Dual-polarized sinuous antennas on silicon dielectric lenses

For millimeter-wave and THz applications, dielectric lenses fed by planar antennas with integrated circuits offer a practical alternative to waveguide-based systems. For planar feeds, dual-slot or slot-ring antennas provide excellent patterns on a lens, but they are limited to a bandwidth of 10-15%. For a broadband solution, log-periodic antennas have been demonstrated, but traditional log-periodic antennas suffer from polarization variation vs. frequency and high cross-polarization levels. DuHameΓs sinuous antenna provides an alternative to the traditional log-periodic design. Like the spiral antenna, it supports a traveling wave which radiates efficiently from certain regions of the structure. However, the sinuous antenna is a more versatile antenna, amenable to dual-linear or dual-circular designs. The sinuous antenna was previously demonstrated in a lens-coupled THz detector, but the radiation patterns and polarization properties of these antennas have not yet been accurately characterized on dielectric lenses. In this paper, we present the simulated and measured patterns of a self-complementary, dual-linear sinuous antenna on an extended hemispherical lens.