Abstract: A scanning Dielectric Travelling Wave Array (DTWA) device suitable for use as a wideband, tunable, two-dimensional beamformer. The device is formed from a set of planar waveguides, elongated waveguide sections and/or progressive delay layers. By controlling the index of refraction (?) of the waveguides, waveguide sections, and/or progressive delay layers, the device to aim at a particular angle of incidence of energy arriving on the top face, in both azimuth and elevation. These indi(cies) of refraction may be controlled with a set of varactors. By observing a constraint on the size of the waveguides as related to the bandwidth of the signals of interest, the waveguide can to receive from or transmit to different directions at the same time. The varactors may be provided by continuous strips of material disposed along the top and bottom of each waveguide section, or as a set of discrete controllable sections distributed along the primary axis of each waveguide section.