Comments on “Development of Cross-Polar Orientation-Insensitive Chipless RFID Tags”

Babaeian and Karmakar present a technique for designing resonant scatterers that display a cross-polarization reflection that remains consistent (i.e., non-zero) regardless of the orientation of the target. The authors claim that this property can be obtained simply by duplicating, rotating, and arranging the position of a unit cell. We will show in this comment that all the design techniques presented by Babaeian and Karmakar in Section III lead to multiple cancellations of the cross-polarization component of the backscattered
$E$
-field. Therefore, the measurement results presented by Babaeian and Karmakar cannot be justified by the theory presented in Section III of the same article.