Micromachined-silicon W-band planar-lens antenna with metamaterial free-space matching

In this work, we present for the first time a miniaturized planar W-band dielectric-lens antenna which is micromachined in a 300 µm silicon wafer. The antenna edge comprises a metamaterial anti-reflection geometry in order to reduce parasitic reflections at the free-space to high-permittivity dielectric interface. Furthermore, the dielectric lens is matched to a standard WR-10 metal waveguide by an optimized tapered dielectric-wedge transition. Prototype lens-antennas were fabricated in a single-mask micromachining process. The radiation pattern for the design frequency of 100 GHz was measured to 13° half-power beam-width in E-plane, a directivity of 14 dB, −15 dB side-lobe level, −15 dB reflected power for almost the whole W-band, for a lens diameter of 10 mm and an operating frequency of 100 GHz.