Two‐dimensional horn imaging arrays (abstract)

Abstract

A two‐dimensional horn imaging array has been demonstrated at 242 and 93 GHz. In this configuration, a dipole is suspended in a pyramidal horn, fabricated by an anisotropic chemical etch technique, on a 1‐μm silicon‐oxynitride membrane. This approach leaves room for low‐frequency lines and processing electronics. Pattern measurements on a 1.45‐λ imaging array agree well with theory, show no sidelobes, and a 3‐dB beamwidth of 35° and 46° for the E and H planes, respectively. Application areas include a superconducting tunnel‐junction receiver for radio astronomy and imaging arrays for real‐time electron density mapping in fusion plasmas.