Electrical Design Factors
Conductor Capacitance
C = 0.31 a/b + 0.23(1 + k) log10 (1 + 2b/d +2b + b2/d2)
Where
k = Substrate dielectric constant
a = Conductor thickness
b = Width of conductor in inches
d = Distance between conductors in inches
Conductor Resistance
R = 0.000227W
Where
W = Width of conductor
Characteristic Impedance
Zo = R + jwL / G + kwC
Where
Zo = Apparent Z of an infinitely long line in ohms
R = Resistance in ohms
L = Inductance in Henries
G = Conductor per unit length of line in mhos
C = Capacitance in farads
Characteristic Impedance for a Micro Strip
Zo = (h/W) (377 / (Sqrt. er) {1 + (2h/PI W)[1 + ln(PI W/h)]}
Where
h = Dielectric thickness
W = Micro Strip width
er = Effective dielectric constant of substrate