How to divide a network into subnetworks to create hierarchical designs in Agilent ADS
In Agilent ADS, a large, complex network may be dived into smaller subnetworks for the purposes of analysis and design. These subnetworks may be regarded as building blocks that can be interconnected to form a complex network. To demonstrate how to create such a hierarchical design, consider the ADS schematic shown in the figure below. Our goal is to set the part of the circuit represented inside the box (drawn with a thick dashed line) as a subnetwork within the main network. If you follow this simple example, then you can easy extrapolate to handle more complicated networks.
1. Highlight the part of the network that you want to set as a subnetwork.
2. Right click the highlighted portion. In the popup menu, select: Component à Create Hierarchy
3. Give the subnetwork a name and click OK.
The highlighted portion has now been put into a circuit block with the name you gave it. The circuit block is small and so may have been disconnected from the main circuit.
4. If the circuit block was disconnected from the main network after you created the hierarchy, reconnect it.
5. To gain access to the insides of the circuit block, select the circuit block, and click the button that pushes into the hierarchy (the button is labeled with a blue arrow pointing down, as shown in the figure below).
You will now be looking under the hood of the circuit block.
Note: You can also access your circuit block from the project tree:
- Note that, in this example, instead of setting numeric values for the inductance, resistance, and capacitance, we have them set as variables (named Ind1, Res1, and Cap1 in the schematic). In order to gain access to these variables from the main network, we must tell ADS to pass them as parameters. To do this, select Design Parameters from the File menu (i.e. FileàDesign Parameters).
7. Click on the Parameters tab. Type the name of your first variable (in our case, this would be Ind1) in the box labeled Parameter name. Give this variable some default value like 1 in the box labeled Default Value. Then click the Add button.
Add the other variables in the same way. When you are done, click the OK button.
8. Now pop back out the circuit block into the main network by clicking the button that pushes out of the hierarchy (the button is labeled with a blue arrow pointing up, as shown in the figure below).
When you pop back out you will find that ADS did not update the circuit schematic of the main network to include the variables of the circuit block that you told it to pass.
9. To update the schematic, right click the circuit block. In the popup menu select Component à Update Component definitions
Click OK.
10. And voila! You are now the proud owner of a subnetwork complete with its internal variables at your fingertips. Change the variables (Ind1, Res1, and Cap1) from unity to any value you wish. Optimize over them. Have fun.
And dont forget to add a simulation controller to the main network to simulate!
