Dual polarization antenna fed by a dual mode substrate integrated NRD-guide

The non-radiative dielectric (NRD) waveguide is used for the first time as a dual mode waveguide. The LSE/sub 01/ and LSM/sub 01/ modes are excited independently via a novel microstrip to NRD waveguide dual mode transition. The transition is connected to a new NRD waveguide fed planar patch antenna array where each linear polarization is associated to one mode. Using this circuit, circular and elliptical polarizations may be generated, too, by applying a specified phase shift and amplitude ratio of the two modes.