Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Design & analysis of a 2.4 GHz Design & analysis of a 2.4 GHz CMOS Quadrature VCO using CMOS Quadrature VCO using

AMSS35D4 technologyAMSS35D4 technology

RFSoC – Final ProjectRFSoC – Final ProjectMaster in Electronics EngineeringMaster in Electronics Engineering

Josep Maria Margarit Taulé

Advisor: Xavier Aragonès Cervera

Escola Tècnica Superior d’Enginyeria de Telecomunicació de Barcelona

UNIVERSITAT POLITÈCNICA DE CATALUNYA

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

11 IntroductionIntroduction

22 Design procedureDesign procedure

33 ResultsResults

44 ConclusionConclusion

Introduction Design procedure Results Conclusion

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

11 IntroductionIntroduction

22 Design procedure Design procedure

33 Results Results

44 ConclusionConclusion

Introduction Design procedure Results Conclusion

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

IntroductionIntroduction

Complete design procedure of a 2.4 GHz LC CMOS quadrature VCO.

Process technology: AMSS35D4 (SiGe 0.35 m, 4-metal, thick metal available).

Tasks:

Initial rough calculations Accurate cadence rf-modelled simulation and tuning Result analysis and conclusions

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

11 Introduction Introduction

22 Design procedureDesign procedure

33 Results Results

44 ConclusionConclusion

Introduction Design procedure Results Conclusion

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

SpecsSpecs

Spec Units Value

Vdd V 3.3

Power consumption mW <25

Output load k,pF

f0 GHz 2.4

Tuning range MHz 100

Harmonic distortion dBc <-40

S.E. output amp. V 1 Vpp ± 15%

Phase noise dBc <-100

Phase error º <1

1kΩ 0.4pF

Specs Calculations Single VCO QVCO

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Handy calculationsHandy calculations

First order, simplified expressions from subject topics

Automatic calculation procedure

Specs Calculations Single VCO QVCO

Excel worksheet

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Single VCO (L selection)Single VCO (L selection)

Thick metal (higher Q)

Large L/Q desired: less power consumption

TOTL 2.42nH 2 4.84nH

SL

W L 2 2.4e9 4.84e 9R 7.848

Q 9.6

2PL SR R 1 Q 686.613

Specs Calculations Single VCO QVCO

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Single VCO (varactor selection)Single VCO (varactor selection)

Minimum varactors

Higher QT

TOT 20

var

1C 908.6fF

W L

C8.33%

CC 8.33e 2 908.6fF 75.69fF C

Specs Calculations Single VCO QVCO

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Single VCO (ISingle VCO (Itail tail calculation)calculation)

Losses estimation:

Itail must be:

Specs Calculations Single VCO QVCO

Ptotal load Pinductor PveqR R R R

ptotaltotal

0

RQ

Z

tan k tan ktail

ptotal total 0

2V 2VI

R Q Z

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Single VCO (nmos W-L choice)Single VCO (nmos W-L choice)

From previous Itail calculation (b=2):

But... Transistor losses!

Specs Calculations Single VCO QVCO

m biasptotal

4 Wg 2K ' I

R L

ptotal load Pinductor Pveq PequivnmosR R R R R

L=1 µm

Further considerations:

Adjustments Iterative tran simulations

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Single VCOSingle VCO

Itail =7 mA

gm=13 mS

W=75 µm

L=1 µm

Specs Calculations Single VCO QVCO

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion Specs Calculations Single VCO QVCO

QVCOQVCO

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion Specs Calculations Single VCO QVCO

QVCO (coupling definition)QVCO (coupling definition)

Coupling factor:

couplingnmos

switchingnmos

W

W

Trade-off:

α Phase noise , but phase error !! α =1/3

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion Specs Calculations Single VCO QVCO

QVCO (center frequency tuning)QVCO (center frequency tuning)

Pss simulations

From an initial frequency (f0i):

Cpoly resizing

parasitics var poly20i

1C C C

L W

~350 fF

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

11 Introduction Introduction

22 Design procedure Design procedure

33 ResultsResults

44 ConclusionConclusion

Introduction Design procedure Results Conclusion

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Results (I-Q transient analysis)Results (I-Q transient analysis)

Vtank ~ 900 mV

Tinit ~ 1.5 µs

I-Q tran F/V Harm./Ph. noise Ph. error Summary

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Results (f/V pss analysis)Results (f/V pss analysis)

ftun ~ 2.35-2.45 GHz

KVCO ~ 268 MHz/V

I-Q tran F/V Harm./Ph. noise Ph. error Summary

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Results (harmonic/phase noise analysis)Results (harmonic/phase noise analysis)

Max. Harm. level ~ -43.3 dBc

Phase noise (600 kHz) ~ -118 dBc

I-Q tran F/V Harm./Ph. noise Ph. error Summary

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Results (phase error)Results (phase error)

Phase error:

phase

1.09p360 0.942º

1

2.4e9

I-Q tran F/V Harm./Ph. noise Ph. error Summary

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

Results (summary)Results (summary)

QVCO final parameters

QVCO final results

I-Q tran F/V Harm./Ph. noise Ph. error Summary

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

11 Introduction Introduction

22 Design procedure Design procedure

33 Results Results

44 ConclusionConclusion

Introduction Design procedure Results Conclusion

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Introduction Design procedure Results Conclusion

ConclusionConclusion

Complete design procedure of a 2.4 GHz LC CMOS quadrature VCO (SiGe 0.35 m, 4-metal, thick metal tech process)

Tech. main drawback: low QL Itail

Design key points:

L selection (highest L-Q at main frequency)

But... Ctotal>Cparasitics!!

gds to be considered!

Coupling factor trade-off (Phase noise vs. Phase error)

Josep Maria Margarit Taulé Design & analysis of a 2.4-GHz CMOS QVCO using AMSS35D4

Design & analysis of a 2.4 GHz Design & analysis of a 2.4 GHz CMOS Quadrature VCO using CMOS Quadrature VCO using

AMSS35D4 technologyAMSS35D4 technology

RFSoC – Final ProjectRFSoC – Final ProjectMaster in Electronics EngineeringMaster in Electronics Engineering

Josep Maria Margarit Taulé

Advisor: Xavier Aragonès Cervera

Escola Tècnica Superior d’Enginyeria de Telecomunicació de Barcelona

UNIVERSITAT POLITÈCNICA DE CATALUNYA