Radiating Performances of Periscope Antenna at Millimetric Wavelengths

In radio links, the periscope antenna is used mainly to avoid terrain obstructions. This type of antenna comprises of a parabolic reflector located on the ground which radiates vertically and illuminates a passive reflector located at the top of a pylon. This passive reflector reflects the beam in the desired direction. Most of the studies about periscope antenna concern the gain problems and rarely the radiation pattern. Due to the large dimension of the periscope antenna, it is very difficult to investigate the radiation patterns. Our studies at millimetric wavelengths allow to reduce these dimensions. So that the radiation patterns of a periscope antenna over 360° can be measured and conclusions can be drawn concerning the influence of periscope antenna parameters :height, shape and dimensions of the passive reflector and, also, the effects of the support and the pylon.