Specifications

15
Page 29
安捷倫科技高頻元件量測研討會
Feb.23, 2006
• near field / low freq approximation
L(ω) = L
0
+ L
1
ωR + L
2
(ωR)
2
+ …
C(ω) = C
0
+ C
1
ωR + C
2
(ωR)
2
+ …
• neglecting far field radiation
• [L
0
] & [C
0
] frequency independent
• [Z
0
] matrix reload very fast
Momentum RF
Quasi-Static Electromagnetics
Low Frequency approximation :
|'|1
'||
rr
rr
−−≈
−−
jke
jk
[Z] matrix load is frequency
independent !
[Z].[I]=[V]
[S]
Mesh strips, Vias and slots with rectangles
and triangles (conformal surface mesh)
Performs mesh reduction while maintaining
integrity of solution
Model surface current in each mesh cell
(linear distribution)
Solve matrix equation for the unknown
current coefficients
Calculate S-parameters
Electro- and magnetostatic
Green’s functions
Quasi-static frequency
scaling (jw, 1/jw)
L’s and C’s are real and
frequency independent
R’s are complex (DC loss +
skin effect √w)
mesh
topology
reduction
reduction
1
cell
4
cells
10
cells
Page 30
安捷倫科技高頻元件量測研討會
Feb.23, 2006
Comparison of Models
• quasi-static inductance . . . . . .
• quasi-static capacitance . . . . .
• DC conductor loss (s) . . . . . . . .
• DC substrate loss (s) . . . . . . . .
• dielectric loss (tgd) . . . . . . . . . . . . . . . . . . . . . . . . . . .
• skin effect loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Layout
S parameters
RF
Spice model
DC
Spice Momentum