High power RF phase-directed power combiners include magic H hybrid and/or superhybrid circuits oriented in orthogonal H-planes and connected using E-plane bends and/or twists to produce compact 3D waveguide circuits, including 8×8 and 16×16 combiners. Using phase control at the input ports, RF power can be directed to a single output port, enabling fast switching between output ports for applications such as multi-angle radiation therapy.