docs100 ao getting started

AWR Design Environment 10

Analog OfficeGetting Started Guide

AO Getting Started GuideAWRDE 10 Edition

AWR Corporation1960 E. Grand Avenue, Suite 430El Segundo, CA 90245USAPhone +1 310.726.3000Fax +1 310.726.3005Website www.awrcorp.com

U.S. Technical Support Phone 888.349.7610

LEGAL NOTICES

2013 AWR Corporation. All rights reserved. AWR is a National Instruments Company. Printed in the United States of America. No partof this guide may be reproduced in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without theexpress written permission of AWR Corporation.

Trademarks

Advancing the wireless revolution, AnalogOffice, APLAC,AWRand the AWR logo, AXIEM,MicrowaveOffice, and TX-Lineare registered trademarks of AWR Corporation.

ACETM, AnalystTM, AWR ConnectedTM, AWR Design EnvironmentTM, AWR Signal IntegrityTM, AWR.TVTM, AWR User ForumTM,EMSightTM, EM SocketTM, iFilterTM, iMatchTM, iNetTM, MRHBTM, RFATM, RFBTM, RFITM, TDNNTM, TestWaveTM, Unified Data ModelTM,and Visual System SimulatorTM are trademarks of AWR Corporation.

All other product and company names herein may be the trademarks or registered trademarks of their respective owners.

The information in this guide is believed to be accurate. However, no responsibility or liability is assumed by AWR Corporation for its use.

Table of Contents1. Introducing the AWR Design Environment ........................................................................................... 11

About This Guide ....................................................................................................................... 11Prerequisites ...................................................................................................................... 11Contents of This Guide ........................................................................................................ 12Conventions Used in This Guide ............................................................................................ 12

Getting Additional Information ...................................................................................................... 12AWR Knowledge Base ........................................................................................................ 12Documentation ................................................................................................................... 13Online Help ....................................................................................................................... 14Website Support ................................................................................................................. 14Technical Support ............................................................................................................... 14

2. AWR Design Environment Suite ........................................................................................................ 21Starting AWR Programs ............................................................................................................... 22AWR Design Environment Suite Components .................................................................................. 23Basic Operations ......................................................................................................................... 24

Working with Projects ......................................................................................................... 24Working with Schematics and Netlists in MWO/AO .................................................................. 25Working with System Diagrams in VSS .................................................................................. 26Using the Element Browser .................................................................................................. 27Creating a Layout with MWO/AO ....................................................................................... 211Creating Output Graphs and Measurements ........................................................................... 214Setting Simulation Frequency and Performing Simulations ........................................................ 216Using Scripts and Wizards .................................................................................................. 217

Using Online Help ..................................................................................................................... 2173. AO: Simulation in Analog Office ....................................................................................................... 31

DC Analysis .............................................................................................................................. 31Creating a New Project ........................................................................................................ 31Setting Default Project Units ................................................................................................. 32Creating a Schematic ........................................................................................................... 32Back Annotating Voltages and Currents on the Schematic ........................................................... 34Simulating the Circuit .......................................................................................................... 35Tuning the Circuit ............................................................................................................... 36DC Sweep ......................................................................................................................... 37Adding a Graph .................................................................................................................. 39Post-Analysis Tuning ......................................................................................................... 310

Small Signal AC Analysis ........................................................................................................... 311Copying a Schematic ......................................................................................................... 311Setting Up the Frequency Sweep .......................................................................................... 312Setting Up Measurements ................................................................................................... 313

Transient Analysis ..................................................................................................................... 316Large Signal Analysis ........................................................................................................ 316Pulse Signal ..................................................................................................................... 322

4. AO: IV Curve Measurements ............................................................................................................. 41IV Curve of a NMOS ................................................................................................................... 41

Creating a New Project ........................................................................................................ 41Setting Default Project Units ................................................................................................. 41Creating a Schematic ........................................................................................................... 42Placing Elements in a Schematic ............................................................................................ 42Editing Element Parameters .................................................................................................. 43

Getting Started Guide iiiAWR Proprietary

Adding a Graph .................................................................................................................. 44Running the Simulation and Analyzing the Results .................................................................... 45Tuning nmos Parameters and Viewing Graph and Layout ........................................................... 46

5. AO: Differential Pair Amplifier .......................................................................................................... 51Creating a Differential Amplifier and Simulating .............................................................................. 51

Creating Differential AMP Schematic .................................................................................... 51Adding Pins ....................................................................................................................... 54Creating a Test Bench .......................................................................................................... 56Simulation Settings and Measurements ................................................................................... 59Optimizing the Output Voltage ............................................................................................. 517

Creating a Layout ...................................................................................................................... 520Layout Tips and Tricks ....................................................................................................... 520Editing Database Unit and Grid Size ..................................................................................... 520Creating and Assigning a Pads Layout ................................................................................... 521Viewing Layout and Placement ............................................................................................ 522Routing the Nets ............................................................................................................... 529

Post-Route Simulation ............................................................................................................... 538Connectivity Checking ....................................................................................................... 538Extracting Vdd Net and Simulating ....................................................................................... 540

6. AO: Tonal Analysis ......................................................................................................................... 61Bipolar Limiting Amplifier Circuit ................................................................................................ 61

Editing an Existing Project ................................................................................................... 61Specifying Port Types .......................................................................................................... 61Setting Default Project Frequencies ........................................................................................ 63Setting Up the Harmonic Balance Simulator ............................................................................ 63Adding a Graph and Measurements for 1-Tone Simulation ......................................................... 64Adding a Sweep Variable Control Block ................................................................................. 65Performing a 2-Tone Simulation ............................................................................................ 68

7. AO: CMOS Mixer .......................................................................................................................... 71Single Balanced CMOS Mixer Circuit ............................................................................................ 71

Importing a Schematic ......................................................................................................... 71Creating Test Benches ......................................................................................................... 71Setting Defaults .................................................................................................................. 75Adding Graphs and Measurements ......................................................................................... 77Adding Equations .............................................................................................................. 711Performing Noise Analysis ................................................................................................. 714Optimizing the Circuit ........................................................................................................ 717

Index .......................................................................................................................................... Index1

AWR Proprietaryiv AWR Design Environment 10

Contents

Chapter 1. Introducing the AWR Design EnvironmentWelcome to the AWR Design EnvironmentTM suite!

The AWR Design Environment (AWRDE) suite comprises three powerful tools that can be used together to create anintegrated system and RF or analog design environment: Visual System SimulatorTM (VSS), Microwave Office (MWO),and Analog Office (AO) software. These powerful tools are fully integrated in the AWR Design Environment suiteand allow you to incorporate circuit designs into system designs without leaving the AWR Design Environment.

VSS software enables you to design and analyze end-to-end communication systems. You can design systems composedof modulated signals, encoding schemes, channel blocks and system level performance measurements. You can performsimulations using VSS's predefined transmitters and receivers, or you can build customized transmitters and receiversfrom basic blocks. Based on your analysis needs, you can display BER curves, ACPRmeasurements, constellations, andpower spectrums, to name a few. VSS provides a real-time tuner that allows you to tune the designs and then see yourchanges immediately in the data display.

Microwave Office and Analog Office software enables you to design circuits composed of schematics and electromagnetic(EM) structures from an extensive electrical model database, and then generate layout representations of these designs.You can perform simulations using one of AWR's simulation engines -- a linear simulator, an advanced harmonic balancesimulator for nonlinear frequency-domain simulation and analysis, a 3D-planar EM simulator (the EMSightTM tool), theAPLAC simulators, or an optional HSPICE simulator -- and display the output in a wide variety of graphical formsbased on your analysis needs. You can then tune or optimize the designs and your changes are automatically andimmediately reflected in the layout.

Analog Office provides a single environment to fully interact with a comprehensive and powerful set of integrated toolsfor top-down and front-to-back analog and RFIC design.

The toolset spans the entire IC design flow, from system-level to circuit-level design and verification, including designentry and schematic capture, time- and frequency-domain simulation and analysis, physical layout with automateddevice-level place and route and integrated design rule checker (DRC), 3D full field solver-based extraction with industrygold standard high-speed extraction technology from OEA International, and a comprehensive set of waveform displayand analysis capabilities supporting complex RF measurements.

OBJECT ORIENTED TECHNOLOGY

At the core of the AWR Design Environment capability is advanced object-oriented technology. This technology resultsin software that is compact, fast, reliable, and easily enhanced with new technology as it becomes available.

About This Guide

This Getting Started Guide is designed to get you up and running quickly in the AWRDE by demonstrating MWO, VSS,or AO capabilities through working examples.

Prerequisites

You should be familiar withMicrosoftWindows and have a working knowledge of basic circuit and/or system designand analysis.

This document is available as a PDF file on your Program Disk (MWO_Getting_Started.pdf, AO_Getting_Started.pdf,or VSS_Getting_Started.pdf, depending on your product), or you can download it from the AWR website atwww.awrcorp.com.

Getting Started Guide 11AWR Proprietary

If you are viewing this guide as online Help and intend to work through the examples, you should obtain and print outthe PDF version for ease of use.

Contents of This Guide

Chapter 2 provides an overview of the AWRDesign Environment suite including the basic menus, windows, componentsand commands.

In theMicrowave Office Getting Started Guide the subsequent chapters take you through hands-on examples that showyou how to use MWO software to create circuit designs.

In the Visual System Simulator Getting Started Guide the subsequent chapters take you through hands-on examples thatshow you how to use VSS software to create system simulations and to incorporate Microwave Office circuit designs.

In the Analog Office Getting Started Guide the subsequent chapters take you through hands-on examples that show youhow to use Analog Office to create circuit designs and display various measurements in graphical form.

In theMMICGetting Started Guide the subsequent chapters take you through hands-on examples that show youMonolithicMicrowave Integrated Circuit (MMIC) features and designs.

Conventions Used in This Guide

This guide uses the following typographical conventions:

ConventionItem

Shown in a bold alternate type. Nested menu selections areshown with a ">" to indicate that you select the first menuitem and then select the second menu item:

Anything that you select (or click) in the AWRDE, likemenu items, button names, and dialog box option names

Choose File > New Project

Shown in a bold type within quotation marks:Any text that you enter using the keyboard

Enter "my_project" in Project Name.

Shown in italics:File names and directory paths.

C:\Program Files\AWR\AWRDE\10 or C:\Program Files(x86)\AWR\AWRDE\10 is the default installation directory.

Shown in a bold alternate type with initial capitals. Keycombinations are shownwith a "+" to indicate that you pressand hold the first key while pressing the second key:

Keys or key combinations that you press

Press Alt + F1.

Getting Additional Information

There are multiple resources available for additional information and technical support for MWO, VSS, and AO.

AWR Knowledge Base

www.awrcorp.com/download/kb.aspx

AWR Proprietary12 AWR Design Environment 10


Videos - Short videos on how to accomplish specific tasks; longer videos for training on specific topics.

Examples - Full listing of examples available either in the install or download.

Solution Finders - Step-by-step guides for problem solving (licensing problems, understanding error messages, etc).

Application Notes - Documents the AWR technical staff writes covering specific software features.

Frequently Asked Questions (FAQs) - Answers to common customer questions.

Visual Basic Scripts - Examples of scripts the AWR technical staff writes.

Release Notes - Archive of release notes for previous versions of AWR software.

Documentation

Documentation for the AWR Design Environment includes:

What's New in AWRDE 10? presents the new or enhanced features, elements, system blocks, and measurements forthis release. This document is available via the Windows Start button Programs > AWRDE 10 menu, or by choosingHelp > What's New while in the program.

The AWR Design Environment Installation Guide describes how to install the AWRDE and configure it for locked orfloating licensing options. It also provides licensing configuration troubleshooting tips. This document is available onyour Program Disk as install.pdf, or downloadable from the AWR website at www.awrcorp.com under Support.

The AWRDE User Guide provides an overview of the AWRDE including chapters on the AWRDE user interface;using schematics/system diagrams; data files; netlists; graphs, measurements, and output files; and variables andequations in projects. In addition, an appendix providing guidelines for starting a new design is included.

The AWRDE Simulation and Analysis Guide discusses simulation basics such as swept parameter analysis,tuning/optimizing/yield, and simulation filters; and provides simulation details for DC, linear, AC, harmonic balance,transient, and EM simulation/extraction theory and methods.

The AWRDE Dialog Box Reference provides a comprehensive reference of all AWRDE dialog boxes with dialogbox graphics, overviews, option details, and information on how to navigate to each dialog box.

The AWRDE API Scripting Guide explains the basic concepts of AWRDE scripting and provides coding examples.It also provides information on the most useful objects, properties, and methods for creating scripts in the AWR ScriptDevelopment Environment (AWR SDE). In addition, this guide contains the AWRDE Component API list.

The AWR Design Environment Quick Reference document lists keyboard shortcuts, mouse operations, and tips andtricks to optimize your use of the AWR Design Environment. This document is available within the AWRDE bychoosing Help > Quick Reference or on your Program Disk as Quick_Reference.pdf. This is an excellent document toprint and keep handy at your desk.

Context sensitive Help is available for most operations or phases of design creation. To view an associated Help topic,press the F1 key during design creation.

Documentation for MWO and AO includes:

TheMWO/AO Layout Guide contains information on creating and viewing layouts for schematics and EM structures,including use of the Layout Manager, Layout Process File, artwork cell creation/editing/properties, Design RuleChecking, and other topics.

The MWO/AO Element Catalog provides complete reference information on all of the electrical elements that youuse to build schematics.

TheMWO/AOMeasurement Catalog provides complete reference information on the "measurements" (i.e., computeddata such as gain, noise, power, or voltage) that you can choose as output for your simulations.



Documentation for VSS includes:

The VSS System Block Catalog provides complete reference information on all of the system blocks that you use tobuild systems.

The VSS Measurement Catalog provides complete reference information on the measurements you can choose asoutput for your simulations.

The VSS Modeling Guide contains information on simulation basics, RF modeling capabilities, and noise modeling.

Online Help

All AWR documentation is available as on-line Help.

To access online Help, choose Help from the menu bar or press F1 anywhere in the program. Context sensitive help isavailable for elements and system blocks in the Element Browser and within schematics or system diagrams. Contextsensitive Help is available for measurements from the Add/Modify Measurement dialog box.

Website Support

Support is also available from the AWR website at www.awrcorp.com. You can go directly to this site from the AWRDesign Environment suite Help menu. The Support page provides links to the following:

the current software version

the Knowledge Base, which contains Frequently Asked Questions (FAQs) fromMWO,VSS, and AO users, ApplicationNotes, Tutorials, and project examples

All MWO, VSS, and AO documentation

Technical Support

Technical Support is available Monday - Friday, 7 a.m. - 5 p.m., PST.

Phone: 888.349.7610 / Fax: 310.726.3005 / E-mail: .



Chapter 2. AWR Design Environment SuiteThe basic design flow in the AWR Design EnvironmentTM suite is shown in the following flow chart.

Create Project

File > New Project or File > New with Library

Set Units, Environment OptionsOptions > Project Options

Create Schematics/DiagramsProject > Add Schem./Sys. Diagram

View > View Schematic

(MWO/AO) Create LayoutView > View Layout

Set Frequency, Simulation Options(MWO/AO) Options > Def. Circuit Options

(VSS) Options > Def. System Options

Create Graphs/MeasurementsProject > Add Graph

Project > Add Measurement

Simulate Circuit(MWO/AO) Simulate > Analyze(VSS) Simulate > Run Sys. Sim.

Tuning(MWO/AO) Optimizing

Set Optimization Goals Manually Vary Parameters

Automatically:

Simulate > Optimize Simulate > Tune

Project > Add Opt Goal Simulate > Tune Tool

*Updates Schem./Sys. Diagrams

*(MWO/AO) Updates Layout

*Simulates

*Updates Results/Graphs

Automatically:

*Updates Schem./Sys. Diagrams

*(MWO/AO) Updates Layout

*Simulates

*Updates Results/Graphs

This chapter describes the windows, menus and basic operations for performing the following tasks in the AWR DesignEnvironment (AWRDE) suite:

Creating projects to organize and save your designs

Creating system diagrams, circuit schematics, and EM structures

Placing circuit elements into schematics

Placing system blocks into system diagrams


Incorporating subcircuits into system diagrams and schematics

Creating layouts

Creating and displaying output graphs

Running simulations for schematics and system diagrams

Tuning simulations

NOTE: The AWRDE Quick Reference document lists keyboard shortcuts, mouse operations, and tips and tricks tooptimize your use of the AWRDE. Choose Help > Quick Reference to access this document.

Starting AWR Programs

To start the AWRDE suite:

1. Click the Windows Start button.

2. Choose Programs > AWRDE 10 > AWR Design Environment 10.

The following main window displays.

Title bar

Menu bar

Toolbar

Project Browser

System diagrams

Circuit schematics

Workspace

Status window

Tabs

Status bar


Starting AWR Programs

If the AWRDE suite was not configured during installation to display in your Start menu, start the application bydouble-clicking the My Computer icon on your desktop, opening the drive and folder where you installed the program,and double-clicking on MWOffice.exe, the AWRDE application.

AWR Design Environment Suite Components

The AWRDE suite contains the windows, components, menu selections and tools you need to create linear and nonlinearschematics, set up EM structures, generate circuit layouts, create system diagrams, perform simulations, and displaygraphs. Most of the basic procedures apply to Microwave Office (MWO), Visual System SimulatorTM (VSS), andAnalog Office (AO). The major components of the AWRDE suite are:

DescriptionComponent

The menu bar comprises the set of menus located along the top of the window for performinga variety of MWO, VSS, and AO tasks.

menu bar

The toolbar is the row of buttons located just below the menu bar that provides shortcuts tofrequently used commands such as creating new schematics, performing simulations, or tuning

toolbar

parameter values or variables. The buttons available depend on the functions in use and theactive window within the design environment (as well as any customization of toolbar buttongroups). Position the cursor over a button to view the button name/function.

The workspace is the area in which you design schematics and diagrams, draw EM structures,view and edit layouts, and view graphs. You can use the scrollbars to move around the workspace.You can also use the zoom in and zoom out options from the View menu.

workspace

Located by default in the left column of the window, this is the complete collection of data andcomponents that define the currently active project. Items are organized into a tree-like structure

Project Browser(Project tab)

of nodes and include schematics, system diagrams and EM structures, simulation frequencysettings, output graphs, user folders and more. The Project Browser is active when the AWRDEfirst opens, or when you click the Project tab. Right-click a node in the Project Browser to accessmenus of relevant commands.

The Element Browser contains a comprehensive inventory of circuit elements for building yourschematics, and system blocks for building system diagrams for simulations. The Element

Element Browser(Elements tab)

Browser displays by default in the left column in place of the Project Browser when you clickthe Elements tab.

The Layout Manager contains options for viewing and drawing layout representations, creatingnew layout cells, and working with artwork cell libraries. The Layout Manager displays bydefault in the left column in place of the Project Browser when you click the Layout tab.

Layout Manager(Layout tab)

The Status Window displays error, warning, and informational messages about the currentoperation or simulation. The Status Window displays by default at the bottom of the workspacewhen you click the Status Window tab.

Status Window (StatusWindow tab)

The bar along the very bottom of the design environment window that displays informationdependent on what is highlighted. For example, when an element in a schematic is selected, the

Status bar

element name and ID displays. When a polygon is selected, layer and size information displays,and when a trace on a graph is selected, the value of a swept parameter displays.

You can invoke many of the functions and commands from the menus and on the toolbar, and in some cases byright-clicking a node in the Project Browser. This guide may not describe all of the ways to invoke a specific task.


AWR Design Environment Suite Components

Basic Operations

This section highlights the windows, menu choices, and commands available for creating simulation designs and projectsin the AWRDE suite. Detailed use information is provided in the chapters that follow.

Working with Projects

The first step in building and simulating a design is to create a project. You use a project to organize and manage yourdesigns and everything associated with them in a tree-like structure.

Project Contents

Because MWO, VSS, and AO are fully integrated in the AWRDE suite, you can start a project based on a system designusing VSS, or on a circuit design using MWO or AO. The project may ultimately combine all elements. You can viewall of the components and elements in the project in the Project Browser. Modifications are automatically reflected inthe relevant elements.

A project can include any set of designs and one or more linear schematics, nonlinear schematics, EM structures, orsystem level blocks. A project can include anything associated with the designs, such as global parameter values, importedfiles, layout views, and output graphs.

Creating, Opening, and Saving Projects

When you first start the AWRDE suite, a default empty project titled "Untitled Project" is loaded. Only one project canbe active at a time. The name of the active project displays in the main window title bar.

After you create (name) a project, you can create your designs. You can perform simulations to analyze the designs andsee the results on a variety of graphical forms. Then, you can tune or optimize parameter values and variables as neededto achieve the desired response. You can generate layout representations of the designs, and output the layout to a DXF,GDSII, or Gerber file. See Appendix B, New Design Considerations in AWRDE User Guide for advanced guidelines onstarting a new design.

To create a project choose File > New Project. Name the new project and the directory you want to write it to by choosingFile > Save Project As. The project name displays in the title bar.

To open an existing project, choose File > Open Project. To save the current project, choose File > Save Project. When yousave a project, everything associated with it is automatically saved. AWR projects are saved as *.emp files.

Opening Example Projects

AWR provides a number of project examples (*.emp files) in the C:\Program Files\AWR\AWRDE\10\Examples\ orC:\Program Files (x86)\AWR\AWRDE\10\Examples\ directory to demonstrate key concepts, program functions andfeatures, and show use of specific elements. You can filter project examples by keyword or search for an example byfile name. An inverted triangle in the column header indicates the column on which your search is filtered.

To search for and open example projects referenced in this guide:

1. Choose File > Open Example.

The Open Example Project dialog box displays with columns for the project name and keywords associated with eachexample project.

2. Filter the list using "getting_started" as a keyword by Ctrl-clicking the Keywords column header and typing"getting_started" in the text box at the bottom of the dialog box.


Basic Operations

As shown in the following figure, the example list is filtered to display only those projects that have the "getting_started"keyword associated with them.

Working with Schematics and Netlists in MWO/AO

A schematic is a graphical representation of a circuit, while a netlist is a text-based description. An MWO/AO projectcan include multiple linear and nonlinear schematics and netlists.

To create a schematic, right-click Circuit Schematics in the Project Browser, choose New Schematic, and then specify aschematic name.

To create a netlist, right-click Netlists in the Project Browser, choose New Netlist, and then specify a netlist name andtype.

After you create a schematic or netlist, a window for it opens in the workspace and the Project Browser displays the newitem as a subnode under Circuit Schematics or Netlists. Subnodes of the new schematic or netlist which contain all of theoptions that define and describe the schematic or netlist (such as frequencies or harmonic balance options) can be displayedin the Project Browser by choosing Options > Environment Options to display the Environment Options dialog box, thenselecting the Show options as sub-nodes check box on the Project tab. In addition, the menu and toolbar display newchoices particular to building and simulating schematics or netlists.


Basic Operations

Right-click and chooseNew Schematic

Right-click and chooseNew Netlist

or

A Schematic window orNetlist window opens inthe workspace

Working with System Diagrams in VSS

A VSS project can include multiple system diagrams. To create a system diagram, right-click System Diagrams in theProject Browser and choose New System Diagram.


Basic Operations

Right-click and chooseNew System Diagram

A System Diagramwindow opens in theworkspace

You are prompted to name the new system diagram.

After you name the system diagram, a window opens in the workspace and the Project Browser displays the new systemdiagram. Subnodes of the system diagram which contain all of the options that define and describe the system diagramcan also be displayed in the Project Browser by choosing Options > Environment Options then selecting the Show optionsas sub-nodes check box on the Project tab of the Environment Options dialog box. After you name the system diagram,the menus and toolbar display new selections and buttons for building and simulating systems.

Using the Element Browser

The Element Browser gives you access to a comprehensive database of hierarchical groups of circuit elements forschematics and system blocks for system diagrams. The Libraries folders in the Element Browser provide a wide rangeof electrical models and S-parameter files from manufacturers.

Circuit elements include models, sources, ports, probes, measurement devices, data libraries, and model libraries thatcan be placed in a circuit schematic for linear and non-linear simulations.

System blocks include channels, math tools, meters, subcircuits, and other models for system simulations.


Basic Operations

To view elements or system blocks, click the Elements tab. The Element Browser replaces the Project Browser window.

To expand and collapse the model categories, click the + or - symbol to the left of the category name to view or hideits subcategories. When you click on a category/subcategory, the available models display in the lower window pane.If there are more models than the window can show, a vertical scroll bar displays to allow you to scroll down to seeall of the models.

To place a model into a schematic or system diagram, simply click and drag it into the window, release the mousebutton, right-click to rotate it if needed, position it, and click to place it.

To edit model parameters, double-click the element graphic in the schematic or system diagram window. An ElementOptions dialog box displays for you to specify new parameter values. You can also edit individual parameter valuesby double-clicking the value in the schematic or system diagram and entering a new value in the text box that displays.

Expand, then clickdesiredsubcategory

Drag desired modelinto schematic orsystem diagramwindow

Elements tabdisplays the ElementsBrowser

Buttons foradding portsand ground

Right-click and chooseDetails

Adding Subcircuits to Schematics

Subcircuits allow you to construct hierarchical circuits by including a subcircuit block in a schematic (insert a schematicinside of another schematic!). The circuit block can be a schematic, a netlist, an EM structure, or a data file.

To add a subcircuit to a schematic, click Subcircuits in the Element Browser. The available subcircuits display in thelower window pane. These include all of the schematics, netlists, and EM structures associated with the project, aswell as any imported data files defined for the project.

To add a data file as a subcircuit, you must first import it and add it to the project as a node. To do so, choose Project> Add Data File > New Data File. Any imported data files are automatically shown in the list of available subcircuits inthe Element Browser.

To place the desired subcircuit, simply click it and drag it into the schematic window, release the mouse button, positionit, and click to place it.


Basic Operations

To edit subcircuit parameters, select the subcircuit in the schematic window, right-click, and choose Edit Subcircuit.Either a schematic, netlist, EM structure, or data file opens in the workspace. You can edit it in the same way that youwould edit the individual circuit block types.

Adding Subcircuits to System Diagrams

Subcircuits allow you to construct hierarchical systems and to import results of circuit simulation directly into the systemblock diagram.

To create a subcircuit to a system diagram, choose Project > Add System Diagram > New System Diagram or ImportSystem Diagram and then click Subcircuits under System Blocks in the Element Browser. The available subcircuitsdisplay in the lower window pane.

To place the desired subcircuit, simply click and drag it into the system diagram window, release the mouse button,position it, and click to place it.

To edit subcircuit parameters, select the subcircuit in the system diagramwindow, right-click, and choose Edit Subcircuit.

To add a system diagram as a subcircuit to another system diagram, you must first add ports to the system that isdesignated as a subcircuit.

Adding Ports to Schematics and System Diagrams

To add ports to a schematic or system diagram, expand the Ports category in the Element Browser. Under Circuit Elementsor System Blocks, click Ports or one of its subgroups, for example, Harmonic Balance. The available models display inthe lower window pane.

Drag the port into the schematic or system diagram window, right-click to rotate it if needed, position it, and click toplace it.

For a shortcut when placing ports and ground, click the Ground or Port buttons on the toolbar, position the ground orport, and click to place it.

To edit port parameters, double-click the port in the schematic or system diagram windows to display a dialog box inwhich you can specify new parameter values.

Connecting Element and System Block Nodes

You can connect elements directly by positioning the elements so their nodes touch. Small green boxes display to indicatethe connection. You can also connect elements with wires.

To connect element or system block nodes with a wire, position the cursor over a node. The cursor displays as a wirecoil symbol. Click at this position to mark the beginning of the wire and slide the mouse to a location where a bendis needed. Click again to mark the bend point. You can make multiple bends.

To start a wire from another wire, select the wire, right-click and choose Add wire, then click to mark the beginningof the wire.

To terminate a wire, click on another element node or on top of another wire.

To cancel a wire, press the Esc key.


Basic Operations

Adding Data to Netlists

When you create a netlist, an empty netlist window opens into which you type a text-based description of a schematic.Netlist data is arranged in blocks in a particular order, where each block defines a different attribute of an element suchas units, equations, or element connections. For more information about creating netlists, see Creating a Netlist inAWRDE User Guide.

Creating EM Structures

EM structures are arbitrary multi-layered electrical structures such as spiral inductors with air bridges.

To create an EM structure, right-click EM Structures in the Project Browser, and choose New EM Structure.

After you specify an EM structure name and select a simulator, an EM structure window opens in the workspace andthe Project Browser displays the new EM structure under EMStructures. Subnodes of the new EM structure which containthe options that define and describe the EM structure can be displayed as described in Working with Schematics andNetlists in MWO/AO. In addition, the menu and toolbar display new choices particular to drawing and simulating EMstructures.

An EM structure window opensin the workspace

Right-click and chooseNew EM Structure

Adding EM Structure Drawings

Before you draw an EM structure, you must define an enclosure. The enclosure specifies things such as boundaryconditions and dielectric materials for each layer of the structure.


Basic Operations

To define an enclosure, double-click Enclosure under your new EM structure in the Project Browser to display a dialogbox in which you can specify the required information.

After you define the enclosure, you can draw components such as rectangular conductors, vias, and edge ports in theLayout Manager.

You can view EM structures in 2D (choose View > View Layout) and 3D (choose View > View 3D Layout), and you can viewcurrents and electrical fields using the Animate buttons on the EM 3D Layout toolbar.

Double-click to definean Enclosure

Display 2D and 3D viewsof the structure

Click to open theLayout Manager

Creating a Layout with MWO/AO

A layout is a view of the physical representation of a circuit, in which each component of the schematic is representedby a layout cell. In the object-oriented AWRDE, layouts are tightly integrated with the schematics and EM structures


Basic Operations

that they represent, and are simply another view of the same circuits. Any modifications to a schematic or EM structureare automatically and instantly reflected in their corresponding layouts.

To create a layout representation of a schematic, click the schematic window to make it active, then choose View > Layout.A layout window tab opens with an automatically-generated layout view of the schematic.

You can also click the View Layout button on the toolbar to view the layout of a schematic.

The resulting layout contains layout cells representing electrical components floating in the layout window. Choose Edit> Select All then choose Edit > Snap Together to snap the faces of the layout cells together. The following figure showsthe layout view from the previous figure after a snap together operation.

When you choose View > Layout, default layout cells are automatically generated for common electrical components suchas microstrip, coplanar waveguide, and stripline elements. Components of the schematic that do not map to default layoutcells display in blue in the schematic window after the layout is generated; components that do have default layout cellsdisplay in magenta. You must use the Layout Manager to create or import default layout cells for components withoutthem. For more information see Using the Layout Manager.

You can draw in the layout window using the Draw tools to build substrate outlines, draw DC pads for biasing, or to addother elements.

Modifying Layout Attributes and Drawing Properties

To modify layout attributes and drawing properties, as well as create new layout cells for elements that do not havedefault cells, click the Layout tab. The Layout Manager replaces the Project Browser window.


Basic Operations

Right-click to modifylayout attributes orimport an LPF

Right-click to importa cell library or createyour own using a CellEditor

Activate layers forviewing and drawing

Click the Layout tab todisplay Layout Manager

Using the Layout Manager

The Layer Setup node in the Layout Manager defines layout attributes such as drawing properties (for example, line coloror layer pattern), 3D properties such as thickness, and layer mappings. To modify layer attributes, double-click the Defaultnode under Layer Setup. You can also import a layer process file (LPF) to define these attributes by right-clicking LayerSetup and choosing Import Process Definition.

The Cell Libraries node in the Layout Manager allows you to create artwork cells for elements that do not have defaultlayout cells. The powerful Cell Editor includes such features as coordinate entry, boolean operations for subtracting anduniting shapes, array copy, arbitrary rotation, grouping, and alignment tools. You can also import artwork cell librariessuch as GDSII or DXF into the AWRDE suite.

After creating or importing cell libraries, you can browse through the libraries and select the desired layout cells toinclude in your layout. Click the + and - symbols to expand and contract the cell libraries, and click the desired library.The available layout cells display in the lower window pane. To place a cell into the layout window, simply click anddrag the cell, release the mouse button, position it, and click to place it.


Basic Operations

Expand and contract,click desired library

Drag layout cell intolayout window

You can import layouts as GDSII or DXF files. To export a layout, click the layout window to make it active, and chooseLayout > Export. To export a layout cell, select the cell name in the Layout Manager, right-click and choose Export LayoutCell.

Creating Output Graphs and Measurements

You can view the results of your circuit and system simulations in various graphical forms. Before you perform asimulation, you create a graph and specify the data or measurements that you want to plot. Measurements can includegain, noise or scattering coefficients, for example.

To create a graph, right-click Graphs in the Project Browser and choose New Graph to display a dialog box in which tospecify a graph name and graph type. An empty graph displays in the workspace and the graph name displays underGraphs in the Project Browser. The following graph types are available:

DescriptionGraph Type

Displays the measurement on an x-y axis, usually over frequency.Rectangular

Displays the in-phase (real) versus the quadrature (imaginary)component of a complex signal.

Constellation

Displays passive impedance or admittances in a reflection coefficientchart of unit radius.

Smith Chart

Displays the magnitude and angle of the measurement.Polar

Displays the measurement as a histogram.Histogram


Basic Operations

DescriptionGraph Type

Displays the sweep dimension of the measurement as the angle andthe data dimension of the measurement as the magnitude.

Antenna Plot

Displays the measurement in columns of numbers, usually againstfrequency.

Tabular

Displays the measurement in a 3D graph.3D Plot

To specify the data that you want to plot, right-click the new graph name in the Project Browser, and choose AddMeasurement. An Add Measurement dialog box similar to the following displays to allow you to choose from acomprehensive list of measurements.

To compare the existing graphs with different simulation settings, while the graph window is active choose Graph >Freeze Traces, then make the necessary changes and run the simulation again.


Basic Operations

Setting Simulation Frequency and Performing Simulations

To set the MWO/AO simulation frequency, double-click the Project Options node in the Project Browser, or chooseOptions > Project Options and then specify frequency values on the Frequencies tab in the Project Options dialog box. Bydefault, all the schematics use this frequency for simulation. You can overwrite this frequency with an individual schematicfrequency by right-clicking the schematic name under Circuit Schematics in the Project Browser and choosing Options.Click the Frequencies tab, clear the Use project defaults check box and then specify frequency values.

To set VSS system simulation frequency, double-click the SystemDiagrams node in the Project Browser or choose Options> Default System Options, and then specify frequency values on the Simulator tab in the System Simulator Options dialogbox.

Type the data rate

Type the numberof samples persymbol

To run a simulation on the active project, choose Simulate > Analyze. The simulation runs automatically on the entireproject, using the appropriate simulator (for example, linear simulator, harmonic balance nonlinear simulator, or 3D-planarEM simulator) for the different pieces of the project.

When the simulation is complete, you can view its output on the graphs and then easily tune and/or optimize as needed.

You can perform limited simulations by right-clicking the Graphs node or its subnodes to simulate only the graphs thatare open, only a specific graph, or simulate for just one measurement on a graph.

Tuning and Optimizing Simulations

The real-time tuner lets you see the effect on the simulation as you tune. The optimizer lets you see circuit parametervalues and variables change in real-time as it works to meet the optimization goals that you specified. These features areshown in detail in the linear simulator chapter.


Basic Operations

You can also click the Tune Tool button on the toolbar. Select the parameters you want to tune and then click the Tunebutton to tune the values. As you tune or optimize, the schematics and associated layouts are automatically updated!When you re-run the simulation, only the modified portions of the project are recalculated.

Using Scripts and Wizards

Scripts and wizards allow you to automate and extend AWRDE functions through customization. These features areimplemented via the Microwave Office API, a COM automation-compliant server that can be programmed in anynon-proprietary language such as C, Visual BasicTM, or Java.

Scripts are Visual Basic programs that you can write to do things such as automate schematic-building tasks within theAWRDE. To access scripts, choose Tools > Scripting Editor or any of the options on the Scripts menu.

Wizards are Dynamic Link Library (DLL) files that you can author to create add-on tools for the AWRDE; for example,a filter synthesis tool or Load Pull tool. Wizards display under the Wizards node in the Project Browser.

Using Online Help

Online Help provides information on the windows, menu choices, and dialog boxes in the AWRDE suite, as well as fordesign concepts.

To access online Help, choose Help from the main menu bar or press the F1 key anytime during design creation. TheHelp topic that displays is context sensitive-- it depends on the active window and/or type of object selected. The followingare examples:

Active window = graph, Help topic = "Working with Graphs" topic.

Active window = schematic (with nothing selected), Help topic = "Schematics and System Diagrams in the ProjectBrowser".

Active window = schematic (with an element selected), Help topic = the Help page for that element.

Active window = schematic (with an equation selected), Help topic = "Equation Syntax".

Active window = schematic layout (with nothing selected), Help topic = "Layout Editing".

Context sensitive Help is also available via:

Help buttons in most dialog boxes.

Help for each element or system block in the Element Browser by selecting a model and pressing Alt + F1, or byright-clicking on a model and choosing Element Help. The Element Options dialog box also has an Element Help button.

Help for each measurement in the Add/Modify Measurement dialog box by clicking Meas Help.

Help for using the AWR script development environment, accessed by selecting a keyword (i.e., object, object model,or Visual Basic syntax), and pressing F1.


Using Online Help


Using Online Help

Chapter 3. AO: Simulation in Analog OfficeThis chapter familiarizes you with different simulations in Analog OfficeTM. Simulation in Analog Office ismeasurement-based; the circuit cannot be simulated until a measurement is set up. After the circuit is simulated, addinga newmeasurement only simulates the circuit for the newmeasurement unless a parameter or simulation setting is alteredon an existing measurement. The example circuit that follows is kept extremely simple and generic to focus your attentionon tool use. Design examples in the following chapters of this guide illustrate key features of Analog Office. When usinga foundry library, the library elements display in the Element Browser under the Libraries node in a subcategory with thefoundry name.

For more information about Analog Office and its features, you can visit the AWR website at www.awrcorp.com.

You can also search the AWR Knowledge Base at www.awrcorp.com/download/kb.aspx for the following relevantarticles:

How to Change the Color in Schematic and Layout

How to Change the Component Text Size

This chapter introduces the following procedures:

Setting up a simulation

Adding graphs and measurements

Tuning a circuit

Performing DC analysis

Performing small signal AC analysis

Performing harmonic balance and transient analysis


DC Analysis

In this simple BJT amplifier example you annotate the circuit schematic with simulated DC voltages and currents.

Creating a New Project

The example you create in this chapter is available in its complete form as BJT_Amp_Complete.emp. To access this filefrom a list of Getting Started example projects, choose File > Open Example to display the Open Example Project dialogbox, then Ctrl-click the Keywords column header and type "getting_started" in the text box at the bottom of the dialogbox. You can use this example file as a reference.

To create a project:

1. Choose File > New Project.

2. Choose File > Save Project As. The Save As dialog box displays.

3. Navigate to the directory in which you want to save the project, type "BJT_Amp.emp" as the project name, and thenclick Save.


Setting Default Project Units

To set default project units:

1. Choose Options > Project Options. The Project Options dialog box displays.

2. Click the Global Units tab and verify that the settings match those in the following figure. You can choose units byclicking the arrows to the right of the display boxes.

3. Click OK.

Creating a Schematic

To create a schematic:

1. Choose Project > Add Schematic > New Schematic. The New Schematic dialog box displays.

2. Type "DC Bias", and click Create. A schematic window displays in the workspace and the schematic displays underCircuit Schematics in the Project Browser.

3. Click the Elements tab in the lower left of the window to display the Element Browser. The Element Browser replacesthe Project Browser window.

4. Under Circuit Elements, expand the Nonlinear group by clicking the "+" to the left of the group name, then click theBJT subgroup.

5. From the list of models displayed in the bottom window, select the GBJT3 model and drag and drop it on the "DCBias" schematic.

6. Double-click the GBJT3 model on the schematic to display the Element Options dialog box. On the Parameters tab,click the Show Secondary button to show all secondary parameters for the model. Note that the parameters are set todefault values.

7. Change the CJE parameter to "0.3", the TF parameter to "0.01", and the CJC parameter to "0.3", then click OK.


DC Analysis

8. Expand the Lumped Element group and then click the Resistor subgroup.

9. Select the resistor (RES) and drag it to the schematic. Attach it to the collector as shown in the following figure, thenrepeat this step to add resistors to the base and emitter of the BJT as shown in the following figure. Remember toright-click to rotate the resistor before clicking to place it. For more information see Connecting Element and SystemBlock Nodes and Using the Element Browser.

10. Double-click an RES element. In the Element Options dialog box, change its parameters to those shown in the followingschematic. Repeat this step for the other two RES elements.

NOTE: You can also simply double-click the parameter value displayed on the schematic to open a text box in whichyou can modify a parameter.

11. In the Element Browser, under Circuit Elements expand the Sources category and then click the DC subgroup. Selectthe DCVS element (DC voltage source) and connect it to the circuit schematic as shown in the following figure.Change its parameters to match those shown.

Placing Ground on a Node

To add ground to a node:

1. Choose Draw > Add Ground.

2. Move the cursor onto the schematic and position the ground on the bottom node of DCVS as shown in the followingfigure, then click to place it.

3. Repeat these steps to add a ground to the Re resistor.

C

B

E

1

2

3

GBJT3ID=GP1

RESID=RcR=500 Ohm

RESID=RB1R=22000 Ohm

RESID=ReR=100 Ohm

DCVSID=V1V=3.3 V


DC Analysis

Back Annotating Voltages and Currents on the Schematic

To back annotate the circuit:

1. In the Project Browser under Circuit Schematics, right-click the DC Bias schematic and choose Add Annotation.

2. Add a measurement to calculate the DC current for all the elements using the settings shown in the following figure,then click OK.

3. Similarly, add the following measurement to calculate the DC voltages, then click OK.


DC Analysis

Simulating the Circuit

To simulate the circuit choose Simulate > Analyze or click the Analyze button on the toolbar. The current and voltagesdisplay in the schematic window.


DC Analysis

CB

E

1

2

3

GBJT3ID=GP1

0.0885mA1.35 V

5.27 mA0.666 V

5.36 mA0.536 V

RESID=RcR=500 Ohm

5.27 mA

RESID=RB1R=2.2e4 Ohm

0.0885mA

RESID=ReR=100 Ohm

5.36 mA

DCVSID=V1V=3.3 V

5.36 mA3.3 V

0 V

Tuning the Circuit

Tuning a circuit in Analog Office is a very simple, interactive task. In this example, you tune the base resistor RB1 andanalyze how the annotation results change.


DC Analysis

To tune a parameter:

1. Choose Simulate > Tune Tool or click the Tune Tool button on the toolbar.

2. Move the cursor into the schematic window to see the Tune Tool cursor. Click the R parameter of the RB1 resistorwith the Tune Tool. The R parameter should change colors to indicate that it is ready for tuning. Click elsewhere inthe schematic to deactivate the Tune Tool.

3. Choose Simulate > Tune or click the Tune button on the toolbar to display the Variable Tuner. Inside the tuner you seethe R parameter of the RB1 resistor with a range of values. You can edit those values as desired.

4. Slide the tuner bar and note how the DC voltage and current values in the schematic change for different values ofR. As you slide the tuner, the Analog Office simulator automatically calculates and displays new values.

5. Click Revert > Initial to return to the original values, then close the Variable Tuner.

DC Sweep

To perform a DC sweep:

1. Double-click the DCVS element name as shown in the following figure to activate the edit box. Replace the elementname with DC_V and then click outside of the box. Note that the element is replaced with the dynamic voltage sourceDC_V. You can also right-click the DCVS element in the schematic and choose Swap Element. From the list ofelements, select DC_V and then click OK.

DC_VID=V1Sweep=NoneV=3.3 V

Double-click hereto change theelement name

2. Set the sweep parameters as shown in the following figure, then click OK.


DC Analysis

3. In the Element Browser, expand the MeasDevice category, then click the Probes subgroup. Select the V_PROBEelement and connect it to node 2 of the BJT element as shown in the following figure. This is an easier method ofmeasuring the voltage at a node. It can also be done without using a probe, as demonstrated in the next chapter.

C

B

E

1

2

3

GBJT3ID=GP1

RESID=RcR=500 Ohm

RESID=RB1R=22000 Ohm

RESID=ReR=100 Ohm

V_PROBEID=VP1

DC_VID=V1Sweep=LinearVStart=0 VVStop=5 VVStep=0.1 V


DC Analysis

Adding a Graph

To add a graph:

1. In the Project Browser, right-click Graphs and choose New Graph. You can also click the Add New Graph button onthe toolbar. The New Graph dialog box displays.

2. Select Rectangular as the graph type, type "DC Sweep" as the graph name, and then click Create. The new graphdisplays in a window in the workspace and its name displays as a subnode under Graphs in the Project Browser.

Individual graphs displayunder Graphs

Adding a Measurement

To add measurements to the graph:

1. Right-click the "DC Sweep" graph in the Project Browser and choose AddMeasurement. The AddMeasurement dialogbox displays. You can also click the Add New Measurement button on the toolbar.

2. Add a measurement by specifying the settings shown in the following figure, then click OK.


DC Analysis

3. Choose Simulate > Analyze or click the Analyze button on the toolbar. The simulation response shown in the followingfigure displays.

0 1 2 3 4 5Voltage (V)

DCSweep

0

0.2

0.4

0.6

0.8

1

VDC(V_PROBE.VP1) (V)DC Bias

Post-Analysis Tuning


DC Analysis

In this example you analyze how the DC Sweep curve changes while tuning the base resistor, and see the effect of tuningon a DC sweep source.

To see tuning effects on a graph:

1. In the Project Browser under Circuit Schematics and DC Bias, double-click an annotation measurement. In the EditSchematic Annotation dialog box, ensure that DC_V.V1 is set to Select with tuner and then click OK. (Click OK even ifno changes are necessary.) Repeat this step for the other annotation measurement.

2. Choose Simulate > Tune or click the Tune button on the toolbar to display the Variable Tuner. An additional Vdcparameter displays in the tuner with a range of values. You can alter these values as needed.

3. Slide the tuner bar for the R parameter of the RB1 resistor. Note how the DC Sweep graph changes for different valuesof R.

4. Slide the tuner bar up for Vdc to sweep the DC source. The numbers in the tuner are the number of sweep points, notthe actual DC values. As you slide the tuner bar up notice how the current and voltage values change on the schematicfor every possible value of Vdc source, but the DC Sweep graph remains unchanged. Remember that these values arestored in memory and are displayed upon sliding the tuner; Analog Office does not resimulate the circuit when youvary the Vdc value. Varying RB1 still resimulates and generates new sweep data.

5. Click Revert > Initial to return to the original values.

Small Signal AC Analysis

In this section you perform small signal AC analysis and observe the linear voltage gain.

Copying a Schematic

To copy and modify an existing schematic:

1. In the Project Browser, select the "DC Bias" schematic under Circuit Schematics, then drag and drop the schematiconto the Circuit Schematics node. A new schematic window named "DC Bias_1" displays.

2. Right-click "DC Bias_1" in the Project Browser and choose Rename Schematic. Rename the schematic to "SmallSignal".

3. In the Element Browser, expand the Lumped Element category, then click the Capacitor subgroup. Select a capacitor(CAP) and drag it to the Small Signal schematic. Attach a total of three capacitors (CAP) to the schematic as shownin the following figure, right-clicking as necessary to rotate them.

4. Edit the capacitor parameters as shown in the following figure.

Placing Ports on a Node

To place a port on a node:

1. Choose Draw > Add Port.

2. Move the cursor onto the schematic and position a port on the C1 capacitor node as shown in the following figure,then click to place it.

3. Repeat these steps to add a port to the C2 capacitor node.

You can also add a port by clicking the Port button on the toolbar and sliding the cursor onto the schematic.



4. Edit the port parameters as shown.

5. Replace the DC_V element with a DCVS element as previously shown in the "DC Sweep" section.

6. Edit the element parameters as shown in the following figure.

C

B

E

1

2

3

GBJT3ID=GP1

RESID=RcR=500 Ohm


RESID=ReR=100 Ohm

V_PROBEID=VP1

CAPID=C1C=39 pF

CAPID=C2C=39 pF

CAPID=C3C=22 pF

DCVSID=V1V=3.3 V

PORTP=1Z=0.001 Ohm

PORTP=2Z=500 Ohm

Setting Up the Frequency Sweep

To set up the frequency sweep:

1. Choose Options > Project Options. In the Project Options dialog box, click the Frequencies tab. Set the frequencies asshown in the following figure and then click Apply. The frequency list displays under Current Range.



2. Click OK.

Setting Up Measurements

To set up the measurements:

1. Add a new rectangular graph named "Bode Plot".

2. Add a measurement for the magnitude of the voltage gain using the settings in the following figure.



3. Click Apply.

4. Clear the dB check box, then select Angle under Complex Modifier to plot the phase, then click OK.

5. Right-click inside the "Bode Plot" graph window and choose Properties, or double-click the legend box inside thegraph. Click the Axes tab, select X under Choose axis, and select the Log scale check box.

6. Select Right 1 under Choose axis and click the Add axis button to add extra y-axes as Left 2 and Right 2.

7. Click the Measurements tab and specify the settings in the following figure, then click Apply. Similarly assign the nextmeasurement to Left2 axis then click OK. Note that you could also plot magnitude and phase on the right and lefty-axes of the same plot.



8. Choose Simulate > Analyze or click the Analyze button on the toolbar. The simulation response shown in the followingfigure displays.

.001 .01 .1 1 10 100Frequency (GHz)

Bode Plot

-40

-20

0

20

40-200

-100

0

100

200DB(|VTG(2,1)|)Small Signal

Ang(VTG(2,1))(Deg)Small Signal



9. Open the "DC Bias" schematic and disable tuning on the RB1 resistor by clicking the Tune Tool button on the toolbar,then clicking the R parameter to toggle off its tuning. The parameter value should change to black. Click elsewherein the schematic to deactivate the Tune Tool.

10. On the "Small Signal" schematic, click the Tune button on the toolbar to display the Variable Tuner. Vary the valueof RB1 and analyze how the gain changes. Move the cursor over the variable name in the tuner and the correspondingschematic name displays. Click Revert > Initial to return to the original values.

Transient Analysis

In this example you set up the circuit for both harmonic balance simulation and transient simulation using the HSPICEsimulator. The harmonic balance simulations calculate the steady state behavior of the circuit, whereas HSPICE simulationsfollow the transient process. There are two conditions under which the results of these two simulations agree:

For steady state behavior, HSPICE simulations run to steady state (a large number of periods so the transient effects"die out").

For transient effects, harmonic balance simulations run with a large period (a small fundamental frequency so transienteffects "die out" before the trigger signal repeats, but also with a large number of harmonics, so the sharp transitionsare well represented).

These cases are demonstrated by using an AC (sinusoidal) signal source and a pulse voltage source in a circuit.

Large Signal Analysis

To perform a large signal analysis:

1. Right-click the "Small Signal" schematic in the Project Browser and choose Duplicate Schematic. A duplicate schematicnamed "Small Signal_1" is created.

2. Right-click "Small Signal_1" in the Project Browser, and choose Rename Schematic. Rename the schematic to "LargeSignal".

3. Disable tuning on the RB1 resistor by clicking the Tune Tool button on the toolbar, then click the R parameter to toggleoff its tuning. Click elsewhere in the schematic to deactivate the Tune Tool.

4. Right-click PORT1 and choose Toggle Enable to disable it. The disabled port displays in gray.

5. Change the port number (P parameter) of PORT2 to "1". (You can also replace PORT2 with a 500 ohm resistor toground, in which case you should add a new V_PROBE there.)

6. In the Element Browser, expand the Sources category, then click the AC subgroup. Add a Dynamic AC voltage source(AC_V) and a ground to the schematic as shown in the following figure. Edit the AC_V element parameters as shown.Note that the default setting for AC_V is Signal=Pulse and you need to change this to Signal=Sinusoid.


Transient Analysis

CB

E

1

2

3

GBJT3ID=GP1

RESID=RcR=500 Ohm


RESID=ReR=100 Ohm

V_PROBEID=VP1

CAPID=C1C=39 pF

CAPID=C2C=39 pF

CAPID=C3C=22 pF

DCVSID=V1V=3.3 V

AC_VID=V2Signal=SinusoidSpecType=Use doc freqsSpecBW=Use doc # harmsSweep=NoneTone=1Mag=0.05 VAng=0 DegOffset=0 VDCVal=0 VACMag=1 VACAng=0 Deg

PORTP=1Z=0.001 Ohm

PORTP=1Z=500 Ohm

Setting up the Simulation

To set up the simulation:

1. In the Project Browser, right-click the "Large Signal" schematic and choose Options.

2. In the Options dialog box click the Frequencies tab, clear the Use project defaults check box, select the Single pointcheck box, and specify "1" as the Point (GHz) under Modify Range, then click the Apply button.

3. Click the Harmonic Balance tab and ensure that the parameters are set to the values shown in the following figure.


Transient Analysis

4. Click the HSPICE tab and ensure that the parameters are set to the values shown in the following figure.

5. Click the Transient tab and edit the parameters to the values shown in the following figure. Click the More button,click the Results tab, and then select Show only last 2 periods. Click OK twice to save the settings.


Transient Analysis

Adding Measurements

To add a graph and measurements:

1. Add a rectangular graph named "Time Domain".

2. Create an output voltage waveform measurement using the settings in the following figure, then click Apply.


Transient Analysis

3. Create an additional measurement by selecting HSPICE Trans as the Simulator and then clicking Apply.

4. Select AC_V.V2 as the Measurement Component for input voltage waveform, then click OK.

5. Choose Simulate > Analyze or click the Analyze button on the toolbar. Note the difference in the results of the twosimulators.

6. In the Project Browser, right-click the "Large Signal" schematic and choose Options. In the Options dialog box, clickthe HSPICE tab and then click More to display the HSPICE Options dialog box.

7. Click the Advanced tab, and in the Miscellaneous category, change ACCURATE to True by clicking in the text box todisplay a drop-down menu, then click OK.

8. Run the simulation again. The HSPICE and harmonic balance results should match more closely, as shown in thefollowing figure. Since in this case HSPICE is using the harmonic balance settings, you can increase the number ofharmonics for Tone1, and set DELMAX in the Limits category to a desired maximum size step for better resolutionin the HSPICE waveforms.


Transient Analysis

0 0.5 1 1.5 2Time (ns)

Time Domain

-1

-0.5

0

0.5

1Vtime(PORT_1,1)[*] (V)Large Signal

Vtime(PORT_1,1)[*] (V)Large Signal.HS

Vtime(AC_V.V2,1)[*] (V)Large Signal

9. Add another rectangular graph named "Spectrum".

10. Create a measurement for the spectrum of the output voltage using the settings in the following figure, then clickApply.


Transient Analysis

11. Create an additional measurement by selecting HSPICE Trans as the Simulator and then click Apply and OK.

12. Right-click in the "Spectrum" graph window and choose Properties to display the Graph Properties dialog box. Onthe Axes tab, select Left1 under Choose axis, clear the Auto limits check box, select the Log scale check box, and specify"0.001" as Min and "1" as Max. Click Apply, and then OK.

13. Run the simulation. The simulation response shown in the following graph should display.

0 1 2 3 4 5Frequency (GHz)

Spectrum

.001

.01

.1

1|Vharm(PORT_1)|[*] (V)Large Signal

|Vharm(PORT_1)|[*] (V)Large Signal.HS

Pulse Signal

To perform a simulation with a pulse signal:

1. Make a copy of the "Large Signal" schematic and rename it "Pulse Signal".

2. In the Project Browser, right-click the "Pulse Signal" schematic and choose Options. In the Options dialog box on theFrequencies tab, select the Single Point check box and type "0.005" as the Point (GHz) under Modify Range, then clickthe Apply button.

3. Click the Harmonic Balance tab and type "4096" as the Number of harmonics for Tone1.

4. Click the HSPICE tab and ensure that the parameters are set to the values shown in the following figure.


Transient Analysis

5. Click the Transient tab and edit the parameters to the values shown in the following figure, then click OK.

6. In the schematic, double-click the AC source (AC_V) and change the Signal parameter to Pulse. Notice that theparameters change. Edit the parameters to the values shown in the following figure.


Transient Analysis

7. Add a new rectangular graph named "Time Domain Pulse".

8. Add Vtime measurements (expand the Nonlinear category and select Voltage as the Measurement Type and Vtime asthe Measurement) to this graph for the "Pulse Signal" schematic at PORT_1 with both the harmonic balance andHSPICE Trans simulators.

9. Run the simulation. In the first example the transient simulation takes a long time, and in this example harmonicbalance takes a long time. Here, due to the long time constant and the brief pulse, accurate harmonic balance resultsrequired 4096 harmonics for Tone 1, which may not be practical for very large circuits.

10. Right-click the "Time Domain Pulse" graph and choose Properties to display the Graph Properties dialog box. On theAxes tab, select x under Choose axis, clear the Auto limits check box, specify "0" as Min and "10" as Max, then clickApply and OK.


Transient Analysis

0 2 4 6 8 10Time (ns)

Time DomainPulse

-0.5

0

0.5

1

1.5

p2p1

Vtime(PORT_1,1)[*] (V)PulseSignal

Vtime(PORT_1,1)[*] (V)PulseSignal.HS

p1: Freq = 0.005 GHz

p2: Freq = 0.005 GHz


Transient Analysis


Transient Analysis

Chapter 4. AO: IV Curve MeasurementsThe following examples show you some of the key features of Analog OfficeTM. This exercise includes a simple IV curvemeasurement for an nmos, with the results displayed using the harmonic balance simulator.

This chapter includes the following procedures:

Creating a new project and schematic

Setting project defaults

Adding graphs and measurements

Running a simulation and analyzing results

Displaying an IV Curve using a DC current-driven current tracer element block

Tuning parameters and viewing layout and analyzing results


IV Curve of a NMOS

In this example you display the IV characteristic of an NMOS. The example you create in this chapter is available in itscomplete form as iv_curve.emp. To access this file from a list of Getting Started example projects, choose File > OpenExample to display the Open Example Project dialog box, then Ctrl-click the Keywords column header and type"getting_started" in the text box at the bottom of the dialog box. You can use this example file as a reference.

Creating a New Project

To create a new project:

1. Choose File > New with Library > AWR Example Libraries > Generic_GenBic35.

2. Choose File > Save Project As. The Save As dialog box displays.

3. Navigate to the directory in which you want to save the project, type "iv_curve" as the project name, and click Save.

Setting Default Project Units

To set default project units:

1. Choose Options > Project Options. The Project Options dialog box displays.

2. Click the Global Units tab and verify that your settings match those in the following figure. You can choose units byclicking the arrows to the right of the display boxes.


3. Click OK.

Creating a Schematic

To create a schematic:

1. Choose Project > Add Schematic > New Schematic, or right-click Circuit Schematics in the Project Browser and chooseNew Schematic.

2. Type "IV nmos", and click Create. A schematic window displays in the workspace and a schematic node displaysunder Circuit Schematics in the Project Browser.

Placing Elements in a Schematic

Use the scroll bars along the right and bottom of the schematic window to view different portions of the schematic asyou work, or to view the entire schematic choose View > View All.

To place elements on a schematic:

1. In the Element Browser, expand the Circuit Schematics node Libraries group and then expand the Generic GenBic35subgroup. Click the CMOS subgroup, then select the nmos1 element and place it on the schematic as shown in thefollowing figure.

2. Expand the MeasDevice group and then click the IV subgroup. Select the IVCURVE element (a DC current/voltagecurve tracer), place it on the schematic, and connect it to the nmos as shown in the following figure. To activate thewire tool simply move the cursor to any terminal. (To view the connection more clearly you can move the text blockthat displays the IVCURVE parameters, as shown.)


IV Curve of a NMOS

DG

S

1

2

3

4

Gen:Bic35:nmos1ID=M1l=0.35 umng=1w=5 um

Swp Step

IVCURVEID=IV1VSWEEP_start=0 VVSWEEP_stop=4 VVSWEEP_step=1 VVSTEP_start=-1 VVSTEP_stop=0 VVSTEP_step=0.2 V

3. Click the Ground button on the toolbar and move the cursor onto the schematic. Position the ground on node 3 of thenmos element and click to place it as shown in the previous figure.

4. Add a wire to connect nodes 3 and 4 of the nmos element as shown in the previous figure.

Editing Element Parameters

To edit the element parameters:

1. Double-click the IVCURVE element. The Element Options dialog box displays.

2. Set the sweep parameters as shown in the following figure and then click OK.


IV Curve of a NMOS

NOTE: You can also double-click the parameter value displayed on the schematic to display a text box in which youcan modify a single parameter.

Adding a Graph

To add a graph:

1. Right-click Graphs in the Project Browser and choose New Graph. You can also click the Add New Graph button onthe toolbar. The Create Graph dialog box displays.

2. Select Rectangular as the graph type, type "IV nmos" as the graph name, and then click Create. The graph displays ina window in the workspace and displays as a subnode under Graphs in the Project Browser.

Adding a Measurement

To add measurements to the graph:

1. Right-click the "IV nmos" graph in the Project Browser and choose Add Measurement. The Add Measurement dialogbox displays. You can also click the Add Measurement button on the toolbar.

2. Add a measurement using the settings in the following figure, then click OK.


IV Curve of a NMOS

Running the Simulation and Analyzing the Results

To run the simulation and analyze the results:

1. Choose Simulate > Analyze or click the Analyze button on the toolbar. The simulation response shown in the followinggraph should display.


IV Curve of a NMOS

0 1 2 3 4 5Voltage (V)

IV nmos

0

2

4

6

8

IVCurve() (mA)IV nmos

2. Choose File > Save Project to save the project.

Tuning nmos Parameters and Viewing Graph and Layout

In this section you observe the layout and iv characteristics change while tuning the width and the fingers of the device.

1. Select the "IV nmos" schematic to make it active, then click the Tune Tool button on the toolbar. In the schematic,click the ng andW parameters to make them tunable. Tunable parameters display in blue. Press the Esc key to deactivatethe Tune tool.

2. Click the View Layout button on the toolbar to display the layout view of the nmos. You can also choose View > ViewLayout.


IV Curve of a NMOS

3. Click the View 3D Layout button on the toolbar to display the 3D view of the nmos. You can also choose View > View3D Layout.

4. Click the Tune button on the toolbar to display the Variable Tuner. Notice there are two parameter columns, one forthe W parameter and another for the ng parameter.

5. In the Variable Tuner set the Max parameters for W and ng to "20" and "5" respectively as shown in the followingfigure. Slide the tuner bar for W and notice how the current curves move. Also notice the values are updated in theschematic and the layout changes accordingly. Similarly, slide the tuner bar for the ng parameter and observe. Toobserve all the windows together, choose Window > Tile Vertical.

6. Close the Variable Tuner box.

7. Save and close the project.


IV Curve of a NMOS


IV Curve of a NMOS

Chapter 5. AO: Differential Pair AmplifierThis example uses a generic bicmos design kit called GenBic35. If you have a different design kit you can use that aswell to go through this tutorial. Regardless of the design kit used, the practice is common in Analog OfficeTM.

This example is meant to familiarize you with the layout capability of Analog Office, not to teach design principles.Some of the results may not be desirable from a design point of view; they are designed to show the capabilities of thesoftware. This chapter introduces the following procedures:

Creating a differential amplifier schematic

Simulating and Optimizing the circuit

Placing layout cells

Routing nets

Extracting interconnects

Post-route Simulation


Creating a Differential Amplifier and Simulating

The example you create in this chapter is available in its complete form as diff_amp.emp. To access this file from a listof Getting Started example projects, choose File > Open Example to display the Open Example Project dialog box, thenCtrl-click the Keywords column header and type "getting_started" in the text box at the bottom of the

docs100 ao getting started

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