μWaveRiders: Setting Up a Successful AWR Design Environment Design - UI and Simulation

24 Aug 2022 • 5 minute read

The Team RF "μWaveRiders" blog series is a showcase for Cadence AWR RF products. Monthly topics will vary between Cadence AWR Design Environment release highlights, feature videos and spotlights, and software tips, tricks, and customization. Subscribe to receive email notifications about our latest μWaveRiders blog posts.

When starting a new design, it's important to take the time to consider design recommendations that prevent problems that can arise later in the design cycle. This two-part compilation of guidelines for starting a new design is the result of years of Cadence AWR Design Environment platform Support experience with designs. Pre-design decisions for user interface, simulation, layout, and library configuration lay the groundwork for a successful and efficient AWR design. This blog covers the user interface (UI) and simulation considerations designers should note prior to starting a design.

User Interface Considerations

Design Environment Colors: Setting up personalized colors for display of various objects on AWR Design Environment platform schematics, system diagrams, layouts, and equations allows designers to work in a familiar environment, simplifying the design process. Access the Environment Options dialog box Colors tab by choosing Options > Environment Options.

Setting design colors

Simulation Considerations

Project units: AWR software supports per-process technology native units, allowing different designs within the same project to specify values in different units. Determine your project units strategy by setting unit modifiers or by using base units. Project units can be problematic for equations when units change, or when importing a schematic into a project that uses different units. Standardizing to base units prior to export ensures that a consistent set of schematic parameter values are in place for group design projects. Units used for each process are specified as part of a Layer Process File (LPF). When configuring units with a layout license, access the LPF Options dialog box Units option by choosing Options > Drawing Layers. When configuring units without a layout license, access the Project Options dialog box Global Units tab by choosing Options > Project Options.
Testbenches: When designers need to perform many different types of analysis on the same schematic, using a testbench to analyze the design is a more efficient method than the error prone method of copying and pasting the original schematic into separate windows. A testbench is created for each specific measurement to be performed, and requires that a design includes all of the elements, except sources. The testbench method includes the design as a subcircuit with the sources and terminations added, leaving the original schematic unaltered.
Multi-processor configuration: The Cadence AXIEM 3D planar EM simulator, Cadence Analyst 3D FEM EM simulator, and EMSight simulator can be configured to use multiple processors. Each uses a different method for setting the number of processors it uses.

For the AXIEM 3D planar and Analyst 3D FEM EM simulators, access the Options - EM Structure dialog box Job Scheduler tab by right-clicking the EM structure in the Project Browser and choosing Options. Specify a value for Max Threads. A value of 0 specifies use of all available processors, up to a maximum of 8. To use more than 8 threads (AXIEM) or processes (Analyst), you must set the exact number of threads/processes to use. A negative value specifies use of the maximum on the machine minus this number. A positive value specifies to use that maximum number. To apply this setting globally, access the EM Options dialog box Job Scheduler tab by right-clicking the EM Structures node in the Project Browser and choosing Options.

For the EMSight simulator, you need to configure two system environment variables. To access these variables, from your computer Start menu open (Windows) Settings and search for "Environment Variables" in the "Find a setting" search box. Select the system option. In the System Properties dialog box, click the Environment Variables button at the bottom of the window to open the Environment Variables dialog box. In this dialog box, click the New button below the System Variables section to open a New System Variable dialog box. Add new "MKL_NPROCS" and "OMP_NUM_THREADS" variables and set the Variable value to "2" or the desired number of processors. Use of multiple processors is only evident during the solving phase of a simulation.

New System Variable dialog box

To apply this setting to a document, access the Options dialog box Job Scheduler tab Max Threads option by right-clicking the schematic node in the Project Browser and choosing Options. To apply this setting globally, right-click the Circuit Schematics node in the Project Browser and choose Options to access the Circuit Options dialog box with the same option.

X-models: X-models, or EM-based models, are used for distributed elements when the highest degree of accuracy in representing a discontinuity, such as a bend or tee, is desired. When properly used, X-models offer the accuracy of EM simulation with the speed of linear simulation. AWR software installs many common, pre-filled X-model tables in the em_models folder. When you know what your nominal parameter values are, you can search in the folder for a table that has values within 10% of those values. If a suitable table is not found, you can fill your own table using one of several installed projects configured for the substrates that have X-models. Filling a table is time-consuming, but it only has to be done once. To find these projects, choose File > Open Example and search for the keyword "autofill".

Related Resources

Blogs

Product Specs

AWR Design Environment Platform

Contact Us

For questions, general feedback, or suggestions for future blog topics, write to team_rf_blogs@cadence.com.

Subscriptions