Periodic and Quasi-Periodic Structures for Antenna Applications

Printed periodic and quasi-periodic structures can be employed to control reflection and transmission properties of incident waves as a function of structure geometry. As this can be done mostly independently for both polarizations, different kinds of polarizers (reflection and transmission polarizer from linear to circular polarization or twist polarizers) can be realized. A local variation of element geometry allow the design of printed reflector antennas. Including the dual polarization properties for such antennas, dual function or dual frequency antennas can be built, or these properties can be exploited for the realization of compact, low-profile folded reflector antennas. Examples for these structures are presented, includimg antennas for 60 and 77 GHz with a diameter of 100 mm and a depth of 25 mm only.