Date post: | 28-Mar-2015 |
Category: |
Documents |
Upload: | diego-rodgers |
View: | 215 times |
Download: | 0 times |
TEMASEK LABORATORIES
Dielectric Resonance in Multi-phase Composites
Leader: S. M. MatitsineMembers: K. M. Hock, L. Liu, A. Qing, X. Xu,
K. N. Rozanov, A. N. Lagarkov, Y. B. Gan
TEMASEK LABORATORIES
10 mm/0.1 mm Cu Fibre in 0.5 mm Carbon Fibre
Typical sample To Increase Thickness
TEMASEK LABORATORIES
Resonance condition = 2L
Resonance shift fres v/2L = (c/n)/2L = (c/2L)/n = f0/n
Refractive index n = Re(rr)
Absorption coeff. = Im(rr)
/n
L
v
r r
Background
TEMASEK LABORATORIES
Near-field MeasurementNear-field Measurement
HP
Vector-analyser Metal Plate and sample
Frequency : 2 ~ 20 GHz
Calculation : ’ , ” , ’ , ”
HP
TEMASEK LABORATORIES
Host - 15% Al powder (15 um)Sample thickness0.2 mm
Samplethickness1 mm
With Cu fibre (10 mm/0.1 mm)
an
d
an
d
an
d
TEMASEK LABORATORIES
Bulk
Thin sample
Possible Reason for Resonance Shift in Thin Sample
TEMASEK LABORATORIES
Measurement Results – Cu fibre resonance
TEMASEK LABORATORIES
2b
2a
ed
abC
)/ln(2)/ln(2
1
(Lagarkov, et al 1998)
kaib
aL d2ln2
(Lagarkov and Sarychev 1996)
d = host permittivitye = effective permittivity
LCfres 2
1
Lagarkov’s and Sarychev’s Theory:
- Resonance shift depends on powder size, fibre length and thickness- Powders are assumed to be spherical and non-magnetic
TEMASEK LABORATORIES
Scanning Electron Microscope (SEM) Images of Aluminium powder
15 um
15 um
5 um
4 um
Taken by Gao Xingsen, Dept Mat. Sci., NUS, May 2002
TEMASEK LABORATORIES
E
E
Impedance Analyzer Measurement - 15% Al Sample
TEMASEK LABORATORIES
HFSS* Simulation – Cu fibre in anisotropic host (15% Al)
*FEM simulation - ANSOFT
= 6 = 33
TEMASEK LABORATORIES
HFSS* Simulation – Cu fibre in 15% Al host
*FEM simulation - ANSOFT
Thickness
= 6 = 33
TEMASEK LABORATORIES
Compare with Measurement Results
Agree
Agree
Explain by Anisotropy
TEMASEK LABORATORIES