Successes in RF CMOS Circuit Design

Henrik Sjöland

2007-09-06

Some Successes

1st Success: Transmitter Linearization2nd Success: CMOS VCO’s3rd Success: CMOS Receivers4th Success: CMOS at High Frequencies5th Success: Adaptive Antenna Matching

…and the PhD:s

1st Success: Transmitter Linearization

• Major project in first 2 stages• Led by Dr. Lars Sundström• Important then – Even more important now!• Required for spectrally efficient systems (3G,LTE, ..)• Both in terminals and base stations• Analog & Digital Pre-Distortion• Power Feedback• LINC

Power Amplifier Characteristics

Principle ofPredistortion

PA

PAPD

Analog Predistortion

• 5th order complex polynomial• 3.3V, 20mA (only 30% in polynomial)• Bandwidth (3dB) 120MHz• Differential 200Ω interface• Hand-tuning of coefficients• Standard 0.8um CMOS process• ISCAS ’99• Improved circuit at ESSCIRC ’01

Eric Westesson

Saturated Class A PA without and with Predistortion

35dB

Eric Westesson

Power Feedback

Power FeedbackBo Shi

• 3.3V, 19mA• RF input bandwidth ~1GHz• Differential 200Ω interface• Standard 0.6um CMOS process• Presented at ISCAS ’99

Power Feedback –Spectrum and Efficiency

10dB

Bo Shi

Direct Synthesis with LINC

• Generate constant envelope phasors at high power levels to be combined prior to the antenna

LINC Signal Vector

SCS withBiCMOSCircuit

Bo Shi

• 5V, 100mW• Operates with IF at 200MHz• Standard 0.8um BiCMOS process• Presented at ESSCIRC ’99, JSSC 2000

SCS withTranslinearBiCMOSCircuit

Bo Shi

• 5V, 70mW• Operates with IF at 200MHz• Standard 0.8um BiCMOS process• Presented at VLSI Symp. 2000

Experimental Results

55dB

Bo Shi

• PHS signalπ/4 shifted DQPSK

• 384 Kbps

SCS withTranslinearCMOS Circuit

Bo Shi

• 5V, 80mW• Operates with IF at 100MHz• Standard 0.35um CMOS process• Presented at CICC ’01

Experimental Results

48dB

Bo Shi

• IS-95 signalOQPSK

• 1.2288 Mbps

2nd Success: CMOS VCO:s• Varactors: Continuous and switched• Phase noise improvements• Low voltage VCO:s• Quadrature VCO:s• High frequencies (presented tomorrow)

CMOS VaractorsPietro Andreani

• MOS device versus ”standard” diode varactor• Strong/weak inversion MOS versus

accumulation/depletion MOS • Embedded in VCO’s with bond wire inductors• ESSCIRC ’98, ISCAS ’99 and 2000, JSSC 2000

A-MOS Varactor

Pietro Andreani

• S. Mattisson ’97• Lee et al., Castello et al.,

VSLI Symposium ’98

Differential Switched Tuning

• Digital coarse frequency tuning• High linearity• Flexibility• Doubled Q compared to

single-ended scheme• IEEE TCAS-II, 2002

b0 b0 b0

C W Cb1 b1 b1

2C 2W 2C

b2 b2 b2

4C 4W 4C

To differentialresonator

Henrik Sjöland

Monolithic CMOS VCO’s with Low Phase Noise (I)

Henrik Sjöland

• High frequency noisefrom tail current is eliminated

• L and C uncritical• designed when he

was at UCLA in Prof. Abidi's group

Phase Noise and Layout

• Better performance than commercial modules• 0.35μm BiCMOS6M process (one thick metal)• ISSCC 01, JSSC December 2001

Henrik Sjöland

Monolithic CMOS VCO’swith Low Phase Noise (II)

• All noise from the tailcurrent is eliminated

• Off-chip inductor is uncritical

Piero AndreaniHenrik Sjöland

Phase Noise and Layout

Piero AndreaniHenrik Sjöland

• 1.4 V, 9 mA• Digital 0.35um CMOS process• CICC ’01, VLSI Symp. ’01, JSSC ’02

Low Voltage 2.4GHz CMOS VCO

• 1V, 5.5mA, 2.4GHz,15% tuning, -136dBc/Hz @ 3MHz offset, Asia-Pacific ‘02

• 0.7V, 2.8mA, 2.4GHz,13% tuning,-130dBc/Hz @ 3MHz offset, Rawcon ‘02

0.9mm

1.0 mm

Niklas Troedsson

Low Voltage Quadrature VCO + Buffer

• 1.3V, 5.4mA,1.8GHz (DCS)• 0.25um• -138dBc/Hz @ 3MHz offset • Norchip ’03• Springer Journal ‘05

I− I+

Vctrl

OI+

Vctrl

Q− Q+

Vctrl

OQ−OQ+

VctrlI− I+ Q− Q+

OI−

1700 1750 1800 1850 1900 1950−145

−140

−135

−130

−125

−120

Oscillation Frequency (MHz)

Pha

se N

oise

@ O

ffset

Fre

quen

cy

600kHz offset

3MHz offset

Niklas Troedsson

CAD tool for integrated inductors

Homepage:www.indentro.com

Niklas Troedsson

3rd Success: CMOS Receivers

• Linear Frontend• Low Voltage Frontends• Dual Band Frontend• Gm-C Filters

Merged LNA and Mixer forWCDMA Front End

2.7 V, 8 mA, 2.1 GHz3.2 dB NF, -1.5 dBm IIP3< -71 dBm LO @ antennaVLSI Symp. ’01, JSSC ’03 Henrik Sjöland

1V CMOS Bluetooth Front-End

0.25um CMOS 1V, 2.5mA, 2.4GHz14dB Conversion Gain5dB NF-5dBm IIP3, -15dBm CP1ESSCIRC ‘02

Fredrik Tillman

Linearized 1V CMOS front-end

-28 -24 -20 -16 -12

RF input power (dBm)

(dB

m)

-60

-40

-20

0

VLSI Symposium ‘03 Fredrik Tillman

Low Voltage Quadrature Front-End

CMOS chip featuring:• QVCO• VCO Buffers• LNA• Novel Quadrature Passive Mixers

VLSI symposium 2004

Problem of Quadrature Passive Mixers

New Quadrature Passive Mixer

LNA and Mixer Schematic

Fredrik Tillman

Low Voltage Quadrature VCO + Buffer

• 1.3V, 5.4mA,1.8GHz (DCS)• 0.25um• -138dBc/Hz @ 3MHz offset • Norchip ’03• Springer Journal ‘05

I− I+

Vctrl

OI+

Vctrl

Q− Q+

Vctrl

OQ−OQ+

VctrlI− I+ Q− Q+

OI−

1700 1750 1800 1850 1900 1950−145

−140

−135

−130

−125

−120

Oscillation Frequency (MHz)

Pha

se N

oise

@ O

ffset

Fre

quen

cy

600kHz offset

3MHz offset

Niklas Troedsson

Die Photo and Measured Results

LNA+mixer QVCO+buffer

0.83mm

1.98mm

Fredrik Tillman Niklas Troedsson

RF bandwidth 1.7-1.86GHzConversion gain 16dB

Noise figure 6dBCP1 -18dBmIIP2 27dBm

IIP3 -6dBmIF phase error < 1.8o

Power consumption 9.6mW

Supply voltage 1.2V

Dual Band Front-End

Kittichai Phansathitwong

Chip Photo and Experimental Results

• Chip area of 1.4 mm2

• 0.18um CMOS• 2 GSSG pads

1V 1.8V

2.2GHz 4.0GHz 2.2GHz 4.0GHz

Noise Figure (dB) 3.5 3.0

15

-17

-6

-26

2.4

3.0

Conv. Gain (dB) 10

3.2

11.5

-11

0

-17

15

1-dB comp. (dBm) -11 -17

IIP3 (dBm) 0 -6

S11 (dB) -18 -23

Power Consumption(mW)

2.4 4.7 4.7

Kittichai Phansathitwong

CMOS gm-C IF Filter for Bluetooth

Specifications• 1MHz pass band• 3MHz center frequency• Out-of-band rejection > 40 dB, falling

asymptotically with 60 dB/dec• Group delay ripple less than 1μs• 2.5V, 2.4mA• CICC 2000

Pietro Andreani

Polyphase gm-C ArchitecturePiero Andreani

Lowpass passive stage

Polyphase activegm-C stage

Lowpass activegm-C stage

Transconductor

CMOS gm-C Polyphase IF Filter

Specifications• Bluetooth application

• 5th order Butterworth

• B = 1MHz, fc= 3MHz

• Notch stage at fc ± 1MHz

• ESSCIRC 2000Pietro Andreani

Transfer Function and Image Band without and with Bias Adjustment

Piero Andreani

59dB 69dB

Summary of Results

Pietro Andreani

Parameter ValueVdd 2.4 V

Idd 3.2 mAOrder 5th + 2nd (10th + 4th bp.)

Center frequency (fc) 3 MHz

Suppression @ fc ± 1MHz > 40 dB

Noise (BN=2MHz) 170 µVrms

SFDR > 53 dB

Image band rejection > 59 dB out-of-band

Dimensions 680 µm x 550 µm

Bandwidth 1 MHz

Group delay variation 0.5 µs

4th Success: CMOS at High Frequencies

Measured:• 23GHz QVCO (presented tomorrow)• 8GHz beamforming transmitter

Under fabrication/measurement:• 10GHz quadrature receiver• 60GHz VCO:s• 24GHz beamforming receiver• 23GHz homodyne receiver• 24GHz beamforming transmitter• 60GHz frequency-doubling PA

8GHz beamforming transmitter

Schematics

PA

QVCO and Buffer

Board and Die

Measurement results

103 104 105 106

-140

-120

-100

-80

-60

-40

-20

Phase noise measurement of three chips and simulation

Phas

e no

ise

(dB

c/H

z)

f (Hz)

chip 1, FOM=180 dBchip 2, FOM=182 dBchip 3, FOM=181 dBSimulation, FOM=181 dB

7.7 7.8 7.9 8 8.1 8.2-7

-6

-5

-4

-3

-2

-1

Maximum output power

f (GHz)

Out

put p

ower

(dB

m)

chip 1, tuning range: 4.5%chip 2, tuning range: 4.9%chip 3, tuning range: 4.6%

0 10 20 30 40 50 60 70 80 900

10

20

30

40

50

60

70

80

90

Theoretical phase offset

Mea

sure

d ph

ase

offs

et

chip 1chip 2chip 3

5th Success: Adaptive Antenna Interfaces

• Antenna impedances seldom 50Ω due to e.g.- Small antennas- Wide bands- Different surroundings

In cooperation with Perlos

AntennaInterface

PA

LNAf

control

Peter Sjöblom

Matching Networks for DVB-H

• TV in your PDA/Phone• 470-702MHz, wide band, low frequency• Reconfigurable matching• 130nm UMC CMOS

Peter Sjöblom

Q and Range of Switched C

• Probe measurements• To appear in TCAS-II

Peter Sjöblom

Mismatch and Matching Domain

• Measured data:- Two mismatch networks, HighZ and LowZ- Impedance Tuing Unit

Peter Sjöblom

Measured Noise Improvement

Low Z High Z

Peter Sjöblom Fredrik Ahlberg

PhD students in Analog/RF

Currently active in industry at LU

(+2 missing)

Conclusions• Many successful RF projects• Lots of RF CMOS circuits designed

(Not all mentioned today)• Skilled researchers produced• Made possible by cooperation in the Centre• Hope to continue this success!