HFSS15: When HFSS Needs Port Calibration (deembedding)

• If regular (perfect) ports are used, HFSS does not need any port calibration

• • If imperfect ports are used (internal lumped port), HFSS also needs some port calibration (deembedding)

• If wave ports are used port calibration is not required

• If lump ports are used, parasitic inductance of port geometry can be removed 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 meaured/simulated

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

Z Matrix Method

Measured/Calculated

(1)

Dembedded

(2)

(3)

(4)

S matrix calculation from the series impedances to be deembedded

Experimental Formula

(5)

Where:

Input: w = width of the lumped port [mm]

len = length of the lumped port[mm]

t = 0.0

Output: L[nH]

And

(6)

(7)

(8)

(9)

(10)

(11)

Z* is the global impedance matrix

Z is the Global impedance matrix after deembedding