Birdcage coils have a number of limitations, especially at ultra-high field. Monopole antenna arrays have been proposed as an alternative to birdcage coils, as the design is simpler and they do not use capacitors. We evaluated the potential of using monopole arrays for 3T and 7T MRI brain scans. To be able to benchmark performance, we compared the field produced by the monopole array with the field produced by the birdcage coil. We show that monopole arrays can potentially achieve better field homogeneity and sensitivity than the birdcage coil. We fabricated a monopole array and demonstrated decoupling between individual monopoles.