11

LOW POWER MILLIMETER WAVE ACTIVE SIGE SUB-HARMONIC UP-CONVERSION MIXER WITH

ULTRA LOW DRIVING POWER

Jinna Yan

Nanyang Technological University

Singapore

22

Agenda

• Introduction

• System Architecture

• Literature Review

• Design of Up-conversion Mixer-- Schematic

-- Layout

-- Post-layout simulation results

• Conclusion

33

Introduction

• Why 60GHz? Unprecedented amount of spectrum

-- Spectral efficiency not a dominant constraint

-- 2GHz bandwidth per channel License free

-- Few regulatory specifications Small wavelength

-- Multi-antenna ideal for small form factor devices

44

Introduction-cont..

• Targeted Application:-- Wireless personal area

networks

-- Short range <10m

-- High data rate >2Gbps

• System requirements:-- Highly integrated, low cost

-- Small in size

-- Low power

55

• Sub-harmonic up conversion using sliding IF topology

• LO operating at a relatively lower frequency, alleviates the

design for synthesizer

• IF signals has a bandwidth greater than 10GHz centered at

12GHz

• LO signal bandwidth of 3.5GHz at 24GHz

System Architecture

66

Literature Review I:

Ref: A Frequency Tripler Using a Subharmonic Mixer and Fundamental Cancellation

• Topology:

-- Fully differential sub-harmonic core mixer

-- Three transistor architecture

77

Literature Review II:

• Topology:

-- Double balanced Gilbert mixer

-- mHEMT FET technology

-- Chip area 3mm X 3mm

Ref: 60 GHz MMIC double balanced Gilbert mixer in mHEMT technology with integrated RF, LO, and IF baluns

88

Schematic of Designed Up-conversion Mixer

Q1Q2 Q3Q4

C1

L1

L3

TL1

C7

C5

C6

C3

C4

L2

C2

C8

IF+

IF-

LO(180)

LO(0)

LO(90)

LO(270)

RF_BIAS

LO_BIAS LO_BIAS

RF+

RF-

TL2

Q5Q6 Q7Q8

Q1Q2 Q3Q4

C1

L1

L3

TL1

C7

C5

C6

C3

C4

L2

C2

C8

IF+

IF-

LO(180)

LO(0)

LO(90)

LO(270)

RF_BIAS

LO_BIAS LO_BIAS

RF+

RF-

TL2

Q5Q6 Q7Q8

99

Features of Designed Up-conversion Mixer

• RF output signal has a bandwidth of 11GHz

• Use of two transistor topology to reduce voltage supply

requirement

• Pesudo-differential LO core

• Designed CPW transmission lines load

1010

Schematic of Common Emitter Buffer

Q1 Q2

C1

L1

L2C3

C2

C4

IN+

IN-RF_BIAS

OUT+

OUT-

Q3TAIL_BIAS

C5

C6

Q1 Q2

C1

L1

L2C3

C2

C4

IN+

IN-RF_BIAS

OUT+

OUT-

Q3TAIL_BIAS

C5

C6

1111

Layout of Up-conversion Mixer Core & Buffer

• Process:

-- Jazz Semiconductor

-- 0.18µm SiGe BiCMOS

-- High ft of 200GHz

• Chip size: -- 0.88mm X 0.78mm

(inc. pads)DIFFERENTIAL RF

DIFFERENTIAL IF

QUADRATURE LO

BIAS

BIAS

MIXER

BUFFER

DIFFERENTIAL RF

DIFFERENTIAL IF

QUADRATURE LO

BIAS

BIAS

MIXERMIXER

BUFFERBUFFER

1212

Sparameters @ IF and LO Ports

- 30

- 20

- 10

0

0 10 20 30 40 50Frequency (GHz)

Spar

amet

ers

@ IF

Por

t

- 20

- 15

- 10

- 5

0

Spar

amet

ers

@ LO

Por

t

1313

Conversion Gain vs. LO Power

- 25

- 20

- 15

- 10

- 5

0

- 20 - 17 - 14 - 11 - 8 - 5LO Power @ 24 GHz (dBm)

Conv

ersi

on G

ain

(dB)

1414

Gain Flatness vs. RF Output Frequency

- 5

- 4

- 3

- 2

- 1

0

1

58 62 66 70Frequency (GHz)

Conv

ersi

on G

ain

(dB)

1515

Voltage Conversion Gain vs. IF Input Signal Power

- 12

- 8

- 4

0

- 30 - 25 - 20 - 15 - 10 - 5 0

I F Power @ 12 GHz (dBm)

Conv

ersi

on G

ain

(dB)

1616

Output Frequency Spectrum

- 140

- 100

- 60

- 20

20

20 30 40 50 60 70 80Frequency (GHz)

Spec

trum

@ R

F Po

rt (

dBm)

1717

• Power consumption (Mixer Core): 1.7mA @ 1.8V

• Max. Gain: -0.1dB

• RF output 3dB gain flatness: 59GHz ~ 70GHz

• Input referred P1dB: -12.3dBm

• LO power drive requirements: -14dBm

• Spur suppression: >20dBc

Overall Specification

1818

• A low power active sub-harmonic mixer has been designed

for the 60GHz SOC

• It provides a elegant solution to upconvert low frequency

signals without a high frequency VCO

• Features achieved include high bandwidth, high linearity and

low LO drive power levels

Conclusion

1919

Thank you

Q & A