Transcript Free Space Materials Characterization2010

Agilent
Technologies
Free Space Materials
Characterization
Shelley Blasdel Begley
Application Development Engineer
Page 1
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Agilent
Technologies
Agenda
What is it?
Free Space Measurement Systems
Calibration
Measurement Results
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
What is Free Space Materials Characterization?
Measuring Electromagnetic Properties of Materials
Using Free Space Measurement Technique.
Important for:
Circuit design
Military Applications
Car Radar Applications
New Materials Research
Incoming Inspection
Quality Assurance
Health and Safety
and more…
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Electromagnetic Materials
Radar Absorbing and Stealth Materials
Radome Materials
Electronic Substrate and Packaging Materials
Specific Absorption Rate (SAR) Phantoms
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Transmission Free-Space System
Computer
(not required for
PNA)
Network Analyzer
GP-IB or LAN
85071E Materials
Measurement Software
With Option 100
Free Space Calibration
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Sample holder
fixtured between two antennae
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Lightwave Analogy
Lens
Incident
Bio-dielectrics: Theories, Mechanisms,
Applications, Stamford Hall, Leicester,
UK
Lightwave Analogy
Lens
Incident
Reflected
Bio-dielectrics: Theories, Mechanisms,
Applications, Stamford Hall, Leicester,
UK
Lightwave Analogy
Lens
Incident
Reflected
Bio-dielectrics: Theories, Mechanisms,
Applications, Stamford Hall, Leicester,
UK
Lightwave Analogy
Lens
Incident
Transmitted
Reflected
Bio-dielectrics: Theories, Mechanisms,
Applications, Stamford Hall, Leicester,
UK
Network Analyzer Block Diagram
Incident
Fixture
Transmitted
MUT
SOURCE
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Reflected
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Network Analyzer Block Diagram
Fixture
Incident
Transmitted
MUT
SOURCE
Reflected
SIGNAL
SEPARATION
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Network Analyzer Block Diagram
Fixture
Incident
Transmitted
MUT
SOURCE
Reflected
SIGNAL
SEPARATION
INCIDENT
(R)
REFLECTED
(A)
RECEIVER / DETECTOR
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Network Analyzer Block Diagram
Fixture
Incident
Transmitted
MUT
SOURCE
Reflected
SIGNAL
SEPARATION
INCIDENT
(R)
REFLECTED
(A)
TRANSMITTED
(B)
RECEIVER / DETECTOR
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Network Analyzer Block Diagram
Fixture
Incident
Transmitted
MUT
SOURCE
Reflected
SIGNAL
SEPARATION
INCIDENT
(R)
REFLECTED
(A)
TRANSMITTED
(B)
RECEIVER / DETECTOR
PROCESSOR / DISPLAY
Reflected
Incident
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= S11
Transmitted
= S21
Incident
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Transmission Algorithms
Algorithm
Measured S-parameters
Output
Nicolson-Ross
S11,S21,S12,S22
er and mr
Precision (NIST)
S11,S21,S12,S22
er
Fast
S21,S12
er
(85071E also has three reflection algorithms)
Before a Measurement Can be Made…
Calibration is required!
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
TRM Calibration
Thru
Reflect
Match
Hard to get broadband absorbers for match
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
TRL Calibration
Thru
Move the antenna away to
compensate for the
thickness of the short.
Move it back for the next
step.
Reflect
Move the antenna away
on a quarter-wavelength
and then back in the
original position.
Line
Precise positioning fixtures are expensive
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Gated Reflect Line (GRL) Calibration
Two Tiered Process
Two port calibration at waveguide or coax input into antennas
removes errors associated with network analyzer and cables.
ECal, SOLT or TRL
Cal done here
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Gated Reflect Line (GRL) Calibration
Two Tiered Process
Two additional free space calibration standards remove errors
from antennas and fixture.
Line
(empty fixture)
Reflect
(metal plate of
known thickness)
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – How it works
GRL Cal Error Model (forward only)
2-port Cal Terms
1
D
Ms
Tr
GRL Error
Adapter
MUT
2-port Cal Terms
S21
Tt
S11
S22
GRL Error
Adapter
Ml
S12
•Coax or Waveguide 2-port Cal corrects errors from end of cable back into
the instrument.
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – How it works
GRL Cal Error Model (forward only)
2-port Cal Terms
1
D
Ms
Tr
GRL Error
Adapter
MUT
2-port Cal Terms
S21
Tt
S11
S22
GRL Error
Adapter
Ml
S12
•Coax or Waveguide 2-port Cal corrects errors from end of cable back into
the instrument.
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – How it works
GRL Cal Error Model (forward only)
2-port Cal Terms
1
D
Ms
Tr
GRL Error
Adapter
MUT
2-port Cal Terms
S21
Tt
S11
S22
GRL Error
Adapter
Ml
S12
•Coax or Waveguide 2-port Cal corrects errors from end of cable back into
the instrument.
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – How it works
GRL Cal Error Model (forward only)
2-port Cal Terms
1
D
Ms
Tr
GRL Error
Adapter
MUT
2-port Cal Terms
S21
Tt
S11
S22
GRL Error
Adapter
Ml
S12
•Coax or Waveguide 2-port Cal corrects errors from end of cable back into
the instrument.
•Errors from Antennas and Fixture can be thought of as being lumped into
a GRL error adapter.
•The GRL error adapter is quantified by measurements of reflect and line
standards.
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – How it works
Time Domain of Empty Free Space Fixture
gate
Transmitting
Antenna
Receiving
Antenna
Air
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – How it works
GRL Cal Error Model (forward only)
2-port Cal Terms
1
D
Ms
Tr
GRL Error
Adapter
MUT
2-port Cal Terms
S21
Tt
S11
S22
GRL Error
Adapter
Ml
S12
•Coax or Waveguide 2-port Cal corrects errors from end of cable back into
the instrument.
•Errors from Antennas and Fixture can be thought of as being lumped into
a GRL error adapter.
•The GRL error adapter is quantified by measurements of reflect and line
standards.
•The original 2-port Cal is modified to correct for the error adapter.
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – How it works
GRL Cal Error Model (forward only)
2-port Cal Terms
1
D
Ms
Tr
GRL Error
Adapter
MUT
2-port Cal Terms
S21
Tt
S11
S22
GRL Error
Adapter
Ml
S12
•Coax or Waveguide 2-port Cal corrects errors from end of cable back into
the instrument.
•Errors from Antennas and Fixture can be thought of as being lumped into
a GRL error adapter.
•The GRL error adapter is quantified by measurements of reflect and line
standards.
•The original 2-port Cal is modified to correct for the error adapter.
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free-space X-Band System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space 40 – 60GHz System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
A Simple Free Space Powder Fixture
Close Up
Powder in Tray Placed
Between Antennae
Bio-dielectrics: Theories, Mechanisms,
Applications, Stamford Hall, Leicester, UK
Free Space 75 – 110GHz Standard Gain Horn System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space W-band System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space 75-110GHz Quasi-Optical System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space 75-110GHz Quasi-Optical System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space 75-110GHz Quasi-Optical System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space 75-110GHz Quasi-Optical System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space 75-110GHz Quasi-Optical System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Free Space 75-110GHz Quasi-Optical System
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Measurement Results
Real part of Epsilon
Rexolite measured with 110Ghz PNA and GRL Cal
2.57
2.56
y = -3E-14x + 2.5265
2.55
2.54
e'
2.53
2.52
2.51
2.5
2.49
2.48
2.47
7.500E+10
8.000E+10
8.500E+10
9.000E+10
9.500E+10
1.000E+11
1.050E+11
1.100E+11
frequency (hz)
Std Gain Horn
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QO table
Linear (QO table)
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Measurement Results
Imaginary part of Epsilon
Rexolite measured with 110Ghz PNA and GRL Ca l
0.03
0.025
y = -2E-14x + 0.003
0.02
0.015
e"
0.01
0.005
0
7.500E+10
-0.005
8.000E+10
8.500E+10
9.000E+10
9.500E+10
1.000E+11
1.050E+11
1.100E+11
-0.01
-0.015
-0.02
frequency (hz)
Std Gain Horn
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QO table
Linear (QO table)
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Conclusion
Free Space is a useful method for
measuring electromagnetic
properties of a of materials.
Innovative calibration overcomes
challenges of previous free space
error correction methods.
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
For More Information
Visit our website at:
www.agilent.com/find/materials
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
References
R N Clarke (Ed.), “A Guide to the Characterisation of DielectricMaterials at RF and Microwave Frequencies,” Published by The
Institute of Measurement & Control (UK) & NPL, 2003
J. Baker-Jarvis, M.D. Janezic, R.F. Riddle, R.T. Johnk, P. Kabos, C. Holloway, R.G. Geyer, C.A. Grosvenor, “Measuring the
Permittivity and Permeability of Lossy Materials: Solids, Liquids, Metals, Building Materials, and Negative-Index Materials,” NIST
Technical Note 15362005
“Test methods for complex permittivity (Dielectric Constant) of solid electrical insulating materials at microwave frequencies and
temperatures to 1650°, ” ASTM Standard D2520, American Society for Testing and Materials
Janezic M. and Baker-Jarvis J., “Full-wave Analysis of a Split-Cylinder Resonator for Nondestructive Permittivity Measurements,”
IEEE Transactions on Microwave Theory and Techniques vol. 47, no. 10, Oct 1999, pg. 2014-2020
J. Krupka , A.P. Gregory, O.C. Rochard, R.N. Clarke, B. Riddle, J. Baker-Jarvis, “Uncertainty of Complex Permittivity
Measurement by Split-Post Dielectric Resonator Techniques,” Journal of the European Ceramic Society
No. 10, 2001, pg. 2673-2676
“Basics of Measureing the Dielectric Properties of Materials”. Agilent application note. 5989-2589EN, April 28, 2005
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
mm-Wave Free Space Results
Rexolite
expected
value
e’ = 2.53
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Free Space Materials Characterization
15 October 2008
Apendix
•Section
• •Title•
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal – System Considerations
•Determine Sample Position
Fixture with Metal Plate
•Determine Sample Size
•Choose Metal Plate
Metal Plate
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal - Considerations
• Choose Number of
points to Avoid Aliasing
Empty Fixture
Minumum Number of Points =
Receiving
Antenna
1 + Range * (Stop Frequency –
Start Frequency)
Where Range is the needed
alias free range in Seconds
Transmitting
Antenna
20nS
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Cal - Considerations
• Choose Time Domain Parameters
Empty Fixture
Air at
3.5nS
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Fixture with Metal Plate
Metal Plate
at 3.5nS
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
Quasi Optical System Schematic
Additional information available at : http://www.terahertz.co.uk/TKI/Agilent/Agilent_VNA_QO.html
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Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
MUT and GRL Error Adapters
After 2-Port Calibration
MUT
O21
O11
S21
O22
S11
O12
T12
S22
T22
S12
T11
T21
Six Unknowns
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021 = O12
T21 = T12
O11
T11
O22
T22
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
MUT and GRL Error Adapters
After O11 and T11 are embedded into the original 2-Port calibration.
MUT
O21
S21
O22
S11
O12
T12
S22
T22
S12
T21
Four Unknowns
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O21 = O12
T21 = T12
O22
T22
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Metal Plate Standard
P11 = P22 = -1
P21=P12=0.
MUT
O21
O22
O12
S21
S11 S22
S12
T12
T22
T21
O21O12
 plate_1  
1  O22
 plate_2
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T21T12

1  T22
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008
GRL Thru Standard (Air)
A11=A22=0
A21 = A12 = e j
MUT
e ud
O21
O22
= frequency
e= permittivity of air
m= permeability of air.
d= thickness of the metal plate
O12
S21
S11 S22
S12
T12
T22
T21
A 21A12O21O12T22
air_1 
1  O22T22
air_2
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A21A12T21T12O22

1  T22O22
Agilent Technical Forum
Free Space Materials Characterization
15 October 2008