Abstract: An RF transparent antenna shield structure is disclosed particularly useful for missile nose cone radome and other severe environment applications. The structure comprises a solid metal wall member perforated to form a triangular grid array of windows each of which has fitted within it a dielectric plug member the end faces of which are flush with the opposite surfaces of the metal wall member. The thickness of the wall member and the dielectric constant of these plug members are chosen such as provide a resonant radome thickness. The waveguide-space junction susceptances are tuned out by capacitive iris members concentrically disposed on the plug member end faces, to yield acceptable uniformity of insertion phase and attenuation even at relatively extreme incidence angles.