Antennas for Chipless Tags Based On Remote Measurement of Complex Impedance

Antenna design for chipless tags based on remote measurement of complex impedance is discussed. Such antennas need to be printable and de-embeddable from the terminating reactive network used for coding the tag information. We demonstrate that certain antennas have a low radar cross-section (RCS) under matched condition, while maintaining a fairly uniform RCS under various reactive terminations including open and short. Therefore, effect of such antennas can be deembedded after being modeled as two-port networks whose parameters can be extracted using conventional Vector Network measurement techniques. The category excludes minimum-scatter antennas such as dipoles.