Abstract: A microwave radio frequency bidirectional energy flow-capable antenna method and related antenna of the physically conformal microstrip transmission line, traveling wave and leaky wave characterizations; the antenna is especially suited to vehicle mounting. The disclosed antenna operates in an EH1 or other above dominant mode energy wave propagation configuration, a configuration at least partially achieved by an array of selected-location radiating element shortings to an antenna-underlying transmission line ground plane element. Comparisons of the disclosed antenna with characteristics of a similarly classified antenna of somewhat lesser desirable but know characteristics are included.

Abstract: The RF tag system of the present invention minimizes the effect of the RF tag on the overall radar cross section (RCS) of the object with which it is associated, tailors the signal reflected from the tag to match the actual RCS of the object with which it is associated, utilizes an RF tag design that reduces degenerative RF coupling at the tag, and is designed to exploit the operational features of conventional pulse Doppler radars. In accordance with one embodiment of the present invention, a radio frequency tag system is provided including an interrogator and a tag. The tag is secured to an object. The interrogator is configured to generate a transmitted electromagnetic interrogation signal at a predetermined interrogation frequency. The tag comprises an antenna array including a plurality of receiver antennas and a plurality of transmitter antennas.

Abstract: A rectangular antenna has a T-bar of planar cross section for providing a axial to cavity transition. A narrow slot having a length equal to one half the wavelength of the upper end point of the frequency range utilized is centered within the T-bar. Tuning stubs are located in predetermined positions directly under the T-bar for reducing the effect of the TE.sub.30 mode.