| T O P I C R E V I E W |
| somikoda |
Posted - Apr 17 2011 : 17:10:46
Hello!
When I'm calculating the inductance of a rectangular PCB-strand in FastHenry2, the inductance result differ with a factor 1000 compared with analytical/Q3D results. According to various books, the partial inductance of a PCB-strand is about 500nH/m which indicates that the calculated inductance results from FH2 is wrong. Can anyone shed some light over this matter?
The dimensions of the strip are: length=30mm, width=5, thickness=0.018.
FastHenry2: 17615.1nH (@1GHz)
.Units MM
.Default sigma=5.8e4
N1 x=0.1 y=0 z=0
N2 x=0.1 y=0 z=30
E1 N1 N2 w=5 h=0.018 nhinc=5 nwinc=7
.external N1 N2
.freq fmin=1e6 fmax=100e9 ndec=1
.end
Analytical: 18.1nH L = (0.0002*l)*(log((2*l)/(w+t))+0.5+(0.2235*((w+t)/l)))
Q3D: 17.6nH (@1GHz)
Regards
Somikoda |
| 2 L A T E S T R E P L I E S (Newest First) |
| Mathias |
Posted - Nov 02 2011 : 15:20:33
I had the same problem.
The reason was the first line. your first line contains
.Units MM
FastHenry ignors always the first line. So it uses the unit Mils.
|
| Enrico |
Posted - Sep 07 2011 : 23:15:34
I'm not sure about your result, running your input file into FastHenry2 gives:
Freq = 1e+009
Row 0: 0.0332692+1.76151e-008j
Meaning 17.6nH @ 1GHz
Best Regards,
Enrico
|
|
|
