In order to use a large reflector antenna with a conventional feeding strucutre, the surface of the antenna must be known to a small fraction of the wavelength in order to enable the synthesis of a feed which provides optimum illumination. At millimeter wave frequencies, this results in very tight tolerances, as the wavelength is on the order of 1 mm. Moreover, as gravitational effects can cause varying deformations in the reflector surface as a function of the scan angle, this tight tolerance often results in the need for active surfaces where the surface accuracy is sensed and mechanically compensated. In this work, we aim to develop a 64 element W-band phased array feed that, when placed in the focal plane of a large reflector antenna, is able to electrically compensate for imperfections in the reflector using phased array techniques. Such a technology will result in a significant reduction in the cost and complexity of large collecting-area millimeter wave telescopes.