title: Design of transmission-type phase holograms for a compact radar-cross-section measurement range at 650 GHz.
abstract: A design formalism is presented for transmission-type phase holograms for use in a submillimeter-wave compact radar-cross-section (RCS) measurement range. The design method is based on rigorous electromagnetic grating theory combined with conventional hologram synthesis. Hologram structures consisting of a curved groove pattern on a 320 mmx280 mm Teflon plate are designed to transform an incoming spherical wave at 650 GHz into an output wave generating a 100 mm diameter planar field region (quiet zone) at a distance of 1 m. The reconstructed quiet-zone field is evaluated by a numerical simulation method. The uniformity of the quiet-zone field is further improved by reoptimizing the goal field. Measurement results are given for a test hologram fabricated on Teflon.
authors.affiliation: MilliLab, SMARAD Radio Laboratory, TKK Helsinki University of Technology, P.O. Box 3000, FI-02015 TKK, Finland.eero.noponen@gmail.com
authors.forename: Eero
authors.initials: E
authors.lastname: Noponen
authors.forename: Aleksi
authors.initials: A
authors.lastname: Tamminen
authors.forename: Matti
authors.initials: M
authors.lastname: Vaaja