A Planar Polarization-Agile Array with Shared Aperture at K/Ka-Band

The planar array, this paper proposes, supports two orthogonal polarizations and dual-band operation in a single aperture. It consists of single-band elements operating at 29 GHz and dual-band elements which additionally work at 19.8 GHz. The latter are self-diplexing to avoid additional diplexers and both provide horizontal and vertical linear polarization. The elements alternate on a rectangular grid with a lattice constant of half a free-space wavelength at 30 GHz. The simulated array performance is experimentally verified with two passive 5x5-demonstrators, the active characteristics being obtained by postprocessing. The antennas are realized in standard printed circuit board (PCB) technology on a stack with four-layers. The -10 dB reflection bandwidth reaches 1.5 GHz at the Ka-band and 0.7 GHz at the K-band. The isolation exceeds 20 dB in both bands.