Project 1 ADS Tutorial             (Due Sept 22 in class)

By Dr. Fei Wang

Objective The objective of the tutorial is to become familiar with the basics of Agilent ADS software. Part 1 Start ADS software: ADS software has been installed in every computer in dedicated laboratory. Just double click the ADS icon on desktop, or follow “Start à Programs Advanced Design Systems 2008 "Advanced Design System". Then ADS software will start. The “ADS Quick Start” in “Getting Started with ADS” window may help you understand some basics of ADS software. Please do read through. In ADS, we will create new projects. Projects are saved as a folder in designated location. Each project could be composed by several designs. These designs could be simulated individually or together as a system. Once you read through the ADS Quick Start. You may close the “Getting Started with ADS” window.   Part 2 Simulate a RLC circuit Download “Project1_RLC.rar” from beachboard. Extract the folder to your own saving media. From ADS main window, use FileàOpen project to open the just saved Project1_RLC. (note: if a blank design window pops up after you open the project, just close it) This project should contain a design called “rlc1.dsn”. Double click it to open the design. The design should look like this.

Part 2 Simulate a RLC circuit Download “Project1_RLC.rar” from beachboard. Extract the folder to your own saving media. From ADS main window, use FileàOpen project to open the just saved Project1_RLC. (note: if a blank design window pops up after you open the project, just close it) This project should contain a design called “rlc1.dsn”. Double click it to open the design. The design should look like this. Now, click the gear icon . This will start the S-Parameter simulation. The data plotting window will show after simulation ends. The window is blank so far. Please spend a few minutes now to study the data plotting window. ADS could do several kind of plots. The rectangle plot is the most commonly used one. In addition, it could plot Polar plot and Smith Chart plot as well. Also, you could plot computed results by adding equations.

Now, click the “rectangular plot” icon. A red rectangular shape will appear and you could place it anywhere in the blank area and left click your mouse. Then the following window should appear.

Select DataSet -> S(1,1) -> Add -> dB Select DataSet -> S(2,1) -> Add -> dB The screen should appear as:

Click OK, and the following S-parameter plot should appear. S11 is a measure of the reflected wave as a function of frequency. S21 is a measure of gain. S parameter is call scattering matrix. For a two port network, S parameter could be understood as:

Here, Vn+ is the amplitude of voltage incident on port n. (n=1,2) Vn- is the amplitude of voltage reflected from port n.   Therefore, S11 is the ratio V1- /V1+ àReflection coefficient at port 1. S21 is the ratio V2-/V1+ à Gain of the system.   Print this and turn it in. ( plot 1 )

Now, let’s practice how to use Equation to manipulate your plots. Click on the Eqn icon. Then the following window should appear. Enter equation as shown: ratio=S(1,1)/S(2,1). Then click ok

Now, open a new rectangular plot window. In the “Dataset and Equations” drop-down list, choose Equations. Then add ratio->magnitude into traces. The window should look like the following. Click Ok. Then the new value “ratio” defined by yourself is plotted as a function of frequency. (you may need this technique in your project 2)

Questions for part 1&2 (To answer these questions, you need to carefully read the quick start for ADS) In RLC project simulation, please explain why maximum gain happens when reflection at port 1 reaches minimum. What is the difference between an ADS Project and an ADS Design? Explain S-parameter simulation controller. When it is used, for what?List some other simulation controllers ADS provides, briefly state what they are used for. Part 3 Build a transmission line transient design

You should build the following design. Create a new project for this part. Try to find the corresponding components and set

parameters as indicated

To label the node “Vsrc, V1 or V2”. Click the  icon. Then the following window will appear. Type in pin label and click the corresponding wire is your schematic.

Simulate the design. Add the following traces to the rectangular plot. Select DataSet -> V1 -> Add Select DataSet -> V2 -> Add Select DataSet -> Vsrc -> Add Your plot should look like this:

Include your design schematic and simulation result plot in your report.   (Save part 3 in your thumb drive, you will need the result to answer questions in project 2)

(Save part 3 in your thumb drive, you will need the result to answer questions in project 2)