266
10 Characterization of Atherosclerotic Lesions by Inversion of Eddy-. . .
0.36
0.38
0.4
0.42
0.44
0.46
0.48
0.5
9.5 9.55 9.6 9.65 9.7 9.75 9.8 9.85 9.9 9.95 10
Resistance (Ohms)
Frequency (E10)
Response of Lesion at 100GHz
original
variation 1
variation 2
variation 3
variation 4
0.28
0.3
0.32
0.34
0.36
0.38
0.4
9.5 9.55 9.6 9.65 9.7 9.75 9.8 9.85 9.9 9.95 10
Reactance (Ohms)
Frequency (E10)
Response of Lesion at 100GHz
original
variation 1
variation 2
variation 3
variation 4
Fig. 10.12 Frequency response of the five lesions in the vicinity of 100 GHz. Both conductivity
and permittivity effects are included. Left: resistance; right: reactance
-1
-0.5
0
0.5
1
8.8
9
9.2
9.4
9.6
9.8
10
Resistance (Ohms)
Frequency (E8)
Frequency Response of Probe in Freespace at 1GHz
1
1.02
1.04
1.06
1.08
1.1
1.12
1.14
8.8
9
9.2
9.4
9.6
9.8
10
Reactance (Ohms)
Frequency (E8)
Frequency Response of Probe in Freespace at 1GHz
Fig. 10.13 Frequency response of the coil in the vicinity of 1 GHz. Left: resistance; right:
reactance
The freespace response of the coil at 100 GHz has already been given in Fig. 10.4.
The corresponding results at 1 GHz and 10 GHz are given in Figs. 10.13 and 10.14.
10.7 Determining Coil Parameters
Figure 10.15 is the equivalent circuit of a real coil. VIC-3D ® can only model the
inductor, L 0 , and Z W , the change in the impedance due to the presence of the
workpiece. The remaining parameters must be inferred by measurement. Because
VIC-3D ® can model only the right-hand branch, we must subtract the effects of Y p