A Switchable Linear to Circular Polarization Converter Using PIN Diodes

International audienceIn this paper, we present a method to design a switchable polarizer using p-in diodes. An antenna-filterantenna architecture with four metal layers (receiving and transmitting radiating elements, ground plane, and bias lines) is implemented to convert an impinging linearly-polarized electromagnetic wave to a circularly-polarized one. Furthermore, by controlling opportunely the bias current flowing on the two pin diodes flip chipped on the transmitting radiating element, the transmission wave can be switched to either left-handed circular polarization (LHCP) or right-handed circular polarization (RHCP). Full-wave electromagnetic simulations of a single element show a transmission loss < 0.8 dB for both polarization (LHCP/RHCP) and 180° phase difference in the frequency band (27-31 GHz)