Metamaterial system endowing object with adjustable radar profile

Abstract

Vehicles with adjustable metamaterial systems, integrated on the outside or inside of their non-conductive fuselage, have the ability to control their radar cross section dynamically for the purposes of evading detection or spoofing their size by looking larger or more numerous. The frequency response of a metamaterial system can be obtained by combining the RF properties of the individual metamaterial layers that comprise it. A first metamaterial layer that can controllably switch between transmissive and reflection in a relevant frequency band and a second absorptive layer results in a controllable radar cross-section with the ability of controlling the amplitude of the reflected radar pulse. The first layer can be modulated with a repetitive waveform to change the phase of a reflected wave that results in a doppler shift in frequency. The frequency of the modulation can result in a change in range, velocity, or combinations of both. The waveform used can also create a linear change of phase or can be made pseudorandom to create decoy targets that appear to move with random ranges and velocities as detected by a radar. The metamaterial layers can also have a separate passband for allowable communications, navigations, or for other wireless uses within the vehicle. The passband itself can also be switchable or tunable to allow for multiple passband frequencies.