Abstract: A waveguide antenna for a radar antenna array, particularly for use in motor vehicles, includes a metal waveguide extending in an x direction and having a longitudinal axis, which, for the propagation of a radar wave of a first mode in the x direction, delimits an inner space, wherein in order to specifically convert the first mode to a second mode of the radar wave which is different from the first mode and to couple the second mode out of the waveguide, a plurality of structural elements arranged in the x direction are provided which extend into the inner space and wherein adjacent structural elements have a distance which is larger than half a waveguide wavelength of the radar wave of the first mode or larger than half a free-space wavelength, depending on which of the two wavelengths is smaller.

Abstract: A waveguide antenna for a radar antenna array, particularly for use in motor vehicles, includes a metal waveguide extending in an x direction and having a longitudinal axis, which, for the propagation of a radar wave of a first mode in the x direction, delimits an inner space, wherein in order to specifically convert the first mode to a second mode of the radar wave which is different from the first mode and to couple the second mode out of the waveguide, a plurality of structural elements arranged in the x direction are provided which extend into the inner space and wherein adjacent structural elements have a distance which is larger than half a waveguide wavelength of the radar wave of the first mode or larger than half a free-space wavelength, depending on which of the two wavelengths is smaller.

Abstract: A traveling wave device for the combining or splitting of symmetric and asymmetric traveling wave energy includes a feed waveguide for traveling wave energy, the feed waveguide having an input port and a launching port, a reflector for coupling wave energy between the feed waveguide and a final waveguide for the collection and transport of wave energy to or from the reflector. The power combiner has a launching port for symmetrical waves which includes a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which includes a sawtooth rotated about a central axis.