FIGURE 2.

Resulting average ${\mathrm{B}}_1^{+}$ in the region of interest (ROI), peak specific absorption rate (SAR)_10g in the phantom, and SAR efficiency in the ROI. The effect of number of periods, width, and modulation was optimized sequentially. After finding the optimal number of periods, the optimal width was found for the optimal width and after that the optimal modulation was found for the optimal number of periods and width. Red dashed line indicates performance for the fractionated dipole array. All results were normalized to 1W accepted power on both channels