When HFSS Needs Port Calibration (Deembedding)

• If wave ports are used, HFSS does not require any port calibration.
• If internal lumped ports are used, HFSS requires some port calibration (deembedding).
• If lumped or circuit ports are used, parasitic inductance of port geometry can be removed either through calibration or de-embedding.

Deembedding Extension/Transition Effects

Deembedded to the Discontinuity

Deembedding Extension/Transition Z-matrix Method (Simplified Approximation)

Impedance Matrix Z* is Measured/Simulated

Where Z₁ and Z₂ are known, then calculate/deembed Z matrix

Z Matrix Method

Measured/Calculated

(1)

Dembedded

		(2)
		(3)
		(4)

S matrix calculation from the series impedances to be deembedded

Formula

Where:

Input:

w = width of the lumped port [mm]

len = length of the lumped port[mm]

u = len/w

Output:

L[nH]

*From C.R.Paul, Inductance. Loop and partial, Wiley, 2010

And

(6)

Currently, R_s = 0

		(7)
		(8)
		(9)
		(10)
		(11)

Z* is the global impedance matrix

Z is the Global impedance matrix after deembedding.