Methods for transmit beamforming in multiple-input multiple-output (MIMO) radar based on the design of multiple correlated waveforms have been proposed. This paper points out that this approach couples the spatial (beamformer) and temporal (waveform) parts of the problem, significantly complicating the design. It is shown here that the most general form of transmit beamforming can be achieved in a decoupled form, using orthogonal (uncorrelated) waveforms and a multi-rank transmit beamformer. This formulation allows the use of standard beamformer design procedures. Examples are provided to illustrate the design of multi-rank beamformers for search and tracking applications. The examples include single and multiple beamformers, adaptive beamformers, and wide beams for illumination. These examples are illustrated by simulation results.