Lab

Hopefully you've all got Cadence and Momentum up and running now. Next we want to try it out, compare a TSMC inductor model with an EM simulation of the physical layout on the substrate you defined when setting up Momentum. 

First review the inductor, Q value and self resonance frequency. What happens as the frequency approaches the SRF? Is it still working as an inductor?

Start with a spiral inductor from the design kit (e.g. "spiral_std_mu_z", open properties for the inductor, press "Finder", select a working frequency, self resonance frequency and desired L value and minimum Q.  In the "Optimal Objective" select which parameter you wish to optimize for.  Press "FIND" and select one of the solutions.

Next we want to create a layout from the schematic model, launch Layout, go to "Connectivity, Generate, All from source" Press "shift+F" to look at the layout.

Now we want to remove everything but the inductor, but to do so we must flatten the hierarchy. Select all, Go to "Edit -> Hierarchy -> Flatten, check all the boxes. Now delete all components but the inductor.  Also delete "net1 and net2" rectangles. 

Next, launch momentum, create pins on the inductor, 

In the momentum menu; Ports -> Synchronize with Layout. Followed by "Auto-generate". You should now have two ports listed. Next we want to do via simplification. Go to Layout-> "Switch to simplification by user". Layout -> perform via simplification -> use same settings for all via layers, "Local Via Arrays" and set Max distance between vias to 0.5 um

Go to frequencies and set up your sweep.

Run the simulation

When its done -> go to Tools -> Auto-create Circuit Simulator Views. 

Now we should have the block available in the schematic editor. (look for it in the library)

Now place the Momentum block and the TSMC inductor model in the same schematic. Attach PORTS to each model and simulate the S-parameters.  (Open ADE-L, press "sp" and set up the ports and frequency range). Run the simulation. Now you have S parameters for the schematic model and the Momentum block.

Next we want to calculate the L and Q for the ideal model and the momentum model. Open the calculator and add expressions to calculate Q and L. 

Plot the schematic and momentum models Q and L over frequency.  

Published Oct. 17, 2019 9:36 AM - Last modified Oct. 17, 2019 9:38 AM