USA As Represented by Secretary of the Navy

United States of America As Represented by the Secretary of the Air Force

Spectra Research, Inc.

Gary A Thiele

John William Sellers, Jr

Eugene E Mayle, Jr

Ronald George Riechers

Paul Donald Zidek

Dan S Janning

Michael R Crews

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 EHor 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.

Conformal microstrip leaky wave antenna

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. The tag is positioned to receive the interrogation signal at the receiver antennas and is operative to return a reflected signal to the interrogator via the transmitter antennas in response to receipt of the interrogation signal. The tag is configured to generate the reflected signal by (i) suppressing reflection of the interrogation signal, and (ii) generating reflected radiation characterized by a frequency spectrum including a plurality of return bands, each of the return bands being characterized by a predetermined return band frequency. The interrogator is configured to detect radiation reflected at the return band frequencies, discriminate between return bands of different frequencies, and identify a binary code defined by the reflected radiation across the plurality of return bands.

Radio frequency tag system

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.

Modified T-bar fed slot antenna

Growing community of inventors

Dayton, OH, United States of America

Gary A Thiele