Model description and parameter extraction

AN2657

12/18

Figure 6.

Simulated version of the PowerFLAT

To minimize the simulation time and increase accuracy, the structure was split into two parts

(drain and gate). In this way, the reciprocal coupling between the input and output parts are

not considered. To take into account such effect, an extra capacitor (Cgd-package) has

been used. To complete the package model an extra inductor (Lvia) associated with the

source has been added. This inductor represents the effect created by the "via holes"[8] [9].

The S-parameters concerning the electromagnetic simulation of the gate section of the

package are shown in Figure 7.

Figure 7.

S-parameters of the simulated package

Moreover, using the measured S-parameters of the packaged device, it was possible to

extract the Cgd-package and the Lvia. Observing Figure 8, it is possible to see the circuit

representing the union between the package model and the device model.

freq (1.000MHz to 50.00GHz)

Input Reflection Coefficient

5

10

152025 30 3540

45

050

-14

-12

-10

-8

-6

-4

-2

0

-16

2

freq, GHz

Forward Trans mission, dB

5

10 15 20253035

4045

050

-150

-100

-50

0

50

100

150

-200

200

freq, GHz

Forward Trans mission, phase