Design and Measurement of a Planar Metasurface Cloaked Dipole Antenna Element for Multifunction Apertures

Motivated by the desire to allow placement of two separate arrays in one aperture, we have designed, fabricated, and measured a 1 GHz planar cloaked dipole antenna intended to provide low interference to co-polarized electromagnetic waves in a frequency band around 10 GHz. This interference is characterized by the antenna’s extinction cross section. The antenna was designed to have reduced interference by using an altered structure and the addition of a scattering cancellation cloak, whereby a capacitive metasurface cloak positioned around the dipole provides scattering that destructively interferes with the mainly inductive scattering of the dipole itself. This article presents the design process using full-wave electromagnetic simulations, from a unit-cell design to an optimized full antenna element. A prototype was fabricated from a copper-coated low-loss dielectric, and its extinction and monostatic radar cross sections were measured. Simulations showed a decrease in both cross sections of more than 10 dB over a frequency bandwidth of more than 9 GHz compared to the uncloaked case, with measured results in agreement for the monostatic radar cross section and to approximately the lowest measurable level of −45 dBsm for the extinction cross section.