Radial line planar antenna with feed phase control by microstrip lines

A radial line planar antenna with external feeding phase control is presented. The coupling mechanism from the radial waveguide to the patches is achieved by inner small microstrip lines. The fed amplitude is controlled by the dimensions of these lines, whereas the phase is modified by outer transmission lines. The coupling internal lines are also placed in order to minimize the mutual reflections effects. Due to the clear physical separation between the feeding amplitude and phase area, the distance among the radiating patches is free under radiation pattern requirements.