A 60 GHz transreflector antenna for a 1 Gbit/s wireless link

We have developed a low-cost transreflector antenna designed for operation from 57 to 64 GHz. The antenna uses a parabolic transreflector, fabricated from a parallel-strip conductive grating inserted into a dielectric molding. The reflector is fed by a Rexolite-filled, single-mode circular waveguide horn. The horn protrudes through the center of a dielectric polarization twist-reflector, which rotates the polarization of the secondary radiation and re-reflects it back through the transreflector. The transreflector diameter is 9.5 inches, and the focal length is 3.2 inches. The feed horn is designed to efficiently illuminate the transreflector while providing a good input match to WR-15 rectangular waveguide. Our production prototype has measured peak gain between 40.5 and 41.5 dBi, a half-power beamwidth of 1.5 degrees, a peak side lobe level of -17.5 dB and input return loss greater than 12.5 dB. The cross-polarization rejection exceeds 33 dB in the principal planes.