Hello,

I simulated a cylindrical via in momentum with the following dimensions:

Height= 8mils

Diameter=8mils

Via pad (square)=13.5mils

Metal thickness=1.4mils

Substrate parameters are

GETEK

Dielectric constant=3.83

Loss tangent=0.008

Configuration of the substrate is:

Strip METAL

GETEK dialetric VIA

GROUND

I then simulated in ADS a VIA2 component (with the same dimensions) from the Tlines Microstrip Palette.

The inductance given by momentum was different than the inductance given by the VIA2 component.

Inductance of via (momentum)=58.7pH

Inductance VIA2 =21pH

Why is that?

I would expect them to be the same.

Any clues?

Thanks

I simulated a cylindrical via in momentum with the following dimensions:

Height= 8mils

Diameter=8mils

Via pad (square)=13.5mils

Metal thickness=1.4mils

Substrate parameters are

GETEK

Dielectric constant=3.83

Loss tangent=0.008

Configuration of the substrate is:

Strip METAL

GETEK dialetric VIA

GROUND

I then simulated in ADS a VIA2 component (with the same dimensions) from the Tlines Microstrip Palette.

The inductance given by momentum was different than the inductance given by the VIA2 component.

Inductance of via (momentum)=58.7pH

Inductance VIA2 =21pH

Why is that?

I would expect them to be the same.

Any clues?

Thanks

Momentum may underestimate the low-frequency inductance by about 10% because it assumes current to always flow on the surface of the via, never distributed evenly inside the via as it would be at low frequencies.

The best way to solve your problem would be if you could package up the project as a *.zap file (Archive Project command) and send it to technical support.