---

Previous: ADS Tutorial (Thirteen) Working with Touchstone / S-Parameter files in ADS

---

In this section, we will learn about  Multi-Dimensional Parameter Sweeps ADS, which can help us explore the impact of different parameter combinations on circuit performance.

So far, we have been performing simple S-parameter simulations. However, there are cases where we need to run sweeps on variables to examine the performance of a circuit.

First, we copy the TestBench we used previously and name the copy “TestBench_MyFilter_ParameterSweep”:

Open the copied schematic and delete unnecessary components, leaving only the S-parameter simulation controller and NETLIST INCLUDE.

First, we need to create some variables and assign them to components. We select Insert Variable from the toolbar . Then we double-click to add a variable.

First, we create a variable named “myL” to scan the inductance. To be close to reality, we set the Variable Value to 41 (no need to add units), and then click . Then create a variable named “myC”, set the Variable Value to 22, and then click (do not click , otherwise it will overwrite the currently set variable). Then click “OK” to add the variables we need:

We enter the sub-design and modify the L1 and C1 values ​​to the variables we just defined (note the units):

Here we only put in two variables. In actual design, we can add or delete variables as needed.

The S-parameter simulation controller we placed previously uses frequency (freq) as the X-axis by default. Since our sweep variables this time are the values ​​of capacitance and inductance, we need to select “Simulation-S_Param” in the Library Palettes and then select it to sweep:

Then double-click and define the parameters of this scan as myL, starting from 10 and scanning to 100, with a step length of 5, and a total of 19 tests.

Then we select the “Simulations” tab and connect it to the existing simulator. We have previously created an S-parameter simulation called “SP1”, so we fill in “SP1” and click “Apply”.

Then click to execute the simulation. We add a plot of dB(S(2,1)):

Then we can see that the simulation results we get are a cluster of curves, each corresponding to a different inductance value:

Because we also defined the variable myC, we can create a nested loop to sweep. In this case, we duplicate a PARAMETER SWEEP and change “SweepVar” to “myC”. To create a nested loop, we need to connect them. We change “SiminstanceName[1]” of Sweep2 to “Sweep1”. We set the range of myC to 5-50:

Double-click the two PARAMETER SWEEPs, and we can see that the number of steps is 19, so we need to perform 19*19=361 simulations in total. Click to simulate:

All data combinations are presented in the plot.

---

Next article: ADS Tutorial (XV) Multi-Dimensional Data Processing in ADS