RF Transformer design with ADS Momentum

[Gunar]

rf transformer design

hello everybody,

I've drawn a small spiral inductor with the momentum layout-editor in layer cond, and the same inductor in layer cond2. In between there is my substrate with epsilon_r. So I've got a transformer now.

For s-parameter simulation I inserted 4 ports, one at each connection of my inductors. Port1 and 2 are above in layer cond (for the first inductor), Port 3 and 4 are below in layer cond2 (for the second inductor).

After simulation I receive a 4x4 matrix of s-parameters.

How can I now determine the inductivity of my two inductors L1 and L2, and the magnetic coupling M as well as the coupling factor k = M / sqrt(L1*L2) of my transformer?

I'm especially confused, because I expected a 2x2 S-Matrix ...

Thanks in advance,
Gunar

 

[psmon]

momentum transformer

Use differential ports. Then you have 2X2 matrix.

 

[Gunar]

rf transformer

Unfortunately it's not possible to set the ports as differential. The Error Message is:
> Port P1 cannot be associated with port number 2.
> If they are in the same reference plane, and you want to associate them:
> Please set both ports to the correct Port Type before
> setting ^Associate with port number^

But I found another solution. Refering to Agilent Application Note 1373-1, the 2x2 Matrix in the upper left of my 4x4 Matrix can be seen as the scattering parameters I was searching for: differential stimulus and differential response.

But anyway: thanks a lot! (I'm still not really familar with ADS)
Gunar

 

[jk_olivo]

I have exactly the same problem...

I have 2 spiral on the layer "cond" and I would like to define two pair of differential port but Momentum gives back to me this message

Port P2 cannot be associated with port number 1.
If they are in the same reference plane, and you want to associate them:
Please set both ports to the correct Port Type before
setting ^Associate with port number^


I have followed the procedure: I have defined the positive port as differential and set it with normal polarity... then I have defined the negative port as differential and set it with reverse polarity...

But always this message...

I post the layout screenshot.

 

[yulong]

I am doing the same job. Thank you for the post!

 

[chatangxiaosi]

To "jk_olivo",

If you want to set P1 differential with P2, and P3 differential with P4,
P1&P2, P3&P4 should be "in the same reference plane".

Apparently, P1&P2 are in the opposite direction. in you picture.