Synthesis of a waveguide phased array element

A synthesis of a simple matching structure for a waveguide phased array element is presented. The matching is in the form of a double-tuned response. Short dielectric discs in combination with a below cutoff section of waveguide approximately realizes the lumped circuit parameters of the ideal double-tuned circuit. The departure from the ideal realization is explained in terms of the dispersive character of the structure and the interdependence of the resonator circuits. Design examples of linearly polarized and wide-scan ( cone) polarization diverse arrays are carried out for bandwidths greater than 10 percent. The completed designs are evaluated considering the multimode nature of the aperture discontinuity.