elektr0
Full Member level 5
Hallo,
i measured the complex propagation constant gamma from MSL with Thru-Reflect-Line Calibration.
Papers from Dylan and Marks (NIST) explain how to calculate the complex characteristic impedance from the measured gamma.
gamma / Z = jwC + G
gamma * Z = R + jwL
RC+LG = Im (gamma * gamma) / jw
If we neglect G and use Rdc (measured) as R, we can solve for the capacitance
per unit length.
Then it is possible to obtain Z in magnitude and phase from gamma / Z = jwC.
The calculated phase looks good compared to HFSS calculation, but
there is an offset in the calculated magnitude of Z.
The frequency dependency seems good, but agreement to the HFSS simulation is only given, if I add a value of about 55 to it.
Can anybody see the mistake.....
elektr0
i measured the complex propagation constant gamma from MSL with Thru-Reflect-Line Calibration.
Papers from Dylan and Marks (NIST) explain how to calculate the complex characteristic impedance from the measured gamma.
gamma / Z = jwC + G
gamma * Z = R + jwL
RC+LG = Im (gamma * gamma) / jw
If we neglect G and use Rdc (measured) as R, we can solve for the capacitance
per unit length.
Then it is possible to obtain Z in magnitude and phase from gamma / Z = jwC.
The calculated phase looks good compared to HFSS calculation, but
there is an offset in the calculated magnitude of Z.
The frequency dependency seems good, but agreement to the HFSS simulation is only given, if I add a value of about 55 to it.
Can anybody see the mistake.....
elektr0