Comparison of power deposition by in-phase 433 MHz and phase-modulated 915 MHz interstitial antenna array hyperthermia systems

The interstitial microwave antenna array hyperthermia (IMAAH) system produces a pattern of specific absorption rate (SAR) that is nonuniform within a 2-cm square array when driven in phase at 915 MHz. It was found that phase modulation makes the time-averaged SAR pattern significantly more uniform in planes perpendicular to the antennas. To drive antennas in phase at 433 MHz similarly improves SAR uniformity when the antennas are of resonance length.>