Why Do I Get Out of Memory Errors When I Simulate Multiple Tones in AWRDE

I get an "Out of Memory" error and program crashes when I simulate with multiple tones.

This problem is caused by the Harmonic Balance simulator trying to solve for too many frequency components: a combination of multiple tones, each with multiple harmonics, and the intermodulation components among all of these. To reduce the amount of memory required to perform the simulation, you can:

1. Consider using the APLAC Multi-Rate Harmonic Balance (MRHB) feature, available since the AWR2010 release (version 9.03 and later). Select Help > Contents and Index, and click the Index tab. Search for MRHB to find the help page on the simulation control block required. This page also includes a link to documentation describing MRHB in more detail.

2. Reduce the number of intermodulation components considered. Go to Options > Default Circuit Options > Harmonic Balance?tab, and make sure the boxes for Limit harmonic order and Apply Max order to intermods only are checked. Then reduce the Max value as necessary to reduce the number of intermodulation components taken into account.

3. Reduce the number of harmonics for each tone. If the number of harmonics (or time resolution) is specified on the signal sources in the schematic, then reduce the number (or increase resolution) there. Otherwise, for tones 1, 2, and 3, go to Options > Default Circuit Options > Harmonic Balance?tab and reduce number of harmonics in the Tone Harmonics section.