A 100-GHz high-gain tilted corrugated nonbonded platelet antenna

A compact 100-GHz corrugated platelet array antenna with an internal tilt has been developed based on a untilted platelet antenna design similar to W-band electroformed horns for the background emission anisotropy scanning telescope (BEAST). The antenna results in a gain of 20 dB, and a beam launching bandwidth across the full range of W-band 75-110 GHz as measured by a vector network analyzer (VNA), with beam tests performed at 90 GHz. The side lobes are down by about -25 dB, a requirement comparable to feed horns used for observation of the cosmic microwave background. The design and fabrication presented in this paper is straightforward and inexpensive. One innovative feature of this array is that the horn can be disassembled and modified to change its properties since the plates are not permanently bonded. A second innovative feature is the ability to direct the horns with an internal tilt without significantly adversely affecting sidelobes and cross-polar pickup. This is useful for large focal plane arrays of detectors where horns must be directed toward a central region such as a telescope mirror.