Dual-polarized directivity enhanced active metamaterial antenna for polarimetric radar applications

An active substrate integrated waveguide based dual-polarized directivity enhanced full-space scanning composite right/left handed leaky-wave antenna for polarimetric radar applications is proposed. The proposed antenna is realized by using reflection type amplifiers to compensate both radiation and material losses, thereby increasing the effective aperture dimension and directivity of the antenna without compromising all unique features of metamaterial leaky-wave antenna including full frequency-scanning (backfire-to-endfire) capability and bilateral operation. Bilateral operation is essential in radar applications to allow both transmitting and receiving operations. The proposed dual-polarized full frequency-scanning polarimetric radar antenna may be operated in either: 1) linear slant (+45° and -45°) polarization mode, 2) linear horizontal/vertical polarization mode, or 3) right/left-handed circular polarization mode. This paper demonstrates the operation of the proposed active antenna in horizontal/vertical polarization mode. The realized active antenna shows directivity enhancement compared to its all passive counterpart.