TX-RX K/Ka Band Polarizer Based on a SIW Polarization Twister

A K/Ka band polarizer obtained stacking a SIW polarization rotator and a meander-lines polarizer is presented. The rotator is realized with SIW cavities that selectively twist the polarization of the incident wave. In this way, incident 30GHz horizontally polarized waves are converted in RHCP signals, while incident 20GHz waves with the same polarization are converted in LHCP signals. The proposed polarizer may be used with linearly polarized aperture antennas and, for this reason, it can be considered as an after-market add-on that does not affect the performance parameters of the antenna itself.