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SiP/SoC Integration of RF SAW/BAW

FiltersKen-ya Hashimoto

Chiba Universityk.hashimoto@ieee.org

http://www.em.eng.chiba-u.jp/~ken

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Integration trends in mobile phones, RF-subsystem

• dual band• >200 L-R-Cs• 10 ICs• 4 RF-filters• 1 IF-filter

• triple band• 100 L-R-Cs• 3 ICs• 3 RF-filters• no IF-filter

• quad band• 30 L-R-Cs• 2 ICs• 4 RF-filters

• quad band + UMTS• 20 L-R-Cs• 1 IC• 6 RF-filters

?

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• RF SAW and BAW Devices• Front-End Modules• SiP/SoC Integration• Variable Filters

ContentsContents

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• RF SAW & BAW Filters••• FrontFrontFront---End ModulesEnd ModulesEnd Modules••• SiPSiPSiP///SoCSoCSoC IntegrationIntegrationIntegration••• Variable FiltersVariable FiltersVariable Filters

ContentsContents

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SAW Resonator FilterSAW Resonator Filter

• Mass Production by Photolithography• High Frequency, Low Loss, High Stability• Cheap(?), Small(?)

Interdigital Transducer (IDT)

Reflector (Al)λ

Piezo-Substrate （42oYX-LiTaO3)

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Ladder-Type SAW FilterLadder-Type SAW Filter

Topology

• Low Loss• High Power Durability• Moderate Out-of-Band Rejection

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Antenna Duplexer for US PCS

Rx Band

Tx Band λ/4

λ/4

TX-port

RX-port

Antenna-port

SAW filter, TX

SAW filter, RXstrip line

strip line

Fujitsu FAR-D6CZ-1G9600-D1XC

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• Good Out-of-Band Rejection

• Balun Function• Transformer Function• Lower Power Durability

Symmetrical & Anti-

symmetricalResonances

Double Mode SAW (DMS) Filter

arsω ωr

ω

Inse

rtio

n lo

ss (d

B)

Frequency

Electrically Isolated I/O

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-8-7-6-5-4-3-2-10

800 850 900 950 1000 1050-80-70-60-50-40-30-20-10

0

Frequency [MHz]

Scat

terin

g pa

ram

eter

. S21

[dB

]

Scat

terin

g pa

ram

eter

. S21

[dB

]

Fujitsu FAR-F5EB-942M50-B28E

Performance of Double-Mode SAW FilterPerformance of Double-Mode SAW Filter

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Balanced Input and Output

Unbalanced Input and Output

+

-

+-

Balanced/Unbalanced TransmissionBalanced/Unbalanced Transmission

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Front-endBPF LNA

Inter-stageBPF LPFMixer

Front-endBPF LNA LPFMixer

Balun IF-Amp

IF-Amp

Embedded Balun in Frontend SAW Inter-stageBPF

Embedded Balun in Interstage SAW

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Vout+

Vout-

Vin

DMS Filter (Ideally No Common Signal)

Acoustically Coupled but Electrically Isolated

Common Signal Generation by Parasitics

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Vout+

Vout-

Vin

Vin

Vout+Vout-

Z-conversion by DMS Filter

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resonator

cavity

Piezoelectric Thin Film (AlN)

Film Bulk Acoustic Resonator, FBAR

Si

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Avago’ FBAR PCS DuplexerACMD-7402 (3.8*3.8*1.3mm)

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• Higher Q (Lower IL, Sharper TB)• Better Power Handing• Robustness Against Electrostatic-Discharge• RF Integration Possibilities

Merits of FBAR Filters

Advantageous for Above 2 GHz Applications

• Higher Price• Balun & Z-Conv. Functions Not Realized• Only Applicable to Huge Markets

Demerits

17G. G. Fattinger, et al., IEEE Microwave Symp. (2004) pp.927-930

Cascaded Coupled FBAR FilterCascaded Coupled FBAR FilterCascaded Coupled FBAR Filter

Electrically Isolated I/OBy Infineon

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FBAR with Balun & Transformer Func.

50Ω:50Ω

50Ω:200Ω By Infineon

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0

4.5 5.0 5.5 6.0

-40

-30

-20

-10

-50

Frequency (GHz)

Att

enua

tion

(dB

)

FBAR filter

SAW filter

Filter Response for Wireless LAN

Influence of Electrode Resistance Obvious for SAW at 5 GHz Range

FBAR Beneficial over 2 GHz?

Fujitsu Labs

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Acoustic MigrationAcoustic MigrationStress-Induced Movement of Grain Boundary ⇒ Electrode Shortage

Electrode Scarcely Stressed in BAW Case

Countermeasure: Development of New Electrode Material System

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60

50

40

30

20

10

0

0.7 0.8 0.9 1 1.1 1.2 1.3Frequency, f [GHz]

Inse

rtion

loss

[dB

]

Wideband and Low Loss SAW Filter Using Cu/15oYX-LiNbO3 Structure

Not achievable performance by current FBAR

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60

50

40

30

20

10

0

0.7 0.8 0.9 1 1.1 1.2 1.3Frequency, f [GHz]

Inse

rtion

loss

[dB

]

Wideband and Low Loss SAW Filter Using Cu/15oYX-LiNbO3 Structure (Continued)

Bandwidth Reduction by New Design

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••• RF SAW & BAW FiltersRF SAW & BAW FiltersRF SAW & BAW Filters• Front-End Modules••• SiPSiPSiP///SoCSoCSoC IntegrationIntegrationIntegration••• Variable FiltersVariable FiltersVariable Filters

ContentsContents

24Othello-G Chip (5x5mm2)RF-IC from Analog Devices

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Avago’s UMTS2100 Front End ModuleAFEM-7708 4 4×7×1.1 mm3

26M.Solal, et al., “Some Recent Advances in SAW Duplexers and PA Duplexers Modules” , 3rd Intern. Symp. on Acoustic Wave Devices for Future Mobile Communication Systems, 2D-1 (2007)

Triquint’s PAiD (TQM676011)

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Merit of PAiD

• Miniaturization• Optimal Placement for Components• User Friendly• Co-Design Taking Nonlinearity, Complex Z,

and Z Variation of PA into Account

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M.Solal, et al., “Some Recent Advances in SAW Duplexers and PA Duplexers Modules” , 3rd Intern. Symp. on Acoustic Wave Devices for Future Mobile Communication Systems, 2D-1 (2007)

Balanced RX

OB Rejection Improvement by Using DMS Filters

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Skyworks' Single Packaged Radio　BiCMOS Base for EGSM900 + DCS1800

HBT (GaAs)

pHEMT (GaAs)

SAW External C*2+Xtal

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SAW+SiGe+CMOS

GaAs HBT

6026: 10×10mm2

3178: 7×8mm2

Polaris 2 Total Radioby RF Micro Devices

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Polaris II

SMD SAW+SiGe, CMOS Chip

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B.Wilkins, “Wafer Level Packaging of SAWs Enables Low Cost 2.5G and 3G Radio Modules” , 3rd Intern. Symp. on Acoustic Wave Devices for Future Mobile Communication Systems, 3B-3 (2007)

Miniaturized FEM Employing WLP SAW & RF CMOS

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B.Wilkins, “Wafer Level Packaging of SAWs Enables Low Cost 2.5G and 3G Radio Modules” , 3rd Intern. Symp. on Acoustic Wave Devices for Future Mobile Communication Systems, 3B-3 (2007)

Miniaturized FEM Employing WLP SAW & RF CMOS

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U.Bauernschmitt, et al., “RF Front-Ends for Multi-Mode, Multi-Band Cellular Phones” , 3rd Intern. Symp. on Acoustic Wave Devices for Future Mobile Communication Systems, 3B-2 (2007)

Configuration in Next Generation•Large SAW Filter Count

•Use of SP9T SW

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••• RF SAW & BAW FiltersRF SAW & BAW FiltersRF SAW & BAW Filters••• FrontFrontFront---End ModulesEnd ModulesEnd Modules• SiP/SoC Integration••• Variable FiltersVariable FiltersVariable Filters

ContentsContents

36L. Elbrecht, et al., IEEE Microwave Symp. (2004) pp.395-398

SOC Integration

By Infineon

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CMOS/BAW-SoC?•FBAR Fab. After IC Fab. ⇒ SoC Beneficial

•No Bonding Pad ⇒ SoC Beneficial

•Difference in Fab. Process ⇒ SiP Beneficial

•Different Yield Difficulties ⇒ SiP Beneficial

•Film Thickness Control for Each Frequency ⇒SiP Beneficial

•Size Reduction by High Z Design

•Digital Compensation Possible?

38M.A. Dubois, et al., IEEE J. Solid State Circuits, Vol. 41 (2006) pp. 7-16

RF Front End FBAR Integration

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Performances of Integrated FBAR

Balanced Topology Offers Improved OB Rejection

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M.A.Dubois, et al., “Above-IC Integration of BAW Resonators and Filters for Communication Applications” , 3rd Intern. Symp. on Acoustic Wave Devices for Future Mobile Communication Systems, 2B-3 (2007)

Integrated FBAR VCO

41M.A.Dubois, et al., “Above-IC Integration of BAW Resonators and Filters for Communication Applications” , 3rd Intern. Symp. on Acoustic Wave Devices for Future Mobile Communication Systems, 2B-3 (2007)

Phase Noise of Integrated FBAR VCO

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••• RF SAW & BAW FiltersRF SAW & BAW FiltersRF SAW & BAW Filters••• FrontFrontFront---End ModulesEnd ModulesEnd Modules••• SiPSiPSiP///SoCSoCSoC IntegrationIntegrationIntegration• Variable Filters

ContentsContents

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RF-SiP/SoC• Miniaturization, Multi-Functional, Low Loss• Reduction of Influence of Parasitics• Optimal Design for Particular Devices

→ Adjustability for Digital Compensation and Variable Filters

• Giving Controllability to Passives By Combining with Actives

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Reconfigurable Front-End

RF-BPF

RF-BPFPA

LNA

Low Loss, Narrow TB, Temperature Stable & Variable Filters Realizable?

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Possible Variable Filters• Ferromag. Resonance Based⇒ Bulky & Non-Linearity (IMD)• Tuned LC (L, M-Strip, Ferroelec., etc.) Based⇒ Low Q (High Loss, Gradual TB), Bulky• Active Circuit Based⇒ Non-Linearity (IMD)• Acoustic Resonator Based⇒ Small Adjustability (?)• Dielectric Resonator Based⇒ Bulky (?)

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Switching RF Configuration

PA

LNA

MEMS SW

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MEMS-Based Resonator Filter

Wideband, RF Operation & Low Z Possible?Use of Ferroelectric Piezo Film

Or Low Loss & Wideband Z Transformer