Ken-ya HashimotoChiba University

k.hashimoto@ieee.orghttp://www.te.chiba-u.jp/~ken

Part 1: What is SAW Device?

Introduction to Surface Acoustic Wave (SAW) Devices

April 2, 2018

•SAW Transversal Filter•SAW Unidirectional IDT Filters•SAW Resonator Filters•Duplexers•Oscillators•SAW Wireless Tags and Sensors

Contents

•SAW Transversal Filter•SAW Unidirectional IDT Filters•SAW Resonator Filters•Duplexers•Oscillators•SAW Wireless Tags and Sensors

Contents

Surface Acoustic Wave

Bulk Acoustic Wave (BAW):•Longitudinal Wave (Primary Wave)

•Transverse Wave (Share Wave, Secondary Wave)

Surface Acoustic Wave (SAW):

(Rayleigh SAW)Propagation of

Seismological Waves

Surface Acoustic Wave (SAW) Device

Vout

Vin

Piezoelectric substrate

Interdigital Transducers (IDT)

SAW

• Mass Production by Photolithography• Low loss, Miniature & Low price• Operation inVHF-UHF ranges

Line width /4=0.5m (f=2GHz)

Impulse Response

• Independent Control of Amplitude and Phase Responses

SAW Transversal Filters

Impulse Response Frequency Response

t f

t

t

dtjftthfH )2exp()()(

dfjftfHth )2exp()()(

f

f

Piezoelectricity

(a) Equilibrium (b) Extension

p p

(c) CompressionNecessity of Crystalline

AsymmetryDepending on Crystal Orientation

Electric Flux (Electric Field) Stress (Strain)

p: Dipole Moment8

Piezoelectricity

(a) Equilibrium (b) Extension

E E

(c) Compression

Stress (Strain) Electric field (Electric Flux)

E: Electric Field

9

Non-Piezoelectric Case

(a) Equilibrium

No Electric Output

(b) Extension (c) Compression

10

Electrostriction

(a) Equilibrium (b) Compressive

E E

(c) Compressive

Stress (Strain) {Electric field (Electric Flux)}2

p: Dipole Moment

Negligible for Weak Electric field11

Why Acoustic Wave Devices?

• Temperature Stability

]1)/[exp(0 kTqVII

cf. For Si, 3000ppm/oC

ppm 10day 1sec. 1

For watch,

Trade-Off Between Temp. Stability & Bandwidth

T drift

(a) Wider Transition Bandwidth

(b) Narrower Transition Bandwidth

T drift

Efficient Use of Frequency Resources Narrow Transition Bandwidth (Or Improve Production Yield)

-45-40-35-30-25-20-15-10

-505

-0.2 -0.1 0 0.1 0.2 -1

-0.8-0.6-0.4-0.2

00.20.40.60.81

Tran

sfer

func

tion

in d

B

Relative Frequency

Tran

sfer

func

tion

in d

B

Fourier-Transform-Based Design

Ripple due to truncation [Gibb’s Phenomenon]

t

w(t)t

thd(t)w(t)

hd(t)

Influence of Truncation

dfWHfH dw )()()(

Convolution Relation

Window Functions

t f

t f

Hamming:w(t)=0.54+0.46cos(2t/T)

Blackmann:w(t)=0.42+0.5cos(2t/T) +0.08cos(4t/T)

Blackmann-Harris:w(t)=0.35875+0.48829cos(2t/T)+0.14128cos(4t/T)+0.01168cos(6t/T)

0

0.2

0.4

0.6

0.8

1

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

Wei

ght

Relative Position

HammingBlackmann

Blackmann-Harris

-120

-100

-80

-60

-40

-20

0

0 2 4 6 8 10

rectangularHammingBlackmann

Blackmann-Harris

Relative frequency

Am

plitu

de in

dB

Frequency Response of Window Functions with same T

-70-65-60-55-50-45-40-35-30-25-20-15-10-505

-0.2 -0.1 0 0.1 0.2

-0.8-0.6-0.4-0.2

00.20.40.60.81

-1

Tran

sfer

func

tion

in d

B

Relative frequency

Tran

sfer

func

tion

in d

B

Design by Fourier Transform + Design by Fourier Transform + Window Function

454137 49 53

10 dB/div

Frequency (MHz)43.7541.7539.75 45.7547.75

1 dB/div

50ns/div

Frequency (MHz)

SAW Transversal Filter for CATV

Ref. 15dB

8070605040302010

0

67.5 68 68.5 69 69.5 70 70.5 71 71.5 72 72.5

Inse

rtion

loss

in d

B

Frequency in MHz

ExperimentSimulation

SAW IF Filter for IS-95

Effects of Diffraction(2D SAW Propagation)

Courtesy of Fujitsu Labs.

(a) For Wide Aperture (b) Narrow Aperture

For Weighted IDT

Variation with Aperture Size

DAT

CD player Amp.

E

SR

SLR

Power source Load

E

SR

SLR

Power source Load

?

Low Frequency Design

High Frequency DesignHigh Zin and Low Zout for Minimum Interference

RL=RS for Maximum Power Transfer

How about for this case?

Triple Transit Echo (TTE)Interdigital Transducers (IDT)

• Mechanical Reflection + Electrical Regeneration Mutual-Connection Dependent

• Trade-Off: TTE Insertion Loss• Intrinsic for Bidirectional IDTs

504540353025201510

50

-0.2 -0.1 0 0.1 0.2

Inse

rtion

loss

in d

B

Relative FrequencyS21 S21

0

Influence of TTE

Bragg Reflection

p

Bragg Condition

p=n

Double-Electrode IDT

Single-Electrode IDT

absorber absorber

Guard electrode

Transversal SAW Filter

ꞏAbsorbers for Suppression of Reflection at Substrate Edges

ꞏDummy Electrode for Suppression of Reflection and Charge Concentration at Edges

ꞏGuard Electrode for Suppression of EM Feedthrough

•SAW Transversal Filter•SAW Unidirectional IDT Filters•SAW Resonator Filters•Duplexers•Oscillators•SAW Wireless Tags and Sensors

Contents

PLL/VCO

DuplexerIF-BPFRF-BPF

AntennaLNA

PA

PLL/VCO

A/D

D/A

A/D

D/A I

Q

I

Q

PLL/VCO

IF-BPFRF-BPF

Heterodyne Transceiver

Red：SAW Devices

Single Phase Unidirectional Transducer (SPUDTs)

(b) Embedded Reflector(Complex but Wideband)

(a) Combination with Reflector(Simple but Narrowband)

• TTE Suppression• Low Loss• Frequency Response Weighting for Excitation Profile

• Reflection Bandwidth < IDT Bandwidth Reflector Weighting

Independent Weighting to both Excitation and Reflection

pI

CtCrCtCr

For +X Direction, m22 )12()(2 npI

X

For -X Direction

Unidirectional Cond. 8/ ,2/

Unidirectional Condition

Ct: Excitation Center

Cr: Reflection Center

(d) With Excit. & Ref.

(b) With Excit., Ref.-Less

(c) Excit.-Less, With Ref.

(a) Excit.-Less, Ref.-Less

For Independent Weighting to Excitation and Reflection

EWC(Electrode-Width-Control)/SPUDT

Scat

terin

g C

oeffi

cien

t (dB

)

-40-35-30-25-20-15-10-50

0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2Relative Frequency

=90o

=0oLT=50pI

LI=20pI

pI=0.02

Filter Response with Reduced TTE

Low Loss and Suppressed TTE

Resonant SPUDT (R-SPUDTs)

Reversed Reflection WeightingDirect Pulse

Multiple Echoes

Extension of Impulse Response

With Reflection

Without Reflection

• Skirt Characteristics are Defined by Impulse Response Length

• Out-of-Band Characteristics are Defined by Excitation Profile

-60

-50

-40

-30

-20

-10

0

0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.220

30

40

50

60

70

80

Relative Frequency

Scat

terin

g C

oeffi

cien

t (dB

)

Gro

up D

elay

/

p

|S21|LT=0LI=34pI pI|max=0.1

Designed Example

Sharp Passband Shape + Flat Group Delay

-1-0.8-0.6-0.4-0.2

00.20.40.60.8

1

2 4 6 8 10 12 14 16 18 20

Excitation

ReflectionForward

Relative Position

Wei

ghtin

g Fu

nctio

n

Optimized weighted function

Courtesy of EPCOS AG

Weak Resonant SPUDT Filter

Courtesy of EPCOS AG

Strong Resonant SPUDT Filter

•SAW Transversal Filter•SAW Unidirectional IDT Filters•SAW Resonator Filters•Duplexers•Oscillators•SAW Wireless Tags and Sensors

Contents

DuplexerRF-BPF

AntennaLNA

PA

PLL/VCO

A/D

D/A

A/D

D/A I

Q

I

Q

PLL/VCO

RF-BPF

Homodyne Transceiver

• Circuit Simplification Reducing Component Number• No Image Signal Relaxing Specs to RF Filters

(a) 1-Port Resonator

(b) 2-Port Resonator Filter

SAW Resonator

Piezoelectric Material

+

-

C0

Mk-1

V F

i v

C0

Lm

Rm

Cm

Analogies between VF and Iv reduce toML, R, k 1/C

(a) Electric + Mechanical Circuit

Application of Electric Field to Piezoelectric Material,

(b) Electrical Equiv. Circuit

VFvdtkvdtdvM

(a) Electrical Equiv. Circuit (b) Equiv. Mechanical Circuit

•Resonance Frequency r=1/ CmLm•Anti-Resonance Frequency a=1/ Lm(Cm

-1+C0-1)-1

•Resonance Q (Steepness of Resonance) Q=rLm/Rm

•Capacitance Ratio (Weakness of Piezoelectricity)C0Cma/r)2-1]-1

Determine Insertion Loss and Skirt Characteristics

Determine Insertion Loss and Bandwidth

k

M

F

k0C0

Lm

Rm

Cm

-0.6-0.4-0.20

0.20.40.60.81

0.96 0.98 1 1.02 1.04

Adm

ittan

ce [S

]

Frequency [GHz]

fr fa

•Resonance Frequency r=1/ CmLm•Anti-Resonance Frequency a=1/ Lm(Cm

-1+C0-1)-1

Transverse Mode

Frequency

Adm

ittan

ce

r a

B

GIn-harmonic Resonance

Countermeasure

Influence of Diffraction

Transverse Modes

10

100

1k

428 430 432 434 436 438

Impe

danc

e (

)

Frequency (MHz)

(a)

(b)

(c)

SAW Resonator on Quartz

433.00 MHz

431.625 MHz

434.635 MHz

Field Distribution Observed by Laser Probe

Power Leakage to Bus Bar Regions

Reduction of Excitation Efficiency for Higher ModesLoss Increase by Scattering at Discontinuities

IDT Apodize

Dummy Electrode Weighting

Spurious Modes Penetration ⇒Leakage to Bus Bar Regions

[Dummy]Reflection at Gaps ⇒Strong Wave Confinement

T.Omori, K.Matsuda, N.Yokoyama, K.Hashimoto, and M.Yamaguchi, “Suppression of Transverse Mode Responses in Ultra-Wideband SAW Resonators Fabricated on a Cu-grating/15oYX-LiNbO3Structure”, IEEE Trans. Ultrason., Ferroelec., and Freq. Contr., 54, 10 (2007) pp. 1943-1948.

Piston Mode BAW Resonator

Active Region

xFrame Frame

R.Thalhammer, J.Kaitila, S.Zieglmeier, and L.Elbrecht, “Spurious mode suppression in BAW resonators,” Proc. IEEE Ultrason. Symp. (2006) pp. 456-459

M.Solal , J.Gratier, R.Aigner, K.Gamble, B.Abbott, T.Kook, A.Chen, and K.Steiner, “Transverse modes suppression and loss reduction for buried electrodes SAW devices,” Proc. IEEE Ultrason. Symp. (2010) pp. 624-628

Piston Mode SAW Resonator

Ladder-Type SAW Filter

Topology

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

r a

Inse

rtion

Los

s (dB

)

Frequency Inse

rtion

Los

s (dB

)

Frequency

r a

Parallel-ConnectionSeries-Connection

YsYp

Ys

Yp Yp

Inse

rtion

Los

s (dB

)

Frequency

sp

p s

r

ar

a

-Connection

Null Generation

at Both Sides

Performance of Ladder-Type SAW Filter

W-CDMA-Rx

-50-45-40-35-30-25-20-15-10-50

1900 2000 2100 2200 2300 2400-5

-4

-3

-2

-1

0

Tx Rx

Frequency (MHz)

Fujitsu FAR-F6CP-2G1400-L21M

Scat

terin

g Pa

ram

eter

S21

(dB

)

Scat

terin

g Pa

ram

eter

S21

(dB

)

• Good Out-of-Band Rejection

• Balun Function• Transformer Function• Low Loss• Lower Power Durability

Symmetrical & Anti-

symmetricalResonances

Double Mode SAW (DMS) Filter

Inse

rtio

n lo

ss (d

B)

Frequency

rs ar

Electrically Isolated I/O

Structure of Pitch-Modulated IDT & ReflectorConventional Structure Pitch-Modulated Structure

IDT IDTREFECTOR

Modulated

ModulatedGap Controlled

Presented at IEEE 2004 UFFC Conf.

-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

]

DMS Filter with Modulated Structure

Integrated RF Circuit

Current Antenna and RF Stage are Unbalanced

(a) Balanced I/O

(b) Unbalanced I/O

+

-

+-

Front-endBPF LNA

Inter-stageBPF IF-BPFMixer

Front-endBPF LNA IF-BPFMixer

Balun IF-Amp

IF-Amp

Discrete SAW Filter & Balun

Inter-stageBPF

SAW Filter with Balun Function

Vout+

Vout-

Vin

DMS Filter (Ideally No Common Signal)

Acoustically Coupled but Electrically Isolated

Common Signal Generation by Parasitics

Vout+

Vout-

Vin

Vin

Vout+Vout-

Z-conversion by DMS Filter

•SAW Transversal Filter•SAW Unidirectional IDT Filters•SAW Resonator Filters•Duplexers•Oscillators•SAW Wireless Tags and Sensors

Contents

Role of Duplexer in FDD Transceiver

Power Amplifier

Low Noise Amplifier

Detection of Weak Rx Signal

Efficient Excitation of Tx Signal

-100 dBm

+25 dBm

Tx->Rx Leakage Suppression in Tx Band = DuplexerMinimization of RF Power Loss

Jammer (-15 dBm Max)

Power Amplifier

Low Noise Amplifier-100 dBm

+25 dBm

Tx->Rx Leakage Suppression in Rx BandNon-Generation of Jummer Signal from DPX

Taiyo Yuden FAR-D6CZ-1G9600-D1XC

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

Frequency Allocation

800 MHz Bands

1.5~2.5 GHz Bands

3.5 GHz Ban

70

RF Front End of One Generation Before….

PA ModulesDuplexers

Filter Array

Relation Between Stress T and Strain S

Elastic Deformation

0

Plastic Deformation

Fracture

Linear Region

Stress, T

Stra

in, S

4/}])2cos{(})2[cos{(

2/}])cos{(})[cos{(

4/4/)2cos(

cos}2/{

cos}4/{

3/)coscos(

2/)coscos()coscos(

babab2

a)3(

bababa)2(

2a

)2(a

2)2(b

2)3()1(b

a2)3()1(

a

3bbaa

)3(

2bbaa

)2(2baa

)1(

ttTTs

ttTTs

TstTs

tTssT

tTssT

tTtTs

tTtTstTtTsS

a

a

a

Case 2: When T=Tacos(at)+Tbcos(bt) (|Ta|>>|Tb|),

Linear Vibration+Gain Compression

H2+DC Generation

IMD: Inter-Modulation Distortion

IMD2 Generation

IMD3 Generation

Spectrum Regrowth in PA and DPX= Self Mixing of Tx Signals

Jammer Signal Emission Toward Adjacent Channels

Inter Modulation Distortion in Nonlinear Circuit for WCDMA System

Sign

al in

tens

ity

fa

fb2fa-fb(3rd order)

Tx filter Rx filter

fb+fa(2nd order)

fb-fa(2nd order)

2fa+fb(3rd order)

Rx signal + Nonlinear distortion product

Jammer Jammer

Band1Tx: 1920-1980 MHzRx: 2110-2170 MHz

190MHz 1730 - 1790 MHz 4030 – 4150 MHz

5950 – 6010 MHz

Band2Tx: 1850-1910 MHzRx: 1930-1990 MHz

80MHz 1770 - 1830 MHz 3780 – 3900 MHz

5630 – 5810 MHz

Jammer Frequency

Jammer Frequency

3)3(2)2()1(

31

21 TsTsTsS

0 Stress, TSt

rain

, S

Only True for Asymmetric Cases

In Elastic Region (w/o Hysteresis)

0 Stress, T

Stra

in, S

For Symmetric Cases,s(2n)=0

3)3()1(

31 TsTsS

Tx Rx

Tx band:53 dB typ.

Rx band:48 dB typ.

Tx Rx

Tx band:59 dB typ.

Rx band:53 dB typ.

FBAR (Tx) + DMS (Rx) Duplexer

DMS Offers Balanced Output

R.Ruby and M.Gat, “FBAR Filters- 2012,” Proc. 2012 International Symposium on Acoustic Wave Devices for Future Mobile Communications) G1 -1~4

With Improved Temperature Stability

LT/Sapphire Wafer Bonding

M. Miura, T. Matsuda, Y. Satoh、M. Ueda, O. Ikata, Y. Ebata, and H.Takagi, “Temperature Compensated LiTaO3/Sapphire Bonded SAW Substrate with Low Loss and High Coupling Factor Suitable for US-PCS Application,” Proc. IEEE Ultrasonics Symposium (2004) pp. 1322-1325

LT

Sapphire

IDT

Performance Example

M. Miura, T. Matsuda, Y. Satoh、M. Ueda, O. Ikata, Y. Ebata, and H.Takagi, “Temperature Compensated LiTaO3/Sapphire Bonded SAW Substrate with Low Loss and High Coupling Factor Suitable for US-PCS Application,” Proc. IEEE Ultrasonics Symposium (2004) pp. 1322-1325

81M Kadota, N.Takaeshi, N.Taniguchi, E.Takata, M.Miura, K.Nishiyama, T.Hada, and T.Komura, “Surface Acoustic Wave Duplexer for US Personal Communication Services with Good Temperature Characteristics,” Jpn. J. Appl. Phys., 44 6B (2005) pp. 4527-4531

SiO2 On-Top DepositionSiO2: Stiffness Increase with Temperature

M Kadota, N.Takaeshi, N.Taniguchi, E.Takata, M.Miura, K.Nishiyama, T.Hada, and T.Komura, “Surface Acoustic Wave Duplexer for US Personal Communication Services with Good Temperature Characteristics,” Jpn. J. Appl. Phys., 44 6B (2005) pp. 4527-4531

Performance Example

Rich Ruby, “A Decade of FBAR Success and What is Needed for Another Successful Decade,” Proc. SPAWDA (2011) pp. 365-369

Use of SiO2 for Temperature Compensation

5

-25-20-15-10-50

68 70 72 74 76 78

-

FWHM of 4 peak (cm-1)

-25-20-15-10-505

80 85 90 95 100

TC

F (p

pm/o C

)

FWHM of 3 peak (cm-1)

TC

F (p

pm/o C

)

Relation Between FTIR FWHM and TCF in

SiO2 Properties Change with Deposition Condition

Use of SiOF FimsAnticipated from FTIR Data⇒ Experimental Verification

S.Matsuda, M.Hara, M.Miura, T.Matsuda, M.Ueda, Y.Satoh, and K.Hashimoto, “Use of Fluorine Doped Silicon Oxide for Temperature Compensation of Radio Frequency Surface Acoustic Wave Devices,” IEEE Trans. Ultrason., Ferroelec., and Freq. Contr., 59, 1 (2012) pp. 135-138

Material CharacterizationQuantitative Evaluation of Acoustic Properties of Thin Films with High Accuracy

Ultrasonic Microscope System

Dependence of SAW Vel. on SiO2 (1 m)/ (001)Si SurfaceK.Sakamoto, S.Suzuki, T.Omori, K.Hashimoto, J.Kushibiki, and S.Matsuda, “Characterization of Elastic Properties of SiO2 Thin Films by Ultrasonic Microscopy,” Proc. IEEE Ultrason. Symp. (2014) pp. 893-896

f=225 MHz

Piezo-LayerMetal Metal

Use of Extremely Thin Piezo-Layer

High z Layer (AlN)

Base-Substrate (Si)

low z Layer (SiO2)

Energy Confinement in Thin Piezo-Layer

K2 EnhancementBAW Loss Reduction

Murata’s IHP SAW Duplexer

IL TX 1.5 dB, Rx: 1.9 dB

TCF: 8 ppm/oC

Iso.: 56 dB for Tx and 60 for Rx

Temperature Stability

T.Takai, H.Iwamoto, Y.Takamine, H.Yamazaki, T.Fuyutsume, H.Kyoya, T.Nakao, H.Kando, M.Hiramoto, T.Toi, M.Koshinoand N.Nakajima “Incredible High Performance SAW resonator on Novel Multi-layerdSubstrate”, Proc. IEEE Ultrason. Symp. (2016)

Conventional LT

IHP

For Further Increase in Channel Capacity

SNR1log2 BCB: Bandwidth

SNR1log2 NBCN: No. Antenna

ifon X

Multi-Input Multi-Output（MIMO)

Carrier Aggregation

ifon X

Requirements to Pico Cell Duplexer?

Pico Cell

Band 1 Band 7

4

Frequency

Spec

trum

123 5678 N

=2/T

SPConv. IFFT FFT PS

Conv.PSConv.

SPConv.Transmission

OFDMA System Setup

Orthogonal Frequency Division Multiple Access, OFDMA

Peak to Average Power Ratio (PAPR)

Use of Effective Coding = Increase of PAPR (Random Variation in time)Necessity of Linearity ImprovementNecessity of Durability Improvement for Peak Power

Power Durability

Generation of Voids and Hillocks = Acousto-Migration

Where is the Weakest?

Increase in Substrate Temperature for Given Input Power

Life Time Modelling kTEP /expTF

,, E:constant, k: Boltzmann Constant, T: Absolute Temperature

・Electrode Material and Structure・Heat Reduction (Loss Reduction)・Improving Thermal Conductivity: Wafer Bonding, ScAlN？

・Reduction of Power Density

For High Power?

2Ys 2Ys

Ys Half Input Voltage

Doubled Electrode Area

Increase in Chip Size…

Peak to Average Power Ratio (PAPR)

Increase in Peak Power → Cause of Different Failure Mechanism

•SAW Transversal Filter•SAW Unidirectional IDT Filters•SAW Resonator Filters•Duplexers•Oscillators•SAW Wireless Tags and Sensors

Contents

C2

eout

C1

Quartz Oscillation Circuit

Quartz Tuning Fork

215 =32,768Hz Osc. Counting 215 Pulses Gives 1 Sec.

ppm 10day 1sec. 1

How Accurate?

Use of Acoustic Vibration

High Quality Factor = Long Vibration Sustain Insensitive to Noise

High Temperature Stability

Global Positioning System (GPS)

2222 )()()( nnnn zzyyxxd

xn, yn, zn : position of the n-th satellitedn: distance from the n-th satellite

Present position (x, y, z) is given by solvingNn ,,2,1

Oscillation Spectrum (Phase Noise)Conversion of AM Noise to PM Noise via Saturation

H()

1/f Noise (Flicker)Thermal

(Johnson)

Long Term Stability (Ageing)Mid Term Stability (Temp. Drift)Short Term Stability (Fluctuation)

Frequency Synthesizer (v=Ms/N)

Phase-Locked Loop (PLL)

• Use of Stable s ⇒Accurate & Stable

• Programmable Divider ⇒ Tunable

VVCO

SedLPFN Counter

M Counter

Loop Filter

H() VCO (Voltage Controlled Oscillator） Determines Thermal Noise Level

Phase Noise Deterioration at Counter Change

Influence of Phase Noise

BPF s(t)c(t)mixer

s(t)

c(t)

c

Mixing with Local Oscillation c(t) with Noise

s1(t)c(t) s2(t)c(t)Conversion of Thermal and 1/f Noise in Adjacent Channel to Desired Channel

Spectrum After Mixing

Base-BandProcessing

High Speed ADC

Software Defined Radio (SDR)

Multiple Standard (GSM, UMTS, GPS, etc.) Support by Software Loading from HDD

System Upgrade by Software Download

ADC: Analog-to-Digital Converter

Data Stream

Base-BandProcessing

High Speed ADC

For SDR Realization

frequency

Spec

trum

Target SignalExtremely Large Dynamic Range Necessary

High Speed & Extremely Large Dynamic Range ADC Possible?

Data Stream

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

0 0.5 1 1.5 2

Sign

al A

mpl

itude

time

Sampling Theorem

Low Pass Filtering of Periodically Sampled DataRecovery of Original Signal

Sampled Signal

Signal with Thermal Noise

After Digitization

Pulse Miss-Count

After Digitization with Hysteresis

t

2Vc

Jitter

Jitter Generation by Thermal Noise

Influence of Jitter to High Speed ADC

Jitter Causes Amplitude Fluctuation (Error)

http://www.analog.com/jp/digital-to-analog-converters/da-

converters/products/tutorials/CU_tutorials_MT-007/resources/fca.html

Influence of Jitter Significant at High Frequency

Influence of Jitter and Freq. to SNR

http://www.analog.com/jp/digital-to-analog-converters/da-

converters/products/tutorials/CU_tutorials_MT-007/resources/fca.html

How to Reduce Jitters• Low Jitter (Low Noise) Oscillation Using

High Q Resonators

cf: Atomic Clock (Very Accurate But Not Precise)

Stabilization by Quartz Oscillator (Very Precise But Not Accurate Enough)

Very Precise and Very Accurate Oscillation

•SAW Transversal Filter•SAW Unidirectional IDT Filters•SAW Resonator Filters•Duplexers•Oscillators•SAW Wireless Tags and Sensors

Contents

AT-cut Quartz

Quartz Micro-Balance (QMB)

• Temperature Stability• Phase (or Frequency) Output High Resolution• Low Price

Mass Loading

Sensor Applications: Physical (Film Thickness, Pressure), Chemical(Gas, Liquid), Bio

Vout

Vin

Piezo-Substrate

IDT

SAW

• High f (f K fm) High Sensitivity• Moderate Temperature Stability• Surface Protection (Packaging) ?

SAW Sensor

Area 1 mm2 & f=1 GHz give K f ~ 107 / kg 1 ppm of f deviation=Resolution 0.1 pg.

SAW Sensor Configuration

Frequency Detection

Phase Detection~m

f ~m

SAW Chemical Sensor

• Sensitive Layer: A calixarene (10 nm)• Object: tetrachloroethene• f0: 434 MHz

Time [min]Freq

uenc

y D

evia

tion

[Hz]

0

-200

-400

-6000 10 20 30

Con

tent

[ppm

]

0

20

40

60

Pattern Recognisition with Sensor Array

Sensor : Sensitive FilmA Calix[4]resorcinearene 1B Calix[4]resorcinearene 2C Cyclodextrine-functiona-

lized polymer 1D Cyclodextrine-functiona-

lized polymer 2

C DA B

Sensor Array

p-xylenem-xylene

humidity

What is SAW ID-TAG?

Antenna

Transceiver

• Large Group Delay (Separation with Environmental Echoes)

• Wireless, Batteryless

Separation of SAW Signal in Time Domain

Excited Signal

Environmental Echo

Sensor Echo

RF Response

time

Which Frequency?

•5.2 GHz (ISM Band)Wideband (100MHz), Short Accessible Distance (<1m), Hard to Realize SAW Devices

•2.45 GHz (ISM Band) Wideband(22MHz), Short Accessible Distance (2-3m), Price of SAW Devices?

•433.92 MHz (RKE Band) Narrowband(1.7MHz), Long Accessible Distance (>10m), Low SAW Device Cost

SAW ID Tag with 5 reflectors in one track (f0 = 2.45 GHz) using pulse position coding

Pulse position coding schema

OIS - W

Baumer Ident (2.45 GHz ISM)

Brake temperature of a train entering a station

60,00

70,00

80,00

90,00

100,00

Time

Tem

pera

ture

°C

reader antenna

Brake (with attached SAW temperature transponder, not seen)

The dynamic range of monitoringthe torque with SAW can be up to several tenths of kHz

SAW Torque Sensor

strain in ‰

ph

ase

dif

fere

nc

e in

de

g.

0

50

100

150

200

150

0 0.05 0.10 0.15 0.20

SAWsensors

rotatingshaft

Tx antennas

Rx antennas

measurement set-up

SAW pressure sensor

diaphragm

adhesive

cover-plateclosed cavity withreference-pressure

antenna

1.001.201.401.601.802.002.202.402.602.803.00

14:30

:5514

:30:59

14:31

:0414

:31:09

14:31

:1314

:31:18

14:31

:2214

:31:27

14:31

:3214

:31:36

14:31

:41

pressure[Bar]

time

Two Track Railway Crossing

Adjacent Water Channel