april 2, 2019 introduction to surface acoustic wave (saw ...surface acoustic wave (saw) device vout...
TRANSCRIPT
Ken-ya HashimotoChiba University
[email protected]://www.te.chiba-u.jp/~ken
Part 1: What is SAW Device?
Introduction to Surface Acoustic Wave (SAW) Devices
April 2, 2019
•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 (Shear 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 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)
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
69
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
80M 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
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pressure[Bar]
time
Two Track Railway Crossing
Adjacent Water Channel