A full-wave analysis of offset reflector antennas with polarization grids

A full-wave analysis is presented of offset reflector antennas with polarization grids which uses the equivalent grating approach proposed by the authors (ibid., vol.AP-35, p.367-71, Apr. 1987). Two types of antenna are compared: one has a parallel straight strip grating (grid A) and the other has a curved strip grating (grid B) whose pattern is designed so that the antenna system does not generate a cross-polarized component. The key future method is the definition of the equivalent grid. This method quantitatively evaluates the scattering, includes a physical interpretation of the phenomena and gives a physical interpretation of the phenomena and gives a suggestion for the design of the strip patterns. Cross-population suppression effects are quantitatively evaluated as functions of the strip parameters, the size and the location of the grid. It is noted that the cross-polar peaks of the patterns with grid A move with the tilt angle of the grid. The mechanism of this movement is also explained