System R&D on Multi-Standard RF Transceiver for 3G and beyond Advanced System Technology

System R&D on Multi-Standard RF Transceiver for 3G and beyond

Advanced System Technology

2


Overview• Radio front end for 3G wireless terminals and beyond :

driving aspects , re-configurable RF front end , technology

• Multimode receiver architecture :- key aspects of the receiver and architecture - research technology areas

• Multimode transmit chain : - key aspects of the transmit chain- research technology areas

• Summary

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THE PATH TOWARD 4G (Europe)

GSM 900MHzDCS 1800MHzPCS 1900MHz

200 KHzGMSK9.6kbps

GPRS

200 KHzGMSK multislot115kbps

EDGE

200 KHz8PSK384kbps

WCDMA FDD 1.9-2.2GHz

5MHzHPSK384kbps/2Mbps

2G 2.5G

3G

3.5G

WCDMATDD 2Mbps

HSDPA 10Mbps

4G

MCCDMA 100Mbps

?

WLAN 802.11b 2.4GHz

20MHzDSSS11Mbps

20MHzOFDM54Mbps

WLAN 802.11a 5GHz

20MHzOFDM54Mbps

HIPERLAN2 5GHz

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MULTIMODE 3G TERMINALS

Future wireless terminals will have to be multimode , multi-bands and able to do handover between multiple standards

3 key aspects of the RF transceiver : Low cost : component count Low power consumption for battery life enhancement Performance to enable high data rates and high sensitivity

-transceiver architecture-Passive comp.integration-Technology partitionning

-Power amplifier system-Technology partitionning

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Transceiver component count and board area

GSMMonobandComp.

GSMDualbandComp.

Dualband Dualmode Comp.

GSMBoard area mm2

1992 450 - - 4000

1995 240 - - 2500

1998 150 210 - 1000

2001 85 100 200 500

2005 60 75 100 300

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The handover issue• Simultaneous reception in multiple standards or

discontinuous reception (compressed mode) ?• Simultaneous reception main drawback : parallel

transceivers for the different standards have to be implemented in the same phone

cost and battery life are affected• Discontinuous reception : allows use of

reconfigurable architectures (lower cost and longer battery life) but effect of discontinuous connection of the mobile on the network operation is not clear

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3G Multimode Terminal

GSM/DCSRF RECEIVER

GSM/DCSDUAL PA

GSM/DCS RXANALOGBASEBAND

GSM/DCSRF AND BB TX

GSM/DCSSYNTHESIZER

WCDMARF RECEIVER

WCDMA PA

WCDMAANALOGBASEBAND

WCDMARF AND BB TX

WCDMASYNTHESIZER

GSM / DCS

DIGITAL BASEBAND

WCDMA

DIGITAL BASEBAND

VOICE

CODEC

AND

AUDIO

Safe approach but bulky and high cost

The ‘velcro’ solution : duplication of physical layers

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WCDMA FDD CHIP SET REFENCE DESIGNW -C D M A RF Block diagram

Q D e m

2

PA 2

ISO

P P A

QM OD

V GA IF TXIFBPF

U P C ON V

BPF 1B P F 2

SW ITC H

LNA DW NCO NV

R F B PF

B aseB and

V GA IF R X

IFBPF

+V CC

D U P

CPL

P A

+

_

+

_

+

_ _

+

_

+

_

2

V C X O

760 MH z

2330 +/- 30M H z

Matching

Loop f ilters and resonant c ircuitintegration related to PLL f requency

} I

} Q

C1 L1C2

C3

L2

C5

L3

C4

+V CC

C6 C7

L1 1

L5

L4

C9C8

C1 0 C1 1

C1 2 C1 3

C1 4

C1 5

C1 6

C1 7

L9

L7

L8

L6

L4

C1 8 C1 9L1 0

2

2Hi/Low Linearity

H i/Low Gain

Gain Control

} Q

} I

Gain Control

Gain Control

C H IP 1

C H IP 2

C H IP 3

1/2 C H IP 4

1/2 C H IP 4

L1 2

Div id er

Div id er

Matching

L1 3

2

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3G Reconfigurable Terminal

GSM / DCS

WCDMA

DIGITAL BASEBAND

VOICE

CODEC

AND

AUDIO

RECEIVERRF FRONT END:band select , LNA,down conversion

ANALOG BB :channel filter , AGC ADC

ANALOG BBDAC , filters , mixer , AGC

PROGRAMMABLESYNTHESIZERS

POWER AMPLIFIERS

+CONTROL

MODE SELECT

PROG

PROG

MODE SELECTPOWER CONTROL

UPConv.

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3G multimode system approach

• Architecture : global considerations of RF system to achieve good balance between performance and current consumption.– Receiver : from antenna to ADC converter & Digital

Filtering– Transmit : consider the power amplifier in the global

definition of the transmit chain

• Design and implementation :co-design with different technologies (ICs , passives , MEMS ) should allow optimum power consumption : requires CAD tools ; characterization ; models with parasitic effects

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multimode enabling technologies• Semiconductor :

- deep submicron CMOS for reconfigurable functions such as analog BB , analog filters ,synthesizers , digital filters and future combination with digital BB functions- SiGe for high sensitivity (low noise with optimum power consumption) high linearity RF front end functions .- Mix of technologies inside modules for power amplification : GaAs HBT for high linearity standards , LDMOS for low cost /low linearity modulations , CMOS for linearisation functions

• Passives : high Q passive components for integration in ICs or on dedicated technologies to reduce the radio bill of material .

• RF filters :Small selective RF filters for multimode receivers covering .9 to 5GHz with low losses (FBAR?)

• MEMs : mems switches if they have low cost , reliability , low actuation voltage could simplify the architecture of multimode radios .

• Antennas : small and integrated antennas will be mandatory for future MIMO architectures

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RECEIVE PATH KEY ASPECTS

• Re-configurable receiver has to be compatible with the multi-standard handover issue• Receiver architecture and technology partitioning has to address high sensitivity

requirements (-117dBm in UMTS)• Receiver architecture and basic blocks performances have to be compatible with

multiple bands and both TDD and FDD access• Frequency Synthesizers have to be fast for handover issue and cover multiple bands

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Multimode direct conversion receiver for mobile terminal

LNAWCDMABAND

SELECT

FROMANTENNA

WCDMABAND

SELECT

LNADCS

BANDSELECT

FROMANTENNA

LNAGSMBAND

SELECT

FROMANTENNA

ADC

ADC

AGCVCO RF0/90°

I/QDEMOD

CHANNELSELECT

I TOBASEBAND

Q TOBASEBAND

PROG

RF=LO0

RF=LO

WCDMA GSM

DC offsetcancel

DC offsetcancel

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RESEARCH TECHNOLOGY AREAS

• Architectures for re-configurable multi-band receivers : ZIF requires re-configurable analog baseband Ips (filters , ADCs,…) in deep sub-micron CMOS

• Fast lock-time multi-band synthesizers with integrated VCOs• RF filters to replace SAW • MEMs configuration switches with low actuation voltages• What about RF band-pass sampling in a far future ?

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TRANSMIT PATH KEY ASPECTS

• The transmit path has to up-convert and amplify signal with constant (GMSK)or variable envelops (WCDMA, EDGE)

TX architecture has to be compatible with both types of modulation • The RF power amplifier is the biggest contributor on battery life of

the whole radio

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WCDMA Power Amplifier Output Power

RFMD 2161 (Vsupply = +3.4 V, Vmode = 0 V)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

21161161-4-9-14-19-24-29-34-39-44-49

Pout @ antenna, in dBm

pd

f, in %

0

5

10

15

20

25

30

35

40

45

PA

E,

in %

POWER DISTRIBUTIONEFFICIENCY

POWER DISTRIBUTION OVER TIME :

There is a need for power efficiency in the 0dBm range and lower .The transceiver system has to be understood globally (baseband+RF+power amplifier ) for the best use of different technologies (linearisation , power management , amplification ,…)

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RESEARCH TECHNOLOGY AREAS

• Transmit path architectures : find architectures for multi-bands , multiple types of modulations and OFDM in the future . Direct conversion , polar modulations ,…

• Linearisation techniques to enhance the efficiency of RF power amplifiers • What about mems for reconfigurable matching networks inside power

amplifiers ?

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SUMMARY• The trend is to re-configurable radio front-ends for multiple reasons : multi-standard , cost , small form

factors , MIMO , future ‘ubiquitos systems ‘• The transceiver has to be considered globally from antenna to digital baseband and use multiple

technologies in a power conscious co-design • Some key functions : re-configurable analog and mixed blocks in deep sub-micron CMOS , low-noise/low

power SiGe blocks for high sensitivity front-ends• Techniques for efficient RF power amplification will be mandatory to save battery life • New technologies like MEMS , FBAR could play significant role if mature

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System R&D on Multi-Standard RF Transceiver for 3G and beyond Advanced System Technology