In this paper, novel U-slot and Yagi-Uda micromachined patch antennas were designed based on the "micromachined elevation " technique to improve the performance of mm-wave cognitive radios in terms of gain, weight and bandwidth. The elevated antennas were fed with a micromachined probe connected to a CPW line on top of a high - substrate. By elevating the antenna from the highr substrate, high-performance antenna designs can coexist with compact feed networks in 3D module configurations. A lOdB impedance bandwidth of 31%> and 25% were obtained for the U-slot and Yagi designs, respectively.