Periodic structures placed near a dielectric waveguide can cause the combined structure to radiate. The direction of radiation is controlled by the period or spacing of the elements in the structure. In the present study a simple coiled spring provided the periodic structure. Beam steering at 94 GHz over the range of

to

was achieved by flexing of the spring. The half-power beamwidth is determined by the total effective length of the structure at the radiated angle. The experimental results indicate that a relatively low-cost beam-steerable antenna for fan-type beams may be constructed.