter-national Electronics Communications and Photonics Conference(SIECPC rsquo11) April 2011

[4] K Yousef H Jia R Pokharel A Allam M Ragab andK Yoshida ldquoDesign of 3D Integrated Inductors for RFICsrdquoin Proceeding of 2012 Japan Egypt Conference on ElectronicsCommunications and Computers (JECECC rsquo12) pp 22ndash25

[5] X N Wang X L Zhao Y Zhou X H Dai and B C CaildquoFabrication and performance of novel RF spiral inductors onsiliconrdquo Microelectronics Journal vol 36 no 8 pp 737ndash7402005

[6] A M Niknejad and R G Meyer ldquoAnalysis design andoptimization of spiral inductors and transformers for Si RFICrsquosrdquo IEEE Journal of Solid-State Circuits vol 33 no 10 pp1470ndash1481 1998

[7] T H Lee The Design of CMOS Radio-Frequency IntegratedCircuits Cambridge University Press 2nd edition 2004

[8] S S Mohan M Del Mar Hershenson S P Boyd and T HLee ldquoBandwidth extension in CMOS with optimized on-chipinductorsrdquo IEEE Journal of Solid-State Circuits vol 35 no 3 pp346ndash355 2000

[9] H T Friis ldquoNoise figure of radio receiversrdquo Proceedings of theIRE vol 32 no 7 pp 419ndash422 1944

[10] H Y Tsui and J Lau ldquoExperimental results and die area efficientself-shielded on-chip vertical solenoid inductors for multi-GHzCMOS RFICrdquo in Proceedings of the IEEE Radio FrequencyIntegrated Circuits (RFIC) Symposium pp 243ndash246 June 2003

[11] H Garcia S Khemchndai R Puildo A Lturri and J Pino ldquoAWideband active feedback LNA with a Modified 3D inductorrdquoMicrowave andOptical Technology Letters vol 52 pp 1561ndash15672010

[12] P Sun Sh Liao H Lin Ch Yang and Y Hsiao ldquoDesign of 31 to106 GHz ultra-wideband low noise amplifier with current reusetechniques and low power consumptionrdquo in Proceedings of theProgress In Electromagnetics Research Symposium pp 901ndash905Beijing China March 2009

[13] A I A Galal R K Pokharel H Kanaya and K Yoshidaldquo1-5GHz wideband low noise amplifier using active inductorrdquoin 2010 IEEE International Conference on Ultra-WidebandICUWB2010 pp 193ndash196 chn September 2010

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2 Circuit Description

As shown in Figure 1 the proposed UWB LNA is a currentreuse cascaded core based on a common source topologywitha shunt resistive feedback technique implemented over theinput stage

This current reuse cascaded amplifier achieved goodwideband input impedance matching through the use ofsource degeneration input matching technique Figure 2shows the small signal equivalent circuit of this LNA inputstage The input port of this UWB LNA is desired tomatch source impedance 119877

119904at resonance frequency 120596

119900 This

matching circuit bandwidth is defined through the qualityfactors of source degeneration and gain-peaking inductors(119871119904and 119871

119892) where the input impedance is given by

119885in = 119895120596 (119871 119904 + 119871119892) +1

119895120596119862gs+ 120596119879119871119904

= 119895120596 (119871119904+ 119871119892) +

1

119895120596119862gs+ 119877119904

(1)

where 119885in is the UWB LNA input impedance and 120596119879is the

current-gain cut-off frequency where 120596119879= 119892119898119862gs and 119892119898

and119862gs are the input stage transconductance and gate-sourcecapacitance respectively 119881

119904represents the RF signal source

119877119904is the output impedance of 119881

119904

Although the shunt resistive feedback loop leads toLNA noise performance degradation [7] it is widely usedin recently proposed LNAs due to its superior widebandcharacteristics Shunt capacitive-resistive feedback techniqueis employed to widen the input-matching bandwidth andincrease the LNA stability

Shunt-peaked amplifiers are known to have wide gainbandwidth and high low frequency power gain [8] To havea high flattened gain of the proposed UWB LNA shunt-peaking technique is used In addition the gate-peaking tech-nique is used to enhance the LNA gain at high frequenciesBesides the shunt- and gate-peaking techniques the shuntresistive feedback loop is used in gain flattening [2 8] TheLNA approximate gain is given by

119860 cong119881out119881119904

cong

11989211989811198921198982[119877119871 (1198771198892+ 1198781198711198892)] [119878119871

1198891]

2 sdot 119878119862gs1 [119878 (119871 1199041 + 1198711198921) + 1119878119862gs1]

(2)

Ultra-wideband applications require good noise perfor-mance in addition to high and flat gain Low noise designtechniques which are suitable for narrowband applicationscannot be used for wideband applicationsMain contributionof cascaded matched stages noise figure is due to first stage[9]The reduction of noise figure of input stagewill lead to thereduction of the overall noise figure of the proposed designOptimization and control of factors affecting the NF willimprove this UWB LNA noise performance An equivalentcircuit of the input stage for noise factor calculation is shownin Figure 3 [1]

An estimated value of the noise figure (NF = 10 log10119891)

of this topology is given in [1] where 119891 is the noise factor ofthe UWB LNAThe noise factor 119891 can be given by

119891 = 1 +

119877119892+ 119877lg + 119877ss + 119877ls

119877119904

+

1205751205721205962

1198622

gs1119877119904

51198921198981

+

119877FB ((1198711198921 + 119871 1199041) 119862gs1)2

119877119904(1198921198981119877FB minus 1)

2

sdot

10038161003816100381610038161003816100381610038161003816

1199042

+ 119904 (

120596119900rfbn

119876rfbn) + 120596

2

119900rfbn

10038161003816100381610038161003816100381610038161003816

2

+

1205741198921198981(119877FB + 119877119904)

2

((1198711198921+ 1198711199041) 119862gs1)

2

120572119877119904(1198921198981119877FB minus 1)

2

sdot

10038161003816100381610038161003816100381610038161003816

1199042

+ 119904 (

120596119900dn

119876dn) + 120596

2

119900dn

10038161003816100381610038161003816100381610038161003816

2

(3)

119891 = 1 +

119877119892+ 119877lg + 119877ss + 119877ls

119877119904

+ 119891gn + 119891rfbn + 119891dn (4)

where

120596119900rfbn = radic

1 + 1198921198981119877119904

(1198711198921+ 1198711199041) 119862gs1

119876rfbn =1

119877119904+ 12059611987911198711199041

sdot radic(1 + 119892

1198981119877119904) (1198711198921+ 1198711199041)

119862gs1

120596119900rfbn = radic

1

(1198711198921+ 1198711199041) 119862gs1

119876dn =1

(119877119904|| 119877FB) + 1205961198791119871 1199041

sdot radic(1198711198921+ 1198711199041)

119862gs1

(5)

where119891gn119891dn and119891rfbn are gate drain and feedback resistornoise factors respectively and 120572 120575 and 120574 are constants equalto 085 41 and 221 respectively

It is clear from (4) that to reduce the noise figure highquality factors of 119871

1199041and 119871

1198921are desired It can also be noted

that the noise factor is inversely proportional to feedbackresistor119877

119891 In otherwords weak feedback topology decreases

the noise factor value while strong feedback implementationdegrades the noise performance of the suggested UWB LNA

In addition the noise factor formula given by (4) statesthat the noise figure is also inversely proportional to thetransconductance of the input stage (119892

1198981) This goes along

with the known fact that noise performance trades off withpower consumption

For output matching the series resonance of the shuntpeaking technique is used to match the proposed UWB LNAto the load impedance119877

119871while the series drain resistance119877

1198892

is used to extend the output matching bandwidthThis proposedUWBLNA (LNA1) has an operating band-

width of 31ndash106GHzThe proposed LNA2 whose schematic


1198711199041

1198711198891

1198711198892

1198711198921

1198711198922

11986211198622

119877119891119862119891

1198771198662

119881in

1198771198661

1198811198661

119881119889119889

119881out1198722

1198721

1198771198892

119877119871


119871119904

119871119892

119885in

119877119904

119881119904

119903119900119862 119892119898119881gs gs


119877

1198942

1198902119904

119877119878

1198711198661 119877 1198902 1198902

1198942119892119862 1

119881 1

119877119904

1198902

1198711199041

119877

1198902

1198921198981119881 1 1198942

119889 1198942119899out

119877

+

minus

FB

rfb

119892 rg

gs

rs

ls

lg lg

gs

ls

gs


1198711199041

1198711198891

1198711198892

1198711198921

1198711198922

1198621

1198622

119877119891119862119891

1198771198662

119881in

1198771198661

1198811198661

119881119889119889

1198623

1198711199043

1198771198893119862out

119871out

119877out

119881out

1198722

1198721

1198723

1198811198663


Metal 6

Port 2(Metal 6)

Metal 2

Port 1(Metal 6)

Metal 4


25 35 45 55 65 75 85 95 105 115Frequency (GHz)

200

180

160

140

120

100

80

60

40

20

00

Gai

n an

d N

F (d

B)

GainNoise figure



20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

150

100

50

0

minus50

minus100

Gai

n (d

B)



20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

60

50

40

30

20

10

00

Noi

se fi

gure

(dB)






25 35 45 55 65 75 85 95 105 115Frequency (GHz)

0

minus50

minus100

minus150

minus200

minus250

minus300

minus350

Refle

ctio

n co

effici

ents

(dB)

11987811

11987822

Figure 9 11987811(dB) and 119878

22(dB) of LNA1

20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175


11987811

(dB)






20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175

minus200


11987822

(dB)






















Reference BW(GHz)

Gain(dB)

NF(dB)

11987811

(dB)11987822













4 Conclusion



References
















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










1198711199041

1198711198891

1198711198892

1198711198921

1198711198922

11986211198622

119877119891119862119891

1198771198662

119881in

1198771198661

1198811198661

119881119889119889

119881out1198722

1198721

1198771198892

119877119871


119871119904

119871119892

119885in

119877119904

119881119904

119903119900119862 119892119898119881gs gs


119877

1198942

1198902119904

119877119878

1198711198661 119877 1198902 1198902

1198942119892119862 1

119881 1

119877119904

1198902

1198711199041

119877

1198902

1198921198981119881 1 1198942

119889 1198942119899out

119877

+

minus

FB

rfb

119892 rg

gs

rs

ls

lg lg

gs

ls

gs


1198711199041

1198711198891

1198711198892

1198711198921

1198711198922

1198621

1198622

119877119891119862119891

1198771198662

119881in

1198771198661

1198811198661

119881119889119889

1198623

1198711199043

1198771198893119862out

119871out

119877out

119881out

1198722

1198721

1198723

1198811198663


Metal 6

Port 2(Metal 6)

Metal 2

Port 1(Metal 6)

Metal 4


25 35 45 55 65 75 85 95 105 115Frequency (GHz)

200

180

160

140

120

100

80

60

40

20

00

Gai

n an

d N

F (d

B)

GainNoise figure



20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

150

100

50

0

minus50

minus100

Gai

n (d

B)



20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

60

50

40

30

20

10

00

Noi

se fi

gure

(dB)






25 35 45 55 65 75 85 95 105 115Frequency (GHz)

0

minus50

minus100

minus150

minus200

minus250

minus300

minus350

Refle

ctio

n co

effici

ents

(dB)

11987811

11987822

Figure 9 11987811(dB) and 119878

22(dB) of LNA1

20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175


11987811

(dB)






20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175

minus200


11987822

(dB)






















Reference BW(GHz)

Gain(dB)

NF(dB)

11987811

(dB)11987822













4 Conclusion



References
















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

150

100

50

0

minus50

minus100

Gai

n (d

B)



20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

60

50

40

30

20

10

00

Noi

se fi

gure

(dB)






25 35 45 55 65 75 85 95 105 115Frequency (GHz)

0

minus50

minus100

minus150

minus200

minus250

minus300

minus350

Refle

ctio

n co

effici

ents

(dB)

11987811

11987822

Figure 9 11987811(dB) and 119878

22(dB) of LNA1

20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175


11987811

(dB)






20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175

minus200


11987822

(dB)






















Reference BW(GHz)

Gain(dB)

NF(dB)

11987811

(dB)11987822













4 Conclusion



References
















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










20 35 50 65 80 95 110 125 140 155 170Frequency (GHz)

0

minus25

minus50

minus75

minus100

minus125

minus150

minus175

minus200


11987822

(dB)






















Reference BW(GHz)

Gain(dB)

NF(dB)

11987811

(dB)11987822













4 Conclusion



References
















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











Reference BW(GHz)

Gain(dB)

NF(dB)

11987811

(dB)11987822













4 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









research article cmos ultra-wideband low noise …downloads.hindawi.com/archive/2013/328406.pdf1 2...

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