Typical transmit arrays for the head use dipole or loop antennas within an RF shield. However, for certain applications an unshielded head coil array is required. This study explores different designs for unshielded head coil arrays using simulations. Using L-curves, the tradeoff which exists between power efficiency, homogeneity and SAR is evaluated for arrays consisting of loops and dipoles of various dimensions. Loops are found to be superior to dipoles. Small loops yield the highest power efficiency, while larger loops improve homogeneity and SAR efficiency.