S21 Adapter


One Inch Spacing using Aluminum Bar Stock

  • Same calibration delay parameters as above
  • DUT = FT50-43 One Turn


One Inch Spacing using Aluminum Bar Stock

  • Same calibration delay parameters as above
  • DUT = Round Cable Snap-Its (0443164251)


Comparison With
Applying and Measuring Ferrite Beads, Part III ~ Measurements Page 7, Figure 8


FT114-43 11T 2x#22 Balun

Port Extension set for (S11 ImagZ == t2s ImagZ) = 10ps


BN-43-202 8.5T #24

Port Extension set for (S11 ImagZ == t2s ImagZ == 0) = -8ps



Measuring and Plotting 43 Ferrite Complex Permeability using SimSmith


Measuring 31 Material
Measuring 43 Material
Measuring 52 Material
Measuring 61 Material
Measuring 67 Material


  • FT37-43 10T μ' at 100kHz computation using:
    Lo = 0.0004606 * Log10(OD / ID) * Ht * Turns2
    10T Lo = 0.0458uH
    10T L = 40.17uH (Measured at 100kHz)
    μ' = 40.17 / 0.0458 ~= 880
  • SimSmith Lo below adjusted for mup ~= 880 at 100kHz
  • SS D1.file = SimSmith compatible Fair-Rite Complex Permeability
    File found in SimSmith Groups.io Files section
  • VNWA files: copy t2s to Mem1, Export Mem1 as Real-Imag
  • Files 43-Material-Fair-Rite.csv bn43-202-1t-thru.s1p FT37-43-x5-s21.s1p

D1 Text D2 Text D Text using μ = μ' - jμ" 
//Fair-Rite
$data=file[]; // Fair-Rite File
mup = $data.R;
$mupp = $data.X;

Plot("F-Rmup",mup,y2);
Plot("F-Rmupp",$mupp,y2);

//BN43-202 1T
$data=file[];  // S11 File
Lo;
$Rs = $data.R;
$Xs = $data.X;
Ls = $Xs/(2*Pi * G.MHz * 1M);
mup = Ls / Lo;
$Q = $Xs / $Rs;
$upp = mup / $Q;

Plot("BN1Tmup",mup,y2);
Plot("BN1Tmupp",$upp,y2);

//BN43-202 1T Using u'-ju"
$data=file[];  // S11 File
Lo;
$mu = -j * $data / (2*Pi * G.MHz * 1M * Lo);
Plot("mup",$mu.R,y2);
Plot("mupp",-$mu.I,y2);


Plotting FT37-43 x 5 Complex Permeability using gnuplot

gnuplot File Text 
set terminal png
set output 'gp-cp.png'
set datafile commentschars "!#" # s1p File comment compatible
set grid xtics ytics
set grid mxtics mytics
set key top right
set xlabel "Frequency MHz"
set title "Measured 43 Material Complex Permeability vs. Frequency"
set yrange [3:1000]
set logscale xy

Lo = 2.05e-9 # Permeability=1 Inductance
i = {0,1}
Zs(a,b) = 50 * (1 + (a+b*i))/(1 - (a+b*i)) # s1p MHz S RI R 50 to Zs
Rs(a,b) = real(Zs(a,b))
Xs(a,b) = imag(Zs(a,b))
Ls(f,a,b) = Xs(a,b)/(2*pi * f * 1e6)
mup(f,a,b) = Ls(f,a,b) / Lo
Q(a,b) = Xs(a,b) / Rs(a,b)
mupp(f,a,b) = mup(f,a,b) / Q(a,b)

plot \
'FT37-43-x5-s21.s1p' using ($1):(mup($1,$2,$3)) with lines title "mu'", \
'FT37-43-x5-s21.s1p' using ($1):(mupp($1,$2,$3)) with lines title "mu\""

gnuplot File Text, Solving for μ = μ' - jμ" 
set terminal png
set output 'gp-cp.png'
set datafile commentschars "!#" # s1p File comment compatible
set grid xtics ytics
set grid mxtics mytics
set key top right
set xlabel "Frequency MHz"
set title "Measured 43 Material Complex Permeability vs. Frequency"
set yrange [3:1000]
set logscale xy

Lo = 2.05e-9 # Permeability=1 Inductance
i = {0,1}
Zs(a,b) = 50 * (1 + (a+b*i))/(1 - (a+b*i)) # s1p MHz S RI R 50 to Zs
mu(f,a,b) =  -i * Zs(a,b) / (2 * pi * f * 1e6 * Lo) # mu() = u' - u"
plot \
'FT37-43-x5-s21.s1p' using ($1):(real(mu($1,$2,$3))) with lines title "mu'", \
'FT37-43-x5-s21.s1p' using ($1):(-imag(mu($1,$2,$3))) with lines title "mu\""


Example Calibration Settings


Cus2 Window


Cus3 Window