April 2, 2018
Introduction to Surface
Acoustic Wave (SAW) Devices
Part 1: What is SAW Device?
Ken-ya Hashimoto
Chiba University
k.hashimoto@ieee.org
http://www.te.chiba-u.jp/~ken
Contents
•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
Surface Acoustic Wave
Bulk Acoustic Wave
(BAW):
•Longitudinal Wave
(Primary Wave)
•Transverse Wave
(Share Wave,
Secondary Wave)
Propagation of
Seismological Waves
Surface Acoustic
Wave (SAW):
(Rayleigh SAW)
Surface Acoustic Wave (SAW) Device
Interdigital Transducers (IDT)
Vin
SAW
Vout
Piezoelectric substrate
• Mass Production by Photolithography
• Low loss, Miniature & Low price
• Operation inVHF-UHF ranges
Line width /4=0.5m (f=2GHz)
SAW Transversal Filters
Impulse Response
• Independent Control of Amplitude
and Phase Responses
Impulse Response Frequency Response
t
f
t
f
t

h(t ) 
 H ( f ) exp(2jft )df

f

H ( f )   h(t ) exp(2jft )dt

Piezoelectricity
Electric Flux (Electric Field)  Stress (Strain)
p
p
(a) Equilibrium (b) Extension
(c) Compression
Necessity of Crystalline
p: Dipole Moment
Asymmetry
8
Depending on Crystal Orientation
Piezoelectricity
Stress (Strain)  Electric field (Electric Flux)
E
(a) Equilibrium (b) Extension
E: Electric Field
E
(c) Compression
9
Non-Piezoelectric Case
(a) Equilibrium
(b) Extension
No Electric Output
(c) Compression
10
Electrostriction
Stress (Strain)  {Electric field (Electric Flux)}2
E
E
(a) Equilibrium (b) Compressive (c) Compressive
p: Dipole Moment
Negligible for Weak Electric field
11
Why Acoustic Wave Devices?
• Temperature Stability
For watch,
1 sec.
 10 ppm
1 day
cf. For Si, 3000ppm/oC
I  I 0 [exp(qV / kT )  1]
Trade-Off Between Temp. Stability & Bandwidth
T drift

(a) Wider Transition Bandwidth
T drift

(b) Narrower Transition Bandwidth
Efficient Use of Frequency Resources  Narrow
Transition Bandwidth (Or Improve Production Yield)
5
0
-5
-10
-15
-20
-25
-30
-35
-40
-45
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-0.2
-0.1
0
0.1
Relative Frequency
0.2
Transfer function in dB
Transfer function in dB
Fourier-Transform-Based Design
-1
Ripple due to truncation [Gibb’s Phenomenon]
Influence of Truncation
hd(t)
t
Convolution Relation

w(t)
t
hd(t)w(t)
t
Hw( f ) 
H

d
( )W (  f )d
Window Functions
t
f
t
f
Hamming:w(t)=0.54+0.46cos(2t/T)
Blackmann:w(t)=0.42+0.5cos(2t/T) +0.08cos(4t/T)
Blackmann-Harris:w(t)=0.35875+0.48829cos(2t/T)
+0.14128cos(4t/T)+0.01168cos(6t/T)
1
Weight
0.8
0.6
0.4
0.2
Hamming
Blackmann
Blackmann-Harris
0
-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8
Relative Position
1
Frequency Response of Window
Functions with same T
0
rectangular
Hamming
Blackmann
Blackmann-Harris
Amplitude in dB
-20
-40
-60
-80
-100
-120
0
2
4
6
Relative frequency
8
10
5
0
-5
-10
-15
-20
-25
-30
-35
-40
-45
-50
-55
-60
-65
-70
-0.2
-0.1
0
0.1
Relative frequency
0.2
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
Transfer function in dB
Transfer function in dB
Design by Fourier Transform +
Window Function
Ref. 15dB
10 dB/div
1 dB/div
50ns/div
37
41 45 49
Frequency (MHz)
53
39.75 41.75 43.75 45.75 47.75
Frequency (MHz)
SAW Transversal Filter for CATV
Insertion loss in dB
SAW IF Filter for IS-95
0
Simulation
10
Experiment
20
30
40
50
60
Effects of Diffraction
70
(2D SAW Propagation)
80
67.5 68 68.5 69 69.5 70 70.5 71 71.5 72 72.5
Frequency in MHz
Courtesy of Fujitsu Labs.
(a) For Wide Aperture
(b) Narrow Aperture
Variation with Aperture Size
For Weighted IDT
Low Frequency Design
CD player
Amp.
DAT
High Zin and Low Zout for Minimum Interference
High Frequency Design
Power source Load
RS
RS
ES
Power source
RL
RL=RS for Maximum
Power Transfer
ES
Load
?
RL
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
Insertion loss in dB
Influence of TTE
0
5
10
15
20
25
30
35
40
45
50
-0.2
-0.1
0
0.1
Relative Frequency
S21
S210
0.2
Bragg Reflection
Single-Electrode IDT
Bragg Condition
p
p=n
Double-Electrode IDT
Transversal SAW Filter
absorber
absorber
Guard electrode
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
Contents
•SAW Transversal Filter
•SAW Unidirectional IDT Filters
•SAW Resonator Filters
•Duplexers
•Oscillators
•SAW Wireless Tags and Sensors
Heterodyne Transceiver
Antenna
LNA
RF-BPF
Duplexer
IF-BPF
A/D
Q
A/D
I
D/A
I
D/A
Q

PLL/VCO
PLL/VCO
PLL/VCO
PA

RF-BPF
Red：SAW Devices
IF-BPF
Single Phase Unidirectional
Transducer (SPUDTs)
(a) Combination with Reflector
(Simple but Narrowband)
(b) Embedded Reflector
(Complex but Wideband)
• TTE Suppression
• Low Loss
• Frequency Response
 Weighting for
Excitation Profile
• Reflection Bandwidth
< IDT Bandwidth 
Reflector Weighting
Independent Weighting
to both Excitation and
Reflection
Unidirectional Condition
Cr Ct
Cr Ct
Ct: Excitation
Center
Cr: Reflection
Center
pI
X

For +X Direction,  2     2m
For -X Direction  2  ( p I   )    ( 2n  1)
Unidirectional Cond.    / 2,     / 8
For Independent Weighting
to Excitation and Reflection
(a) Excit.-Less, Ref.-Less
(b) With Excit., Ref.-Less
(c) Excit.-Less, With Ref.
(d) With Excit. & Ref.
EWC(Electrode-Width-Control)/SPUDT
Scattering Coefficient (dB)
Filter Response with Reduced TTE
0
-5
-10
-15
-20
-25
-30
-35
-40
0.8
LI=20pI
LT=50pI
pI=0.02
=90o
=0o
0.85 0.9 0.95 1 1.05 1.1 1.15 1.2
Relative Frequency
Low Loss and Suppressed TTE
Resonant SPUDT (R-SPUDTs)
Reversed Reflection Weighting
Direct 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
0
-10
-20
80
LI=34pI
LT=0
pI|max=0.1
|S21|
70
60
-30
50
-40
40
-50
30

-60
20
0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2
Relative Frequency
Sharp Passband Shape + Flat Group Delay
Group Delay /p
Scattering Coefficient (dB)
Designed Example
Weighting Function
Optimized weighted function
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
Excitation
Forward
Reflection
2
4
6
8 10 12 14 16 18 20
Relative Position
Weak Resonant SPUDT Filter
Courtesy of EPCOS AG
Strong Resonant SPUDT Filter
Courtesy of EPCOS AG
Contents
•SAW Transversal Filter
•SAW Unidirectional IDT Filters
•SAW Resonator Filters
•Duplexers
•Oscillators
•SAW Wireless Tags and Sensors
Homodyne Transceiver
Antenna
LNA
Duplexer
RF-BPF
A/D
Q
A/D
I
D/A
I
D/A
Q

PLL/VCO
PLL/VCO
PA
RF-BPF

• Circuit Simplification  Reducing Component Number
• No Image Signal  Relaxing Specs to RF Filters
SAW Resonator
(a) 1-Port Resonator
(b) 2-Port Resonator Filter
Application of Electric Field to Piezoelectric Material,
+
Piezoelectric
Material
-
dv
M
 v  k  vdt  F  V
dt
i
C0 V
v
F
Cm
k-1 M

(a) Electric + Mechanical Circuit
C0
Lm
Rm
(b) Electrical Equiv. Circuit
Analogies between VF and Iv reduce to
ML,  R, k  1/C
k
Cm
C0
Lm

M
Rm
(a) Electrical Equiv. Circuit
k0
F
(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
 Determine Insertion Loss and Skirt Characteristics
•Capacitance Ratio (Weakness of Piezoelectricity)
C0Cma/r)2-1]-1
 Determine Insertion Loss and Bandwidth
fr
fa
1
Admittance [S]
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
0.96
0.98
1
1.02
Frequency [GHz]
1.04
•Resonance Frequency r=1/ CmLm
•Anti-Resonance Frequency a=1/ Lm(Cm-1+C0-1)-1
Admittance
Transverse Mode
In-harmonic
Resonance
G
B
Frequency
r
a
Influence of Diffraction
Countermeasure
Transverse Modes
SAW Resonator on Quartz
Impedance ()
1k
(b)
(a)
100
10
428
430
(c)
432 434 436
Frequency (MHz)
438
Field Distribution Observed by Laser Probe
431.625 MHz
433.00 MHz
434.635 MHz
Power Leakage to Bus Bar Regions
IDT Apodize
Reduction of Excitation Efficiency for Higher Modes
Loss Increase by Scattering at Discontinuities
Dummy Electrode Weighting
Reflection at Gaps ⇒
Strong Wave Confinement
[Dummy]
Spurious Modes Penetration ⇒
Leakage to Bus Bar Regions
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-LiNbO3
Structure”, IEEE Trans. Ultrason., Ferroelec., and Freq. Contr., 54, 10 (2007) pp. 1943-1948.
Piston Mode BAW Resonator
Frame
Frame
Active Region
R.Thalhammer, J.Kaitila, S.Zieglmeier, and L.Elbrecht, “Spurious mode
suppression in BAW resonators,” Proc. IEEE Ultrason. Symp. (2006) pp. 456-459
x
Piston Mode SAW Resonator
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
Ladder-Type SAW Filter
• Low Loss
• High Power Durability
• Moderate Out-of-Band Rejection
Topology
Ys
Insertion Loss (dB)
Insertion Loss (dB)
Insertion Loss (dB)
r a
Frequency 
Series-Connection
p
ars
sa
Frequency 
-Connection
Yp
Frequency 
Parallel-Connection
Ys
Yp
rp
r a
Yp
Null
Generation
at Both
Sides
0
-5
-10
-15
-20
-25
-30
-35
-40
-45
-50
0
Tx
Rx
-1
-2
-3
-4
1900
2000 2100 2200 2300
Frequency (MHz)
W-CDMA-Rx
2400
-5
Scattering Parameter S21 (dB)
Scattering Parameter S21 (dB)
Performance of Ladder-Type SAW Filter
Fujitsu FAR-F6CP-2G1400-L21M
Double Mode SAW (DMS) Filter
Symmetrical
& Antisymmetrical
Resonances
Insertion loss (dB)
Electrically Isolated I/O
sr
ar
Frequency 
• Good Out-of-Band
Rejection
• Balun Function
• Transformer Function
• Low Loss
• Lower Power Durability
Structure of Pitch-Modulated IDT & Reflector
Conventional Structure
Pitch-Modulated Structure
Gap Controlled
Modulated
REFECTOR
IDT
Modulated
Presented at IEEE 2004 UFFC Conf.
IDT
DMS Filter with Modulated Structure
850
900 950 1000 1050
Frequency [MHz]
0
-1
-2
-3
-4
-5
-6
-7
-8
Scattering parameter. S21 [dB]
Scattering parameter. S21 [dB]
0
-10
-20
-30
-40
-50
-60
-70
-80
800
Integrated RF Circuit
+
(a) Balanced I/O
+
(b) Unbalanced I/O
Current Antenna and RF Stage are Unbalanced
Discrete SAW Filter & Balun
Inter-stage
Front-end
LNA BPF
Balun Mixer IF-BPF IF-Amp
BPF
SAW Filter with Balun Function
Inter-stage
Front-end
LNA BPF
Mixer IF-BPF IF-Amp
BPF
DMS Filter (Ideally No Common Signal)
Acoustically Coupled but Electrically Isolated
Vin
Vout+
VoutCommon Signal Generation by Parasitics
Z-conversion by DMS Filter
Vout+
Vin
VoutVin
Vout+
Vout-
Contents
•SAW Transversal Filter
•SAW Unidirectional IDT Filters
•SAW Resonator Filters
•Duplexers
•Oscillators
•SAW Wireless Tags and Sensors
Role of Duplexer in FDD Transceiver
Jammer (-15 dBm Max)
Low Noise Amplifier
-100 dBm
Detection of Weak Rx Signal
+25 dBm
Power Amplifier
Efficient Excitation
of Tx Signal
Tx->Rx Leakage Suppression in Tx Band = Duplexer
Minimization of RF Power Loss
Low Noise Amplifier
-100 dBm
+25 dBm
Power Amplifier
Tx->Rx Leakage Suppression in Rx Band
Non-Generation of Jummer Signal from DPX
Taiyo Yuden FAR-D6CZ-1G9600-D1XC
Avago’s FBAR PCS
Duplexer
ACMD-7402 (3.8*3.8*1.3mm)
Frequency Allocation
3.5 GHz Ban
800 MHz Bands
1.5~2.5 GHz Bands
70
RF Front End of One Generation
Filter Array
Before….
Duplexers
PA Modules
Relation Between Stress T and Strain S
Strain, S
Fracture
Elastic
Deformation
Plastic
Deformation
0
Stress, T
Linear Region
Case 2: When T=Tacos(at)+Tbcos(bt) (|Ta|>>|Tb|),
S  s(1) (Ta cosat  Tb cos2t )  s(2) (Ta cosat  Tb cosbt )2 / 2
 s(3) (Ta cosat  Tb cosbt )3 / 3 
 Ta {s  s T / 4}cosat
(1)
(3)
2
a
 Tb{s  s T / 2}cosbt
(1)
(3)
2
a
Linear Vibration
+Gain Compression
H2+DC Generation
IMD2
( 2)
 s TaTb[cos{(a  b )t}  cos{(a  b )t}]/ 2 Generation
 s(2)Ta2 cos(2at ) / 4  s(2)Ta2 / 4
 s T T [cos{(2a  b )t}  cos{(2a  b )t}]/ 4
(3)
2
a b

IMD: Inter-Modulation Distortion
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
Signal intensity
Tx filter
Band1
Tx: 1920-1980 MHz
Rx: 2110-2170 MHz
Band2
Tx: 1850-1910 MHz
Rx: 1930-1990 MHz
Jammer
fb-fa
Rx filter
Rx signal + Nonlinear
distortion product
Jammer
fa
2fa-fb
fb
rd
(2nd order) (3 order)
190MHz
1730 - 1790 MHz
Jammer Frequency
80MHz
1770 - 1830 MHz
Jammer Frequency
fb+fa
(2nd
order)
2fa+fb
(3rd order)
4030 – 4150 MHz
5950 – 6010 MHz
3780 – 3900 MHz
5630 – 5810 MHz
0 Stress, T
Strain, S
Strain, S
In Elastic Region (w/o Hysteresis)
0 Stress, T
1 ( 2 ) 2 1 (3) 3
S  s T  s T  s T  S  s (1 ) T  1 s ( 3 ) T 3 
2
3
3
(1 )
Only True for Asymmetric
Cases
For Symmetric
Cases,
s(2n)=0
FBAR (Tx) + DMS (Rx) Duplexer
Tx
Rx
Tx
Tx band: Rx band:
53 dB typ. 48 dB typ.
Tx band:
59 dB typ.
DMS Offers Balanced Output
Rx
Rx band:
53 dB typ.
With Improved Temperature Stability
R.Ruby and M.Gat, “FBAR Filters- 2012,” Proc. 2012 International Symposium
on Acoustic Wave Devices for Future Mobile Communications) G1 -1~4
LT/Sapphire Wafer Bonding
IDT
LT
Sapphire
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
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
SiO2 On-Top Deposition
SiO2: Stiffness Increase with Temperature
M Kadota, N.Takaeshi, N.Taniguchi, E.Takata, M.Miura, K.Nishiyama, T.Hada, and T.Komura, “Surface Acoustic Wave
81
Duplexer for US Personal Communication Services with Good Temperature Characteristics,” Jpn. J. Appl. Phys., 44 6B (2005)
pp. 4527-4531
Performance Example
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
Use of SiO2 for Temperature Compensation
Rich Ruby, “A Decade of FBAR Success and What is Needed for Another
Successful Decade,” Proc. SPAWDA (2011) pp. 365-369
TCF (ppm/oC)
5
0
--5
-10
-15
-20
-2568
70
72
74
76
78
FWHM of 4 peak (cm-1)
TCF (ppm/oC)
5
Relation Between FTIR
FWHM and TCF in
0
-5
SiO2 Properties Change
with Deposition Condition
-10
-15
-20
-2580
85
90
95
100
FWHM of 3 peak (cm-1)
Use of SiOF Fims
Anticipated 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 Characterization
Quantitative Evaluation of Acoustic Properties
of Thin Films with High Accuracy
Ultrasonic Microscope System
f=225 MHz
 Dependence of SAW Vel. on SiO2 (1 m)/ (001)Si Surface
K.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
Use of Extremely Thin Piezo-Layer
Metal
Metal
Piezo-Layer
low z Layer (SiO2)
High z Layer (AlN)
Base-Substrate
(Si)
Energy Confinement in Thin Piezo-Layer
K2 Enhancement
BAW 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
IHP
Conventional LT
T.Takai, H.Iwamoto,
Y.Takamine, H.Yamazaki,
T.Fuyutsume, H.Kyoya,
T.Nakao, H.Kando,
M.Hiramoto, T.Toi, M.Koshino
and N.Nakajima “Incredible
High Performance SAW
resonator on Novel Multi-layerd
Substrate”, Proc. IEEE
Ultrason. Symp. (2016)
For Further Increase in Channel Capacity
C  B log 2 1  SNR 
B: Bandwidth
C  NB log 2 1  SNR 
N: No. Antenna
ifon X
Multi-Input
Multi-Output
（MIMO)
Carrier Aggregation
Band 1
Band 7
ifon X
Pico Cell
Requirements to Pico Cell Duplexer?
Orthogonal Frequency Division
Multiple Access, OFDMA
Spectrum
123 4 5678
N
=2/T

Frequency
OFDMA System Setup
SP
Conv.
IFFT
PS
Conv.
Transmission
SP
Conv.
FFT
PS
Conv.
Peak to Average Power Ratio (PAPR)
Use of Effective Coding = Increase of PAPR (Random
Variation in time)
Necessity of Linearity Improvement
Necessity of Durability Improvement for Peak Power
Power Durability
Generation of Voids
and Hillocks =
Acousto-Migration
Increase in Substrate Temperature
for Given Input Power
Where is the Weakest?
Life Time Modelling
TF  P   exp E / kT 
,, E:constant, k: Boltzmann Constant,
T: Absolute Temperature
For High Power?
・Electrode Material and Structure
・Heat Reduction (Loss Reduction)
・Improving Thermal Conductivity: Wafer Bonding,
ScAlN？
・Reduction of Power Density
Ys
Half Input Voltage
Doubled Electrode Area
2Ys
2Ys
Increase in Chip Size…
Peak to Average Power Ratio (PAPR)
Increase in Peak Power → Cause of Different Failure
Mechanism
Contents
•SAW Transversal Filter
•SAW Unidirectional IDT Filters
•SAW Resonator Filters
•Duplexers
•Oscillators
•SAW Wireless Tags and Sensors
Quartz Oscillation Circuit
eout
C1
C2
Use of Acoustic Vibration
High Quality Factor =
Long Vibration Sustain
 Insensitive to Noise
High Temperature Stability
Quartz Tuning Fork
215 =32,768Hz Osc. Counting 215 Pulses Gives 1 Sec.
How Accurate?
1 sec.
 10 ppm
1 day
Global Positioning System (GPS)
Present position (x, y, z) is given by solving
2
2
2
2
d n  ( x  xn )  ( y  y n )  ( z  z n )
n  1,2, , N
xn, yn, zn : position of the n-th satellite
dn: distance from the n-th satellite
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=Ms/N)
S N Counter
Loop Filter
ed
LPF
VCO
M Counter
Phase-Locked Loop (PLL)
V
• Use of Stable s ⇒
Accurate & Stable
• Programmable
Divider ⇒ Tunable
VCO (Voltage Controlled
Oscillator） Determines
Thermal Noise Level
H()

Phase Noise Deterioration at Counter Change
Influence of Phase Noise
Mixing with Local Oscillation c(t) with Noise
mixer
c
s(t)c(t)
BPF
s(t)
c(t)
s1(t)c(t)
s2(t)c(t)

Spectrum After Mixing
Conversion of Thermal and 1/f
Noise in Adjacent Channel to
Desired Channel
Software Defined Radio (SDR)
High
Speed
ADC
Base-Band
Processing
Data Stream
ADC: Analog-to-Digital Converter
Multiple Standard (GSM, UMTS, GPS, etc.)
Support by Software Loading from HDD
System Upgrade by Software Download
For SDR Realization
High
Speed
ADC
Spectrum
Target Signal
frequency

Base-Band
Processing
Data Stream
Extremely Large Dynamic
Range Necessary
High Speed & Extremely Large
Dynamic Range ADC Possible?
Sampling Theorem
Signal Amplitude
1
0.8
0.6
Sampled Signal
0.4
0.2
0
-0.2
-0.4
0
0.5
1
time
1.5
2
Low Pass Filtering of Periodically Sampled Data
Recovery of Original Signal
Jitter Generation by Thermal Noise
Signal with
Thermal Noise
2Vc
After Digitization
 Pulse Miss-Count
Jitter
After Digitization
with Hysteresis
t
Influence of Jitter to High Speed ADC
http://www.analog.com/jp/digital-toanalog-converters/daconverters/products/tutorials/CU_tuto
rials_MT-007/resources/fca.html
Jitter Causes Amplitude Fluctuation (Error)
Influence of Jitter Significant at High Frequency
Influence of Jitter and Freq. to SNR
http://www.analog.com/jp/digital-toanalog-converters/daconverters/products/tutorials/CU_tuto
rials_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
Contents
•SAW Transversal Filter
•SAW Unidirectional IDT Filters
•SAW Resonator Filters
•Duplexers
•Oscillators
•SAW Wireless Tags and Sensors
Quartz Micro-Balance (QMB)
Mass Loading
AT-cut
Quartz
• Temperature Stability
• Phase (or Frequency) Output  High Resolution
• Low Price
Sensor Applications: Physical (Film Thickness,
Pressure), Chemical(Gas, Liquid), Bio
SAW Sensor
IDT
Vin
SAW
Vout
Piezo-Substrate
• High f (f K fm) High Sensitivity
• Moderate Temperature Stability
• Surface Protection (Packaging) ?
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
f ~ m
Phase Detection
 ~ m
0
60
-200
40
-400
20
-600
0
0
10
20
Time [min]
30
Content [ppm]
Frequency Deviation [Hz]
•
•
•
SAW Chemical Sensor
Sensitive Layer: A calixarene (10 nm)
Object: tetrachloroethene
f0: 434 MHz
Pattern Recognisition with Sensor Array
Sensor Array
A
B
C
Sensor : Sensitive Film
A Calix[4]resorcinearene 1
B Calix[4]resorcinearene 2
C Cyclodextrine-functionalized polymer 1
D Cyclodextrine-functionap-xylene
lized polymer 2
m-xylene
humidity
D
What is SAW ID-TAG?
Antenna
Transceiver
• Wireless, Batteryless
• Large Group Delay (Separation with
Environmental Echoes)
Separation of SAW Signal in Time Domain
Excited Signal
RF Response
Environmental
Echo
Sensor
Echo
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
Baumer Ident (2.45 GHz ISM)
OIS - W
Brake temperature of a train entering a
station
reader antenna
Temperature °C
100,00
Brake (with attached SAW
temperature transponder, not seen)
90,00
80,00
70,00
60,00
Time
Rx antennas
Tx antennas
SAW
sensors
measurement set-up
phase difference in deg.
SAW Torque
Sensor
150
200
150
100
50
00
0.05
0.10
0.15
0.20
strain in ‰
rotating
shaft
The dynamic range of monitoring
the torque with SAW can be up to
several tenths of kHz
antenna
SAW pressure
sensor
diaphragm
adhesive
cover-plate
Two Track Railway Crossing
Adjacent Water Channel
time
14
:3
0:
14 55
:3
0:
14 59
:3
1:
14 04
:3
1
:
14 09
:3
1:
14 13
:3
1:
14 18
:3
1:
14 22
:3
1:
14 27
:3
1
:
14 32
:3
1
:
14 36
:3
1
:4
1
pressure
[Bar]
3.00
2.80
2.60
2.40
2.20
2.00
1.80
1.60
1.40
1.20
1.00
closed cavity with
reference-pressure